[Progresses in neurology in China, 1995].
Explore the source record for details and available documents.
Cerebrovascular Disorders↗
Biomedical subjects
Y Cheng
Publications and source records attributed to Y Cheng.
[Research on the relationship between estrogen receptor, progesterone receptor, cell proliferation associated antigen in uterine leiomyoma and nuclear body density of myoma, serum reproductive hormone concentrations].
OBJECTIVE: To study the role of sex hormones in the pathogenesis of uterine leiomyoma in order to provide theoretical basis for medical treatment. METHODS: Estrogen Receptor (ER), progesterone receptor (PR) and cell proliferation associated antigen (Ki-67) contents of both normal uterine myometrium and leiomyoma were quantitatively analysed by ABC method and image analyser system (IAS) in 30 and 19 specimens obtained during hysterectomy respectively. Nuclear body density were also measured in 8 of them under electronic microscope. Serum luteinizing hormone (LH), follicular stimulating hormone (FSH), estradiol (E2) and progesterone (P) concentrations were determined by radioimmunoassay in 22 cases on the operation day. 21 age-matched normal cycling women served controls. RESULTS: Contents of ER, PR, Ki-67 and the number, volume densities of nuclear body were significantly higher in leiomyoma than those in normal myometrium (P < 0.01, P < 0.05). ER,PR contents of the two tissues in proliferative phase were greater than those in secretory phase, (P < 0.05), while Ki-67 contents were the opposite (P < 0.01). ER, PR contents of leiomyoma did not correlate with serum E2 and P concentrations, but correlate negatively with serum LH and FSH levels (P < 0.050). Ki-67 contents correlated positively with serum P levels and also showed inverse correlation with serum LH. FSH concentrations (P < 0.05). ER of leiomyoma positively correlated with density of nuclear body (P < 0.05). CONCLUSION: High ER, PR and Ki-67 contents in leiomyoma, may be the result of local high E2, P concentrations, and cause growth and development of leiomyoma. High Ki-67 content in secretory phase may indicate that progesterone has a synergistic effect in the pathogenesis of leiomyoma.
Adult↗
[Ultrasonic diagnosis of malignant trophoblastic tumor (an analysis of additional 41 cases)].
Forty one cases of malignant trophoblastic tumor which were confirmed by pathological examinations were reviewed. The diagnostic correspondence rate by sonography was 92.3% (38/41). The image patterns, types of tumor, differential diagnosis and diagnostic value of sonography were also explored in this paper.
Adult↗
Extracellular ATP may induce neuronal degeneration by a free-radical mechanism.
Explore the source record for details and available documents.
Adenosine Triphosphatases↗
A physical map of the Myxococcus xanthus chromosome.
A physical map of the 9.2-Mbp Myxococcus xanthus DK1622 chromosome at a resolution of 25 kbp was constructed by using a strategy that is applicable to virtually all microorganisms. Segments of the chromosome were used as hybridization probes to subdivide a yeast artificial chromosome (YAC) library into groups of linked clones. The clones were aligned by comparing their EcoRI restriction patterns. The groups of YAC clones ("contigs") were oriented and aligned with the genomic restriction map by means of common genetic and physical markers such as rare restriction sites and transposon insertions. Over 95% of the genome is represented by cloned DNA. Sixty genetic loci including > 100 genes, many of which play a role in fruiting body development, have been mapped in this way. Additional genes can now be located on the chromosome map by hybridization of their sequences to the ordered set of YAC chromosomes. The mapped genetic loci account for approximately 2% of the genome.
Base Sequence↗
Organization of the mouse GP42/Basigin gene: a member of the Ig superfamily.
We have mapped and sequenced the GP42/Basigin gene isolated from a Balb/C mouse genomic library. The genomic organization and upstream, putative regulatory, regions of this gene have not been previously reported. Our data show that exon 5 of the GP42/Basigin gene encodes the carboxy proximal half of the second Ig-like domain, the highly conserved transmembrane region and a portion of the cytoplasmic tail. This inclusion of Ig-like and other functional domains in a single exon is unusual. Splice junction analysis indicates that two reported alternate GP42/Basigin cDNA isoforms are likely due to cloning artifacts. In addition, we find that GP42/Basigin is polymorphic in mice. Our data also support the proposal that the transmembrane domain and portions of the cytoplasmic region of GP42/Basigin have been evolutionarily conserved.
Amino Acid Sequence↗
Aligned defect complex containing carbon and hydrogen in as-grown GaAs epitaxial layers.
Explore the source record for details and available documents.
Journal Article↗
Oxidative mechanisms involved in kainate-induced cytotoxicity in cortical neurons.
