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Biomedical subjects

Q Yang

Publications and source records attributed to Q Yang.

At least 307 records · Page 17Linked to original sources
PubMed1998

[The effect of carboplatin combined chemotherapy on renal function in patients with ovarian carcinoma].

OBJECTIVE: To investigate the changes of renal function during carboplatin (CBDCA) combined chemotherapy in patients with ovarian carcinoma. METHODS: 26 courses of postoperative systemic CBDCA therapy were carried out in 7 patients with ovarian carcinoma. During chemotherapy both systolic maximum and diastolic minimum blood flow velocity (Vmax, Vmin) and resistance index (RI) in renal segmental artery (SA) and interlobular artery (ILA) were meaured by color doppler weekly. Meanwhile renal creatinine clearance rate (Ccr) were also determined. 14 healthy women were taken as controls. RESULTS: From the 1st week to the 3rd week at the begining of CBDCA therapy, Vmax and Vmin in SA and ILA were significantly decreased (P < 0.01). A significant positive correlation was found between Ccr and the values of Vmin in SA and ILA (r = 0.52, P < 0.01). CONCLUSIONS: The results indicated that carboplatin combined chemotherapy could induce disturbances of renal function. The changes of renal function were related to renal blood flow velocity which could be used as a monitoring index of renal function.

Adult↗
PubMed1998

[Subjective and objective of evaluation of UPPP in the treatment of obstructive sleep apnea syndrome in short-term follow-up].

Uvulopalatopharyngoplasty (UPPP) has become a widely accepted method for treating obstructive sleep apnea syndrome (OSAS). The authors studied 52 OSAS patients treated with UPPP and assessed pre- and postoperative parameters including subjective clinical analysis and objective evaluation of computer test. 34(65.38%) OSAS patients felt satisfied of improving snoring sound 3-6 months later following UPPP. 46 patients reported an improvement in their symptoms of daytime somnolence and morning headache. 41 patients underwent follow-up sleep analysis computer (SAC) study; 19 of them (46.34%) had a reduction in AHI more than 50%; meeting our criteria for surgical success. All 41 patients had a significant reduction of total duration of apnea at sleep stage. The study suggests that the effectiveness of UPPP in treating OSAS is limited and subjective clinical symptoms following UPPP do not correlate with the objective finding of SAC; so it is important to stress the significance of follow-up study and necessity to further therapy.

Adult↗
PubMed1998

[Polymorphism analysis of D6S366 STR locus].

The polymorphic STR locus D6S366 was analyzed using PCR and PAG electrophoresis and 7 alleles were detected from 200 unrelated individuals in Wuhan. The allete distribution of the locus was in accordance with Hardy-Weinberg equilibrium. The H, Dp, P, E, and PIC of the D6S366 were calculated in this paper.

Alleles↗
PubMed1998

[Clinical study of tubal pregnancy treated with integrated traditional Chinese and Western medicine].

OBJECTIVE: To explore the therapeutic effect and the mechanism of tubal pregnancy (TP) treated with integrated traditional Chinese and Western medicine (TCM-WM). METHODS: Seventy-eight patients suffering from TP were divided into two groups at random, 50 cases of treated group treated with the method of integrated Methotrexate (MTX) and Ectopic Pregnancy 2 (EP2) decoction, and the other 28 cases treated with MTX alone for control. RESULTS: The nonsurgical method cure rate of the treated group (98.0%) was higher than that of the control group (75.0%, P < 0.01). The intrauterine pregnancy rate of the treated group was 80.0%, that of the control group was 42.9% (P < 0.01). The recurrent TP rate of the treated group (4.0%) was lower than that of the control group (14.2%, P < 0.01). The serum beta-HCG normalizing time of the treated group (25.0 +/- 7.8 days) was shorter than that of the control group (31.9 +/- 6.7 days, P < 0.05). The total disappearance time of TP mass was 1.2 +/- 0.7 months in the treated group, and in the control group was 5.6 +/- 3.7 months (P < 0.01). After treated by EP2 decoction for 4-8 weeks, the deformability of erythrocyte was increased, the aggregation of erythrocyte, the whole blood viscosity and the blood plasma viscosity were reduced. CONCLUSIONS: The integrated method can effectively increase nonsurgical cure rate, tubal patency rate and intrauterine pregnancy rate, decrease recurrent TP rate in treating TP.

Adult↗
PubMed1998

[Reversal effect of Ys-96, a bisbenzylisoquinoline, on adriamycin or vincristine resistance in human cancer cells in vitro].

