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Biomedical subjects

H Yu

Publications and source records attributed to H Yu.

At least 235 records · Page 13Linked to original sources
PubMed2000

A case of progressive systemic sclerosis complicated by massive pleural effusion with elevated CA125.

A tumor marker, CA125, is known to increase in the serum or other body fluids in various malignancies such as ovarian cancer. Here we present a case of progressive systemic sclerosis (PSS) with massive pleural effusion, in which CA125 in the serum and pleural fluid were elevated. The serum level of CA125 decreased in accordance with the change of the pleural effusion. CA125 level may be an indicator for the activity of serositis in some cases with collagen vascular diseases.

CA-125 Antigen↗
PubMed2000

Human macrovascular endothelial cells: optimization of culture conditions.

The purpose of this study is to identify optimal culture conditions to support the proliferation of human macrovascular endothelial cells. Two cell lines were employed: human saphenous vein endothelial cells (HSVEC) and human umbilical vein endothelial cells (HUVEC). The influence of basal nutrient media (14 types), fetal bovine serum (FBS), and mitogens (three types) were investigated in relation to cell proliferation. Additionally, a variety of extracellular matrix (ECM) substrate-coated culture dishes were also tested. The most effective nutrient medium in augmenting cell proliferation was MCDB 131. Compared to the more commonly used M199 medium, MCDB 131 resulted in a 2.3-fold increase in cell proliferation. Media containing 20% FBS increased cell proliferation 7.5-fold compared to serum-free media. Among the mitogens tested, heparin (50 microg/ml) and endothelial cell growth supplement (ECGS) (50 microg/ml) significantly improved cell proliferation. Epithelial growth factor (EGF) provided no improvement in cell proliferation. There were no statistical differences in cell proliferation or morphology when endothelial cells were grown on uncoated culture plates compared to plates coated with ECM proteins: fibronectin, laminin, gelatin, or collagen types I and IV. The culture environment yielding maximal HSVEC and HUVEC proliferation is MCDB 131 nutrient medium supplemented with 2 mM glutamine, 20% FBS, 50 microg/ml heparin, and 50 microg/ml ECGS. The ECM substrate-coated culture dishes offer no advantage.

Animals↗
PubMed2000

Alternative pathways of cell death to circumvent pleiotropic resistance in myeloma cells: role of cytotoxic T-lymphocytes.

Pleiotropic resistance to treatment remains one of the major reasons for therapeutic failures in patients with multiple myeloma. Myeloma cells are frequently resistant to physiological inducers of cell death prior to chemotherapy. Moreover, in the course of treatment cells acquire a multidrug resistant (MDR) phenotype, making eradication of the tumor even more difficult. A necessary prerequisite for circumventing complex pleiotropic resistance is therefore defining the signaling pathways that execute death in myeloma cells. This review discusses evidence that cytokine-expressing autologous tumor cell vaccine may be an efficient tool for elimination of both intrinsically resistant myeloma cells as well as cells with acquired MDR in murine models. The vaccine was similarly potent against wild type cells that were resistant to several death receptor ligands, and their isogenic sublines selected for P-glycoprotein-mediated MDR. The anti-myeloma effect of the vaccine was mediated by granzyme B/perforin-secreting cytotoxic T-lymphocytes. This is an example of therapeutic strategy directed at utilizing death pathways that are preserved in pleiotropically resistant tumor cells.

Cell Death↗
PubMed2000

Heterogeneous populations of ES cells in the generation of a floxed Presenilin-1 allele.

Generation of a floxed Presenilin-1 (PS1) allele involved two recombination events in the embryonic stem (ES) cells. First, a targeting vector containing a loxP site in intron 1 and a floxed CMV-HYG/TK double selection cassette in intron 3 was integrated into the PS1 locus by homologous recombination. The use of a negative selection cassette, PGK-DTA, dramatically increased the recombination efficiency within the targeted locus (75-fold). Second, an expression vector encoding Cre recombinase was introduced to excise the floxed CMV-HYG/TK cassette via site-specific recombination. However, all five ES cell clones testing positive for the proper removal of the CMV-HYG/TK cassette also contained a proportion of ES cells in which recombination had occurred between the distal loxP sites in introns 1 and 3, resulting in excision of the entire floxed region. It is therefore critical to screen for possible recombination events involving all 3 loxP sites, in order to identify ES cells clones bearing high proportions of the desired ES cells. genesis 26:5-8, 2000.

