Biomedical subjects

S Liu

Publications and source records attributed to S Liu.

At least 505 records · Page 28Linked to original sources

PubMed1999

[Changes of placental nitric oxide synthase in patients with pregnancy induced hypertension].

The objective of this study was to determine whether the expression of placental endothelial nitric oxide synthase (eNOS) and/or inducible nitric oxide synthase (iNOS) are changed in pregnancy induced hypertension (PIH). The placentas of 32 patients with PIH and 32 normal pregnancies were studied by immunohistochemistry (Avidin-Biotin-Complex method). The results showed there were eNOS and iNOS antigens in placental tissues from PIH and normal pregnancy. They were all localized in placental villi and syncytiotrophoblast cells. The expression of placenta eNOS decreased significantly in patients with PIH as compared with that of normal pregnancy. The expression of placenta eNOS in mild PIH was higher than that of moderate or severe PIH (P < 0.025, P < 0.005, respectively). There was a negative correlation between blood pressure and the expression of eNOS in placenta (P < 0.0005). There was no significant difference between the expression of iNOS in placenta with PIH and that in normal pregnancy. Also, there was no significant difference of the expression of iNOS in placenta between the mild and moderate PIH, or the mild and severe PIH. Furthermore, there was no correlation between blood pressure and the expression of iNOS in placenta with PIH. It is concluded that the decrease of the expression of eNOS in placenta may be associated with the pathogenesis of PIH.

Adult↗

PubMed1999

[Biological characteristics and damaging regularities of grubs endangering the growth of Ophiopogen japonicus (Thunb.) Ker-Gawl].

OBJECTIVE: To provide a scientific basis for prevention and control of the damage done to Ophiopogen japonicus by grubs. METHOD: Conducting laboratory observation along with field investigation. RESULT: The grubs endangering the growth of O. japonicus are mainly Hoplosternus incanus, Holotrichina paraullela and Anomala corpulenta, H. incanus takes two years to make a generation and overwinters in the form of second or third-instar larvae. H. parallela and A. corpulenta generate yearly and overwinter in the form of third-instar larvae. The extent of the damage done to O. japonicus by grubs is related to such factors as the number of sequential cropping years, the model of intercropping and the type of soil. CONCLUSION: Prevention and control of the pest grub should be based primarily on proper agricultural (cultivating) measures.

Animals↗

PubMed1999

[The clinical characters of tuberculous otitis media].

OBJECTIVE: To sum up the clinical characters of tuberculous otitis media. METHOD: 2 cases of tuberculous otitis media and other reports are reviewed. RESULT: The onset of this disease is sudden and rapid with little discharge coming from the ear. Sometimes one or more perforation and granulation tissue can be found. Necrotizing bone may be seen by radiography. CONCLUSION: According to the tuberculous history of patients or their families and the clinical features, the diagnosis and the treatment to this disease are not difficult.

Adult↗

PubMed1999

[The study of ethanol-water used as reversed-phase high performance liquid chromatographic mobile phase].

The viscosity of ethanol-water at various temperatures was determined. The physicochemical properties and characters of the solvents used as the mobile phase of reversed-phase high performance liquid chromatography(RP-HPLC) were compared between methanol and ethanol. The components of several Chinese medicines have been determined by RP-HPLC with ethanol-water used as mobile phase, and the results were compared with those obtained with methanol-water or acetonitrile-water. It showed that ethanol can be used as RP-HPLC mobile phase by increasing the column temperature moderately.

Chromatography, High Pressure Liquid↗

PubMed1999

[Purification and properties of glutamate dehydrogenase from Pseudomonas pseudoalcaligenes].

Glutamate dehydrogenase was purified from the crude extract of Pseudomonas pseudoal-caligenes. The enzyme had a molecular weight of 290,000 and was composed of six subunits with identical molecular weight of 47,000. The enzyme was highly specific for NADP(H) and the substrates. The biochemical properties such as kinetic parameters and heat stability were also examined. The purified GDH showed considerable loss of activity upon freezing.

Glutamate Dehydrogenase↗

PubMed1999

[Induction of protective immunity in mice against Schistosoma japonicum by nucleic acid vaccine encoding the full-length paramyosin].