OBJECTIVE: Reversal effect of Ys-96, a bisbenzylisoquinoline, on the resistance of human cancer cells to adriamycin or vincristine was studied in vitro. METHOD: In an in vitro culture system of human cancer cells MCF-7 and its adriamycin-resistant line MCF-7/Ad or KB and its vincristine-resistant line KBv200, the sensitivity(IC50) of the resistant cell lines to adriamycin or vincristine was evaluated with a MTT assay. RESULT: IC50 value of adriamycin or vincristine in combination with Ys-96 at a concentration of 1.00 mumol/L against MCF-7/Ad or KBv200 was found to be close to that of adriamycin alone or vincristine alone against the sensitive cell line MCF-7 or KB. CONCLUSION: The drug resistance of MCF-7/Ad or KBv200 could be essentially reversed by Ys-96 at a concentration of 1.00 mumol/L.

Benzylisoquinolines↗
PubMed1998

[Experimental study on human collagen and autologous fat injected into canine vocal cords].

OBJECTIVE: To explore the histological fate of human collagen and autologous fat injected into vocal cords in treating glottic insufficiency. METHODS: Human collagen and autologous fat were injected respectively into two dogs(group A) to correct glottic incompetence caused by left vocal cord paralysis. Autologous fat and human collagen 0.3 ml were injected respectively into left and right vocal cords of 9 dogs (B, C, D groups, 3 dogs in each group). These animals were killed after 1, 3 and 5 months. The histology, volume and curative effect of both substances were evaluated. RESULTS: Autologous fat grafts survived in the canine vocal cords after 5 months but the absorption was rapid. The average speed of reduction in volume was 38.51% from 1 to 5 months and the effect of treatment couldn't last long. Human collagen was easily injected and well-tolerated. The injected collagen was colonized by host fibroblasts and capillaries. At the same time, new host collagen deposited. There was a trend to allow the eventual replacement of the implant by new host tissue. The average speed of reduction in volume was 0.65% and the curative effect was constantly stable from 1 to 5 months. CONCLUSION: The results suggested that autologous fat has only a potential use for short-term(< 5 months) augmentation of vocal cord. Human collagen can be used as long-term augmentative material to manage glottic insufficiency caused by various etiologies.

Adipose Tissue↗
PubMed1998

[Synthesis and antibacterial activity of 7-substituted-1-ethyl(2-fluoro-ethyl)-6,8-difluoro-1,4-dihydro-4- oxoquinoline-3-carboxylic acid].

Eighteen 7-substituted-1-ethyl (2-fluoroethyl)-6, 8-difluoro-1, 4-dihydro-4-oxoquinolone-3-carboxylic acid were designed and synthesized. The results of preliminary antibacterial test showed that most of the compounds exhibited definite activities in test against pathogenic bacteria. Especially, compound 17 and 18 showed better activities and surpassed fleroxacin when compared in vitro.

Anti-Infective Agents↗
PubMed1998

[Clinical value of diagnostic score for appendicitis: results of a prospective intervention study].

The clinical benefit of a diagnostic score for acute appendicitis was tested in a prospective interventional multicenter study on patients with abdominal pain. The study was performed in two consecutive phases: standard diagnostic work-up with no additional diagnostic support (870 patients) and additional diagnostic support with a score (614 patients). The two groups were comparable with respect to signs, symptoms and investigations related to acute appendicitis. Diagnostic performance of the final examiner decreased with the score: specificity from 86% to 78%, positive predictive value from 67% to 50% and accuracy from 88% to 81%. There were no differences in the perforated appendix, negative appendectomy and complication rate, however, the delayed appendectomy rate (2% versus 8%) and the delayed discharge rate (11% versus 22%) were significantly lower with diagnostic support by the score. In summary, the score cannot be recommended as a standard diagnostic tool for diagnostic decision making in acute appendicitis.

Abdomen, Acute↗
PubMed1998

[Investigation on the luminescence properties of Er ions in Er-doped sol-gel silica glasses].

Er-doped sol-gel silica glasses which have room temperature photoluminescence at 1.54 microm and doped concentration of 10(20)/cm(3) have been prepared. The examination results Indicated: (1) PL spectrum has largest intensity at the 0.5W% doped concentration; (2) the intensity of PL decreased 74%, when the temperature raised form 4K to 300K; (3) The Er ion and O ions formed complexes with coordinated numbers of 8 or 9.

