PubMed Health⌕ Search

Biomedical subjects

Y Fu

Publications and source records attributed to Y Fu.

At least 217 records · Page 12Linked to original sources
PubMed1997

[The relationship between insulin resistance and abnormalities of cellular calcium metabolism and cell membrane abnormalities in patients with essential hypertension].

OBJECTIVE: To investigate the relationship between the insulin resistance (IR) and the abnormalities of cellular calcium metabolism and cell membrane in patients with essential hypertension. METHODS: Plasma insulin and glucose before and during OGTT, membrane ATPase activity, cholesterol (C) and phospholipid (P), lipid peroxides (MDA), intracellular total calcium concentration [(Ca2+)i] and calcium binding capacity of inner surface of membranes were determined in 26 normotensive (NT) subjects, 17 hypertensives (HT), and 16 hypertensives associated with IR (HT + IR). RESULTS: The HT + IR group had higher levels of plasma glucose and insulin than that in the NT group and HT group with significant differences. The HT + IR group consistently demonstrated depressed activity of each Na(+)-K(+)-ATPase and Ca(2+)-ATPase studied with significant differences when compared with the NT group, but no difference was found if compared with the HT group. There was a higher [(Ca2+)i] in the HT + IR group than those in the NT group and even in the HT group with significant differences, respectively. Insulin sensitivity in the HT + IR group was significantly lower than that in both groups of HT and NT, respectively. The membrane C/P molar ratio and MDA content in the HT + IR group and HT group were significantly higher than those in the NT group, respectively. CONCLUSIONS: It is likely that there is a causal relation between IR and abnormalities of cellular calcium metabolism and membrane lipids in patients with essential hypertension.

Aged↗
PubMed1997

Differential expression of Rb2/p130 and p107 in normal human tissues and in primary lung cancer.

Two proteins, p107 and pRb2/p130, which are structurally and functionally similar to the product of the retinoblastoma gene (pRb), were cloned by taking advantage of their ability to bind transforming proteins of DNA tumor viruses through a particular region called the "pocket domain." Like pRb, both proteins play a fundamental role in growth control. Using immunocytochemical techniques, we examined a variety of normal human tissues for the expression of pRb2/p130 and p107. Both proteins were expressed ubiquitously, although a different tissue distribution and/or level of expression were found in various organs. Terminally differentiated cells, such as neurons and skeletal muscle, showed high expression levels for Rb2/p130, whereas p107 was expressed at higher levels in other cell types such as epithelia of the breast and prostate. We then examined the expression pattern of Rb2/p130 in 158 specimens of human lung cancer and found an inverse correlation between the histological grading of the tumors, the development of metastasis, and the level of expression of Rb2/p130.

Blood Cells↗
PubMed1997

[Artificial biological skin for preventing adhesion of repaired tendon in white rats].

To study the effect of tendon healing and adhesion after tendon repaired using the artificial biological skin (Biofill) produced in Brazil, we divided randomly 46 rats [correction of mice] into groups, compared the pelvic limbs with themselves, observed by eyes and light microscopy, and made biomechanical and histological detection in 1st, 2nd, 3rd and 4th weeks postsurgically. The results showed that the speed and strength of tendon healing had light affect in three weeks after operation, and had no difference between experimental groups and control groups after 4 weeks. It is indicated that artificial skin "Biofill" can effectively prevent tendon adhesion after tendon repaired and have not obviously influenced in the intrinsic self-healing process of tendon.

Achilles Tendon↗
PubMed1996

Dynamics and equilibrium behavior of cytonuclear disequilibria under genetic drift, mutation, and migration.

A simple two-locus drift model for cytonuclear systems is developed, in which the stochastic dynamics of cytonuclear genotypic frequencies are specified. Random union of zygotes is assumed. Trajectories for the first two moments of both genotypic and allelic disequilibria are given under three scenarios: (i) random drift alone; (ii) random drift with mutation; and (iii) random drift with migration. Steady state solutions for the cytonuclear disequilibria are reported. The utility of this simple two-locus drift model in testing the neutrality of mitochondrial DNA markers in artificial hybrid zones is briefly illustrated

DNA, Mitochondrial↗
PubMed1996

Progesterone receptor immunoreactivity at the maternofetal interface of first trimester pregnancy: a study of the trophoblast population.

