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Biomedical subjects

S Chen

Publications and source records attributed to S Chen.

At least 865 records · Page 48Linked to original sources
PubMed1997

[Effects of chronic hypoxia on the expression of oncogene jun fos and myb mRNA in rat lung].

This paper is to investigate the expression of oncogene jun fos and myb mRNA in the lung of rats exposed to chronic hypoxia. 15 SD rats were put in low oxygen chamber (FiO2 = 0.1), 8 hrs daily for 1, 2 and 3 weeks. Five rats breathing room air served as control. Oncogene expression in lung tissue assessed by the use of in situ hybridization. The results showed that (1) there was a slight expression of jun mRNA but not fos and myb mRNA in the control normoxic rats' lung; (2) it was found that a less expression of jun mRNA in lung after 1 week hypoxia, but after 2 week hypoxia jun mRNA elevated again and significantly increased after 3 week hypoxia as compared with that in normoxia; (3) the oncogene myb mRNA expression showed significant increase in 1 and 2 week hypoxia and returned to normal status in 3 week hypoxia; (4) after 1 to 3 week hypoxia, a significant increased expression of fos mRNA was found as compared with that in normoxia. It is suggested hypoxia may induce increased expression of proto-oncogene jun myb and fos, which may be related to proliferation of pulmonary arterial smooth muscle cells and fibroblasts.

Animals↗
PubMed1997

[The morbidity of osteoporosis and it's associated factors in a home for the aged in Guangzhou City].

Osteolysis is one of the common diseases in aged people. In order to provide data for the planning of health program of the aged, a study was carried out to collect the morbidity data of osteolysis and it's associated factors in a home for the aged in Guangzhou City in March 1995. 326 cases (aged 57-95) were studied with 113 of males and 213 of females. Bone density was detected with monophoton bone densimeter at the position of the low one third of radius. A questionnaire was administered to collect the data of associated factors of osteolysis. Body weight and body length were measured. The out-off point of bone density for the diagnosis of osteolysis was 0.488 g/cm2 for females and 0.535 g/cm2 of males. The results showed that the morbidity for osteoporosis was 34.6%. The morbidity of female was significantly higher than that of males (P < 0.05). The body weight and body height of osteolysis group were significantly lower than those of normal group. The bone density of smokers and alcohol drinkers was significantly lower than that of others. The bone density of the people who exercised was significantly higher than that of those who didn't. In conclusion, it is necessary to focus our health care on aged female for the prevention and treatment of osteoporosis. The physical exercises will be benefit to the prevention of osteoporosis.

Aged↗
PubMed1997

[Application of atracurium to critical care patients in ICU].

Fifty-two patients entered ICU after heart operation with cardiopulmonary bypass. These patients with ventilation atracurium (ATC) were given 3 micrograms-6 micrograms/kg/min for 5-48 hours. No complications happened. After ATC was used, the patients could open eyes, and cooperate with the doctor when they regain consciousness. The circulation index was normal. The limbs of these patients relaxed. In the 52 cases, 30 did't use sedatives, and 22 used senall dose of sedatives for sleep at night. We conclude that ATC does not require hepatic or renal function for termination of effect and action is terminated by the "Hoffman elimination" the ester hydrolysis. The time of effect is short and there is no cumulation effect. There is no vagal or ganglionic blocking activity, so ATC does not influence circulation and myocardial function. Maintenance relaxation keeps ventilation steady and oxygen supply normal.

Adolescent↗
PubMed1997

[Effect of antihypertensive agents on plasma endothelin, nitric oxide and so on in essential hypertension].

Ninty patients with mild to moderate essential hypertension (EH) were randomly divided into three groups and treated with Enalapril (E), Metoprolol (M) and Nifedipine (N) respectively. After a six-week-treatment, SBP and DBP of each of the three groups decreased significantly (vs. pre-treatment, P < 0.001). Plasma concentration of ET, NO, cGAMP and MDA in group M remained unchanged, and that of MDA in group N, especially of the stage II EH, decreased remarkably (vs. pretreatment, P < 0.05; vs. that of stage I EH, P < 0.05). While that of ET, NO, cGMP, and MDA in group E changed significantly (vs. Pretreatment, P < 0.01) and that of ET and MDA of stage II EH in group E exhibited more remarkable changes (vs. that of stage I, P < 0.05). It is suggested that E, and at some degree N, may protect the vascular endothelium from being damaged in EH, and also may contribute to prevent EH from development.

Adrenergic beta-Antagonists↗
PubMed1997

[Lenticular-vitreoretinal surgery for complicated retinal detachment].

