[Cardiologic progress in China, 1995].
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Catheter Ablation↗
Biomedical subjects
S Chen
Publications and source records attributed to S Chen.
[Progresses in organ transplantation in China, 1995].
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Animals↗
[Detection of human cytomegalovirus DNA in vascular plaques of atherosclerosis by in situ hybridization].
To examine the possible role of HCMV in the etiology of atherosclerosis, we searched for the presence of HCMV DNA in arterial vascular tissues by in situ hybridization. Biotin labelled HCMV DNA probe was used on specimens of arterial wall taken from patients with clinically significant atherosclerosis. Evidence for the presence of HCMV DNA was obtained in 13 specimens out of 32 atherosclerosis specimens. In contrast, only 1 specimen was positive in the control group (Total 15 specimens of normal arterial and venous wall), suggesting that there is a close relationship between human cytomegalovirus infection and atherosclerosis development. The results also showed that the positive hybridization signals were mainly observed in the nuclei of smooth muscular cells, rarely found in outer layer of arterial walls, cell membrane and cytoplasm. It was indicating that HCMV infection might be an etiological agent in the development of atherosclerosis.
Adult↗
[A clinical trial of lansoprazole in the treatment of duodenal ulcer].
To evaluate the efficacy of a second generation acid pump inhibitor-lansoprazole (L) a controlled clinical trial in 72 patients of duodenal ulcer was carried out with omeprazole (O) as control. The results showed that the ulcer healing rate after 4-week treatment was 97.4% in lansoprazole group and 91.2% in omeprazole, while the effective rate was 100% and 97.1% respectively (P > 0.05). Ulcer related pain was relieved more quickly in lansoprazole group. The pain relief rate after treatment of 3 days was different significantly between the two group, being 74.3% (L) and 51.6% (O) respectively (P < 0.05). No marked side-effect was observed in lansoprazole group. It is shown that lansoprazole is effective and safe for treatment of duodenal ulcer.
2-Pyridinylmethylsulfinylbenzimidazoles↗
[G gamma/A gamma, A gamma I/A gamma T ratios of fetal hemoglobin of Han, Hui, Uygur and Kazak newborns in Xinjiang and gene mapping analysis of two cases with abnormal ratio].
The G gamma/A gamma, A gamma I/A gamma T ratios of fetal hemoglobin of 372 cord blood samples of newborns (Han 102, Hui 102, Uygur 99, and Kazak 69) in Urumchi were determined by HPLC. The means of G gamma ratios of 4 ethnic groups (Han, Hui, Uygur, and Kazak) were 66.83%, 68.33%, 70.44% and 69.70%, respectively. 4 cases (Hui 3 and Kazak 1) with low G gamma (< 50%), and 25 cases (Han 5, Hui 4, Uygur 11 and Kazak 5) with high G gamma (> 80%) were found. The occurrences of low G gamma in Hui and Kazak were 2.94% and 1.45% while in Han and Uygur no single case with low G gamma was found. Those of high G gamma in 4 ethnic groups were 4.9% (Han), 3.9% (Hui), 11.1% (Uygur) and 7.2% (Kazak), respectively. A gamma T heterozygotes in Han 21, Hui 23, Uygur 26 and Kazak 29 cases, and one A gamma T homozygote in each ethnic group were found. The average values of A gamma I were 56.83%, 55.58%, 50.94% and 54.68% respectively. The frequencies of A gamma T gene were 0.113, 0.123, 0.141 and 0.225, respectively. The gene arrangement of a low G gamma case was identified as-GA gamma I-/-G gamma-A gamma I-, and that of a high G gamma case as -G gamma-AG gamma-A gamma I(A gamma T)-/-G gamma-A gamma T(A gamma I)-.
China↗
[Influence of thoracic spinal subarachnoid microinjection of noradrenaline on the effect of electroacupuncture].
Influence of thoracic spinal subarachnoid microinjection of noradrenaline (NA, 40 mg/20 microliters) on the effect of electroacupuncture (EA) at Neiguan (PC6) was observed in 40 rabbits anesthetized with urethan-chloralose. Results showed that: 1) EA of Neiguan (PC6) could significantly accelerate the recovery of ST-segment and T-wave of electrocardiogram induced by acute myocardial ischemia (AMI); 2). Subarachnoid microinjection of NA also could promote the recovery of ST, T and blood pressure of post-AMI; and 3) Subarachnoid microinjection of NA could strengthen the effect of EA of Neiguan (PC6) to promote the recovery of ST and T of Post-AMI. It suggests that alpha-receptors of intra-thoracic spinal cord participate in the action of EA of Neiguan (PC6) ameliorating AMI, and the upper thoracic segement is one of the links for connecting Neiguan and the heart.
