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Biomedical subjects

Y S Yang

Publications and source records attributed to Y S Yang.

At least 37 records · Page 2Linked to original sources
PubMed2001

Distribution of Th1 and Th2 cell populations in human peripheral and decidual T cells from normal and anembryonic pregnancies.

OBJECTIVE: To examine whether maternal immune responses during normal pregnancy are Th2 biased and whether there are specific changes when anembryonic pregnancy occurs. DESIGN: Prospective study. SETTING: Department of Obstetrics and Gynecology at a university hospital. PATIENT(S): We studied 32 pregnant women receiving elective abortions of normal pregnancies and 35 women with anembryonic pregnancies between 6 weeks and 10 weeks of gestational age. INTERVENTION(S): Using the multilabeling capability of three-color flow cytometry, it is possible to measure intracellular cytokines and cell surface markers simultaneously to determine which cells are the cytokine-producing cells. MAIN OUTCOME MEASURE(S): We examined the extent and proportion of mononuclear cells expressing specific T-cell surface markers and cytokines, interferon gamma, and interleukin 4 in the peripheral blood and deciduae. Secreted cytokines in the supernatants after 24-hour culture were also compared. RESULT(S): During the unstimulated status, the proportion of IL-4-secreting cells significantly exceeded that of IFN-gamma-secreting cells in the peripheral blood and decidua in normal pregnancies and was significantly decreased when anembryonic pregnancies occurred. Consequently, the Th1/Th2 ratios were increased during anembryonic pregnancies. However, after 24-hour culture, only another Th2-type cytokine, IL-10, was markedly increased and exceeded IFN-gamma secretion in cultures from both the peripheral blood and decidua in normal pregnancies. CONCLUSION(S): The decidual T lymphocytes are Th2 predominant. When anembryonic pregnancy occurs, this Th2 predominance disappears.

Cytokines↗
PubMed2001

Maternal serum C-reactive protein level does not change significantly after fetal reduction: it could be used as an indicator of chorioamnionitis.

PURPOSE: This study was aimed at investigating the diagnostic value of maternal serum C-reactive protein (CRP) in the recognition of chorioamnionitis in patients undergoing fetal reduction. METHODS: Seventy-one gravidas with high-order multifetal pregnancies, including 46 with triplets, 18 with quadruplets, and 7 with quintuplets, who underwent transabdominal fetal reduction to twins during the 10th-14th gestational week were recruited. The subjects were followed up clinically and ultrasonographically 1 week and 1 month after fetal reduction for signs of infection, premature uterine contraction, and premature rupture of the membranes CRP levels were measured prior to fetal reduction and at follow-up examinations, and were compared. RESULTS: Among the 71 mothers, 65 (92%) were normal after fetal reduction. The CRP levels were not significantly different prior to the procedure (0.27 +/- 0.26 mg/dL), and 1 week (0.23 +/- 0.24 mg/dL) and 1 month (0.24 +/- 0.20 mg/dL) later. There was no correlation between the number of fetuses reduced and the CRP levels. Six (8%) experienced leakage of amniotic fluid after fetal reduction. Three patients had normal CRP levels at that time and at the following tests. The pregnancies continued smoothly after conservative treatment. The other three patients had elevated CRP levels when leakage of amniotic fluid occurred. Fever and uterine irritability developed subsequently despite parenteral antibiotics and tocolytic therapy. Daily checks showed increasing CRP levels. The pregnancies were aborted, and the histology of the placental membranes revealed chorioamnionitis with infiltration of acute inflammatory cells. CONCLUSIONS: The absorption of inactive gestational tissue after fetal reduction did not affect CRP levels. CRP may be used as a marker of intrauterine infection after fetal reduction.

C-Reactive Protein↗
PubMed2001

Mouse embryo toxicity of IL-6 in peritoneal fluids from women with or without endometriosis.

