Search PubMed⌕ Search

Biomedical subjects

X Huang

Publications and source records attributed to X Huang.

At least 541 records · Page 30Linked to original sources
PubMed1996

[Cytoreductive surgery plus combined chemotherapy for the treatment of advanced ovarian cancer].

OBJECTIVE: To evaluate the impact of cytoreductive surgery plus combined chemotherapy on advanced ovarian cancer. METHODS: From Jan. 1980 to Dec. 1992, 76 patients admitted to our hospital for primary treatment, were eligible for retrospective evaluation. 26 patients with stage II and 50 with stage II. All patients with ovarian cancer were given cytoreductive surgery followed by systemic and intraabdominal chemotherapy. Regimens were CAP (Cyclophosphamide, Adriamycin, Cisplatin), AP (Adriamycin, cisplatin) or CE (Carboplatin, Epi-adriamycin). RESULTS: In 52 patients no residual tumor was found in 24 patients there were residual lesions less than 2cm in diameter. Postoperative chemotherapy ranged from 1 to 12 courses. The overall 5-year-survival rate was 33.6%, with 34.9% for stage II and 29.5% for stage II (P > 0.1). The 5-year-survival rates of cases with and without residual tumor were 16.5% and 37.6% respectively, the rates of those cases receiving less or more than 8 courses of chemotherapy were 20.0% and 60.1% respectively. CONCLUSION: The prognosis of ovarian cancer following cytoreductive surgery is influenced by residual tumor, and the number of courses of chemotherapy.

Adolescent↗
PubMed1996

[The inhibition of yohimbine injected intrathecally on electroacupuncture-induced analgesia and release of beta-endorphin from rat brain].

Yohimbine (30 micrograms/8 microliters, ith), an antagonist of alpha 2-adrenergic receptor, can inhibit electroacupuncture-induced analgesia (EAA) for 15 min, with its biggest effect reducing the pain threshold of electroacupuncture (EA) to the level of sham electroacupuncture (SEA). Yohmbine also completely inhibit the increase of beta-endorphin in the push-pull liquids from ventriculus lateralis cerebri caused by EA. But yohimbine itself produce no effect on pain threshold and the concentration of beta-endorphin. These results suggest that EAA and the increased release of beta-endorphin caused by EA are related to the activation of alpha 2-adrenergic receptor in the spinal cord.

Acupuncture Analgesia↗
PubMed1996

[Comparative study of the diagnostic preciseness of scrotoscope and B-ultrasonography on scrotal lesions].

Thirty patients with scrotal lesions were examined with both scrotoscope and B-ultrasonography. In comparison with the outcome of pathological results, the total diagnostic effectiveness rate of the scrotoscope (73.3%) was significantly higher than that of B-ultrasonography (46.7%). Scrotoscope (86.7%) was far more precise than B-ultrasonography (60%) in distinguishing a benign lump from a tumour (P < 0.05). However, when applied to separate a cyst from a solid lump, and epididymitis from epididymal tuberculosis, the two methods did not reveal remarkable difference (P > 0.05). Scrotoscope allows biopsy and removal of the lump under direct vision. It is handy and safe and is desirable to use on a larger clinical scale.

Adult↗
PubMed1996

[Study on pharmacokinetic characteristics of tetramethylpyrazine and hemodynamics of heart blood stasis in dogs].

"Blood stasis syndrome pharmacokinetics" means the pathophysiological state of blood stasis syndrome affectes significantly the pharmacokinetic parameters. In order to provide scientific evidence for the new hypothesis, the authors studied the hemodynamic changes induced by quantitative coronary artery stenosis and pharmacokinetics of tetramethylpyrazine (TMP) in dog model with heart blood stasis (HBS) and in normal dog (for control) simultaneously. Compared with healthy dog, serum TMP concentration, drug concentration time, area under curve (AUC) and t1/2 beta in HBS dog were increased significantly (P < 0.01). The mechanism might be related with the abnormal changes in hemodynamics (indude decrease in cardiac output, left ventricular systolic pressure and coronary blood flow, etc.) caused by coronary artery stenosis.

Animals↗
PubMed1996

[A study on the pathogenetic role of the viral structural proteins of hemorrhagic fever with renal syndrome].

In order to clarify the pathogenesis of hemorrhagic fever with renal syndrome (HFRS), we detected HFRS virus structural proteins expressed in perepheral blood mononuclear cells (PBMC) by using immunohistochemical technique. Meanwhile we also determined plasma endothelin (ET), substance P (SP) and some sensitive markers of renal function with radioimmunoassay. The result showed that in HFRS patients, from the day of admission up to the thirteenth day of illness, the antigens of HFRS virus membrane protein (MP) and nucleocapsid (NP) could simultaneously be found in PBMC, though their expressive degree gradually decreased when the condition of the patients became better. Based on the external appearance and nucleus pattern of PBMC we recognized the MP and NP positive cells were mainly monocytes among which only a few presented faint IgM and C3 stain. On admission there was difference in expressive intensity between MP and NP. The MP expressive intensity was in parallel with plasma ET/SP ratio, the general condition and the severity of renal damage. These data suggest that HFRS virus can invade PBMC, replicate in them, and express their structural proteins. MP may be related with the pathogenesis of HFRS virus and the increase of plasma ET/SP ratio may be an important factor aggravating kidney injury.