The aim of our study was to localize oestrogen receptor (ER) and progesterone receptor (PR) in the trophoblast population at the maternofetal interface in early pregnancy. Rat monoclonal antibodies to human ER and PR were used to study 44 cases of chorionic villi and 82 cases of decidua using an immunocytochemical method. The PR-immunoreactive products were localized in the nuclei of syncytiotrophoblast and cytotrophoblast cells of the villi. Specific staining was also present in the cytoplasm. Villous stroma and vessels were stained occasionally. Using cytokeratin staining in an adjacent section or double staining with PR and cytokeratin, the distribution of invading trophoblast cells and their PR expression were examined. In decidual stroma, a type of interstitial cell was identified which simultaneously expressed cytokeratin and PR in the cytoplasm, indicating that the invading trophoblast cells may express PR. All extravillous populations at the interface were positive for PR, including the syncytial lining of the decidual surface, the cytotrophoblast column, the cytotrophoblast shell and the interstitial trophoblast. The immunoreactivity of PR was also localized in the nuclei of vascular endothelial cells, whereas Factor VIII was localized in the cytoplasm of the same cells, thus confirming their endothelial nature. In contrast to PR, little ER could be detected in the trophoblast cell population using anti-ER antibody D75 in our study.

Adult↗
PubMed1996

Photooxidation of troglitazone, a new antidiabetic drug.

Troglitazone (CS-045) is a new oral antidiabetic drug reported to be effective in insulin-resistant diabetes and to show antihypertensive effects. Photooxidation of troglitazone gave the quinone and quinone epoxide as the major final stable products. An intermediate observed by NMR spectroscopy was shown to be the hydroperoxydienone, which is moderately stable at room temperature. The rate constant of singlet oxygen quenching by troglitazone is 2.14 x 10(8) M(-1) s(-1) and the reaction rate constant in acetone-d6 is 8.64 X 10(6) M(-1) s(-1). Only the chroman ring of troglitazone reacts with and quenches singlet oxygen significantly, and its reactivity and products are analogous to those of alpha-tocopherol. The reactivity of CS-45 toward singlet oxygen is much larger than that of the related compounds lacking the chroman ring.

Chromans↗
PubMed1996

Parkinsonism due to chronic subdural hematoma.

A 75-year-old male presented with bilateral parkinsonism due to chronic subdural hematoma. The hematoma was removed through a small craniotomy. The parkinsonism rapidly improved following operation, suggesting a strong relationship between the hematoma and parkinsonism. We recommend surgical intervention in such cases.

Aged↗
PubMed1996

[A case of middle cerebral artery occlusion caused by dissecting aneurysm].

We reported a case of middle cerebral artery occlusion caused by a dissecting aneurysm that was successfully treated by intra-arterial fibrinolysis. A 38-year-old man suddenly developed left hemiparesis and became confused. He was transferred to our hospital one hour and 27 minutes after the ictus. Right carotid angiogram (CAG) revealed aneurysmal dilatation of the horizontal portion of the middle cerebral artery and occlusion of the anterior trunk. Twelve million IU of tissue plasminogen activator was injected to fibrinolyze the thrombus of the occlusion site through a microcatheter. After this, the patient became alert and hemiparesis disappeared. It took three hours and 30 minutes to gain recanalization after the ictus. Right CAG obtained the next day demonstrated the patency of the anterior trunk and the characteristic finding of the dissecting aneurysm viz "double lumen" as a result of fibrinolysis of the thrombus in the false lumen. Right CAG obtained two weeks later demonstrated "string and pearl sign" instead of the "double lumen" as a result of partial thrombosis in the false lumen. Follow-up CAG obtained nine months after the ictus demonstrated marked reduction of the aneurysmal size as the result of progressing thrombosis of the false lumen. The characteristic angiographic findings of the dissecting aneurysm such as "double lumen" and "string and pearl sign" seemed to be mostly influenced by the status of the thrombus in the false lumen. In case of major cerebral arterial occlusion caused by the embolus or thrombus from the dissecting aneurysm, intra-arterial fibrinolysis seems to be a possible treatment modality, even though it is accompanied by the risk of giving rise to subarachnoid hemorrhage.

Adult↗
PubMed1996

[Studies of aetiology and management about iatrogenic injuries of bile duct].