Alleles↗
PubMed2000

Dramatic suppression of plasma and urinary prostate specific antigen and human glandular kallikrein by antiandrogens in male-to-female transsexuals.

PURPOSE: Prostate specific antigen (PSA) and human glandular kallikrein (hK2) are mainly produced by the prostate and their genes are regulated by androgens through the androgen receptor. We determine whether PSA and hK2 change significantly in plasma and urine after antiandrogen treatment in male-to-female transsexuals. MATERIALS AND METHODS: Plasma and urine PSA and hK2 were measured with highly sensitive immunofluorometric procedures capable of detecting within 1 or 6 ng./l. PSA or hK2, respectively. Study groups consisted of 10 men treated with cyproterone acetate only (group 1), 15 transdermal estradiol plus cyproterone acetate (group 2) and 31 ethinyl estradiol plus cyproterone acetate (group 3). Plasma and urine samples were collected before initiation of treatment as well as after 4 months of hormonal therapy. For a subset of group 3 patients blood and urine samples were also obtained after 12 months of treatment. RESULTS: Cyproterone acetate, a steroidal antiandrogen, alone or with estradiol was able to suppress greater than 90% of plasma and urinary PSA and hK2 concentration after 4 or 12 months of therapy. CONCLUSIONS: Cyproterone acetate therapy causes dramatic suppression of plasma and urinary PSA and hK2 in men without prostate cancer. Since cyproterone acetate is used for prostate cancer treatment, suppression of PSA after hormonal therapy may not accurately reflect therapy success in reducing tumor burden.

Adolescent↗
PubMed2000

Serum total and free prostate-specific antigen for breast cancer diagnosis in women.

Prostate-specific antigen (PSA) is a serine protease expressed at high levels in prostate epithelium, and elevated PSA in serum is a well-established marker of prostate cancer. Recently, the relative proportions of free PSA and PSA complexed to the serine protease inhibitor alpha 1-antichymotrypsin have become important variables in distinguishing between prostate cancer and benign prostatic hyperplasia. Numerous studies have demonstrated the production of PSA in female tissues such as the breast, and low levels of PSA are present in female sera. The objective of this study was to measure and compare the relative proportions of free PSA and PSA complexed to the serine protease inhibitor alpha 1-antichymotrypsin in the serum of women with breast cancer or benign breast disease or women with no known malignancies. PSA was measured with an established immunoassay for total PSA and a novel immunoassay for free PSA, both of which had a detection limit of 0.001 microgram/liter (1 ng/liter). The percentage of breast cancer patients with free PSA as the predominant molecular form (> 50% of total PSA) in serum was five times higher than that of healthy women or women with benign breast disease, and PSA decreased in the serum of breast cancer patients after surgery. The diagnostic use of free PSA for breast cancer is limited at this point, due to the low diagnostic sensitivity (approximately 20%); however, free PSA as the predominant molecular form shows a high diagnostic specificity (approximately 96%) in comparison to women free of breast cancer or with benign breast disease. These results suggest that the clinical applicability of free PSA for breast cancer diagnosis and the biological mechanism behind its increase should be further investigated.

Adult↗
PubMed2000

Serum and urinary prostate-specific antigen and urinary human glandular kallikrein concentrations are significantly increased after testosterone administration in female-to-male transsexuals.