In our previous experiments, evidence of free radical formation has been demonstrated in gerbil brain after kainic acid (KA) administration. In the present study, the mechanisms involved in KA-induced free radical formation and subsequent cell degeneration were investigated using high density cortical neuron cultures. A free radical trapping agent, alpha-phenyl-N-tert- butyl-nitrone (PBN), as well as the combined action of superoxide dismutase and catalase attenuated KA neurotoxic effect. Calpain-induced xanthine oxidase (XO) activation may play an important role in KA excitotoxicity since calpain inhibitor I as well as allopurinol, a selective XO inhibitor, significantly protected the cortical neurons from KA-induced cell death. However, XO activation may not be the only source producing free radicals, other free radical generating systems such as nitric oxide synthase may also play a role in KA insult.
Allopurinol↗
A novel cyclic AMP response element, CACTTGATC, mediates forskolin induction of the myelin basic protein promoter in the rat Schwannoma line, D6P2T.
The rat Schwannoma cell line D6P2T constitutively expresses the mRNA encoding the major myelin protein, P0, but only expresses the mRNA encoding myelin basic protein (MBP) after exposure to forskolin or other substances that raise the levels of intracellular cyclic AMP. In this study we have investigated the molecular basis for forskolin induction of MBP transcription in D6P2T cells. We have found that a 9-bp sequence element, CACTTGATC, located between nucleotides -85 and -77 in the MBP promoter, is necessary for forskolin induction of chloramphenicol acetyltransferase (CAT) expression after transient transfection of MBP promoter-CAT fusion constructs into D6P2T cells. Although similar DNase I footprints, one of which is located within the above 9-bp sequence element, are produced by nuclear extracts prepared from both forskolin-treated and untreated cells, this same sequence can be shown to interact with a forskolin-inducible protein complex using an electrophoretic mobility shift assay. In addition, mutation of this 9-bp sequence abolishes both formation of this new protein--DNA complex and forskolin-inducible CAT expression from the heterologous SV40 promoter. Finally, we have shown that the appearance of this forskolin-inducible protein--DNA complex precedes that of MBP mRNA. Taken together, these data strongly support the notion that the induction of MBP transcription by forskolin in D6P2T cells is mediated by the binding of a forskolin-inducible protein complex to the MBP promoter sequence CACTTGATC.
Animals↗
Effects of extracellular ATP on Fe(2+)-induced cytotoxicity in PC-12 cells.
Extracellular ATP is known to cause a variety of changes, including the alteration of ion fluxes, cell growth, and other physiological activities. Recently, it has been suggested that ATP acts as an excitatory synaptic transmitter, which may produce a Ca2+ influx via the activation of a P2y purinoceptor. Rat pheochromocytoma (PC-12) cells are known to resemble rat sensory neurons and to possess a P2y purinoceptor. In this study, we demonstrated that extracellular ATP dose-dependently increased PC-12 cell death in the presence of ferrous ions. Voltage-sensitive calcium channel blockers and calpain and xanthine oxidase inhibitors were found to be effective at protecting PC-12 cells from Fe2+/ATP-induced lipid peroxidation and cell death. These results suggest that xanthine oxidase activation induced by calpains and subsequent free radical formation may be responsible for Fe2+/ATP-induced neuronal cell death.
Adenosine Triphosphatases↗
Extended-spectrum beta-lactamases in clinical isolates of Enterobacter gergoviae and Escherichia coli in China.
Resistance to ceftazidime, detected in isolates of Escherichia coli 5518 and Enterobacter gergoviae 3773 from our hospital, was transferred, together with resistance to aminoglycosides, trimethoprim, sulfonamide, and other beta-lactam antibiotics, by conjugation to E. coli JP559. Both E. coli transconjugants were resistant to ampicillin, all cephalosporins, and aztreonam but remained susceptible to cefoxitin and imipenem. The enzymes of the two transconjugant strains readily hydrolyzed cephalosporins in a spectrophotometric assay. Hybridization results suggested that the extended-spectrum beta-lactamase produced by E. coli 5518 was a non-TEM, non-SHV enzyme, the origin of which is currently unknown. The beta-lactamase produced by E. gergoviae 3773 was of the SHV type and was further proved to be SHV-2 by DNA sequencing. Thus, extended-spectrum beta-lactamases are occurring in China as well as in other parts of the world.
Cloning, Molecular↗
[Myocardial function after fluid resuscitation with addition of 1-6-FDP in severely burned rabbits].
An experimental study is designed for the evaluation of the effect of fluid resuscitation with addition of 1-6FDP on myocardiac function in severely burned rabbits. 60 rabbits were divided into four groups. Group A (n = 15) served as control without treatment. The animals in group B (n = 15) were treated with 1-6-FDP immediately after burning. The animals in group C (n = 15) were treated with balanced saline solution (BSS). The animals in group D(n = 15) were treated with BSS plus 1-6-FDP. All rabbits sustained 25% TBSA full thickness burn. LVSP, LV +/- dp/dt max and PV were measured before burn, immediately after burn, and 1, 3, 5, 7 h, after burn, except that PV was not measured immediately after burn. The results showed that depression in myocardial contractility and relaxation were noted immediately after severe burn. Fluid resuscitation alone did not significantly improve myocardial function (P > 0.05 compared with control). The administration of 1-6-FDP showed a beneficial effect in improving myocardial contractility and relaxation within 3 hours postburn. With fluid resuscitation plus 1-6-FDP, myocardial contractility and relaxation were improved statistically significantly as compared with the control group (P < 0.01).