AIM: To investigate the immune efficacy of nucleic acid vaccination in mice against full-length paramyosin of Chinese Schistosoma japonicum. METHODS: C57BL/6 and BALB/c mice were vaccinated intramuscularly with the nucleic acid vaccine (pCMV-SjC97) encoding the full-length gene of paramyosin of Chinese S. japonicum. Each group was immunized three times at weeks 0, 3 and 6. Mice vaccinated with pCMV blank vector served as negative control. Mice were challenged three weeks after final DNA boosting by percutaneous infection with cercariae. Six weeks after infection the mice were perfused, worm burden and eggs in the livers, spleens and intestines were counted. Sera from vaccinated mice were collected from the tail vein at weeks 0, 3, 6 and 9, respectively. RESULTS: C57BL/6 mice vaccinated with pCMV-SjC97 produced predominantly IgG2a and IgG2b; whereas in BALB/c mice, IgG1, IgG2a and IgG2b antibodies. Immunization with the pCMV-SjC97 in C57BL/6 mice could confer significant worm reduction rate (35.5%-41.4%, P < 0.05) and egg reduction rate (liver: 44.5%-59.6%, P < 0.05; spleen: 56.7%-82.4%, P < 0.05; intestines: 57.9%, P < 0.05), but not in BALB/c mice. CONCLUSION: The nucleic acid vaccine, pCMV-SjC97, could induce protective immunity in C57BL/6 mice significantly.

Animals↗

PubMed1999

[SDS-PAGE and EITB analysis of the protein components of different isolates of Schistosoma japonicum in China and Japan].

AIM: To make a supplementary observation on the protein components prepared from adult S. japonicum of 4 different isolates from Zhejiang, Jiangxi, Taiwan Provinces of China and Japan in origin and to observe antigen reactivity of the above-mentioned isolates together with adult worms from Anhwi, Hubei, Sichuan and Yunnan isolates against heterologous anti-Oncomelania h. hupensis (collected from Guangxi, China and Japan) sera by EITB. METHODS: SDS-PAGE and EITB. RESULTS AND CONCLUSION: SDS-PAGE showed that by Coomassie blue staining, male S. japonicum from Jiangxi, Zhejiang, Taiwan Provinces and Japan isolales revealed 7-17 bands while female worms revealed 1-6 bands. The protein patterns of Taiwan and Zhejiang male worm were similar, but slight difference could be seen above 81 kDa. By silver staining, male worms of the 4 isolates revealed 10-23 bands while female worms revealed 1-19 bands. Male worms from Japan not only showed less bands but also differed in their pattern as compared to those of other Chinese isolates. Results of EITB revealed that each of the 4 isolates had slightly different pattern but all of the tested isolates had common antigens with their heterologous snail hosts i.e., Oncomelania h. hupensis from Guangxi, China and Japan.

Animals↗

PubMed1999

[Cloning, sequencing and expression of the full-length gene encoding paramyosin of Schistosoma japonicum in vivo].

AIM: To clone and sequence the gene encoding paramyosin of S. japonicum (Chinese strain) and to study the expression of the DNA-based vaccine encoding the full-length paramyosin of S. japonicum in vivo. METHODS: Total RNA was isolated from adult S. japonicum using TRIzol reagent. The full-length cDNA encoding paramyosin of S. japonicum was amplified by RT-PCR and cloned into pGEM-T vector and sequenced by the method of dideoxy-mediated chain-termination. The cDNA encoding paramyosin of S. japonicum was subcloned into the expressive plasmid vector pCDNA/AMP(pCMV-Sjc97), and the recombinants were identified by restriction enzyme digestion and sequencing. The immunofluorescence assay was used to study the expression of Sjc97 in vivo in mice. RESULTS AND CONCLUSION: The 2.6 kb cDNA encoding the full-length paramyosin of Chinese S. japonicum has been successfully cloned and sequenced for the first time. The full-length sequence of paramyosin of S. japonicum was determined. Comparison of the nucleotide sequence and the deduced amino acid sequence of Sjc97 with that of S. japonicum paramyosin (Philippine strain) (Sjp97), S. japonicum paramyosin(Japanese strain) (Sjj97), S. mansoni (Sm97), B6 and Y6 clone (the partial cDNA encoding paramyosin of Chinese strain) showed that Sjc97 differed from Sjp97 by 16/2,601 nucleotide and 3/866 amino acid substitutions (99.4% on nt-level and 99.7% on aa-level in homology); from Sjj97 by 20/2,601 nucleotide and 2/866 amino acid substitutions (99.2% on nt-level and 99.8% on aa-level in homology); and from B6 by 11/1,329 nucleotide and 1/443 amino acid substitutions (99.0% on nt-level and 99.8% on aa-level in homology); from Y6 by 13/1,329 nucleotide and 1/443 amino acid substitutions (98.9% on nt-level and 99.8% on aa-level in homology); Sjc97 differed from the Sm97 by 2,235/2,601 nucleotide and 34/866 amino acid (91.0% on nt-level and 96.0% on aa-level in homology). The plasmid expression vector encoding the full-length paramyosin of Chinese S. japonicum has been successfully constructed. The pCMV-Sjc97 vaccine could express Sjc97 protein in vivo in mice after intramuscular immunization.