BACKGROUND: The genes that encode prostate-specific antigen (PSA) and human glandular kallikrein (hK2) are up-regulated by androgens and progestins in cultured cells, but no published studies have described the effect of androgen administration in women on serum and urinary PSA or hK2. METHODS: We measured serum and urinary PSA and hK2 before, and 4 and 12 months post testosterone treatment by immunofluorometric methods in 32 female-to-male transsexuals. RESULTS: Mean serum PSA increased from 1.1 ng/L to 11.1 ng/L and then to 22 ng/L by 4 and 12 months post treatment, respectively; the corresponding mean values in urine were 17, 1420, and 18 130 ng/L, respectively. Serum hK2, another kallikrein closely related to PSA, remained undetectable at the three time points. However, urinary hK2 concentration rose from below the detection limit (<6 ng/L) before treatment to 18 and 179 ng/L by the 4th and the 12th month of treatment, respectively. All changes were statistically significant (P <0.001) at 4 months. CONCLUSIONS: Testosterone administration increases serum and urinary PSA and urinary hK2 in women. These measurements may be useful as indicators of androgenic stimulation in women.

Adolescent↗
PubMed2000

Cell proliferation, apoptosis, Bcl-2 and Bax expression in obstructed opossum early metanephroi.

PURPOSE: Complete ureteral obstruction (CUTO) in the fetal kidney induces tubular and glomerular cysts, interstitial fibrosis, and halts renal development. Previous studies have shown that apoptosis is a predominant mechanism in the chronically injured kidney following obstruction, but the precise cellular and molecular mechanisms are poorly understood. MATERIALS AND METHODS: We have used CUTO in opossum pups with early metanephric kidneys, sacrificed at two weeks, to evaluate the role of cell proliferation, apoptosis and apoptosis regulating genes, Bcl-2 and Bax. RESULTS: Obstructed fetal kidneys demonstrate high apoptosis in the renal pelvis and tubulointerstitium, compared with sham operated animals. Apoptosis is accompanied by statistically significant increased cell proliferation in the interstitium but not in tubules. Apoptosis in the tubules is accompanied by increased Bax and decreased Bcl-2 staining. In the nephrogenic zone apoptosis is increased, even though it is not statistically significant. Bcl-2 and Bax in the nephrogenic zone are unchanged compared with sham, but cell proliferation is increased. CONCLUSIONS: We suggest that abnormal patterns of cell kinetics may contribute to disease pathogenesis in the obstructed fetal kidney.

Animals↗
PubMed2000

Evidence for a dose-response effect between p53 (but not p21WAF1/Cip1) protein concentrations, survival, and responsiveness in patients with epithelial ovarian cancer treated with platinum-based chemotherapy.

The prognostic values of p53 and of its downstream mediator p21WAF1/Cip1 in patients receiving adjuvant chemotherapy for epithelial ovarian cancer have not been clearly established. Tumor extracts from a series of 120 patients treated postsurgically with cisplatin or carboplatin alone or together with other chemotherapeutics for primary ovarian carcinoma were assayed both for p53 protein by an immunofluorometric assay developed by us and for p21 protein by a commercially available immunoassay. Relative risks (RRs) for cancer relapse and death after 24 months of follow-up were determined by multivariate Cox regression analysis. Disease-free (DFS) and overall survival (OS) probabilities were also examined by the Kaplan-Meier method and log-rank tests. All other procedures were similarly nonparametric and based on two-sided tests of significance. Concentrations of p53 were elevated in patients with advanced stage disease (P = 0.02) or poorly differentiated (P = 0.03), suboptimally debulked tumors (P = 0.02), as well as in patients who failed to respond to chemotherapy (P = 0.03), as assessed by computed tomography scanning, serum CA125 determination, and second-look laparotomy. Statistically significant associations between concentrations of p53 and p21 were not found, nor were relationships demonstrated between concentrations of p21 and other clinicopathological variables or treatment response. Univariate analysis showed that p53 concentrations above the median indicated significantly higher risks for relapse (P = 0.04) and death (P < 0.01) and showed trends for increasing risks for relapse (P = 0.04) and death (P < 0.01) when p53 was considered as a four-level categorical variable. Multivariate analyses adjusted for age, stage, grade, and residual tumor size confirmed these observations (RR = 1.50; P = 0.05 for DFS and RR = 1.92; P = 0.03 for OS) for median-dichotomized p53, but the trends were of borderline significance (P = 0.09 for DFS and P = 0.07 for OS). In contrast, p21 positivity was not a significant predictor of favorable outcome in univariate survival analysis, and use of a three-level variable combining positivity or negativity status for both p53 and p21 did not yield greater separation of patients into risk groups (P = 0.07 for DFS and P = 0.06 for OS) than the use of p53 alone. Assessment of p53 expression may be an independent indicator of poor prognosis in ovarian cancer patients treated with adjuvant chemotherapy. The prognostic value of p21 expression, however, could not be demonstrated in our series of ovarian cancer patients.