BACKGROUND: To determine whether there is a factor (or factors) in the peritoneal fluid of endometriosis patients that impairs embryo growth and embryo implantation. METHODS: Growth and development of two-cell mouse embryos which were cultured in media with peritoneal fluid from women with or without endometriosis and interleukin-1-beta (IL-1beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) levels in conditioned media were measured. RESULTS: The blastocyst rate in the non-endometriosis group was 46.4 +/- 31.1%, and that of the endometriosis group was 54.6 +/- 28.7%. Logistic regression analysis using the criteria of blastocyst development in 454 embryos, showed that the peritoneal fluid from endometriosis could promote (p=0.015) but IL-6 could arrest embryo growth to blastocyst (p=0.025). IL-1beta and TNF-alpha levels had no significant effect on blastocyst formation. CONCLUSION: Peritoneal fluid from women with endometriosis was not toxic to mouse embryo development. However, IL-6 in the peritoneal fluid deteriorated the growth and development of mouse embryos.

Adult↗
PubMed2001

Torsion of the previously normal uterine adnexa. Evaluation of the correlation between the pathological changes and the clinical characteristics.

BACKGROUND: Treatment of adnexal torsion remains a clinical dilemma when future fertility is wanted. The purpose of this study was to evaluate the correlation between the pathological changes and the clinical characteristics on patients having torsion of the previously normal uterine adnexa which may help us decide whether detorsion is worthwhile. METHODS: A retrospective study of 69 patients undergoing surgical intervention for adnexal torsion was performed. Among them, 13 patients diagnosed with torsion of the previously normal adnexa were identified. Their clinical and pathological features were compared. RESULTS: Extensive hemorrhagic necrosis of the twisted ovary was observed in five patients, and each of them had their duration of torsion last 48 hours or longer. Three of 13 cases (23.1%) with torsion of the previously normal adnexa had local thrombus formation within the twisted adnexa. Their duration of torsion varied from 18 hours to 288 hours. CONCLUSIONS: The likelihood of preserving viable ovarian tissue is significantly decreased if the duration of torsion lasts 48 hours or longer. Local thrombus formation in the twisted adnexa cannot be predicted simply from the duration of torsion.

Adnexa Uteri↗
PubMed2001

Increase in the production of interleukin-10 early after implantation is related to the success of pregnancy.

PROBLEM: To study the correlation of interleukin (IL)-10, IL-11 leukemia inhibitory factor (LIF), placental growth factor (PIGF), and transforming growth factor (TGF)-beta and outcome of human pregnancy. METHOD OF STUDY: We prospectively measured the serum levels of these cytokines in patients undergoing in vitro fertilization (IVF) programs. A total of 60 women (non-pregnant, n = 27; early abortions, n = 12; normal pregnancies, n = 21) were enrolled. RESULTS: There was no difference in the cytokines studied on D0 and D14 among the three groups of women. The increase in PIGF from D0 to D14 after human chorionic gonadotropin (hCG) injection was greater in pregnant women than in non-pregnant women; however, the difference did not reach significance (P = 0.068). The increase in IL-10 production from D14 to D21 was significant in women with successful pregnancies compared to women in the abortion group. CONCLUSIONS: This increase in IL-10 may be important in sustaining a normal pregnancy early after implantation.

Embryo Implantation↗
PubMed2001

Vitrification of mouse oocytes using closed pulled straws (CPS) achieves a high survival and preserves good patterns of meiotic spindles, compared with conventional straws, open pulled straws (OPS) and grids.

BACKGROUND: We modified the loading of pulled straws into a new closed system, called closed pulled straws (CPS) for holding oocytes for vitrification. The morphological survival, dynamics of meiotic spindles, and fertilization in vitro of vitrified oocytes using CPS were compared with conventional straws, open pulled straws (OPS), and grids. METHODS: Surviving oocytes were stained for spindles and chromosomes after 1, 2 and 3 h incubations, and compared with controls. The capacity of fertilization and embryonic cleavage were examined in vitro. RESULTS: The survival rates of the CPS (79%) and straw (77%) groups were significantly higher (P < 0.05) than the OPS (63%) and grid (39%) groups. At a 1h incubation, vitrified oocytes of four groups had significantly fewer normal spindles than controls (P < 0.05). The straw group was inferior to the others in spindle morphology (P < 0.05). After a 3 h incubation, recovery of vitrified oocytes with normal spindles was significantly improved in all groups (P < 0.05). The percentages of fertilization and blastocyst formation of vitrified oocytes after a 1 h incubation was significantly lower than controls (P < 0.05), but they were improved after 2 or 3 h incubations (P < 0.05). CONCLUSIONS: Oocytes vitrified using CPS, OPS or grids could lessen spindle injuries and expedite recuperation. The survival using OPS or grids is lower. Sufficient culture time for recovery of meiotic spindle would be imperative for fertilization events of vitrified oocytes. CPS has the advantages of achieving a high survival and preserving good spindles.