English Abstract↗
PubMed1998

[Genetic polymorphism of STR loci D19S253 and D8S1179 for Han population in Wuhan].

OBJECTIVE: This article reports a population genetic study on two short tandem repeat loci, D19S253 and D8S1179, in a sample of unrelated Chinese individuals(n=225-233) living in Wuhan. METHODS: PCR and PAGE. RESULTS: Nine alleles were identified for the two loci, the ranges of fragment size were 209bp-241bp and 174bp-206bp respectively. The genotypes distributions of D19S253 and D8S1179 were in accordance with Hardy-Weinberg equilibrium. Family studies confirmed Mendelian inheritance of alleles. No mutation was detected in 100 meiosis for the two STR loci studied. The observed heterozygosities of D19S253 and D8S1179 were 0.8089 and 0.8712. The polymorphism information content(PIC) in Chinese was calculated as 0.7754 for D19S253 and 0.8258 for D8S1179. The power of discrimination(PD) and mean exclusion chance(MEC) were 0.9309 and 0.6133 for D19S253 and 0.9515 and 0.6874 for D8S1179 respectively. The combined PD and cumulative chance of exclusion were calculated as 0. 9966 and 0.8791. CONCLUSION: The results demonstrate that the combined use of the two polymorphic systems provides a high power of discrimination and power of exclusion for use in forensic identification and paternity testing.

Alleles↗
PubMed1998

Iodine-123-vasoactive intestinal peptide receptor scanning in patients with pancreatic cancer.

UNLABELLED: Recent data demonstrated a high sensitivity (>90%) in the visualization of primary/recurrent pancreatic cancer as well as metastases by means of 123I-labeled vasoactive intestinal peptide (VIP). The aim of this study was to investigate the diagnostic value of radioiodinated VIP in patients suffering from adenocarcinoma of the exocrine pancreas. METHODS: Sixty consecutive patients (26 women, 34 men; mean age 59 yr) with histologically verified pancreatic cancer were investigated in this study. Twenty-one patients presented with organ-confined malignancy (19 at study entry and 2 during follow-up after initial surgery developed tumor recurrence), while 25 patients had distant metastases along with the local malignancy, and 7 patients had liver metastases after resection of the primary lesion (6 on study entry and 1 during follow-up showed tumor development). In 5 of these patients, abdominal lymph node metastases were present at the time of scanning. Of 10 patients, who had undergone potentially curative surgery for their cancer, 7 remained free of disease during follow-up until death or for at least 6 mo. Iodine-123-VIP (150-200 MBq; approximately 1 microg VIP) was administered to all patients. Scintigraphic results were evaluated as compared to conventional radiologic imaging methods and surgical exploration. RESULTS: Primary pancreatic tumors were visualized by 123I-VIP in 19/21 patients (90%) with disease confined to the pancreas and in 8/25 patients (32%) suffering both from locoregional and disease metastatic to the liver. The overall 123I-VIP scan sensitivity for primary pancreatic adenocarcinomas was 58% (27/46 scans). Liver metastases were imaged in 29/32 patients (scan sensitivity 90%) and abdominal lymph node metastases in 4/5 patients. In 5 patients, the VIP receptor scan indicated the malignant lesion before CT. In vitro results confirmed specific binding of 123I-VIP to primary pancreatic tumor cells as well as to PANC1 adenocarcinoma cells. CONCLUSION: Iodine-123-VIP receptor scanning has the potential to offer additional information to augment diagnostic standard methods and could influence the decision-making process in the treatment of pancreatic cancer.

Adenocarcinoma↗
PubMed1997

The return of thalidomide: are birth defects surveillance systems ready?

