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Biomedical subjects

Wei-Min Liu

Publications and source records attributed to Wei-Min Liu.

At least 19 recordsLinked to original sources
PubMed2007

Fluorescence turn on of coumarin derivatives by metal cations: a new signaling mechanism based on C=N isomerization.

[reaction: see text] A new sensing mechanism based on C=N isomerization, which shows a very significant fluorescence enhancement to the metal cations in a simple and efficient way, is demonstrated. A coumarin derivative (L) containing a C=N group was designed as an example for illustration. The free ligand L is almost nonfluorescent due to the isomerization of C=N double bond in the excited state. However, the solution of ligand shows about a 200-fold increase of fluorescence quantum yield (about 30%) upon addition of Zn(ClO4)2.

Journal Article↗
PubMed2006

Efficacy of combined laparoscopic uterine artery occlusion and myomectomy via minilaparotomy in the treatment of recurrent uterine myomas.

OBJECTIVE: To evaluate the therapeutic efficacy of laparoscopic uterine artery occlusion combined with myomectomy through a minilaparotomy in the treatment of recurrent uterine myomas, compared with myomectomy alone. DESIGN: Controlled, nonrandomized clinical study. SETTING: University-affiliated tertiary care referral center. PATIENT(S): Eighty-two women with symptomatic, recurrent myomas warranting surgical treatment, who expressed a strong desire to retain their uterus. Fifty-two patients (63.4%) underwent laparoscopic uterine artery occlusion and subsequent minilaparotomy and myomectomy (group I) and 30 patients (36.6%) underwent myomectomy alone (group II). INTERVENTION(S): Occlusion of the uterine arteries was performed with a laparoscopic approach before minilaparotomy and myomectomy. MAIN OUTCOME MEASURE(S): The efficacy of combined laparoscopic uterine artery occlusion and myomectomy via minilaparotomy in the treatment of recurrent uterine myomas was measured by comparing blood loss, need for blood transfusion, postoperative febrile morbidity, recurrence rate of the uterine myomas, and fertility rate in the treatment (group I) and control (group II) groups. RESULTS: The average blood loss was 125 +/- 72.6 and 550 +/- 394.8 mL in groups I and II, respectively. The recurrence rate of uterine myomas was 5.8% (3 of 52) in group I and 36.7% (11 of 30) in group II during an average follow-up period of 42.5 months. Of the sexually active patients who did not use contraception, 19.2% (5 of 26) and 22.4% (4 of 18) became pregnant in groups I and II, respectively (no statistical significance). CONCLUSION(S): This study has demonstrated the superiority of laparoscopic uterine artery occlusion when combined with repeat myomectomy in treating recurrent symptomatic myomas.

Adult↗
PubMed2006

Uterine artery ligation for treatment of pregnant women with uterine leiomyomas who are undergoing cesarean section.

OBJECTIVE: To evaluate the therapeutic effects of uterine artery ligation for pregnant women with uterine leiomyomas, who are undergoing cesarean section. DESIGN: Prospective clinical study without randomization. SETTING: University-affiliated tertiary referral center. PATIENT(S): Forty-eight women with uterine leiomyomas undergoing cesarean section for obstetric reasons were enrolled into the study. Diagnosis was established with ultrasound before or during early pregnancy. INTERVENTION(S): Ligation of the bilateral uterine arteries was performed immediately after closure of the uterine incision wound. MAIN OUTCOME MEASURE(S): Blood loss during cesarean section, dominant leiomyoma size, and future surgical intervention for symptomatic leiomyoma. RESULT(S): Twenty-six (54%) of 48 patients underwent uterine artery ligation during cesarean section (group I), and 22 (46%) received cesarean section only (group II). The average follow-up time was 38.5 months. The average blood loss during surgery was 254 +/- 92.3 mL for group I and 278 +/- 160.5 mL for group II. Hemoglobin on the first postoperative day was 11.2 +/- 0.9 g/dL for group I and 10.4 +/- 1.1 g/dL for group II. One patient in group II required blood transfusion due to hemorrhage. Two patients (7.7%) in group I and 9 (40.9%) in group II underwent myomectomy or hysterectomy for symptomatic leiomyomas within 6-38 months after cesarean section. Reductions in the dominant myoma size (average: 45%) were demonstrated in group I patients postoperatively. Four patients (15.4%) in group I and three (13.6%) in group II had a repeat cesarean section during the follow-up period. CONCLUSION(S): Uterine artery ligation appears to be a promising method for treating pregnant women with uterine leiomyomas, who are undergoing cesarean section, because it is able to reduce postpartum blood loss and minimize the necessity of future surgery. Fertility is apparently not compromised by this treatment, which offers obstetricians with another choice between observation and myomectomy for pregnant women with leiomyomas who are undergoing cesarean section.