Adult↗
PubMed1996

[Long-term effects of CPAP in obstructive apnea syndrome].

OBJECTIVE: To study the long term effects with CPAP in OSAS. METHODS: Eighteen patients with OSAS were treated by CPAP at home for 3 to 27 months from 1987 to 1995, comparing the parameters of polysomnography (PSG) before and after treatment. RESULTS: (1) all the symptoms of OSAS were improved; (2) The parameters of PSG showed that the longest apnea duration from 66 +/- 21s to 43 +/- 24s (P < 0.05); AHI from 66 +/- 16 to 28 +/- 20 n/hour (P < 0.001); The lowest SaO2 from 53% +/- 19% to 75% +/- 11% (P < 0.001); (3) Comparing the body weight and blood pressure, no significant difference was shown before and after treatment with CPAP, but the blood pressure of 6 (50%) OSAS patients with hypertension had decreased to normal range. CONCLUSION: Long term treatment with CPAP in OSAS were effective, after which, the AHI, lowest level of hopoxemia, the longest apnea duration and the sympoms of OSAS were improved. The mechanism could be that the patents' breathing control were restored.

Adult↗
PubMed1996

[Outpatient treatment of obstructive sleep apnea syndrome with CO2 laser: laser-assisted uvulopalatoplasty].

To find a safe and convenient method for the treatment of obstructive sleep apnea syndrome, 89 outpatient cases were treated with CO2 laser-assisted uvulopalatoplasty. All cases had been diagnosed and observed with polysomnographic monitoring. The result of 89 cases of OSAS was judged as good in 67 cases (75.7%). Only 6 cases had a little bleeding during operation, no other complication has been encountered.

Adult↗
PubMed1996

Variety of molecular conformation of plasmid pUC18 DNA and solenoidally supercoiled DNA.

The plasmid pUC18 DNA isolated from Escherichia coli HB101 were analyzed by two-dimensional agarose gel electrophoresis and hybridization. The results show that the DNA sample can be separated into six groups of different structural components. The plectonemically and solenoidally supercoiled pUC18 DNA coexist in it. These two different conformations of supercoiled DNA are interchangeable with the circumstances (ionic strength and type, etc.). The amount of solenoidally supercoiled pUC18 DNA in the samples can be changed by treatment of DNA topoisomerases. Under an electron microscope, the solenoidal supercoiling DNA has a round shape with an average diameter of 45 nm. The facts suggest that solenoidally supercoiled DNA be a structural entity independent of histones. The polymorphism of DNA structure may be important to packing of DNA in vivo.

DNA Topoisomerases, Type I↗
PubMed1995

Cloning and characterization of Lnk, a signal transduction protein that links T-cell receptor activation signal to phospholipase C gamma 1, Grb2, and phosphatidylinositol 3-kinase.

A cDNA encoding a signal transduction protein with a Src homology 2 (SH2) domain and a tyrosine phosphorylation site was cloned from a rat lymph node cDNA library. This protein, which we designate Lnk, has a calculated molecular weight of 33,988. When T lymphocytes were activated by antibody-mediated crosslinking of the T-cell receptor and CD4, Lnk became tyrosine phosphorylated. In activated T lymphocytes, phospholipase C gamma 1, phosphatidylinositol 3-kinase, and Grb-2 coimmunoprecipitated with Lnk. Our results suggest that Lnk becomes tyrosine phosphorylated and links the immediate tyrosine phosphorylation signals of the TCR to the distal phosphatidylinositol 3-kinase, phospholipase C gamma 1 and Ras signaling pathways through its multifunctional tyrosine phosphorylation site.

Adaptor Proteins, Signal Transducing↗
PubMed1995

Characterization of pp60c-src tyrosine kinase activities using a continuous assay: autoactivation of the enzyme is an intermolecular autophosphorylation process.

A continuous assay for pp60c-src tyrosine kinase (srcTK) was developed. A lag in phosphorylation of the peptide RRLIEDAEYAARG was observed that could be eliminated by preincubation with MgATP. The induction time for this lag was dependent upon MgATP and srcTK concentrations. When autophosphorylation was monitored by 32P incorporation from [gamma-32P]ATP, a lag in the time course was also observed. These results demonstrate that autoactivation is an intermolecular process. The electrospray ionization mass spectrum of the enzyme before and after activation demonstrated an increase in the phosphorylation state of the enzyme after incubation with MgATP. The delta 85-N-terminal mutant protein and a full-length G2A pp60c-src mutant, which removes the myristylation site, used in these studies were partially phosphorylated on Y338 and Y530 as isolated. This is the first report of phosphorylation on Y338, but the significance of this site of phosphorylation is unknown. These phosphorylations were insufficient to active the enzyme for transfer of the gamma-phosphoryl of MgATP to the peptides. The unphosphorylated enzyme initially present was converted to a monophosphorylated species upon treatment with MgATP. Y-419 phosphorylation was evident only after treatment with MgATP. These data are consistent with autophosphorylation on Y-419 as predicted. Intermolecular autophosphorylation is consistent with the ability of srcTK to dimerize, which is analogous to activation of receptor tyrosine kinases such as the EGF receptor kinase in response to growth factors. These results indicate that dimerization leading to activation does not require binding to the membrane or a hydrophobic N-terminus in the case of srcTK.

