Biomedical subjects

G Song

Publications and source records attributed to G Song.

At least 37 records · Page 2Linked to original sources

PubMed2001

[Change of prolactin in SD rats with experimental autoimmune thyroiditis].

OBJECTIVE: To verify the effect of prolactin (PRL) on the development and progression of experimental autoimmune thyroiditis (EAT) in SD rats and the inhibitive effect of bromocriptine (BRC) on the development of EAT. METHODS: SD rats were injected with BRC to inhibit the development of EAT and the change of PRL were observed. RESULTS: High level of serum PRL was found in the EAT rats [(8.70 +/- 0.42) microg/L, P < 0.01 vs. control (6.46 +/- 0.67) microg/L], and there was also high levels of thyroid autoantibodies (thyroglobulin antibody, thyroid peroxidase antibody). However, in rats receiving BRC, the levels of thyroid autoantibodies decreased as the PRL level declined (5.30 +/- 0.81) microg/L and the thyroid lesions were mild. CONCLUSION: Hyperprolactinemia plays a role in the development of EAT and control of the hyperprolactinemia with BRC may afford therapeutic benefit.

Animals↗

PubMed2001

[The effect of Paeonol on erythrocyte deformability determined by micropipette aspiration technique].

OBJECTIVE: The effect of Paeonol (PAE) on erythorcyet(RBC) deformability was studied in order to provide experimental data for the application in clinic and the evaluation in pharmacological action. METHODS: Micropipette Aspiration Technique was used to determine the RBC deformation length. The method of calculation was also simplified and a new apparent deformation Index(ADI) was defined. RESULTS: PAE could increase the ADImin and ADImax and decrease Tmax significantly. CONCLUSION: PAE has the effect of deformational ability on RBC. Micropipette aspiration technique is a feasible method for determining the effect of traditional Chinese medicine on erythrocyte deformability.

Acetophenones↗

PubMed2001

[Projections of 5-HTergic fibers to the spinal phrenic nucleus and medullary phrenic premotor neurons in the cat].

Experiments were performed on 6 adult cats. Brainstem neurons that project to the phrenic nucleus were retrogradely labeled by microinjection of WGA-HRP into the spinal phrenic nucleus. The brainstem sections were double processed for HRP histochemical staining with TMB-DAB method and 5-HT immunohistochemical staining with anti-5-HT primary antibody and FITC conjugated immunofluorescent secondary antibody. HRP-5-HT double-labeled neurons were observed mainly in the nucleus raphe pallidus. A few double-labeled neurons were also observed in nucleus raphe obscurus and nucleus raphe magnus. 5-HT immunopositive terminal fibers were observed in the vicinity of HRP single-labeled neurons (phrenic premotor neurons) located in the nucleus ambiguus and ventrolateral solitary tract nucleus. The results indicate that the 5-HTergic neurons in the nucleus raphe pallidus send axonal projections to the phrenic nucleus, and that the brainstem phrenic premotor neurons also receive 5-HTergic axonal projections.

Animals↗

PubMed2001

Afferent projection to the retrotrapezoid nucleus from respiratory related structures in the brainstem of rabbit--a retrograde CB-HRP tracing study.

Experiments were performed on 10 adult rabbits. After microinjection of cholera toxin B-subunit conjugated horseradish peroxidase (CB-HRP) into the retrotrapezoid nucleus (RTN), retrogradely labeled neurons were mainly observed in the Kölliker-Fuse nucleus (KF), the medial parabrachial nucleus (PBM) and the lateral parabrachial nucleus (PBL). A few labeled neurons were also observed in the ventrolateral solitary tract nucleus, the ambiguus and retroambiguus nuclei, and the ventromedial area of retrofacial nucleus. Labeled terminal fibers were mainly observed in the retrofacial nucleus, the ambiguus and retroambiguus nuclei, the ventrolateral area of solitary tract nucleus, and the PBL-PBM-KF. The above results show that the RTN has axonal connections with the pontine and medullary respiratory related structures.

Afferent Pathways↗

PubMed2001

[The value of color Doppler imaging ultrasound in diagnosis of orbital diseases].