Amino Acid Sequence↗

PubMed1999

[Studies on the features of protective immune response induced by recombinant Sjc26GST of Schistosoma japonicum].

AIM: To compare the differences in the protective immune response induced by reSjc26GST between C57BL/6 and BALB/c mice. METHODS: Mice were immunized subcutaneously with reSjc26GST emulsified with Freund's adjuvant. The specific antibody isotypes elicited by reSjc26GST, in vitro lymphocyte proliferation and cytokine responses to reSjc26GST were examined. RESULTS: The level of anti-reSjc26GST IgG was higher in immunized C57BL/6 mice than in BALB/c mice, and examination of the IgG subclasses demonstrated that reSjc26GST-immunized C57BL/6 mice resulted in predominantly IgG1 and IgG2a/IgG2b antibody responses, whereas in BALB/c mice, IgG1 antibody. Cytokine production assays revealed that the quantity of IFN-gamma and IL-2 and IL-5 released from the reSjc26GST-primed splenocytes were significantly higher in C57BL/6 mice than in BALB/c mice. These results showed that the immunization with reSjc26GST in C57BL/6 mice elicited a mixed immune reaction of Th1 and Th2 cell responses as demonstrated by the elevated levels of IgG1, IgG2a/IgG2b and IL-2, IFN-gamma, IL-5, whereas in BALB/c mice, reSjc26GST immunization elicited Th2 response as demonstrated by the elevated levels of IgG1, IL-2 and IFN-gamma. CONCLUSION: Immunization with reSjc26GST could elicit higher humoral and cellular immune responses in C57BL/6 mice than in BALB/c mice.

Animals↗

PubMed1999

[Association expression of genes encoding gst of Schistosoma japonicum and enterotoxigenic Escherichia coli].

AIM: To study the association expression of two genes encoding GST of Schistosoma japonicum and K99 of enterotoxigenic Escherichia coli. METHODS: PCR technique was used to gain the K99 gene. After digestion with BamH I and EcoR I, the gene was cloned into the plasmid vector pUC18 by using recombinant DNA techniques. The other target gene of GST in pSj5 plasmid was obtained by EcoR I digestion, and was then ligated into the recombinant plasmid pUC18-K99. The expressed product was assayed by SDS-PAGE, Western blotting, reversal IHA, ELISA and transmission electron microscopy. RESULTS: Co-expression product of around 50 kDa was obtained. The protein was recognized by anti-GST and anti-K99 antibodies (ELISA and IHA), and acted as pilus on the surface of transformed DH5 alpha E. coli bacteria. CONCLUSION: Co-expression of the genes encoding GST and K99 was successfully achieved.

Animals↗

PubMed1999

[In vivo anti-fecundity effect of recombinant Sjc26 GST against Schistosoma japonicum in immunized mice].

AIM: To observe the anti-fecundity effect of recombinant Sjc26 GST against Schistosoma japonicum and its mechanism. METHODS: Male ICR mice were immunized with rSjc26 GST. Five days after final injection, mice of the immunization and control groups were challenged with 40 +/- 1 S. japonicum cercariae. All mice were sacrified at 6 weeks after challenge. RESULTS: The worm reduction rate was 30.0%, and the egg reduction rates in the liver and in the spleen were 57.1% and 79.9%, respectively. Inhibition of the vitelline gland and testis was also observed by transmission electron microscopy. The number of vitelline globes, vitelline droplets and lipid droplets in the cytoplasm of vitelline cell and the number of lipid droplets in the supporting cells and the number of spermatids in the testis were apparently reduced. CONCLUSION: The damage of the main reproductive organs of Schistosoma japonicum was one of the factors responsible for rSjc26 GST-bound anti-fecundity action.

Animals↗

PubMed1999

[Molecular cloning of a cDNA encoding an antigenic polypeptide containing repeat units of Spirometra erinaceieuropaei plerocercoid].