In the 1960s, thalidomide caused limb deficiencies in thousands of infants worldwide. The limb deficiencies were frequently of the intercalary type. As a result, numerous countries started birth defect surveillance programs. In 1967, the Centers for Disease Control (CDC) started the Metropolitan Atlanta Congenital Defects Program (MACDP), a population-based surveillance system, to provide early warning against new teratogens. Recent studies have shown that thalidomide may be beneficial for a range of conditions, including cancer and AIDS, and it may once again become widely available. Here, we examine the ability of MACDP to detect an increase in the birth prevalence of limb deficiency as an early warning of fetal exposure to thalidomide. We calculated base rates for all limb deficiencies, for bilateral nonsyndromic intercalary or preaxial deficiencies, and for all nonsyndromic intercalary limb deficiencies among Atlanta infants born from 1968 through 1993. We used relative risk estimates from previous studies and a range of pregnancy exposure rates for thalidomide. We tested the statistical power of MACDP to detect subtle changes in the birth prevalence of these defects using Poisson and cumulative sum (CUSUM) techniques. The base rates for all limb deficiencies, for bilateral intercalary or preaxial deficiencies, and for all intercalary limb deficiencies, were 0.53, 0.035, and 0.022/1,000, and the estimated relative risks were 175, 4,570, and 8,180, respectively. We varied the assumed rate of exposure to thalidomide from 1/10,000 to 5/100. With a 1/1,000 exposure rate, both Poisson and CUSUM techniques will detect a rate change in intercalary limb deficiency in about 6 months of monitoring, and a rate change in bilateral intercalary or preaxial deficiencies in about 12 months of monitoring. When monitoring all limb deficiencies, a pregnancy exposure rate of 3.5% or less would go unnoticed by the Poisson method and would take more than 50 years for the CUSUM method to signal an alarm with a 1/1,000 exposure rate. However, for rates of exposure less than 1/1,000, a progressively longer period of time or larger sample are needed to detect a rate change by both methods. Our findings highlight the importance of enlarging the monitored population and correct case classification in birth defects surveillance.

Abnormalities, Drug-Induced↗
PubMed1997

Sample size requirements in case-only designs to detect gene-environment interaction.

With advances in molecular genetic technology, more studies will examine gene-environment interaction in disease etiology. If the primary purpose of the study is to estimate the effect of gene-environment interaction in disease etiology, one can do so without employing controls. The case-only design has been promoted as an efficient and valid method for screening for gene-environment interaction. The authors derive a method for estimating sample size requirements, present sample size estimates, and compare minimum sample size requirements to detect gene-environment interaction in case-only studies with case-control studies. Assuming independence between exposure and genotype in the population, the authors believe that the case-only design is more efficient than a case-control design in detecting gene-environment interaction. They also illustrate a method to estimate sample size when information on marginal effects (relative risk) of exposure and genotype is available from previous studies.

Case-Control Studies↗
PubMed1997

Separable Kvbeta subunit domains alter expression and gating of potassium channels.

Kvbeta subunits have been shown to affect kinetic properties of voltage-gated K+ channel Kv1alpha subunits and increase the number of cell surface dendrotoxin-binding sites when coexpressed with Kv1. 2. Here, we show that Kvbeta1.2 alters both current expression and gating of Kvalpha1 channels and that each effect is mediated by a distinct Kvbeta1.2 domain. The Kvbeta1.2 N terminus or Kvalpha1-blocking domain introduced steady state current block, an apparent negative shift in steady state activation, and a slowing of deactivation along with a dramatic reduction in single channel open probability. N-terminal deletions of Kvbeta1.2 no longer altered channel kinetics but promoted dramatic increases in Kv1.2 current. The conserved Kvbeta1 C terminus or Kvalpha1 expression domain alone was sufficient to increase the number of functional channels. The same effect was observed with the normally noninactivating subunit, Kvbeta2. By contrast, Kv1.5 currents were reduced when coexpressed with either the Kvbeta1 C terminus or Kvbeta2, indicating that the Kvalpha1 expression domain has Kvalpha1 isoform-specific effects. Our results demonstrate that Kvbeta subunits consist of two domains that are separable on the basis of both primary structure and functional modulation of voltage-gated K+ channels.

Animals↗
PubMed1997

Kinetic characterization of the strand separation ("helicase") activity of the DNA packaging enzyme from bacteriophage lambda.