Animals↗
PubMed2001

Automatic identification of human helminth eggs on microscopic fecal specimens using digital image processing and an artificial neural network.

In order to automate routine fecal examination for parasitic diseases, we propose in this study a computer processing algorithm using digital image processing techniques and an artificial neural network (ANN) classifier. The morphometric characteristics of eggs of human parasites in fecal specimens were extracted from microscopic images through digital image processing. An ANN then identified the parasite species based on those characteristics. We selected four morphometric features based on three morphological characteristics representing shape, shell smoothness, and size. A total of 82 microscopic images containing seven common human helminth eggs were used. The first stage (ANN-1) of the proposed ANN classification system isolated eggs from confusing artifacts. The second stage (ANN-2) classified eggs by species. The performance of ANN was evaluated by the tenfold cross-validation method to obviate the dependency on the selection of training samples. Cross-validation results showed 86.1% average correct classification ratio for ANN-1 and 90.3% for ANN-2 with small variances of 46.0 and 39.0, respectively. The algorithm developed will be an essential part of a completely automated fecal examination system.

Algorithms↗
PubMed2001

BR22, a novel protein, interacts with thyroid transcription factor-1 and activates the human surfactant protein B promoter.

Surfactant protein (SP)-B expression is restricted to type II pneumocytes and Clara cells in the lung. Previously, a promoter region of human SP-B gene from -64 to -118 has been identified as critical for the tissue-specific expression of this gene. Two cis-elements for thyroid transcription factor (TTF)-1 and hepatocyte nuclear factor (HNF)-3alpha binding were found within this area. Using an oligonucleotide fragment, we incorporated this region sequence into the promoter of a HIS3 reporter gene in yeast. With this modified yeast a human lung complementary DNA (cDNA) library was screened for DNA-binding proteins, other than TTF-1 and HNF-3alpha, that interacted with this promoter segment. A cDNA clone encoding a novel polypeptide, BR22, was identified that activated the reporter gene expression in yeast. This gene is expressed in many tissues and encodes a protein with bipartite nuclear localization signals. Studies using in vivo yeast two-hybrid analysis, in vitro protein-protein interactions, and coimmunoprecipitation analyses demonstrated that BR22 formed a protein complex with TTF-1. In vivo cotransfection studies further indicated that BR22 could act with TTF-1 to synergistically activate the SP-B promoter in mammalian cells. Our data suggest that BR22 is a TTF-1-associated protein. Through a protein-protein interaction with TTF-1, BR22 can form a complex and activate the human SP-B promoter in vivo.

Amino Acid Sequence↗
PubMed2001

Cre stoplight: a red/green fluorescent reporter of Cre recombinase expression in living cells.

The Cre/lox system is a powerful genetic tool with which to manipulate the genome. Here, we describe the development of a simple reporter system for Cre recombinase, called the Cre Stoplight. In the absence of Cre, the red fluorescent protein is expressed; when Cre catalyzes a recombination event, the green fluorescent protein is produced. Testing this system in transiently transfected cells showed that it produced robust signals (90% of the cells converted from red to green) when equal amounts of the plasmids encoding Cre recombinase and the Cre Stoplight were used. A 1:100 ratio of enzyme to reporter plasmid produced similar results, and a 1:10000 ratio was necessary to significantly reduce the number of cells converting to green (1%).

Cell Line↗
PubMed2001

5-fluorouracil-induced leukoencephalopathy in patients with breast cancer.