74 patients with iatrogenic injuries of bile duct were treated from June 1965 to October 1994 in our hospital. Iatragenic extrahepatic bile duct injuries may be caused by some errors during cholecystectomy. The operator did not realize that cholecystectomy itself is a procedure with inherent and potential risks. The operator was careless, rude and arrogant in operating. The operator lacked experience and skill, and was unable to deal with difficult situation during operation. Also we discussed the management of bile duct injuries, and suggested that intraoperative injuries of extrahepatic bile duct should be reconstructed immediately including repair of or end to end anastomoses of the injuries of bile duct. Cholecystojejunostomy (Roux-en-Y technique) is the best reconstruction procedure for patients with the injuries of bile duct after operation or failure of repetitional repaired and reconstructive operations of bile duct. Satisfactory result could be obtained.

Adult↗
PubMed1996

[Treatment of preterm labor with ritodrine].

OBJECTIVE: To investigate the treatment of preterm labor with the beta-adrenergic agonist ritodrine. METHODS: 126 women with preterm labor were randomly assigned to intravenous infusion of ritodrine or magnesium sulfate treatment. Using minimal effective dosage for inhibition of uterine activity, terminating therapy on time, and repeating the i.v. infusion if contraction restarted were the strategy for treatment. RESULTS: Ritodrine was significantly more effective both in the treating period for suppression of contraction (2.33 +/- 0.63 hr for initiation of inhibiting uterine activity, 9.38 +/- 3.88 days of accumulative treating period) and prolongation of gestation (4.81 +/- 2.83 wks) than that of the magnesium sulfate (P < 0.001, 0.005 and 0.01 respectively), and had a term labor of 73.44%. There was no serious cardiac and pulmonary complications in the ritodrine group. CONCLUSION: The present study has shown that ritodrine as a tocolytic agent is highly effective for the management of preterm labor and relative safe for mother and fetus.

Adrenergic beta-Agonists↗
PubMed1996

[The relationship between human chorionic gonadotrophin and lipoprotein metabolism].

We compared human chorionic gonadotrophin (hCG-beta) with lipids, lipoproteins and apolipoproteins in serum between pre- and postmenopausal women, and observed the changes of levels of hCG-beta in animals suffering from hypertriglyceridemia. The results have shown that the concentration of hCG-beta in postmenopausal women is much higher than that in premenopausal women (P < 0.001). Correspondingly, triglyceride (TG) is elevated (P < 0.05). High density lipoprotein cholesterol (HDL-C) and HDL-C/LDL-C ratio are decreased (P < 0.001, P < 0.01). On the other hand, the tendency of highing hCG-beta level has been found in animal study. The concentration of hCG-beta in male rats suffering form hypertriglyceridemia is higher than that in normal animals (P < 0.05).

Adult↗
PubMed1995

Identification and characterization of a novel related adhesion focal tyrosine kinase (RAFTK) from megakaryocytes and brain.

We have isolated a cDNA encoding a novel human intracytoplasmic tyrosine kinase, termed RAFTK (for a related adhesion focal tyrosine kinase). In addition, we have cloned and characterized the murine homolog of the human RAFTK cDNA. Comparison of the deduced amino acid sequences of human RAFTK and murine Raftk cDNAs revealed 95% homology, indicating that RAFTK is highly conserved between these species. The RAFTK cDNA clone, encoding a polypeptide of 1009 amino acids, has closest homology (48% identity, 65% similarity) to the focal adhesion kinase (pp125FAK). Comparison of the deduced amino acid sequences also indicates that RAFTK, like pp125FAK, lacks a transmembrane region, myristylation sites, and SH2 and SH3 domains. In addition, like pp125FAK, RAFTK contains a kinase domain flanked by large N-terminal (426 residues) and C-terminal (331 residues) domains, and the C-terminal region contains a predicted proline-rich stretch of residues. In fetal tissues, RAFTK expression was abundant in brain, and low levels were observed in lung and liver. In adult tissues, it was less restricted, indicating that RAFTK expression is developmentally up-regulated. Expression of RAFTK was also observed in human CD34+ marrow cells, primary bone marrow megakaryocytes, platelets, and various areas of brain. The human RAFTK gene was assigned to human chromosome 8 using genomic DNAs from human/rodent somatic cell hybrid lines. The mouse Raftk gene was mapped to chromosome 14, closely linked to gonadotropin-releasing hormone. Using specific antibodies for RAFTK, a approximately 123-kDa protein from the human megakaryocytic CMK cell line was immunoprecipitated. Treatment of the megakaryocytic CMK cells with thrombin caused a rapid induction of tyrosine phosphorylation of RAFTK protein. The structural features of RAFTK suggest that it is a member of the focal adhesion kinase gene family and may participate in signal transduction in human megakaryocytes and brain as well as in other cell types.