OBJECTIVE: To study the useful value of color Doppler imaging (CDI) ultrasound in the diagnosis and differential diagnosis of orbital diseases. METHODS: By using the technique of CDI ultrasound, 288 cases with orbital diseases were examined to show color Doppler flow imaging and pulsed wave Doppler (PWD) spectrum. RESULTS: Among 288 cases of the orbital diseases, 38 cases of malignant tumors and 23 cases inflammatory pseudotumors showed the signals of blood flow. From CDI ultrasound examination, there were 18 in 23 cases with benign mixed tumors of the lacrimal gland showing artery blood flow and 22 in 28 cases with neurilemoma showing signals of blood flow. No blood flow was obtained in 62 among 74 cases with cavernous hemangioma, in 16 cases of dermoid cysts or epidermoid cysts and 1 case of lipoma. From CDI, rich blood flow was seen in 4 and scarce in 3 cases with meningioma, and in 6 cases of optic nerve gliomas, there were 5 cases without any blood flow signals. Other 2 cases with benign hemangioendothelioma, 2 hemangiopericytoma and 1 neurofibroma showed rich or scarce blood flow signals. Among 29 cases of venous hemangiomas, 16 cases showed venous flow. Three cases with arteriovenous aneurysms showed artery blood flow in the CDI. Fifteen cases with varicosis exhibited a dynamic blood flow changes in the CDI. Six cases with infantile hemangioma, the decreased blood supply was shown in the CDI after treatment. In the thirteen cases with carotid artery cavernous sinus fistula, including 8 cases of internal carotid artery cavernous sinus fistula (CCF) and 5 dural cavernous sinus fistula (DCF), dilated superior ophthalmic vein (SOV) with arterialized blood flow was seen. In the mean time, PWD showed that the SOV of CCF had a higher velocity and a higher flow volume than that of DCF, while its resistance index was lower than that of the DCF. In 1 case with thrombophlebitis, its SOV showed dilated superior ophthalmic vein without blood flow. CONCLUSIONS: CDI can provide the information of color blood flow in orbital diseases, especially the tumors with rich vascular tissue and orbital vascular diseases. It is important in the diagnosis and differential diagnosis of the orbital diseases in combination with B-mode ultrasound, CT or MRI.

Adolescent↗

PubMed2001

[Cloning and nucleotide sequencing of full length L segment cDNA of Hantavirus strain A9].

OBJECTIVE: Cloning and nucleotide sequencing of full length cDNA sequence of L segment of Hantavirus strain A9. METHODS: The L segment cDNA of Hantavirus strain A9 was amplified by RT-PCR. PCR products were cloned and sequenced. Full length cDNA clone of the L segment was obtained by subcloning. RESULTS: The L segment of strain A9 was 6 533 nucleotides in length and encoded a putative L polymerase that was 2 151 amino acids in length. Analysis of nucleotide and deduced amino acid sequences of the L segment of strain A9 showed a close relationship with the other Hantaviruses most notably the 76-118, Cl-1 and Cl-2 strains, with which they shared a 83.8% nucleotide identity. More distant similarity could also be seen with other Hantaviruses. Sequence comparison performed among the RNA-dependent RNA polymerases of 27 negative stranded RNA viruses revealed that the same existence of six conserved regions and several strictly conserved residues located at the deduced amino acid sequence of A9 L segment. CONCLUSIONS: The nucleotide sequence of L segment of strain A9 was similar to other Hantavirus L segments. Deduced amino acid sequence of A9 L segment shares 6 conserved regions with other RNA virus RNA polymerase. The conserved residues in these polymerases and their possible functions in light of the available structural information have been discussed.

Amino Acid Sequence↗

PubMed2001

[Effects of pressure induced retinal ischemia on ERG in rabbit].

OBJECTIVE: To observe the effects of pressure induced retinal ischemia on electroretinogram(ERG) in rabbit. METHODS: Retinal ischemia was induced in rabbits by increasing intraocular pressure at 30 mmHg, 60 mmHg, 90 mmHg, 120 mmHg for 45 minutes, and retinal function was monitored by eletroretinography. RESULTS: There was no difference on ERG before or after the experiment both in 30 mmHg group and control one. In 60 mmHg pressure induced ischemia eyes, the amplitudes of the b-wave and OPs wave reduced significantly. Four hours after reperfusion, they were totally recovered. After an ischemic insult of 90 mmHg or 120 mmHg for 45 minutes, there was no response of ERG. Four hours later, the amplitudes of the b-wave and OPs wave were 66.912 +/- 20.157 and 16.423 +/- 3.965 the former, 38.852 +/- 23.438 and 8.610 +/- 12.090 the latter, respectively. CONCLUSION: These results suggest that higher intraocular pressure causes more severe retina ischemic damage, and less recovery ability.