The purpose of this study is to determine the characteristic clinical features, radiologic findings, and precipitating and prognostic factors in the patients with breast cancer and with 5-Fluorouracil (5-FU)-induced leukoencephalopathy. We reviewed the medical records of six breast cancer patients who developed leukoencephalopathy after chemotherapy which included 5-FU and also evaluated thorough neurological examinations including mini-mental status examination, cerebrospinal fluid studies, brain images and brain biopsies. Six patients exhibited slowly progressing neurologic symptoms characterized by the impairment of cognitive function, abulia, ataxic gait, and/or akinetic mutism. None of the patients had any specific causes or etiologic factors for leukoencephalopathy. Brain MRI in all patients showed diffuse periventricular white matter changes in the T2-weighted MR image. Brain biopsy in Patient 1 showed fragmented axonal fiber and minimally deprived myelination with many scattered macrophages. Five patients who treated with steroids at the onset of neurological symptoms showed clinical improvement, regardless of their age, sex, the pathology and stage of breast cancer, or the total dosage of chemotherapeutic agents. We conclude that leukoencephalopathy in these cases could be attributable to 5-FU neurotoxicity and suggest that the administration of steroids might be the treatment of choice.

Adenocarcinoma, Mucinous↗
PubMed2001

Epidemiological significance of sero-positive inhabitants against sparganum in Kangwon-do, Korea.

Sparganum is a plerocercoid of pseudophyllidean tapeworms, Diphyllobothrium or Spirometra spp. Human sparganosis is endemic mainly in East and Southeast Asian countries where the custom of eating raw snake or frog meat, or poulticing with snake's skin exists. From January 1995 to November 1999, an epidemiological survey was undertaken to evaluate the serum levels of anti-sparganum specific IgG antibodies in Whachon-gun residents, Korea. An enzyme- linked immunosorbent assay (ELISA) and immunoblot analysis of the sera from 316 subjects were used. In addition, a stool examination from 416 inhabitants and questionnaires regarding the consumption of raw meat were given. Out of 416 inhabitants examined coprologically, one was infected with Clonorchis sinensis and two were infected with Metagonimus spp. The sera from 36 inhabitants (11.4 %) showed a positive reaction to the sparganum antigen. Out of these 36 inhabitants, the sera from 25 people were examined 7, 19, and 50 months later. The sera were found to still show positive reactions without any remarkable changes of anti-sparganum specific antibody titers except for one. An analysis of the questionnaires suggested that a history of eating of raw snakes or frogs was important risk factor for clinical or covert sparganosis (odd ratio=15.6 and 3.1, respectively).

Adolescent↗
PubMed2001

Comparative study of daily activities of pregnant and non-pregnant women after in vitro fertilization and embryo transfer.

BACKGROUND AND PURPOSE: The purposes of this study were to explore daily activity following embryo transfer (ET) in women who had undergone in vitro fertilization (IVF), and to compare the differences between pregnant and non-pregnant cycles. METHODS: This prospective survey was conducted in a medical center in northern Taiwan. Subjects were women who had completed one IVF cycle. Using a structured questionnaire, the subjects were asked whether they had changed their normal daily activities during the 2-week waiting period following ET. Data were collected on the day of ET and on the day of pregnancy testing before the outcome of the treatment was known. After the results of the pregnancy test were known, subjects were divided into pregnant and non-pregnant groups, with 30 subjects in each group. RESULTS: Of the 60 participants, 56 reported that they had tried to rest in bed for more than 2 hours following ET, and 54 reported that they limited their self-care activity on the day of ET. During the 2-week waiting period following ET, 55 walked at a slow pace, 51 limited their social activity, 47 avoided the use of stairs, 45 limited their self-care activity, and 40 adjusted their work load. However, a comparison of daily activity variables between the two groups yielded no significant differences. CONCLUSIONS: Most subjects reported that they restricted their daily activities following IVF/ET, even though their doctors suggested that they return to their normal routines. Bed rest was not correlated with successful IVF.

Activities of Daily Living↗
PubMed2001

Elevated E2: oocyte ratio in women undergoing IVF and tubal ET. Correlation with a decrease in the implantation rate.