Adult↗
PubMed2000

The molecular basis for the aberrant production of plasminogen activator inhibitor type 2 in THP-1 monocytes.

Plasminogen activator inhibitor type 2 (PAI-2) is a urokinase inhibitor that is expressed primarily in monocytes. THP-1 monocytes, however. contain a unique defect in the production of PAI-2 in that the PAI-2 transcript is truncated and the expressed protein inactive (1). Here we describe the basis of this mutation in THP-1 cells. Southern blot analysis of THP-1-derived genomic DNA indicated that there were no obvious deletions in the structure of the PAI-2 gene. However, assessment of the THP-1-derived PAI-2 transcript by RT-PCR indicated that only exons seven and eight of the normal PAI-2 mRNA could be detected. Cloning of the 5' region of the PAI-2 mRNA by 5-'RACE indicated that the PAI-2 cDNA derived from THP-1 cells is approximately 1329 bp long and contains 180 bp of sequence derived from intron 5. followed by sequences corresponding to exons seven and eight of the normal PAI-2 mRNA. The presence of the intron five fragment in endogenous THP-1 derived PAI-2 mRNA was confirmed by Northern blotting. The absence of any wild-type PAI-2 mRNA in these cells suggests that one copy of the PAI-2 allele has been deleted. The remaining allele producing the truncated mRNA appears to have undergone a translocation event and contains a mutation that has disrupted the splicing of the PAI-2 primary transcript.

Cloning, Molecular↗
PubMed2000

ABT-702 (4-amino-5-(3-bromophenyl)-7-(6-morpholinopyridin-3-yl)pyrido[2, 3-d]pyrimidine), a novel orally effective adenosine kinase inhibitor with analgesic and anti-inflammatory properties: I. In vitro characterization and acute antinociceptive effects in the mouse.

Adenosine (ADO) is an inhibitory neuromodulator that can increase nociceptive thresholds in response to noxious stimulation. Inhibition of the ADO-metabolizing enzyme adenosine kinase (AK) increases extracellular ADO concentrations at sites of tissue trauma and AK inhibitors may have therapeutic potential as analgesic and anti-inflammatory agents. ABT-702 is a novel and potent (IC(50) = 1. 7 nM) non-nucleoside AK inhibitor that has several orders of magnitude selectivity over other sites of ADO interaction (A(1), A(2A), A(3) receptors, ADO transporter, and ADO deaminase). ABT-702 was 1300- to 7700-fold selective for AK compared with a number of other neurotransmitter and peptide receptors, ion channel proteins, neurotransmitter/nucleoside reuptake sites, and enzymes, including cycloxygenases-1 and -2. ABT-702 was equipotent (IC(50) = 1.5 +/- 0. 3 nM) in inhibiting native human AK (placenta), two human recombinant isoforms (AK(long) and AK(short)), and AK from monkey, dog, rat, and mouse brain. Kinetic studies revealed that AK inhibition by ABT-702 was competitive with respect to ADO and noncompetitive with respect to MgATP(2-). AK inhibition by ABT-702 was demonstrated to be reversible after 4 h of dialysis. ABT-702 is orally active and fully efficacious in reducing acute somatic nociception (ED(50) = 8 micromol/kg i.p.; 65 micromol/kg p.o.) in the mouse hot-plate assay. ABT-702 also dose dependently reduced nociception in the phenyl-p-quinone-induced abdominal constriction assay. The antinociceptive effects of ABT-702 in the hot-plate assay were blocked by the nonselective ADO receptor antagonist theophylline, and by the A(1)-selective antagonist cyclopentyltheophylline (10 mg/kg i.p.), but not by a peripherally selective ADO receptor antagonist 8-(p-sulfophenyl)-theophylline (50 mg/kg i.p.), by the A(2A)-selective antagonist 3, 7-dimethyl-1-propargylxanthine (1 mg/kg i.p.) or the opioid antagonist naloxone (5 mg/kg i.p.). Thus, ABT-702 is a novel and potent non-nucleoside AK inhibitor that effectively reduces acute thermal nociception in the mouse by a nonopioid, non-nonsteroidal anti-inflammatory drug, ADO A(1) receptor-mediated mechanism.