Bacteriophage lambda is assembled from preformed viral capsids (proheads), tails, and genomes that are excised from a concatemeric DNA precursor. The enzyme responsible for insertion of the genome into the precapsid is known as terminase. This enzyme possesses site-specific endonuclease, ATPase, and DNA strand separation ("helicase") catalytic activities, which work in concert to excise and package a single viral genome during phage assembly. We have previously characterized the endonuclease [Tomka, M. A., & Catalano, C. E. (1993) J. Biol. Chem. 268, 3056-3065] and ATPase [Tomka, M. A., & Catalano, C. E. (1993) Biochemistry 32, 11992-11997] catalytic activities of lambda terminase and present here similar studies on the strand separation activity of the enzyme. Strand separation requires terminase, divalent metal, and adenosine nucleotides with a hydrolyzable beta,gamma-phosphate bond. Two apparent binding sites for ATP-mediated strand separation were identified, one of which appears to be distinct from the high- and low-affinity sites previously observed for ATP hydrolysis [Hwang, Y., Catalano, C. E., & Feiss, M. (1995) Biochemistry 35, 2796-2803]. Salt stimulates the reaction at low concentrations but is strongly inhibitory at elevated concentrations, presumably due to impaired DNA binding. The above results are identical with either a complex DNA mixture (a nicked, annealed DNA duplex in the presence of excess nonspecific DNA) or a purified DNA substrate; however, a kinetic analysis of the reaction revealed that the observed rate was approximately 5-fold greater with the purified DNA substrate. Moreover, while Escherichia coli integration host factor (IHF) stimulates terminase-mediated strand separation with both substrates, the observed stimulation is more pronounced with the complex DNA mixture (10-fold rate increase) than the purified DNA substrate (5-fold rate increase). Our data are consistent with a model where IHF binding to the terminase assembly site forms a binary protein.DNA complex readily distinguishable from bulk DNA. The implications of these results to the process of DNA packaging in bacteriophage lambda are discussed.

Adenosine Triphosphatases↗
PubMed1997

Seroreactivity to an envelope protein of human T-cell leukemia/lymphoma virus in patients with CD3- (natural killer) lymphoproliferative disease of granular lymphocytes.

Natural killer (NK) cells are CD3- large granular lymphocytes (LGL) responsible for immunity against viral infections. A chronic lymphoproliferative disorder of NK cells has been described in which the expanded NK cells display a restricted phenotype and cytotoxic activity. These data raise the hypothesis that proliferating LGL in these patients result from discrete expansions of NK cells responding to an unknown, perhaps viral, antigen. Recently, it was found that mice transgenic for the tax gene of human T-cell leukemia/lymphoma virus (HTLV) develop NK leukemia. Therefore, we studied 15 patients with chronic NK lymphoproliferative disorder for evidence of HTLV infection. Sera were tested using an HTLV-I/II-enzyme linked immunosorbent assay and a modified Western blot assay containing recombinant env proteins. None of the sera met conventional criteria for HTLV seroreactivity. However, sera from 11 patients (73%) reacted with the recombinant HTLV env protein p21E. The anti-p21E reactivity of these sera was then mapped employing the recombinant proteins GD21 and BA21. No reactivity to the immunodominant HTLV epitope GD21 was observed, suggesting that prototypical HTLV infection is unlikely in these patients. This was confirmed by finding no evidence for HTLV nucleic acids by PCR analyses employing primers specific for conserved regions in the env, pol, and pX genes. In contrast, 10 of the 15 sera reacted with the epitope BA21, documenting for the first time an association between a unique seroreactivity and disease. The high incidence of BA21 seroreactivity in these patients suggests that exposure to a protein containing homology to BA21 may be important in the pathogenesis of this lymphoproliferative disorder.

Animals↗
PubMed1997

The AT4 receptor agonist [Nle1]-angiotensin IV reduces mechanically induced immediate-early gene expression in the isolated rabbit heart.

Angiotensin II (ANG II), acting principally at the AT1 receptor, modulates mechanically-induced cardiac growth. The ANG II metabolite Angiotensin IV (ANG IV) has been shown to inhibit ANG II-induced mRNA and protein synthesis in chick cardiomyocytes. This effect did not involve the AT1 receptor, but was likely an action at the AT4 receptor. To determine if ANG IV also modulates a mechanically-induced cardiac growth response, we studied the effects of two AT4 receptor ligands, [Nle1]-ANG IV and [divalinal]-ANG IV, on mechanically-induced immediate-early gene expression (c-fos, egr-1, and c-jun) in the buffer perfused (30 degrees C), ejecting, isolated rabbit heart. Mechanical load alone (high systolic pressure and high end-diastolic volume) induced approximately 23-, 49- and 5-fold increases in c-fos, egr-1 and c-jun mRNA (in comparison to control hearts). Perfusion with [Nle1]-ANG IV (10[-10] mol/l) reduced the mechanically-induced expression of c-/fos and egr-1 by 42% and 48%, respectively (P < 0.05). Mechanically-induced c-jun expression was not significantly reduced. Perfusion with [divalinal]-ANG IV (10[-8] mol/l) had no effect on mechanically-induced immediate-early gene expression. We conclude that AT4 receptor agonism influences mechanical immediate-early gene expression, and propose the hypothesis that AT1 and AT4 receptors initiate opposing effects on mechanically-induced immediate-early gene expression in the isolated rabbit left ventricle.

Angiotensin II↗