OBJECTIVE: To investigate the influence of various estradiol (E2): oocyte ratios on reproductive outcome in women undergoing in vitro fertilization and tubal embryo transfer (IVF-TET). STUDY DESIGN: Two hundred seven women undergoing 251 IVF-TET cycles were recruited in this retrospective study. All the women received a flare-up gonadotropin releasing hormone agonist (GnRHa) protocol to achieve ovarian hyperstimulation. Oocyte retrieval was performed 34-36 hours after human chorionic gonadotropin (hCG) injection, followed by TET two days later. RESULTS: An E2: oocyte ratio > or = 350 pg/mL had a higher E2 level (2,213 +/- 2,258 vs. 1,553 +/- 972 pg/mL, P < .05) and fertilization rate (77 +/- 23 vs. 64 +/- 23%, P < .001) but a lower oocyte number (4.8 +/- 4.7 vs. 7.6 +/- 4.8, P < .001) than in those with a ratio < 350 pg/mL. The pregnancy (17.9% vs. 32.8%, P = .03) and implantation (5.3% vs. 12.9%, P = .008) rates were significantly decreased in cycles with an E2: oocyte ratio > or = 350 pg/mL as compared to those with a ratio < 350 pg/mL. CONCLUSION: IVF-TET cycles with an elevated E2: oocyte ratio correlated with lower pregnancy and implantation rates. The poor reproductive outcome possibly was due to the relatively high E2 concentration, which might have a detrimental effect on endometrial receptivity.

Buserelin↗
PubMed2001

Effectiveness of postoperative adjuvant therapy in improving reproductive outcome of endometriosis-associated infertility.

BACKGROUND AND PURPOSE: Treatment of endometriosis-associated infertility has not yet become standardized. Various protocols including surgical treatment, medical therapy, and a combination of both have been suggested but their use remains controversial. The objective of the present study was to determine whether postoperative adjuvant therapy for endometriosis is effective in improving reproductive outcome. METHODS: Medical records of infertile patients with newly diagnosed endometriosis treated in a university teaching hospital during a 50-month period were reviewed. After exclusion of patients with other major infertility factors, a total of 209 patients were included in the retrospective analysis. These patients were divided into those receiving (n = 78) or not receiving (n = 131) peri- or postoperative adjuvant medical therapy. The adjuvant therapies included danazol (n = 62), gonadotropin releasing hormone analogues (n = 11), progestins (n = 3), oral contraceptives (n = 1), and mixed treatment (n = 1). RESULTS: The pregnancy rate was lower in those receiving adjuvant therapy, although this result was not significant (32.1% vs 45.8%; p = 0.05). When patients using postoperative danazol therapy were considered alone, the pregnancy rate in patients receiving adjuvant therapy was significantly lower than that in patients not receiving it (p = 0.047). When the stage of endometriosis was considered, the pregnancy rate in patients receiving adjuvant therapy was again lower than in those not receiving it in patients with minimal or mild endometriosis (42.9% vs 60%; p = 0.043). However, in patients with moderate or severe endometriosis, the pregnancy rate was not different in the two groups (31% vs 36%; p = 0.56). Postoperative assisted reproductive techniques (ART) including controlled ovarian hyperstimulation/intrauterine insemination (COH/IUI) and in vitro fertilization (IVF) were effective in improving the pregnancy rates for all patients (53.9% with ART vs 33.1% without; p = 0.003) and for patients with advanced endometriosis (47.7% with ART vs 27.2% without; p = 0.016). CONCLUSIONS: Our results suggest that postoperative adjuvant therapy is ineffective in improving reproductive outcome in patients with either early (minimal or mild) or advanced (moderate and severe) endometriosis. This finding suggests that if fertility is the goal of treatment, adjuvant therapy may be unnecessary after surgery. In contrast, our data suggest that empirical ART, including COH/IUI or IVF, may be a better alternative to improve the pregnancy outcome after surgery.

Adult↗
PubMed2001

[Assessment of velopharyngeal function in normal speech by CT].