AIM: To study the gene structure encoding some antigenic polypeptides of plerocercoid of Spirometra erinaceieuropaei (SEP). METHODS: A cDNA library constructed from SEP was immunoscreened using mouse anti-SEP polyclonal antibody. The gene structure was analyzed by computer after the insert of positive clone was subcloned and the nucleotide sequences of the insert were determined. The length of mRNA hybridized with cDNA was detected by Northern blotting. RESULTS: A cDNA clone of 1,084 bp encoding an antigenic polypeptide was isolated. The clone contained one open reading frame composed of 828 bp encoding 276 amino acids. The open reading frame contained tandem repeating unit of 123 bp which appeared 5 times in this clone. The 41 amino acids deduced from 123 bp repeating unit consisted of 53.7% of hydrophobic amino acid residues. In Northern blot assay of poly (A)+RNA, a strong band of about 1.1 kb and a weak band of about 1.7 kb were found in the plerocercoids but no band was found in the adult worms. CONCLUSION: The repeating element derived from the plerocercoids may be associated with the migration of the plerocercoids in the host tissue. The polypeptides with repeating element may act as evasive antigens of the parasite to escape from the destruction of host immune reactions.

Amino Acid Sequence↗

PubMed1999

[Preliminary study on the levels of natural antibodies against Schistosoma japonicum in Microtus fortis in Dongting lake area].

AIM: To explore the detection rate and the levels of natural antibodies to cercarial antigen(CA), juvenile antigen(JA), adult worm antigen (AWA) and soluble egg antigen (SEA), respectively, derived from Schistosoma japoncum in Microtus fortis distributed in Dongting Lake area. METHODS: The antibodies in wild Microtus fortis(WMF), laboratory-bred Microtus fortis (BMF) and laboratory-bred Microtus fortis 15 days after S. japonicum infection (BMFi15) were detected by indirect ELISA and a comparison of the antibody levels between Microtus fortis including WMF, BMF, BMFi15 and albino mice without infection (AM), 15 days after infection(AMi15) and 42 days after infection (AMi42) was made. RESULTS: The positive rates of detection for anti-JA-Ab in WMF and BMF were 94.6% and 94.4%, respectively, followed by 85.5% and 83.3% for anti-AWA-Ab, 58.1% and 59.4% for anti-SEA-Ab, and 14.3% and 13.9% for anti-CA-Ab. The levels of antibodies to the above four antigens in BMFi15 increased significantly, the detection rates being 100% for anti-JA-Ab and anti-AWA-Ab, 84.4% for anti-SEA-Ab and 65.6% for anti-CA-Ab. The levels of antibodies in WME, BMF and BMFi15 had the similar trend(JA > AWA > SEA > CA), and those in BMFi15 to CA, JA, AWA and SEA increased by 1.9, 2.2, 2.1 and 1.5 folds, respectively, when compared with BMF. CONCLUSION: Natural antibodies to Schistosoma japonicum were found in wild and labortorybred Microtus fortis. The levels of antibodies in BMFi15 to four above antigens were apparently higher than those in AMi15.

Animals↗

PubMed1999

[Observation on the dynamics of specific anti-GST antibodies in rabbits immunized with recombinant 26 kDa GST of Schistosoma japonicum].

AIM: To investigate the dynamics of the anti-GST antibodies in rabbits immunized with recombinant 26 kDa GST of Schistosoma japonicum. METHODS: The specific antibodies were detected weekly by GST-ELISA in rabbits vaccinated with purified recombinant 26 kDa GST antigen of S. japonicum plus FCA/IFCA; rabbits immunized with 0.85% saline plus FCA/IFCA served as control group. RESULTS: The specific anti-GST antibodies began to increase at week 4 post-immunization, the mean OD value in rabbits vaccinated with recombinant GST could reach 1.03 +/- 0.46 (adjuvant control group only 0.42 +/- 0.04). The experiment was completed at week 65 post-immunization when the mean OD values for specific anti-GST antibody in immunized rabbits were 0.94 +/- 0.26(0.29 +/- 0.16 in the control group). CONCLUSION: Strong anti-GST antibody responses could be induced in rabbits vaccinated with recombinant 26 kDa GST of S. japonicum.

Animals↗

PubMed1999

[Cloning and expressing of human papillomavirus 16 E7C subgene].