Adenosine Kinase↗
PubMed2000

Allozyme diversity and population genetic structure of Pinus densata Master in northwestern Yunnan, China.

We investigated the levels and patterns of genetic diversity of Pinus densata Master in Yunnan. Horizontal starch-gel electrophoresis was performed on macrogametophytes collected from nine populations in northwestern Yunnan, China. Compared with other gymnosperm species, P. densata has higher mean values for all measures of genetic diversity. Allozyme polymorphism (0.99 criterion) was 97.0% and 71.4% at the species and population levels, respectively. The average number of alleles per locus was 3.1 and 2.0 at the species and population levels. Mean expected heterozygosity was substantially higher in P. densata than average values investigated for other gymnosperms both at the population (Hep = 0.174 +/- 0.031) and at the species (Hes = 0.190) levels. Of the total genetic variation, less than 12% was partitioned among populations (GST = 0.112). Our allozyme survey supports the suggestion that the observed higher diversity in P. densata may be attributed partly to its hybrid origin between two genetically distinct species, P. yunnanensis and P. tabulaeformis. In addition, we suggest that introgression would give rise to the increase in genetic diversity occurring in P. densata.

Alleles↗
PubMed2000

[Measure of vibration protection effect of driver's corset and analysis of its biomechanical effect].

The purpose of this study was to evaluate the vibration protection and biomechanical effect of driver's corset. The frequencies of vertfical and horizontal vibrations were measured at low back of driver. The vehicle driven was ISUZU truck (loading capacity 8 tons). Vibration of the driver's lumbar back was measured real time with wear corset and without wear corset when the truck loaded with 6 tons was driven at the spead of ten, thirty and sixty kilometers an hour on the asphalt road. The results showed: 1. Vibration frequencies at driver's low back was under 10 Hz. It is a low frequency vibration. 2. The value of vertical vibration was higher than the value of horizontal (back and forth) vibration. 3. The vibration value of wear corset was higher than un-wear corset. These indicate the driver's corset is effective for protecting lumbar spine by means of change in the biomechanical characteristics and the resonace requencies of lumbar spine. So the driver's corset is one of the good methods for preventing the back pain of drivers.

Automobile Driving↗
PubMed2000

[Determination of fructose-1,6-diphosphate with aldolase-DNPH by the colorimetric method].

This paper presents a modified method of enzymatic assay for Fructose-1,6-diphosphate(FDP). FDP is split to dihydroxyacetone phosphate (DAP) and glyceraldehyde-3-phosphate (GAP) by the action of aldolase. DAP is hydrolyzed at room temperature to free triose. Under alkaline conditions, the free triose is reacted with 2,4-dinitrophenylhydrazine (DNPH), yielding a 2,4-dinitrophenylhydrazine derivative which dissolve in alkali forming a purple color mixture, with maximum absorption at 540.nm. It is proportional to the contents of FDP. Because the method depends on the colorimetric determination of triose formed from fructose-1,6-diphosphate only by aldolase, glycerophosphate dehydrogenase/triosephosphate isomerase (GDH/TIM) and reduced nicotinamide adenine dinucleotide (NADH) which usually applied in multienzymatic method, are omitted in the modified method. The method is specific, convenient and accuracy for the determination of FDP.

Colorimetry↗
PubMed2000

Immunolocalization of uterine luminal fluid protein (ULF-250) in rat uterus.