OBJECTIVE: To study the efficacy of vitreoretinal (VR) surgery combined with lensectomy/ultrasonic fragmentation. METHODS: Eight-one patients (eyes) with complicated retinal detachment treated with combined lenticular-vitreoretinal (LVR) surgery were reviewed retrospectively. RESULTS: Anatomic success was achieved in 64 (79.01%) eyes, and functional success in 45 (55.56%) eyes. Anterior proliferative vitreoretinopathy (PVR) and intraocular hemorrhage (IOH) significantly reduced the anatomic success rate to 42.86% (P < 0.01) and 58.82% (P < 0.025) respectively. CONCLUSIONS: LVR surgery plays an important therapeutic role in treatment of complicated retinal detachment. The significant factors affecting the surgical outcome are anterior PVR and intra-/post-operative IOH.

Adolescent↗
PubMed1997

[The distribution of motoneuronotrophic factor 1 (MNTF1) and its receptor-like substance in the spinal cord and limb muscles of mice with motoneuron disease].

Using a monoclonal antibody for the motoneuronotrophic factor 1 (MNTF1) and its idiotypic antibody we have detected immunohistochemically the changes in the expression of the positive immunoreactivities for the MNTF1 and its receptor-like substance in the cervical and lumbar spinal cord regions as well as in the limb muscles of the wobbler mice, as the disease progressed from the first to the fourth stage. The results indicated that the positive immunoreactivities for the MNTF1 and its receptor-like substance were mainly located in the soma and neurites of the anterior born motoneurons at spinal layers VIII and IX and in the sarcoplasm of the skeletal muscles of the fore- and hind-limbs, and whereas their nuclei were immunoreactively negative. In the first stage (3 weeks) of the disease there were fewer in numbers of cells containing positive immunoreactivities (P < 0.01) and lesser in their relative amount of immunoreactivities per cell (P < 0.01) in the cervical and lumbar spinal cord as well as in the fore- and hind-limbs muscles of the wobbler mice as compared to those of the normal littermates. In the fourth stage (3 months) of the disease these differences between the wobbler mice and the normal littermates were even more distinct (P < 0.01 and P < 0.01). These results suggested that as syntheses of the skeletal muscle target cell-derived MNTF1 and its receptor-like substance were reduced to levels which were not enough to ensure the survival of motoneurons and consequently leading to muscular atrophy, as the motoneuron disease in wobbler mice deteriated.

Animals↗
PubMed1997

[cDNA cloning of human stem cell factor and its high level expression in E. coli].

The total RNA of HepG2 cell was extracted as the template by ultrocentrifuge method. The full length cDNA (0.8 kb) encoding the human stem cell factor (hSCF) was amplified by RT-PCR method. The cDNA encoding mature hSCF (0.5 kb) was sequenced and was recombined into the expression vector (PBV-220). The expression level of rhSCF in E. coli DH5 alpha was about 15% of the total protein.

Amino Acid Sequence↗
PubMed1997

[The curative effects of anti-TNF monoclonal antibody in E. coli infected mice].

OBJECTIVE: To evaluate effects of monoclonal antibody (McAb) against TNFa on E. coli infected mice. METHODS: 30 mice (10 week old, Kunming) were divided equally into three groups. The first group, as a control, 200 microliters saline (NS)/mouse was injected intravenously; Second group (untreated group), only E. coli (10(7) organisms/200 microliters NS) were injected intra-abdominaly; Third group (treated group), E. coli (10(7) organisms) were injected intra-abdominal and McAb against TNF alpha 2 mg/kg dissolved in 200 microliters NS were injected intravenously. After 24 h, observed the survival rate, compared the serum TNF level in blood and investigated pathology of intestine, lung and liver. RESULTS: There was a higher survival rate in treated group, with the serum TNF level lowered significantly, and the untreated mice had severe pathologic changes in viscera. CONCLUSION: Using anti-TNF alpha McAb was effective in reducing mortality rate in mice after infected with E. coli, but could not prevent the pathologic changes.

Animals↗
PubMed1997

[The role and mechanism of fatty acids in gallstones].

18 Chinese cases and 37 Japanese cases of gallstones were analyzed according to the procedure of extracting fatty acids in the gallstone. High perforamance liquid chromatography (HPLC), showed that the contents of total fatty acid and free fatty acid in pigment stones were obviously higher than those in black stone or cholesterol stone. The ratio free saturated to total saturated fatty acid is the highest in intrahepatic pigment stone and less in extrahepatic pigment stone, which significantly differs from the latter two kinds of stones. This may indicate that phospholipid in the bile catablizes into free fatty acids involved in the formation of stone under the action of phospholipase in the course of pigment stone formation. The action of phosphoipase A1 is more important than phospholipase A2.

Bile Ducts, Intrahepatic↗
PubMed1997

[Effect of light colours and illumination intensity on the sexual behaviour of Hepialus gonggaensis Fu et Huang].

The sexual behaviour of Hepialus gonggaensis has close relations with ecological environment and varies with its ecotypes. The more intense the illumination, the faster the sexual drive of Hepialus gonggaensis begins and the longer its sexual intercourse continues, light colours have a bearing on its sexual intercourse time. This study has provided an evidence for the artificial cultivation of Hepialus gonggaensis.