Adult↗
PubMed2006

Keratinizing squamous cell carcinoma of the cervix in a sexually inexperienced woman: a case report.

BACKGROUND: Even though cervical cancer is largely considered to be a sexually transmitted disease with a viral etiology, other modes of transmission are theoretically possible. CASE: A 38-year-old woman with cervical squamous cell carcinoma adamantly denied having ever had sexual intercourse due to personal, religious and cultural beliefs. CONCLUSION: Because the human papillomavirus may be spread via nonsexual means, Pap smear screening in sexually active and inexperienced women is important.

Abdomen↗
PubMed2005

Expression and hormonal regulation of calcyclin-binding protein (CacyBP) in the mouse uterus during early pregnancy.

Calcyclin-binding protein (Siah-1-Interacting Protein, CacyBP/SIP), is a calcium signaling protein involved in the degradation of beta-catenin, however, little is known about its role in reproductive biology. The present study was to character its temporospatial expression pattern and regulation in mouse uterus and to investigate whether it plays a role in the regulation of normal endometrial events. While prominently expressed in both luminal and glandular epithelia, CacyBP underwent dynamic changes during early pregnancy. CacyBP expression was observed weakly from days 1-4. An intense accumulation in luminal and glandular epithelia as well as decidua surrounding the embryo at later stages (days 5-7) was observed. Most notably, CacyBP accumulation in trophoblast was pronounced at day 7. Using ovariectomized and pseudopregnant mice, we found that progesterone (P(4)) and 17beta-estradiol (E(2)) led to increased expression of CacyBP gene and this could be abolished by Ru486 and tamoxifen, respectively. Antisense oligonucleotides (ODNs) against CacyBP significantly inhibited cultured endometrial stromal cells' (ESCs) apoptosis induced by UV irradiation. Injection of antisense ODNs into mouse uterine horn severely impaired the number of implanted blastocysts. Taken together, our results suggested that CacyBP expression was positively regulated by P(4) and E(2). CacyBP may be involved in the regulation of endometrial cell apoptosis during early pregnancy and play an important role in mouse endometrial events such as pregrancy establishment.

Animals↗
PubMed2005

Leptin-directed embryo implantation: leptin regulates adhesion and outgrowth of mouse blastocysts and receptivity of endometrial epithelial cells.

Leptin is a 16-kDa multifunctional protein. Recent reports indicate that leptin is an important molecule during implantation and placentation, implicated in embryonic-maternal cross-talk and cytotrophoblast invasiveness, however, the role of leptin playing in the process of normal blastocyst implantation has not been well characterized. In the present study, the possible mechanisms of leptin playing in mouse blastocyst implantation were investigated. Leptin and receptor isoforms mRNAs were detected in whole mouse uteri during estrous cycle and peri-implantation periods. Immunofluorescent analysis further confirmed Ob-R protein was present in mouse uterus. The differential amounts of leptin and Ob-R isoforms suggested a role for leptin in such endometrial issues as blastocyst implantation. In vitro culture model for studying embryo implantation, leptin promoted mouse blastocyst adhesion and blastocyst outgrowth on fibronectin. Blastocysts treated with 300 ng/ml leptin had the greatest adhesion rate of 76.58+/-6.41% (P=0.046), and blastocysts treated with 30 ng/ml leptin had the greatest outgrowth rate of 78.64+/-8.48% (P=0.005). In isolated endometrial epithelial cells, leptin upregulated amounts of alpha v and beta 3 integrin, and promoted cell adhesion to such extracellular matrix proteins as fibronectin, laminin and type IV collagen, showing a dose- and time-dependent cell-adhesive capacity. Collectively, the information from the present study may partly account for leptin-induced mouse blatocyst implantation.