Acupuncture Therapy↗
[Status and strategy of parasitosis control in preventive health care in China].
According to the result of nationwide human parasitic disease distribution survey, the public significance of parasitosis control was set forth in terms of preventive health care and economic impact as well as parasitosis control and primary health care. A suggestion was made on the control strategy aiming at the parasitosis of priorities listed in the above survey.
China↗
mRNA expression of vimentin gene in lens of transgenic mouse and DNA amplification in human cataracts.
PURPOSE: To investigate the role of vimentin gene in cataractogenesis. METHODS: The 12.7kb chicken vimentin genes were microinjected into the male pronuclei of 918 fertilized mice eggs. 841 injected embryos were transferred into oviducts of pseudopregnant recipient females, of which 12 pregnant mice gave birth to 49 offspring mice. The integration and expression of exogenous gene in the offspring were analysed by Southern and Northern blot hybridizations. In the human senile cataract, the lens vimentin gene was analyzed with the chicken vimentin gene probe. RESULTS: It showed that four of F1 offspring were transgenic mice in which the chicken vimentin gene was integrated in their genomes. The transgenic band was 12kb, similar to the 12.7kb chicken vimentin fragment injected. One 2kb vimentin mRNA was visualized on E2 mouse lens blot, which revealed that the chicken vimentin gene was efficiently expressed in this transgenic mouse. In the human senile cataract lens, 12kb BamHI-restricted vimentin fragments displayed a stronger hybridization signal than that of the control lens in Southern blot analysis. It implies that the formation of human senile cataract may be associated with the amplification of vimentin gene. CONCLUSIONS: We have successfully developed four transgenic mice bearing chicken vimentin gene and having mRNA expression which can be used for further study. It is to be observed if the normal lens cell function is affected by the expressed product and cataract occurs in our transgenic mice. The cause of the gene amplification in human cataract remains for further investigation.
Adult↗
[Gene therapy in lung cancer].
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Animals↗
[The role of endothelin the development of hypoxic pulmonary hypertension].
To evaluate the role of endothelin in the development of hypoxic pulmonary hypertension, seven pigs (50 +/- 5kg) models with hypoxia induced pulmonary hypertension were established. Swan-Ganz catheter and arterial catheter were inserted into the pulmonary artery and aorta, pulmonary arterial pressure (PAP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO) and arterial blood gases were monitored before and during hypoxia and 5 min, 30 min, 60 min, 120 min after nitrendipine injected (100 micrograms/kg). Plasma endothelin concentration was measured by RIA. It was found that plasma ET concentration was significantly increased, from 5.5 +/- 1.1 ng/L during normoxia to 11.9 +/- 1.2 ng/L during hypoxia (PaO2 = 5.55 +/- 0.24 kPa) (P < 0.002), while PAP increased from 3.88 +/- 0.10 kPa to 5.92 +/- 0.19 kPa. After nitrendipine injection, PAP and ET level were decreased by 1.03 kPa (P < 0.05) and 40% (P < 0.02) respectively compared with those with pure hypoxia. Our results indicate that ET may play an important role in the development of hypoxia induced pulmonary hypertension. Ca++-channel blocker nitrendipine not only relieves hypoxic pulmonary hypertension, but also inhibits the release of endothelin.
Animals↗
[Cloning, sequencing and characterizing repetitive DNA of Glycine max].
One satellite DNA family, cloned from Glycine max, was sequenced and chracterized. The unit of the repetitive sequences was 91bp. They concentrated on the arms of chromosomes M2 and M11, and spreaded on whole chromosomes Sm7 and M12. Southern blot analysis with 18 acessions, belonged to subgenus Glycine and subgenus Soj a of genus Glycine, showed that the repetitive sequences were specific to subgenus Soj a. It was subgenus specific repetitive sequence. This result, from another aspact, supported the idea that the three species in subgenus Soj a should be considered as one species.
Base Sequence↗
[Analysis of genetic properties of meiotic products from an interspecific triploid fusion-hybrid itself constructed by protoplast fusion in Saccharomvces].