OBJECTIVE: To find an objective method to assess velopharyngeal function by CT. METHODS: Three dimensional conformation of the velopharyngeal orifice of 30 subjects with normal speech at rest and /i:/ position were observed and analyzed. The linear distance and area of velopharyngeal orifice were measured and analyzed statistically. RESULTS: The average minimal area of velopharyngeal orifice at/i:/ position was 11.92+/-11.73 mm(2). The physical RVPI was 4.03+/-4.03%. Coronary closure was the most common type of velopharyngeal contraction which accounted for 50%, semi-ring type being 30%, and ring type being 20%. No sagittal closure were seen in this study. There were 70% subjects whose position of velopharyngeal closure was at the level of the first cervical vertebra, 26.7% above the level and 3.3% below it. The arrange of velopharyngeal closure was 9-12 mm in 83.4% subjects, and 3-6mm in 16.6%. CONCLUSION: As a method of assessing velopharyngeal function, CT can not only observe the conformation of velopharyngeal orifice in three dimensions, but also quantitatively analyze the velopharyngeal function.

English Abstract↗
PubMed2000

Solution structure and activity of the synthetic four-disulfide bond Mediterranean mussel defensin (MGD-1).

MGD-1 is a 39-residue defensin-like peptide isolated from the edible Mediterranean mussel, Mytilus galloprovincialis. This peptide is characterized by the presence of four disulfide bonds. We report here its solid-phase synthesis and an easy way to improve the yield of the four native disulfide bonds. Synthetic and native MGD-1 display similar antibacterial activity, suggesting that the hydroxylation of Trp28 observed in native MGD-1 is not involved in the antimicrobial effect. The three-dimensional solution structure of MGD-1 has been established using (1)H NMR and mainly consists of a helical part (Asn7-Ser16) and two antiparallel beta-strands (Arg20-Cys25 and Cys33-Arg37), together giving rise to the common cystine-stabilized alpha-beta motif frequently observed in scorpion toxins. In MGD-1, the cystine-stabilized alpha-beta motif is stabilized by four disulfide bonds (Cys4-Cys25, Cys10-Cys33, Cys14-Cys35, and Cys21-Cys38), instead of by the three disulfide bonds commonly found in arthropod defensins. Except for the Cys21-Cys38 disulfide bond which is solvent-exposed, the three others belong to the particularly hydrophobic core of the highly constrained structure. Moreover, the C4-P5 amide bond in the cis conformation characterizes the MGD-1 structure. MGD-1 and insect defensin A possess similar bactericidal anti-Gram-positive activity, suggesting that the fourth disulfide bond of MGD-1 is not essential for the biological activity. In agreement with the general features of antibacterial peptides, the MGD-1 and defensin A structures display a typical distribution of positively charged and hydrophobic side chains. The positively charged residues of MGD-1 are located in three clusters. For these two defensin peptides isolated from insects and mollusks, it appears that the rather well conserved location of certain positively charged residues and of the large hydrophobic cluster are enough to generate the bactericidal potency and the Gram-positive specificity.

Amino Acid Motifs↗
PubMed2000

Nucleotide binding and sulfation catalyzed by phenol sulfotransferase.

The sulfation of a nucleotide is an indispensable step for the sulfuryl group transfer in a biological system. The product and cosubstrate of sulfotransferase in physiological condition are adenosine 3',5'-bisphosphate (PAP) and 3'-phospho adenosine 5'-phosphosulfate (PAPS), respectively. We find that ribose and adenine, two major parts of the adenosine nucleotide, bind tightly to phenol sulfotransferase (PST) separately, and various nucleotides also bind tightly to PST. We determine the dissociation constants of a variety of nucleotides and examine their potential as cofactors or cosubstrates of PST. Using 4-nitrophenyl sulfate as the sulfuryl group donor, three nucleotides, adenosine 5'-monophosphate (AMP), adenosine 2',5'-bisphosphate (2',5'-PAP), and adenosine 2':3'-cyclic phosphate 5'-phosphate (2':3'-cyclic PAP), are shown here for the first time to be sulfated at 5'-phopho position by a PST catalyzed reaction. Spectrophotometry, HPLC, and (31)P NMR are used to determine the activity of PST and identify the sulfated nucleotides. The V(max) of PST and K(m) of these nucleotides are determined when they are used as cofactors or cosubstrates for the sulfuryl group transfer. The existence and possible physiological significance of these newly reported binding and sulfation of nucleotides by PST in biology is yet to be discovered.

Adenosine Diphosphate↗