OBJECTIVE: To access the production of a novel uterine luminal fluid 250 kD protein (ULF-250) during the various phases of the estrous cycle in relation to estrogen concentration, and to validate that the production and secretion of ULF-250 are regulated by estradiol and progesterone. METHODS: An immunohistochemical method was used to localize ULF-250 in rat uteri during each phase of the estrous cycle, and in uteri of ovariectomized rats treated with estradiol and progesterone. RESULTS: Positive immunostaining of ULF-250 occurred in the epithelial cells of the uterus at all phases of the estrous cycle; whereas the stroma was immunonegative. During the proestrus phase of the cycle, the glandular epithelial cells and glandular luminal content were stained strongly. During the estrus phase of the cycle, intense staining occurred in the glandular and uterine luminal epithelial cells, including the luminal content of the glands. In the metestrus phase of the cycle, only uterine epithelial cells were stained; during the diestrus phase, intense staining of the secreted contents of the uterine cavity and the glandular lumen occurred. The distribution of ULF-250 in the uteri of ovariectomized female rats treated with estradiol alone and estradiol plus progesterone were examined. In both groups, intense staining of the glandular luminal epithelial cells of the uterine endometrium occurred; in the estradiol-treated animals, only the luminal contents were stained. The present findings suggest that progesterone inhibits the secretion of ULF-250 that is stimulated by estradiol. CONCLUSIONS: ULF-250 is produced by the glandular and luminal epithelial cells of the uterine endometrium and fluctuates with the phases of the estrous cycle. Its production is stimulated by estradiol and its secretion is regulated by progesterone.

Animals↗
PubMed2000

[The imbalance of Th1/Th2 cytokine expression in peripheral blood mononuclear cell from asthmatic patients and the effect of erythromycin on these cytokines].

OBJECTIVE: To observe the state of Th1/Th2 cytokine expression in peripheral blood mononuclear cells (PBMCs) from asthmatic patients and the effect of erythromycin (Ery) on it. METHODS: 23 asthmatic patients and 10 healthy volunteers were included. The mRNA expression for Th1/Th2 cytokines in PBMC before and after the culture with Ery were detected by RT-PCR, considering IL-2 and IFN-gamma as Th1 cytokines, and IL-4, IL-6, IL-10 as Th2 ones. RESULTS: The positive rate of mRNA expression for Th2-derived IL-4, IL-6, IL-10 in the study group were 18/23, 19/23 and 10/23 respectively, and those for IFN-gamma and IL-2 produced by Th1 cells were 1/23 and 13/23, respectively. In the control group, the positive rate for IL-4, IL-6, IL-10 were 0/10, 2/10 and 1/10, respectively, and those for IL-2 and IFN-gamma were both 1/10. Comparing with the control group, the positive rate of mRNA expression for IL-4 and IL-6 in PBMC from asthmatic patients were significantly higher (P = 0.00003, 0.001 respectively). After the culture with Ery for 48 h, the positive rate for IL-4 expression in the study group decreased from 18/23 to 5/23 (P = 0.0006), and IL-6 from 19/23 to 9/23 (P = 0.006). The positive rate for IFN-gamma expression was elevated while IL-2 decreased(But both had no statistical significance). There was no difference observed before and after the culture with Ery in the control group. CONCLUSIONS: There is a predominant expression of Th2-type cytokines in PBMC from asthmatic patients. Ery can down-regulate the mRNA expression for IL-4 and IL-6 in asthmatic patients, and might convert the imbalance of Th1/Th2 cytokine expression in asthmatic patients.

Adult↗
PubMed2000

[The effect of methylenum coeruleum in laparoscope cholecystectomy].

OBJECTIVES: To help the operator correctly judge in operation the cystic gall duct and choledoch, and eliminate the operation wound. METHODS: To divide laparoscope cholecystectomy patients with the same weight at the same period into two groups: development group (589 cases) using methylenum coeruleum and conducting cholecysto-puncture visualization during the operation in which colors of cholecyst, cystic gall duct and choledoch turn blue; comparative group (553 cases) using regular laparoscope cholecystectomy. RESULTS: The two groups differed remarkably in operation time, complication, and transferring rate (P < 0.01). CONCLUSIONS: Methylenum coeruleum development technology in operation is a kind of visualization to help the operator judge in operation Calot triangular anatomy construction correctly, reduce the operation time obviously, and increase the rate of success.

Adult↗