Amino Acid Sequence↗
PubMed1995

Fibrinogen alpha genes: conservation of bipartite transcripts and carboxy-terminal-extended alpha subunits in vertebrates.

All three well-studied subunits of the clotting protein fibrinogen (alpha, beta, gamma) share N-terminal structural homologies, but until recently only the beta and gamma chains were recognized as having similar globular C-termini. With the discovery of an extra exon in the human fibrinogen alpha gene (exon VI), a minor form of the alpha subunit (alpha E) with an extended beta- and gamma-like C-terminus has been identified (Fu et al., Biochemistry 31, 11968, 1992). In the present study, the polymerase chain reaction has been used to identify sequences that encode counterparts to alpha E in chicken, rabbit, rat, and baboon. The basic six-exon structure of the fibrinogen alpha genes is shown to be conserved among mammals and birds, as are the intron positions. Bipartite transcripts--still bearing an intron prior to the last exon--are found among the products of the various vertebrate fibrinogen alpha genes. The last exon represents the largest conserved segment of the gene and, in each species examined, encodes exactly 236 amino acids. The C-termini of these alpha E chains align without a single gap and are between 76 and 99% identical. Since the exon VI-encoded domain of alpha E is as well conserved as the corresponding regions of the beta and gamma chains, it follows that it is equally important and that alpha E-fibrinogen plays a vital, if as-yet unrecognized physiological role.

Amino Acid Sequence↗
PubMed1995

Structural and functional studies of the intracellular tyrosine kinase MATK gene and its translated product.

We recently cloned the cDNA which encodes a novel megakaryocyte-associated tyrosine kinase termed MATK. In this study, we have cloned and characterized the human MATK gene as well as the murine homolog of human MATK cDNA and performed functional studies of its translated product. Comparison of the deduced amino acid sequences of human and murine MATK cDNAs revealed 85% homology, indicating that MATK is highly conserved in mouse and human. The human gene consists of 13 exons interrupted by 12 introns. The genetic units which encode the SH3 and SH2 domains are located on separate exons. The putative ATP binding site (GXGXXG) is localized on exon 7, and the entire catalytic domain is subdivided into seven exons (7-13). Somatic cell hybrid analysis indicated that human MATK gene is located on chromosome 19 while the murine Matk gene is located on chromosome 10. The immediate 5'-flanking region was highly rich in GC sequences, and potential cis-acting elements were identified including several SP1, GATA-1, APRE, and APRE1. Antisense oligonucleotides directed against MATK mRNA sequences significantly inhibited megakaryocyte progenitor proliferation. Functional studies indicated that MATK can phosphorylate the carboxyl-terminal conserved tyrosine of the Src protein. These results support the notion that MATK acts as a regulator of p60c-src in megakaryocytic cells and participates in the pathways regulating growth of cells of this lineage.

Adenosine Triphosphate↗
PubMed1995

Angiographic extravasation of contrast medium in acute "spontaneous" subdural hematoma.

Acute spontaneous subdural hematoma is very rare. We have encountered four such cases and verified the arterial origin of the bleeding at operation. None of the patients had a history of head trauma, and each had developed sudden onset of headache and other neurologic deficits, which simulate other cerebrovascular diseases. CT directly revealed subdural hematoma but gave no indication as to the source of the bleeding. Cerebral angiography was performed in all cases, with three of them showing localized extravasation of the contrast material into the subdural space. The extravasation was noted usually in the late arterial phase. This is a useful finding for diagnosing this disease and localizing the bleeding point. It is expected that with more routine use of cerebral angiography in cases of acute spontaneous subdural hematoma, extravasation of the contrast medium will be seen more frequently.

Acute Disease↗