Biomedical subjects

G Song

Publications and source records attributed to G Song.

At least 73 records · Page 4Linked to original sources

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

[Differences in haemozoin production and pathogenicity between chloroquine-sensitive and chloroquine-resistant strains of Plasmodium berghei].

AIM: To better understand the differences in haemozoin formation and pathogenicity between chloroquine-sensitive(N) and chloroquine-resistant(RC) strains of Plasmodium berghei. METHODS: IRC mice were grouped as follows: group Xba I (Normal control, NC), group II (control treated with chloroquine alone, CC), group III (mice infected with N strain), group IV (mice infected with RC strain, RC) and group V (mice infected with RC strain and treated with chloroquine, RCC). Morphologic features of the parasites, parasitaemia, histological and ultrastructural changes of livers among the groups were compared. RESULTS: Severe damages of the hepatic cells of the N group including increased lysosomes and swollen and fused mitochondria were detected. On the contrary, the prominent features in liver section of the RC group were inflammatory cell (notably mononuclear) infiltration and Kupffer cell activation. Numerous trophozoites and schizonts were sequestrated in hepatic sinusoids and less degeneration of parenchymal cells was found except for some swollen and vacuolated mitochondria. Internal food vacuoles containing haemozoin were found in the parasites of the N group, whereas external food vacuoles without haemozoin granules were arranged in foamy appearance within the parasitized cell of the RC group. CONCLUSION: P. berghei RC strain may modify the mode of ingestion and degradation of hemoglobin in the parasites, resulting in impeding haemozoin formation. The difference in virulence between the N and RC strain of P. berghei is probably attributed to the significant differences in the induction of immune response of the host.

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

[Flow injection analysis for trace phosphorus(V) and arsenic(V) determination].

A flow injection analysis method for trace amount P(V) and As(V) determination has been established based on the fluorescence quenching effect of rhodamine 6G due to the formation of an unfluorescence ion-association complex. Rhodamine 6G has a maximum emission wavelength of 555 nm (excitation at 350 nm). The calibration curves were found linear in the range of 0-80 microg/L of P(V) and 0-100 microg/L of As(V). The method has been used for the determination of P(V) and As(V) in copper alloys with satisfactory results.

English Abstract↗

PubMed1998

Effects of total replacement of atrial myosin light chain-2 with the ventricular isoform in atrial myocytes of transgenic mice.

BACKGROUND: In contrast to their well-known and critical role in excitation-contraction coupling of vascular smooth muscle, the effects of the myosin light chains on cardiomyocyte mechanics are poorly understood. Accordingly, we designed the present experiment to define the cardiac chamber-specific functional effects of the ventricular isoform of the regulatory myosin light chain (MLC2v). METHODS AND RESULTS: Postnatal transgenic cardiac-specific overexpression of MLC2v was achieved by use of the alpha-myosin heavy chain promoter. Enzymatically disaggregated atrial and ventricular mouse myocytes were field-stimulated at multiple frequencies, and mechanical properties and calcium kinetics were studied by use of video edge detection and FURA 2-AM, respectively. MLC2v overexpression resulted in complete replacement of the atrial with the ventricular isoform of the regulatory myosin light chain at the steady-state mRNA and protein levels in the atria of transgenic mice. Mechanical properties of transgenic atrial myocytes were enhanced to the level of ventricular myocytes of control animals in association with modest decreases in the amplitude of the calcium transient. CONCLUSIONS: MLC2v modulates chamber-specific contractility by enhanced calcium sensitivity and/or improved cross-bridge cycling of the thin and thick filaments of the cardiomyocyte.

Animals↗

PubMed1998

Altered cardiac annexin mRNA and protein levels in the left ventricle of patients with end-stage heart failure.