Animals↗

PubMed2000

The preparation and characterization of an immobilized l-glutamic decarboxylase and its application for determination of l-glutamic acid.

This paper is to study the preparation and characterization of an immobilized L-glutamic decarboxylase (GDC) and develop a sensitive method for the determination of L-glutamate using a new biosensor, which consists of an enzyme column reactor of GDC immobilized on a novel ion exchange resin (carboxymethyl-copolymer of allyl dextran and N.N'-methylene-bisacrylamide CM-CADB) and ion analyzer coupled with a CO(2) electrode. The conditions for the enzyme immobilization were optimized by the parameters: buffer composition and concentration, adsorption equilibration time, amount of enzyme, temperature, ionic strength and pH. The dynamic response of Na(2)HPO(4)-citric acid buffer system selected is much better than that of the others, 0.10 M HAc-0.10 M NaAc and 0.10 M sodium citrate-0.10 M citric acid. The initial rate of the enzyme reaction v(0) in this buffer system is 1.76 mol. l(-1) min(-1), moreover, the rate of the enzyme reaction appears linear in the first 4 min. The optimum adsorption equilibrium time is around 6 h. The amount of enzyme adsorbed on CM-CADB resin affects the response to substrate L-glutamic acid, the widest range of linearity is obtained with over 30 mg (GDC)/g(resin). The GDC activity immobilized on CM-CADB reaches a maximum when the immobilization temperature was kept around 40 degrees C. pH was kept at 4.4 when measuring the activity of the immobilized GDC. No variation of the activity of immobilized GDC is observed when the capacity is over 2.5 meq/g.(CM-CADB resin). The properties of the immobilized enzyme on CM-CADB were characterized. No significant improvement can be achieved when the substrate concentration exceeds 12.00 mmol/l, where the activity of immobilized GDC is equal to 1.58 mmol/l.min.g. The optimum pH is found to be 5.2, which changes 0.2 unit, comparing with that of the free GDC (5.0). The optimum temperature is found to be around 48 degrees C, which is lower than that of free GDC (55 degrees C). The critical temperature of the free GDC and the immobilized GDC is approximately 50 degrees C and 45 degrees C, respectively. The half-life of the activity is 127 days when the immobilized enzyme was stored in the cold (4 degrees C). An immobilized GDC enzyme column reactor matched with a flow injection system-ion analyzer coupled with CO(2) electrode-data collection system made up the original form of the apparatus of biosensor for determining of L-glutamic acid. The determination conditions are that the buffer solution is 0.10 M Na(2)HPO(4)-0.05 M citric acid at pH 4.4 and t = 37 degrees C. The limit of detection is 1.0 x 10(-)(5) M. The linearity response is in the range of 5 x 10 (-2) - 5 x 10 (-5) M. The equation of linear regression of the calibration curve is y = 43.3x + 181.6 (y is the milli-volt of electrical potential response, x is the logarithm of the concentration of the substrate of L-glutamic acid). The correlation coefficient equals 0.99. The coefficient of variation equals 2.7%.

Journal Article↗

PubMed2000

Protective immunity induced by the full-length cDNA encoding paramyosin of Chinese Schistosoma japonicum.