A genetically stable interspecific triploid fusion-hybrid between a diploid Saccharomyces cerevisiae var. ellopsoideus and a haploid Saccharomyces diastaticus was constracted by protoplast fusion technique. Experimental results indicate that such hybrid can be induced to sporulate as a sexual hybrid. Genetic analysis of the complete and non-complete tetrads demonstrates that the prototrophic interspecific triploid fusion-hybrid HU-KDF-240 selected by nutritional complementation experienced segregation and exchange for the genetic markers, and showed parental ditype and recombination in the meiotic process of sporulation. The results of the tetrad analysis of the hybrid HU-KDF-240 showed a 1:2 segregation ratio for soluble starch fermenting and non-fermenting characters and a 1:1 segregation ratio for genetic markers of the auxotrophic character in 349 complete and non-complete tetrads from 186 asci of the hybrid.
Cloning, Molecular↗
Dynamic association of proteins with the pre-mRNA branch region.
The association of proteins with the branch site region during pre-mRNA splicing was probed using a novel methodology to site-specifically modify the pre-mRNA with the photo-reagent benzophenone. Three sets of proteins were distinguished by the kinetics of their associations with pre-mRNAs, by their association with discrete splicing complexes, and by their differing factor requirements. An early U1 snRNP-dependent cross-link of the branch region to a p80 species was followed by cross-links to p14, p35, and p150 polypeptides associated with the U2 snRNP-pre-mRNA complex. Concomitant with formation of the spliceosome, a rearrangement of protein factors about the branch region occurred, in which the p35 and p150 cross-links were replaced by p220 and p70 species. These results establish that the branch region is recognized in a dynamic fashion by multiple distinct proteins during the course of spliceosomal assembly.
Base Sequence↗
Direct peptide profiling by mass spectrometry of single identified neurons reveals complex neuropeptide-processing pattern.
A novel strategy combining peptide fingerprinting of single neurons by matrix-assisted laser desorption ionization mass spectrometry, molecular cloning, peptide chemistry, and electrospray ionization mass spectrometry was used to study the intricate processing pattern of a preprohormone expressed in identified neurons, the neuroendocrine light yellow cells (LYCs) of the gastropod mollusc, Lymnaea stagnalis. The cDNA encoding the precursor, named prepro-LYCP (LYCPs, light yellow cell peptides), predicts a straightforward processing into three peptides, LYCP I, II, and III, at conventional dibasic processing sites flanking the peptide domains on the precursor. However, matrix-assisted laser desorption ionization mass spectrometry of single LYCs revealed trimmed variant peptides derived from LYCP I and II. The variants were much more abundant than the intact peptides, indicating that LYCP I and II serve as intermediates in a peptide-processing sequence. Using the molecular masses of the peptides as markers to guide their isolation by well established purification methods, the structural identities of the peptides could be confirmed by amino acid sequencing. Furthermore, matrix-assisted laser desorption ionization mass spectrometry could detect colocalization of a novel peptide with the LYCPs.
Amino Acid Sequence↗
Anti-diabetic biguanides inhibit hormone-induced intracellular Ca2+ concentration oscillations in rat hepatocytes.
Rat hepatocytes respond to glycogenolytic stimuli acting via phosphoinositide breakdown (e.g. alpha 1-adrenergic agonists, vasopressin) by oscillations of the free intracellular Ca2+ concentration ([Ca2+]i). We have investigated the action of metformin and phenformin, two anti-diabetic drugs of the biguanide type, on phenylephrine-induced [Ca2+]i oscillations. Metformin and phenformin lowered the frequency of the [Ca2+]i oscillations in a concentration-dependent manner with an IC50 of 0.1 mM and 1 microM, respectively. Simultaneous addition of the biguanides and insulin resulted in a further reduction of the frequency. By contrast, agents which increase the cellular cyclic AMP (cAMP) concentration (glucagon, forskolin, N,2'-O-dibutyryl-cAMP) reversed this inhibition. Furthermore, we investigated whether biguanides influenced the agonist-induced Ca2+ influx across the plasma membrane. When hepatocytes were loaded with the acetoxymethyl ester of fura-2 (fura-2/AM), addition of Mn2+ led to a quench of cellular fura-2, measured at the isosbestic excitation wavelength of 360 nm, until a new steady state was reached. Surprisingly, however, this addition of Mn2+ caused a marked increase of the fluorescence ratio simultaneously measured at 340 and 380 nm during the approach of the 360 nm signal to a new steady state. This observation can be understood on the basis of a compartmentalization of fura-2/AM into intracellular stores sensing the [Ca2+] therein. Subsequent application of phenylephrine resulted in a further decline of the fura-2 signal at 360 nm and a concomitant decrease of the fluorescence ratio. This second phase of the Mn2+ quench and the decrease of the fluorescence ratio could be diminished by addition of either 3 mM metformin or 30 microM phenformin. By contrast, when hepatocytes were loaded with fura-2/pentapotassium salt via a patch pipette, only the initial Mn(2+)-induced quench, measured at 360 nm, but no change of the fluorescence ratio, could be observed. The subsequent addition of phenylephrine and biguanides during the on-going quench caused no further changes, except for a fading oscillatory response. After loading hepatocytes with fluo-3 acetoxymethyl ester, the cells were permeabilized with 5 microM digitonin. Addition of inositol-1,4,5-trisphosphate (IP3) caused a rapid decrease of the remaining cellular fluorescence which could be effectively inhibited by 20 micrograms/ml heparin, indicating a release of Ca2+ from intracellular compartments mediated by IP3. This IP3-induced release of Ca2+ from intracellular stores could be diminished by prior addition of metformin and phenformin.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Partial characterization of the molecular species of phosphatidylserine from human plasma by high-performance liquid chromatography and fast atom bombardment mass spectrometry.