Annexins are a unique family of membrane-associated, Ca2+ and phospholipid-binding proteins found in various tissues. Among the 12 isoforms, Annexin II, V and VI exist in heart tissue in the highest amounts. Annexin VI has been shown to affect intracellular Ca2+ cycling and contractility in isolated cardiomyocytes. Annexin V is present in both cardiomyocytes and non-myocyte cell types in the heart and may play a role in the regulation of cellular ion fluxes, organization and secretion, while the cardiac effects of annexin II are unclear. To identify changes in annexin II, V and VI isoforms that might occur in human heart failure, we measured mRNA and protein levels of these three annexins in transplanted left ventricular tissue of 12 patients with end-stage congestive heart failure due to coronary artery disease (CAD, n=6) or idiopathic dilated cardiomyopathy (DCM, n=6) who underwent cardiac transplantation. Normal heart tissue (C, n=6) was used as a control. Northern blot analyses showed a significant decrease (61%) in annexin VI mRNA levels in heart failure patients compared with controls (1.08+/-0.16 v 2.79+/-0.20 A.U.C. unit, determined by laser densitometry, mean+/-s.e.). In contrast, we found a 67% increase (2. 32+/-0.27 v 3.88+/-0.29) in annexin II mRNA levels and a two-fold increase (1.00+/-0.24 v 2.21+/-0.29) in annexin V mRNA levels in cardiomyopathic hearts as compared to normal hearts. Western blot analyses demonstrated a corresponding decrease (46.1%) in annexin VI protein levels in the heart failure group as compared to controls (2. 63+/-0.22 v 4.88+/-0.52), while annexin II protein levels showed a significant 40.7% increase in patients with heart failure compared to those in normal hearts (5.08+/-0.67 v 3.61+/-0.32). Annexin V protein levels were also significantly increased (45%) in heart failure patients compared with normal (2.14+/-0.19 v 1.48+/-0.11). No difference in either annexins II, V or VI mRNA and protein levels were found between CAD and DCM patients. We conclude that human end-stage heart failure is associated with a down regulation of annexin VI and up regulation of annexin II and V proteins. Coordinate changes were observed in steady-state mRNA levels. These results suggest that these annexin isoforms may contribute to the regulation of intracellular Ca2+ homeostasis in the cardiomyopathic heart.

Adult↗

PubMed1998

The vaccine efficacy of native paramyosin (Sj-97) against Chinese Schistosoma japonicum.

One of the promising anti-schistosome vaccine candidates currently under investigation is paramyosin, a 97-kDa myofibrillar protein located in the muscles and tegument of schistosome worms. Here we describe the results of two vaccination/challenge experiments undertaken in mice using native paramyosin isolated from adult worms of a Chinese strain of Schistosoma japonicum. In both sets of experiments, a relatively low but consistent and significant reduction in worm burden was evident in mice vaccinated subcutaneously with S. japonicum paramyosin and Freund's adjuvant. In contrast, intraperitoneal vaccination of mice with Chinese strain S. japonicum paramyosin without adjuvant did not result in any reduction in worm numbers when compared with a saline control group. These data contrast with the impressive protection figures reported by another group who used a similar intraperitoneal vaccination protocol with native paramyosin extracted from Philippine strain S. japonicum.

Animals↗

PubMed1998

Nucleotide sequence and phylogenetic analysis of the medium (M) genomic RNA segments of three hantaviruses isolated in China.

The medium (M) genome segment of hantaviruses (family Bunyaviridae) encodes the two virion glycoproteins. G1 and G2, as a precursor protein in the complementary sense RNA. We determined the nucleotide sequences of the M genome segments of three Chinese hantavirus isolates, a Hantaan-type (HTN) virus designated A9 and two Seoul-type (SEO) viruses designated L99 and HB55, and compared them to those of other HTN or SEO viruses isolated in Eastern Asia. The M segment of A9 is 3616 nucleotides in length and shows 99.5% identity at the nucleotide level and 99.1% identity at the amino acid level to that of the Chinese HTN isolate HV114. The M segments of L99 and HB55 are 3652 nucleotides in length, one nucleotide longer than the M segments of other sequenced SEO isolates such as SEO 80-39, SR-11, and Biken-1. The Chinese SEO isolates showed 95% nucleotide sequence identity and 99% amino acid sequence identity to SEO 80-39. We also sequenced a 736 nucleotides region of the M genome segment of another Chinese SEO isolate, R22, which revealed errors in the published data. Phylogenetic analysis of the available sequences indicated that both the Chinese HTN- and SEO-type viruses form lineages distinct from those of the isolates from other parts of Eastern Asia.