Animals↗
[Comparative study of ultrasonography and pathology of endometrial carcinoma].
Preoperative sonography was performed in 83 patients with a histologic diagnosis of endometrial cancer. The diagnostic accuracy was 84.3%. Five types of sonographic pattern were described. The sonographic accuracy in distinguishing deep or beyond the uterus invasion from superficial invasion was 92.8%, the specificity was 88.2%, and sensitivity was 100%. Tumor stage was correctly predicted by sonography in 95.2% of the cases.
Adenocarcinoma↗
[Preliminary estimation of malaria transmission potential in areas where Anopheles sinensis is the only vector].
The data, vectorial capacity of Anopheles sinensis in the suburb of Jining city, Shandong Province in 1975, in 1980-1984, and the average gland infection rate of Anopheles sinensis infected with Plasmodium vivax artificially, were calculated by using Macdonald formula (1957). The basic reproduction rates were 4.44, 6.47 and 4.25 in the years 1975, 1980 and 1981, respectively. In 1982-1984, the rate was reduced to 0.69, 0.41 and 0.1, respectively. Since 1982, the incidence rate of malaria in the areas was reduced by 80% annually, indicating that the malaria transmission had been decreased obviously.
Animals↗
[The distribution and pharmacokinetics in lung of bovine serum albumin microspheres for pulmonary targeting in mice].
125I-labeled bovine serum albumin microspheres loaded cisplatinum (CDDP-125I-BSA-MS) with the size range of 7-25 microns were prepared and injected into the tail vein of mice. The results showed that the microspheres were accumulated almost entirely in the lung after i.v. injection (about 97.52% injected dose at the highest concentration). While in blood and other organs almost no accumulation was found. Photomicrographs showed that microspheres reached the lung and lodged in precapillary arteriols and capillaries of lung. The microspheres in lung were eliminated gradually. The pharmacokinetics of microspheres in lung of mice was also studied with "practical pharmacokinetic program-version 87", and was fitted by two-compartment model with i.v. injection or one-compartment model with 1st order absorption, but the meaning of some parameters changed. Based on the analysis of the models and parameters, it was concluded that the pharmacokinetics of microspheres in lungs can be described by the model of "one-compartment of first-order intake and first-order elimination".
Animals↗
[A novel extended-spectrum beta-lactamase in a ceftazidime-resistant isolate of E. coli].
A novel extended-spectrum beta-lactamase (ESbla) encoded on a plasmid of approximately 7.5kb, conferring resistance to beta-lactams tested except cefoxitin and imipenem, was found in a ceftazidime-resistant isolate of E. coli form our hospital. The resistance to beta-lactams was transferred by conjugation to E. coli JP559 together with the aminoglycosides and sulfonamide resistance. Clavulanate, one of beta-lactamase inhibitors, inhibited its activity. This ESbla gene hybridized neither with an intra-genic fragment of SHV-1 nor with that of TEM-1. The molecular origin of that novel ESbla needed to be further studied.
Anti-Bacterial Agents↗
[Nucleotide sequence analysis of SHV-2 beta-lactamase gene in Enterobacter gergoviae].
The extended-spectrum beta-lactamase (ESbla) gene on R-plasmid harbored in E. coli C3773, a transconjugant of the clinical isolate of Ent. gergoviae 3773 from our hospital, was cloned and two fragments were subcloned into M13. The nucleotide sequences of two fragments were determined. The primary structure of this ESbla deduced from nucleotide sequence had only a Gly-->Ser change at position 234 in comparison with SHV-1, which was supposed to be responsible for extended-spectrum activity and resistance to 3rd generation cephalosporins. The result suggested that the ESbla appearing in our hospital was SHV-2.
Cephalosporins↗
Characteristics of two-dimensional and color Doppler ultrasonography in Graves' disease.
Color Doppler flow imaging (CDFI) was performed in 24 patients with Graves' disease and the results were compared with those from 8 patients with Hashimoto's disease, 6 patients with simple diffuse goiter, and 15 normal volunteers. All cases were confirmed by clinical, laboratory tests or pathology. CDFI of Graves' disease showed diffuse or localized hypoechoes within the thyroid glands, rich flow signals in the hypoechoes, accelerated flow velocity, and decreased resistance in the superior thyroid arteries (STA) and arteries within the glands. These appearances were characteristic as compared with the controls. The rate of flow in STA of Graves' disease patients was 8 to 10 times higher than that in the normal volunteers. This study demonstrates that CDFI is convenient and efficient as compared with isotope scan and some other laboratory tests, and can be widely used in the diagnosis of Graves' disease.
Adolescent↗