The full-length cDNA encoding paramyosin of Chinese S. japonicum (Sjc97) has been cloned and sequenced for the first time. The homology of the nucleotide sequence of paramyosin and the deduced amino acid sequence between Chinese, Philippine, Japanese strains and S. mansoni (Sm97) were 99.7, 99.8 and 96% at amino acid level, respectively; 99.4, 99.2 and 91% at nucleotide level, respectively. The immunogenicity and protective efficacy of a DNA vaccine encoding Sjc97 was evaluated in C57BL/6 mice. Mice immunized intramuscularly with pCMV-Sjc97 resulted in predominantly IgG2a and IgG2b immune responses, and immune sera were able to mediate antibody-dependent macrophage mediated cytotoxicity in vitro. Cytokine profiles in immunized C57BL/6 mice demonstrated Th1 bias, with IFN-gamma and IL-2 production and lack of IL-4 and IL-5. Immunization with pCMV-Sjc97 conferred a significant level of protection against cercariae in C57BL/6 mice. These results demonstrate that the nucleic acid encoding Sjc97 was able to induce a Th1 type immune response and confer protective efficacy in C57BL/6 mice when administrated via the intramuscular route.

Animals↗

PubMed2000

TNF-alpha gene expression in macrophages: regulation by NF-kappa B is independent of c-Jun or C/EBP beta.

The interaction of transcription factors is critical in the regulation of gene expression. This study characterized the mechanism by which NF-kappa B family members interact to regulate the human TNF-alpha gene. A 120-bp TNF-alpha promoter-reporter, possessing binding sites for NF-kappa B (kappa B3), C/EBP beta (CCAAT/enhancer binding protein beta), and c-Jun, was activated by cotransfection of plasmids expressing the wild-type version of each of these transcription factors. Employing adenoviral vectors, dominant-negative versions of NF-kappa B p65, and c-Jun, but not C/EBP beta, suppressed (p < 0.05-0.001) LPS-induced TNF-alpha secretion in primary human macrophages. Following LPS stimulation, NF-kappa B p50/p65 heterodimers bound to the kappa B3 site and c-Jun to the -103 AP-1 site of the TNF-alpha promoter. By transient transfection, NF-kappa B p65 and p50 synergistically activated the TNF-alpha promoter. In contrast, no synergy was observed between NF-kappa B p65, with or without NF-kappa B p50, and c-Jun or C/EBP beta, even in the presence of the coactivator p300. The contribution of the upstream kappa B binding sites was also examined. Following LPS stimulation, the kappa B1 site bound both NF-kappa B p50/p65 heterodimers and p50 homodimers. The binding by NF-kappa B p50 homodimers to the kappa B1, but not to the kappa 3, site contributed to the inability of macrophages to respond to a second LPS challenge. In summary, adjacent kappa B3 and AP-1 sites in the human TNF-alpha promoter contribute independently to LPS-induced activation. Although both the kappa B1 and kappa B3 sites bound transcriptionally active NF-kappa B p50/p65 heterodimers, only the kappa B1 site contributed to down-regulation by NF-kappa B p50 homodimers.

Animals↗

PubMed2000

Changes in Ca(2+) cycling proteins underlie cardiac action potential prolongation in a pressure-overloaded guinea pig model with cardiac hypertrophy and failure.

Ventricular arrhythmias are common in both cardiac hypertrophy and failure; cardiac failure in particular is associated with a significant increase in the risk of sudden cardiac death. We studied the electrophysiologic changes in a guinea pig model with aortic banding resulting in cardiac hypertrophy at 4 weeks and progressing to cardiac failure at 8 weeks using whole-cell patch-clamp and biochemical techniques. Action potential durations (APDs) were significantly prolonged in banded animals at 4 and 8 weeks compared with age-matched sham-operated animals. APDs at 50% and 90% repolarization (APD(50) and APD(90) in ms) were the following: 4 week, banded, 208+/-51 and 248+/-49 (n = 15); 4 week, sham, 189+/-68 and 213+/-69 (n = 16); 8 week, banded, 197+/-40 and 226+/-40 (n = 21); and 8 week, sham, 156+/-42 and 189+/-45 (n = 22), respectively; P<0.05 comparing banded versus sham-operated animals. We observed no significant differences in the K(+) currents between the 2 groups of animals at 4 and 8 weeks. However, banded animals exhibited a significant increase in Na(+) and Na(+)-Ca(2+) exchange current densities compared with controls. Furthermore, we have found a significant attenuation in the Ca(2+)-dependent inactivation of the L-type Ca(2+) current in the banded compared with sham-operated animals, likely as a result of the significant downregulation of the sarcoplasmic reticulum Ca(2+) ATPase, which has been documented previously in the heart failure animals. Our data provide an alternate mechanism for APD prolongation in cardiac hypertrophy and failure and support the notion that there is close interaction between Ca(2+) handling and action potential profile.