OBJECTIVE: To develop vaccine against HPV16 is the hotspot in this field, this study was to pave the rudiment for this purpose. METHODS: E7C subgene (encoding aa39 to aa98) was amplified by PCR, and then cloned into pLNCX plasmid. RESULTS: The recombinant pLNCE7C was obtained and identified by gel analysis of the restricted-endonuclease-digested fragments. It was shown that pLNCE7C was expressed in transfected B16 cells. The expression product was identified in the positive cells by Southern blotting and immunohistochemistry method. It was localized mainly in cytoplasm of B16 cells. CONCLUSIONS: The plasmid pLNCE7C containing subgene of HPV16E7C not only remains the antigenesis of E7 gene but also eliminates the transforming activity of it. Meanwhile the expression of pLNCE7C is quite good. Therefore the plasmid pLNCE7C is suitable to develop DNA vaccine against HPV16.

Animals↗

PubMed1999

[Construction and in vivo expression of the recombinant adenovirus containing human pro-UK cDNA].

OBJECTIVE: To construct the recombinant adenovirus which contained human pro-UK cDNA and to provide experimental basis for clinical gene therapy. METHODS: The recombinant plasmid pCA14-pro-UK and the plasmid pJM17 were cotransfected into cultured 293 cells and the replication-deficient adenovirus were harvested, identified, propagated and titered. The recombinant virus were then transferred into balloon-injured femoral arteries of rabbits and the pro-UK expression was detected by immunohistochemistry and Western Blot. RESULTS: PCR amplification and in vitro transfection of A549 cells confirmed that pro-UK had been inserted into adenovirus genome correctly, and immunohistochemistry and Western blot analysis showed that pro-UK expressed evidently in the balloon-injured sites of the rabbit femoral arteries. CONCLUSIONS: The recombinant adenovirus that constructed could express pro-UK cDNA in vivo successfully.

Adenoviridae↗

PubMed1999

[The relation of fetal growth and the biological risk factors of coronary heart disease].

OBJECTIVE: To examine the relationship between fetal growth and the biological risk factors of coronary heart disease (CHD) in adult life in China. METHODS: Follow up stuty of 628 men and women who were singleton born during 1948-1954 whose birth size were measured in detail. RESULTS: Decreasing birth weight increased the probability of myocardial ischaemic symptom related to CHD (beta = -0.0018, P < 0.01). The Odds ratio (OR) related to hypertension increased with decreasing birth weight and ponderal index (PI, kg/m3). The OR were 5.9 in people whose PI were 24 kg/m3 or less compare to people whose PI were more than 28 kg/m3. The OR related to impaired glucose tolerance(IGT) also increased with decreasing birth weight and PI. Insulin resistance, represented by fast insulin, rose with decreasing birth weight and head circumference(for trend, all P < 0.01). Serum TG concentration significantly rose with decreasing birth weight, PI and head circumference (for trend, P < 0.01, P < 0.01, P < 0.05), while HDL-C rose with increasing birth weight and head circumference (for trend, P < 0.05, P < 0.01). All above mentioned relations between birth size and the level of risk factors during adulthood were independent of gestation and adult lifestyle. CONCLUSIONS: In China, low birth measurements which represent the fetal growth retardation might contribute to the present of biological risk factors of coronary heart disease during adulthood, such as hypertension, diabetes, insulin resistance, high serum triglyceride and low HDL-C.

Birth Weight↗

PubMed1999

[Isolating, cloning, and sequencing of HPV16E6E7 gene from a cervical carcinoma biopsy in Shandong Province].

OBJECTIVE: In order to study the structure specificity of HPV16E6E7 gene of a Chinese patient of cervical carcinoma in Shandong province. METHODS: The tissue DNA were abstracted from cervical carcinoma biopsies and the type of HPV was identified by HPV multiple primers PCR. HPV16E6E7 gene was amplified by PCR from the cervical carcinoma tissue DNA with the infection of HPV16 type only, and then cloned the E6E7 gene into pALTERI vector. After sequencing the double strand, the gene was compared with the prototype E6E7 gene of HPV16. RESULTS: A new recombinant plasmid was constructed and named HPV16E6E7-SD. Sequencing results showed one mutation in HPV16E6E7-SD, the 557th neocleotide in the viral neocleotide sequence "T" was changed into "C", and caused the termination cordon TAA of E6 gene to convert into a Gln cordon CAA. CONCLUSIONS: There is a structure difference between HPV16E6E7-SD and the standard strain.

Base Sequence↗