Adenosine Diphosphate↗
PubMed1995

On-column reduction of catecholamine quinones in stainless steel columns during liquid chromatography.

The chromatographic behavior of quinones derived from the oxidation of dopamine and N-acetyldopamine has been studied using liquid chromatography (LC) with both a diode array detector and an electrochemical detector that has parallel dual working electrodes. When stainless steel columns are used, an anodic peak for the oxidation of the catecholamine is observed at the same retention time as a cathodic peak for the reduction of the catecholamine quinone. In addition, the anodic peak exhibits a tail that extends to a second anodic peak for the catecholamine. The latter peak occurs at the normal retention time of the catecholamine. The origin of this phenomenon has been studied and metallic iron in the stainless steel components of the LC system has been found to reduce the quinones to their corresponding catecholamines. The simultaneous appearance of a cathodic peak for the reduction of catecholamine quinone and an anodic peak for the oxidation of the corresponding catecholamine occurs when metallic iron in the exit frit reduces some of the quinones as the latter exits the column. This phenomenon is designated as the "concurrent anodic-cathodic response." It is also observed for quinones of of 3,4-dihydroxybenzoic acid and probably occurs with o- or p-quinones of other dihydroxyphenyl compounds. The use of nonferrous components in LC systems is recommended to eliminate possible on-column reduction of quinones.

Animals↗
PubMed1995

Effect of a chiral 4-alkyl substituent in hallucinogenic amphetamines.

The potency of hallucinogenic amphetamine derivatives of the 1-(2,5-dimethoxy-4-alkylphenyl)-2-aminopropane type drops dramatically when the length of the 4-alkyl substituent exceeds propyl or when the substituent is branched. This investigation was directed toward evaluating changes in behavioral and biochemical pharmacology resulting from introducing chirality into the 4-alkyl group of such analogues. Two diastereoisomeric derivatives of this class containing a 4-(R or S)-2-butyl substituent, 11a,b, respectively, were studied. A slight but nonsignificant potency difference in d-lysergic acid diethylamide tartrate (LSD)-like discriminative stimulus properties and equal affinity for [125I]-(R)-(2,5-dimethoxy-4-iodophenyl) isopropylamine-labeled serotonin 5-HT2A/C radioligand-binding sites were observed. Thus, the portion of the receptor that interacts with the 4-alkyl substituent on hallucinogenic amphetamines does not present a highly asymmetric environment to the ligand. However, since both test drugs had higher binding affinity but lower LSD-like behavioral potency than the prototype compound with a 4-methyl group ((2,5-dimethoxy-4-methylphenyl)isopropylamine, 2), 11a,b may differ in their receptor agonist efficacy from more behaviorally active compounds such as 2.

Amphetamines↗
PubMed1995

Characterization of a highly toxic, large molecular size heat-stable enterotoxin produced by a clinical isolate of Yersinia enterocolitica.

A novel heat-stable enterotoxin (ST) designated as Y-STc was purified to homogeneity from the culture supernatant of a pathogenic strain of Yersinia enterocolitica serotype O3 and its amino acid sequence was determined. The mature Y-STc was found to consist of 53 amino acid residues, which includes the putative pro-sequence. The molecular weight of Y-STc was 5638 and constituted the largest molecular size in the family of currently known STs. The minimum effective dose of purified Y-STc in the suckling mouse assay was 0.6 ng (0.0 pmol), indicating that, despite the long sequence, Y-STc is the most toxic in the ST family.

Amino Acid Sequence↗
PubMed1995

Treatment with rapamycin and mycophenolic acid reduces arterial intimal thickening produced by mechanical injury and allows endothelial replacement.

Rapamycin (RPM) and mycophenolic acid (MPA) inhibit immune responses by antagonizing IL-stimulated lymphocyte activation. These 2 drugs, used alone or preferably in combination, also significantly reduced the response of vascular cells to balloon-catheter arterial injury in rats. When rats were treated for 2 weeks with both drugs starting the day of injury, intimal thickening was significantly reduced (P < 0.001) 14 days after injury; however, by 44 days after injury, intimal thickening had progressed to the extent measured in arteries of untreated control rats. When RPM and MPA were administered for 3 days before and 13 days after injury, arterial intimal thickening was significantly (P = 0.024) reduced and endothelium had regrown in vessels analyzed 44 days after injury. Compared with initiation of treatment on the day of injury, starting the administration of RPM plus MPA before injury appears to limit the activation of cells or actions of factors responsible for the progression of intimal thickening that occurred after the administration of the drugs was terminated. RPM and MPA prevented the development of arterial intimal thickening in a model not dependent upon a rejection response. This direct antiproliferative action on smooth muscle cells by RPM and MPA, in vivo, may prevent the development of arterial intimal thickening associated with chronic rejection.

Animals↗