Amino Acid Sequence↗

PubMed1998

[Molecular cloning and sequencing of genes encoding MSP2 isolates strains from two of Plasmodium falciparum from Chinese patients with cerebral malaria].

OBJECTIVE: To provide the scientific evidence for designing safe and effective vaccines of human cerebral malaria. METHODS: Genomic DNA samples of two isolated Plasmodium falciparum isolate strains prepared directly from 5 cases of cerebral malaria patients' blood in mengla County, Yunnan Province (CMH/YN) and in Yingjiang County, Yunnan Province (CYJ/YN) were used for polymerase chain reaction (PCR) amplification and the two pairs of oligonucleotides for the highly conserved genes encoding FC27 merozoite surface protein 2 (MSP2) of Papua New Guinea strain of Plasmodium falciparum were used as primers. The PCR products were digested with BamH1 and Hind III respectively, and the generated fragment MSP2 were cloned into M13mp18 and M13mp19 vectors and their DNA was analyzed as the templates for DNA sequencing by the dideoxy chain-termination method. RESULTS: Compared with the published findings, FC27, K1, IC1 and CAMP sequences, DNA sequences of MSP2 from two isolated CMH/YN and CYJ/YN of Plasmodium falciparum strains from Chinese patients with cerebral malaria contained identical genes composed of 800 bp, encoding 264 amino acid, which were highly homologous up to 98.8% with that of FC27, K1 strain other than the IC1, CAMP strain. CONCLUSION: It is the first record of DNA sequencing of MSP2 determined from two isolated CMH/YN and CYJ/YN of Plasmodium falciparum strains from Chinese patients with cerebral malaria, MSP2 mutation may be one factor leading to the localized cerebral damage which causes clinical coma of human cerebral malaria.

Amino Acid Sequence↗

PubMed1998

[Effects of stimulation at different areas of nucleus raphe dorsalis on genioglossus and diaphragm activities].

Effects of electrical and chemical stimulation of the dorsal and ventral areas of the nucleus raphe dorsalis (dNRD and vNRD) on genioglossus and diaphragm activities were observed in 48 urethane-anaesthetized and vagotomized rabbits. (1) Long train electrical stimulation at the dNRD facilitated genioglossus and diaphragm activities. (2) Long train electrical stimulation delivered to the vNRD excited genioglossus activity but inhibited diaphragm activity. (3) Effects of microinjection of glutamate at the dNRD and vNRD were similar to the effects of electrical stimulation. The above results suggest that excitation of nucleus raphe dorsalis (NRD) increases genioglossus activity and reduces upper airway resistance. The dNRD and vNRD play different roles in modulating diaphragm activity.

Animals↗

PubMed1998

[Effects of glycine and strychnine microinjected into unilateral and bilateral Bötzinger complex on phrenic nerve discharges in rabbits].

The effects of microinjection of glycine and strychnine into unilateral and bilateral Bötzinger complex (Böt. C) on phrenic nerve discharges were observed in 34 urethane anaesthetized, vagotomized, paralyzed and artificially ventilated rabbits. The results are as follows: (1) microinjection of glycine into unilateral Böt. C induced an increase of respiratory rate and expiratory phrenic nerve discharges; (2) microinjection of glycine into bilateral Böt. C induced non-rhythmic tonic phrenic nerve discharges with an amplitude 40%-70% of control; strychnine could competitively antagonize the effects of glycine; and (3) microinjection of strychnine into bilateral Böt. C induced a decrease of respiratory rate and the amplitude of phrenic nerve discharges, in addition to prolongation of expiratory duration while inspiratory duration remained unchanged. The above results suggest that the Böt. C plays a crucial role in initiating and sustaining expiration.