Action Potentials↗

PubMed2000

Comparison of three treatment options for single brain metastasis from lung cancer.

Whole brain radiotherapy (WBRT), stereotactic radiosurgery (SRS), and the combination of both treatment methods were used for the management of single brain metastasis from lung cancer. The purpose of this study is to compare these three different treatment options in terms of local response, survival, and quality of life. From June 1995 to July 1998, 70 lung cancer patients with new diagnosed single brain metastasis were treated with either WBRT alone (n = 29), or SRS alone (n = 23), or the combination of both methods (n = 18). Multiple endpoints, including survival, freedom from local progression (FFLP), freedom from new brain metastasis (FFNBM), local control, Karnofsky performance status (KPS), and causes of death, were measured from the date of treatment completion and compared using univariate and multivariate analyses. For patients treated with WBRT-alone, SRS-alone, and SRS+WBRT, the median survivals were 5.7, 9.3, and 10.6 months, the median FFLP were 4.0, 6.9, and 8.6 months, the median FFNBM were 4.1, 6.7, and 8.6 months, and the local response rates were 55.6, 87.0, and 88.9%, respectively. Four of the 29 patients treated with WBRT-alone continued with progression of disease. The post treatment KPS showed improvement in 41.4, 82.6, and 88.9% of patients treated with WBRT-alone, SRS-alone, and SRS+WBRT, respectively. The progression of new and/or recurred metastatic brain tumor as the cause of death accounted for 51.7%, 50. 0%, and 28.3% of the patients treated with WBRT-alone, SRS-alone, and SRS+WBRT, respectively. Univariate analyses showed that the significant differences among the three treatment arms were observed based on all of the above mentioned endpoints. However, the comparison between SRS-alone and SRS+WBRT groups indicated that adding WBRT only improves FFNBM (P = 0.0392). Cox regression analyses revealed no significant difference in both of the KPS (P = 0.1082) and causes of death (P = 0.081) among the three arms. Both SRS alone and SRS+WBRT seem better in prolonging life and improving quality of life than WBRT alone for patients with single brain metastasis from lung cancer. But the combined therapy did not show significant advantage over SRS alone in improving survival, enhancing local control, and quality of life except for a more favorable FFNBM. Further investigation via a randomized trial is needed to access the value of adding WBRT to SRS in the management of this group of patients. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 37-45 (2000).

Adult↗

PubMed2000

Changes in cardiovascular risk factors in different socioeconomic groups: seven year trends in a Chinese urban population.

STUDY OBJECTIVE: To analyse trends in socioeconomic differences in cardiovascular disease risk factors among an urban Chinese population using educational attainment as the socioeconomic indicator. DESIGN: Population surveys with randomly selected independent samples were carried out in 1989 and in 1996. Educational attainment, blood pressure, body mass index, cigarette smoking and lack of leisure time physical activity were determined. SETTING: Urban areas of the city of Tianjin, China. PARTICIPANTS: A total of 14 275 respondents aged 25-64 years. MAIN RESULTS: Diastolic blood pressure increased and the proportion of people without leisure time physical activity decreased in both sexes during the study period. The prevalence of smoking and the number of cigarettes smoked daily increased significantly among men. Smoking decreased in the least educated men and increased in those who had studied at least to college level. Body mass index decreased across all educational strata in women, but blood pressure increased in women with at least college level education. CONCLUSIONS: These data reveal a different picture in trends in the association of education and cardiovascular risk factors from those depicted in developed countries. This highlights the need for an effective intervention programme in the study population.

Adult↗

PubMed2000

Associations between socioeconomic status and cardiovascular risk factors in an urban population in China.