Animals↗
PubMed2004

Effect of 2-(3-carboxy-1-oxopropyl) amino-2-deoxy-D-glucose on human esophageal cancer cell line.

AIM: To determine whether 2-(3-carboxy-1-oxopropy1) amino-2-deoxy-D-glucose (COPADG), a derivative of D-amino-glucose, inhibited the growth of human esophageal cancer cell line Eca-109. METHODS: Effects of COPADG on Eca-109 cells cultured in RPMI 1640 medium were examined by a tetrazolium-based colorimetric assay (MTT assay). RESULTS: COPADG inhibited the growth of Eca-109 cells in a dose- and time-dependent manner; the maximum inhibition rate was 83.75%. CONCLUSION: COPADG can directly inhibit the proliferation of Eca-109 cells, which may serve as the experimental evidence for development of new drugs for esophageal cancer therapy.

Antineoplastic Agents↗
PubMed2004

Inhibition of the beta-catenin signaling pathway in blastocyst and uterus during the window of implantation in mice.

Beta-catenin, the mammalian homolog of Drosophila armadillo protein, was first identified as a cadherin-associated protein at cell-cell junctions. Another function of beta-catenin is the transduction of cytosolic signals to the nucleus in a variety of cellular contexts, which usually are elicited by the active form of beta-catenin. The aim of the present study was to examine the potential role of active beta-catenin in the mouse embryo and uterus during embryo implantation. Active beta-catenin was detected differentially in mouse embryos and uteri during the peri-implantation period. Aberrant activation of beta-catenin by LiCl, a well-known glycogen synthase kinase-3 inhibitor, significantly inhibited blastocyst hatching and subsequent adhesion and outgrowth on fibronectin. Results obtained from pseudopregnant and implantation-delayed mice imply an important role for implanting blastocysts in the temporal and spatial changes of active beta-catenin in the uterus during the window of implantation. Collectively, these results suggest that the beta-catenin signaling pathway is inhibited in both blastocyst and uterus during the window of implantation, which may represent a new mechanism to synchronize the development of preimplantation embryos and differentiation of the uterus during this process.

Animals↗
PubMed2004

Combining the uterine depletion procedure and myomectomy may be useful for treating symptomatic fibroids.

OBJECTIVE: To evaluate the therapeutic results of premyomectomy uterine depletion for the treatment of symptomatic fibroids, compared with myomectomy only. DESIGN: Controlled, clinical study without randomization. SETTING: University-affiliated tertiary referral center. PATIENT(S): Four hundred eighty-six women with symptomatic fibroids warranting surgical treatment and who wished to retain their uteri. INTERVENTION(S): Ligation of the uterine arteries was performed by either an abdominal or a laparoscopic approach before myomectomy. MAIN OUTCOME MEASURE(S): Operation time, intraoperative blood loss, postoperative improvement of symptoms, and recurrence rates of fibroids. RESULT(S): Of 342 women with pathology-confirmed fibroids who were included in the study, 108 received myomectomy only (group I), and 234 underwent the uterine depletion procedure followed by myomectomy (group II). Average blood loss was 250 +/- 132.5 mL for group I and 50 +/- 26.9 mL for group II. For patients with menorrhagia, 79 (84%) of 94 women in group I experienced complete resolution; all of the 194 women (100%) in group II had resolution within 2 months of surgery. The recurrence rate of ultrasound-confirmed fibroids was 19.4% (21 of 108) in group I and 0% in group II. Of the sexually active patients who were not using contraception, 50% (49 of 98) in group I and 37.5% (15 of 40) in group II had a live birth. CONCLUSION(S): This study demonstrates the value of uterine depletion before myomectomy for the management of patients with symptomatic fibroids. The procedure reduced blood loss during the operation, resulted in complete resolution of fibroid-related menorrhagia, and has the potential to prevent fibroid recurrence. Fertility capacity was apparently not compromised by this new treatment approach.