Animals↗

PubMed1998

[Cloning of human papillomavirus type 16 E7 gene and expression in E. coli].

OBJECTIVE: To study the biological activity of the E7 gene of human papillomavirus 16 (HPV16). METHODS: E7 gene from the cervical carcinoma of Chinese women was amplified by the PCR. The E7 DNA was sequenced and compared with the prototype E7 gene of HPV 16. RESULTS: It showed no mutations. However when E7 gene was inserted into the prokaryotic expression vector pGEX-2T and the fused E7 protein was efficiently expressed in E. Coli (DH5 alpha). The E7 antibody could combine specifically with this fused protein by Western blot technique. CONCLUSIONS: The result might aid for epidemiological investigation and preparation of the vaccine.

Base Sequence↗

PubMed1998

[Human interleukin-13 cDNA cloning and expression].

OBJECTIVE: To construct an efficient expression system for HIL-13 in prokaryotic cells. METHODS: After Amplified by RT-PCR, The cDNA fragment encoding HIL-13 was inserted into pGEX-2T plasmid and expressed under induced condition. RESULTS: HIL-13 cDNA was obtained. Recombinant plasmid pGEX-2T HIL-13 was constructed and sequenced, the inserted fragment of the recombinant plasmid was confirmed to be HIL-13 cDNA. HIL-13 was expressed as a fusion protein with glutathione-s-transferase (GST-HIL-13, MW = 39,000). CONCLUSIONS: (1) HIL-13 cDNA has been obtained from T lymphocytes. (2) The rate of expression of HIL-13 in prokaryotic cells is about 37%.

Amino Acid Sequence↗

PubMed1998

[Magnetic resonant imaging diagnosis and differential diagnosis in choroidal melanoma].

OBJECTIVE: To evaluate the diagnostic value of magnetic resonant imaging (MRI) for choroidal melanoma. METHODS: 12 cases of choroidal melanoma were diagnosed by means of B-ultra-sonography, computed tomography (CT), MRI and pathology. RESULTS: The MRI features of melanoma were: T(1)WI shows high signal, and T(2)WI shows low signal. CONCLUSION: Besides B-ultra-sonography and CT, MRI is also valuable in the diagnosis and differential diagnosis of choroidal melanoma.

Adult↗

PubMed1998

[The manifestations of 496 cases with thyroid-related immune orbitopathy and normal thyroid function].

OBJECTIVE: To observe the clinical manifestations of thyroid-related immune orbitopathy (TRIO) with normal thyroid function. METHODS: 496 cases with TRIO were collected from 1973 to 1994 and their clinical manifestations were analyzed. RESULTS: The clinical manifestations showed that males are more than females. The disease occurred in middle aged persons with unilateral exophthalmos as the primary early manifestation. Most of the cases had the signs of eyelids and extraocular muscle involvement. CONCLUSIONS: The thyroid-related immune orbitopathy with normal thyroid function can be named thyroid-related immune orbitopathy-II. The clinical characteristics of this disease are unilateral, of signs of eyelids, exophthalmos and enlargement of eye muscles. The pseudo-tumors of the orbit are mainly considered for differential diagnosis.

Adolescent↗

PubMed1998

[Clinical analysis of primary orbital varix].

OBJECTIVE: To analyze and summarize the clinical and imaging signs, diagnosis and treatment of primary orbital varix. METHOD: 218 cases of primary orbital varix in 20 years were analyzed. RESULTS: Positional proptosis was the primary sign. Ultrasound examination showed that a characteristic well-out-lined lesion with low or without reflection of sound appeared in the orbital fat when the internal carotid vein was compressed. CONCLUSION: To recognize the characteristic imaging signs of orbital varix in ultrasound examination is valuable for the choice of treatment.

Adolescent↗