Phosphatidylserine from human plasma was purified and identified by amino normal-phase and octadecylsilyl reversed-phase high-performance liquid chromatography, respectively. The two major molecular species within the human plasma phosphatidylserine, qualitatively determined by negative-ion fast atom bombardment mass spectrometry, are 1-stearoyl-2-oleoyl-sn-glycero-3-phosphoserine and 1-stearoyl-2-arachidonyl-sn-glycero-3-phosphoserine.
Adult↗
A new nude mouse model for postmenopausal breast cancer using MCF-7 cells transfected with the human aromatase gene.
MCF-7 cells transfected with human placental aromatase gene (MCF-7Ca cells) or cells transfected with plasmid vector only (MCF-7Cc cells) were inoculated into nude mice with Matrigel. Tumors formed from both MCF-7Ca and MCF-7Cc cells grew faster in intact mice than in ovariectomized mice, suggesting that the tumors maintained their responsiveness to estrogen stimulation and that their growth was supported by ovarian estrogen. Injections of androstenedione (0.1 mg/mouse/day) to provide the substrate for aromatization to ovariectomized mice bearing MCF-7Ca tumors accelerated their growth but did not affect growth of MCF-7Cc tumors. This result indicates that local production of estrogen by intratumoral aromatase was sufficient to stimulate tumor growth. When ovariectomized mice with MCF-7Ca tumors supplemented with androstenedione were treated with aromatase inhibitors 4-hydroxyandrostenedione (1 mg/mouse/day, s.c.) or CGS 16949A (0.5 mg/mouse/day, s.c.), or with the antiestrogen tamoxifen (10 micrograms/mouse/day, s.c.), tumor growth was significantly inhibited. Tumor aromatase activity measured at the end of treatment was also inhibited by 4-hydroxyandrostenedione when the mice were sacrificed 4 h after the last injection. The tumors of this mouse model are dependent for their growth on estrogens from an endogenous nonovarian source. Thus, it simulates the situation in the postmenopausal breast cancer patient and could be used to evaluate the effect of aromatase inhibitors and antiestrogens.
Androstenedione↗
Location of a folding protein and shape changes in GroEL-GroES complexes imaged by cryo-electron microscopy.
Protein folding mediated by the molecular chaperone GroEL occurs by its binding to non-native polypeptide substrates and is driven by ATP hydrolysis. Both of these processes are influenced by the reversible association of the co-protein, GroES (refs 2-4). GroEL and other chaperonin 60 molecules are large, cylindrical oligomers consisting of two stacked heptameric rings of subunits; each ring forms a cage-like structure thought to bind polypeptides in a central cavity. Chaperonins play a passive role in folding by binding or sequestering folding proteins to prevent their aggregation, but they may also actively unfold substrate proteins trapped in misfolded forms, enabling them to assume productive folding conformations. Biochemical studies show that GroES improves the efficiency of GroEL function, but the structural basis for this is unknown. Here we report the first direct visualization, by cryo-electron microscopy, of a non-native protein substrate (malate dehydrogenase) bound to the mobile, outer domains at one end of GroEL. Addition of GroES to GroEL in the presence of ATP causes a dramatic hinge opening of about 60 degrees. GroES binds to the equivalent surface of the GroEL outer domains, but on the opposite end of the GroEL oligomer to the protein substrate.
Adenosine Triphosphate↗