INTRODUCTION: In developed countries socioeconomic status has been proven to be an important factor in the progression of cardiovascular disease. The present article reports the results of a cross-sectional assessment to investigate the association between socioeconomic status and cardiovascular risk factors in a Chinese urban population. METHODS: In 1996, a behavioural risk factor survey was carried out in Tianjin, the third largest city in China. A sample of 4000 people aged 15-69 years, stratified by sex and 10-year age groups, was drawn randomly from urban areas of the city. The present study covers respondents aged 25-69 years (1615 men and 1592 women). Four socioeconomic indicators (education, occupation, income, and marital status), blood pressure, body mass index, and cigarette smoking were determined in the survey. RESULTS: Educational level seemed to be the most important measure of the four socioeconomic indicators in relation to the cardiovascular risk factors in the study population. People with lower socioeconomic status had higher levels of cardiovascular risk factors. The association between socioeconomic status and cardiovascular risk factors was more consistent among women than men. DISCUSSION: Our findings do not seem to differ from those observed in developed countries.

Adolescent↗

PubMed2000

[Point mutations of N-ras oncogene and abnormal expression of rasp21, p53 proteins in orbital rhabdomyosarcoma].

OBJECTIVE: The point mutations of N-ras oncogene and the abnormal expression of rasp21 and p53 proteins in orbital rhabdomyosarcoma (RMS) were analyzed in order to explore the role of oncogene mutations in the pathogenesis of orbital RMS and its relation to patients' prognosis. METHOD: 21 human orbital RMS tissues were analyzed by dot-blot hybridization and immunohistochemistry using synthetic specific oligonucleotide probes and mutant rasp21, p53 monoclonal antibodies. RESULTS: The second base mutation of codon 12 of the N-ras oncogene was found in 4 patients. The third base mutation of codon 61 was found in 5 patients. The mutant rate was 33.3%. By immunohistochemistry analysis, the overexpression of rasp21 and p53 protein level was found in 42.9% and 76.2% respectively. The prognosis of patients with overexpression of ras p21, p53 was worse than that of normal expression (P < 0.01). CONCLUSION: The mutants of ras and p53 oncogene play important roles in the pathogenesis of orbital RMS, and the abnormal expression of their protein products is related to patients' prognosis.

Adolescent↗

PubMed2000

[Monitor visual function with flash visual evoked potential during orbital surgery].

OBJECTIVE: To evaluate the feasibility and reliability of monitoring visual function with flash visual evoked potential (FVEP) during orbital surgery. METHOD: The visual function of 82 cases was monitored during orbital surgery with FVEP. Of these cases, the intraoperative and postoperative visual functions (IOVF and POVF) were compared. RESULTS: Sixty-nine cases were successfully monitored. Sixty-seven cases obtained the accordance of IOVF and POVF, and there were false positive in 1 case and false negative in 1 case. CONCLUSION: Intraoperative monitoring of visual function with FVEP can show the surgical injury of the optic nerve and unsuitable procedures, and decrease the surgical blind rate.

Adolescent↗

PubMed2000

[A study on methods to measure the social burden of disease and their significance].

OBJECTIVE: To explore the effects of social burden of disease (BOD) on the total BOD. METHODS: With stroke as an example, BOD was measured using the index, disability adjusted life years (DALY), and partial social BOD was measured using another index, time lost for nursing care of hospitalized patients. RESULTS: The burden of stroke was 11.70 DALYs per thousand in men and 9.38 in women, respectively, and the burden for caring of patients with stroke during hospitalization accounted for 2.2% and 2.8% of the total BOD for men and women, respectively. CONCLUSION: Effects of social BOD should be taken into consideration in measurement of total BOD.

Aged↗

PubMed2000

GABAergic neurons in Kölliker-Fuse nucleus and Bötzinger complex with axons projecting to phrenic nucleus.

Experiments were made on 6 adult cats. Brainstem neurons that project to the phrenic nucleus were retrogradely labeled by microinjection of WGA-HRP into phrenic nucleus. The brainstem sections were doubly processed for HRP histochemical staining with the TMB-Co-DAB method, and GABA immunohistochemical staining with anti-GABA primary antibody and FITC conjugated immunofluorescent secondary antibody. HRP-FITC double-labeled neurons were observed in the pontine Kölliker-Fuse nucleus and areas around the retrofacial nucleus (Bötzinger complex). Double-labeled neurons were also observed in the raphe nucleus, the lateral paragigantocellular nucleus, and the vestibular nucleus. The results show that brainstem GABAergic neurons in these structures, especially those in the Kölliker-Fuse nucleus and the B?t.C, send axonal projections to the phrenic nucleus.

Animals↗