Animals↗
PubMed1997

[Long-term results of intravesical N-CWS instillation to prevent recurrence after surgery for bladder cancer].

OBJECTIVE: To evaluate the long term results of intravesical nocardia rubre cell wall skeleton instillation to prevent recurrence after surgery for bladder cancer. METHODS: A randomized and placedo-controlled trial on intravesical N-CWS instillation versus mitomycin-C(MMC) therapy for recurrence prevention in postopenative bladder cancer patients was carried out. RESULTS: Fourty-five patients were treated with N-CWS with 39 followed for 12 to 60 months. Thirteen patients developed recurrence. The 1-year tumor free survival rate was 87.2% and that at 5 years was 66.7%. Thirty patients as treated with MMC serving as controll with 25 followed for the same duration, twelve patients developed recurrence. The 1-year tumor free survival rate was 84% and that at 5 years was 52%. The results indicate that N-CWS gave better results with rare and milder side effects. CONCLUSION: N-CWS is believed to be one of the effective drugs in preventing bladder cancer recurrence after surgery.

Adjuvants, Immunologic↗
PubMed1997

[Damage-loss relationships and integrated control of 3rd instar larvae of Actias selene nigpoana Felder in planting area of Cornus officinalis Sieb. et Zucc].

In the present paper, the damage-loss model of Actias selene ningpoana to Cornus officinalis was tested and the results indicated that the yield loss rates obeyed the equation Y = 100 - EXP(4.6042 - 0.0315X). The economic threshold of the 2hd and 3rd instar larvae of A. selene nigpoana was then determined as 22 and 8 insects per tree respecitively. Suggestions for integrated control have been made based on the research of activities of A. selene ningpoana in the forest.

Animals↗
PubMed1997

[High performance liquid chromatographic determination of quercetin in the extract of Ginkgo biloba L. leaves].

This paper reports the HPLC determination of one of the flavones quercetin in the extract of Ginkgo biloba leaves. Quercetin was separated completely on an YWG-C18 column(0.46 cm x 15 cm), using a mixture of methanol, water and phosphoric acid(50:49.8:0.2) as mobile phase, with UV detection at 360 nm. The results have shown the recoveries to be between 95.3%-103.2% and RSD 1.86%.

Chromatography, High Pressure Liquid↗
PubMed1997

[Minor alkaloids from the capsule of Papaver nudicaule L].

Two minor alkaloids were isolated from the capsule of Papaver nudicaule. On the basis of physicochemical methods and spectroscopic analysis, they were identified as chelidonine, 5-hydroxy-2-hydroxymethylpyridine. Chelidonine was isolated from this plant and 5-hydroxy-2-hydroxymethylpyridine was isolated from genus for the first time.

Alkaloids↗
PubMed1997

[Research on power Doppler ultrasound imaging technique].

In this paper we introduce a method and an implementation of blood flow imaging by means of backscattered Doppler ultrasound power. Compared with Color Flow Map technique based on autocorrelation, this technique is relatively angle independent, aliasing free and more sensitive to blood flow signal with noise background. We present the theory, experimental system and in-vitro experimental results. The realization of this technique means a new stage of color Doppler ultrasound imaging technique in our country is coming.

Blood Flow Velocity↗
PubMed1997

The development of monoclonal antibody against rhTNF and its curative effects on E. coli infected mice.

Fifteen hybridoma cell lines producing monoclonal antibodies (McAb) against recombinant human tumor necrosis factor alpha (rhTNFa) have been established by fusing SP 2/0 cells with spleen cells from a BALB/c mouse immunized with rhTNFa. Following J. M. Davis's Works, semi-solid medium was used for initial cloning. Five of them were studied further. Their main chromosome numbers range were 96 to 105, all of them were IgG1 subclass. The affinities of these McAbs were estimated to be 1.25 x 10(8) mol/L, 1.12 x 10(8) mol/L, 2.34 x 10(8) mol/L, 8.55 x 10(7) mol/L, 1.04 x 10(8) mol/L, respectively. Two groups of mice challenging with E. Coli (10(7) organisms), one group treated with 2 mg/kg anti-TNF monoclonal antibody, the other did not. There was a higher survival rate in treated group, the serum TNF level was significantly lower too, and the untreated mice had severe pathologic changes in viscera.

Animals↗
PubMed1997

[Pharmacognostical identification on the Chinese drug quanshen].

In this paper, 5 kinds of Quanshen that original plants are Polygonum bistorta L., P. viviparum L., P. paleacum Wall., P. sphaerostachyum Meisn., P. macrophyllum D. Don. are made an initial study on the characteristics, microscopical and physichemistical sides. It provide scientific basis for its comprehensive development and ultilization, and to use in clinical.

Chromatography, Thin Layer↗