Adult↗
PubMed2004

Parallel genotyping of over 10,000 SNPs using a one-primer assay on a high-density oligonucleotide array.

The analysis of single nucleotide polymorphisms (SNPs) is increasingly utilized to investigate the genetic causes of complex human diseases. Here we present a high-throughput genotyping platform that uses a one-primer assay to genotype over 10,000 SNPs per individual on a single oligonucleotide array. This approach uses restriction digestion to fractionate the genome, followed by amplification of a specific fractionated subset of the genome. The resulting reduction in genome complexity enables allele-specific hybridization to the array. The selection of SNPs was primarily determined by computer-predicted lengths of restriction fragments containing the SNPs, and was further driven by strict empirical measurements of accuracy, reproducibility, and average call rate, which we estimate to be >99.5%, >99.9%, and>95%, respectively [corrected]. With average heterozygosity of 0.38 and genome scan resolution of 0.31 cM, the SNP array is a viable alternative to panels of microsatellites (STRs). As a demonstration of the utility of the genotyping platform in whole-genome scans, we have replicated and refined a linkage region on chromosome 2p for chronic mucocutaneous candidiasis and thyroid disease, previously identified using a panel of microsatellite (STR) markers.

Alleles↗
PubMed2004

High density DNA microarrays: algorithms and biomedical applications.

DNA microarrays are devices capable of detecting the identity and abundance of numerous DNA or RNA segments in samples. They are used for analyzing gene expressions, identifying genetic markers and detecting mutations on a genomic scale. The fundamental chemical mechanism of DNA microarrays is the hybridization between probes and targets due to the hydrogen bonds of nucleotide base pairing. Since the cross hybridization is inevitable, and probes or targets may form undesirable secondary or tertiary structures, the microarray data contain noise and depend on experimental conditions. It is crucial to apply proper statistical algorithms to obtain useful signals from noisy data. After we obtained the signals of a large amount of probes, we need to derive the biomedical information such as the existence of a transcript in a cell, the difference of expression levels of a gene in multiple samples, and the type of a genetic marker. Furthermore, after the expression levels of thousands of genes or the genotypes of thousands of single nucleotide polymorphisms are determined, it is usually important to find a small number of genes or markers that are related to a disease, individual reactions to drugs, or other phenotypes. All these applications need careful data analyses and reliable algorithms.

Algorithms↗
PubMed2003

Probe selection for high-density oligonucleotide arrays.

High-density oligonucleotide microarrays enable simultaneous monitoring of expression levels of tens of thousands of transcripts. For accurate detection and quantitation of transcripts in the presence of cellular mRNA, it is essential to design microarrays whose oligonucleotide probes produce hybridization intensities that accurately reflect the concentration of original mRNA. We present a model-based approach that predicts optimal probes by using sequence and empirical information. We constructed a thermodynamic model for hybridization behavior and determined the influence of empirical factors on the effective fitting parameters. We designed Affymetrix GeneChip probe arrays that contained all 25-mer probes for hundreds of human and yeast transcripts and collected data over a 4,000-fold concentration range. Multiple linear regression models were built to predict hybridization intensities of each probe at given target concentrations, and each intensity profile is summarized by a probe response metric. We selected probe sets to represent each transcript that were optimized with respect to responsiveness, independence (degree to which probe sequences are nonoverlapping), and uniqueness (lack of similarity to sequences in the expressed genomic background). We show that this approach is capable of selecting probes with high sensitivity and specificity for high-density oligonucleotide arrays.

Cell Line↗
PubMed2003

Pregnancy following treatment of symptomatic myomas with laparoscopic bipolar coagulation of uterine vessels.

BACKGROUND: Laparoscopic bipolar coagulation of uterine vessels (LBCUV) has been employed for women with symptomatic uterine myomas, but its effect on subsequent pregnancy has not been characterized. METHODS: Four-hundred and twenty-three women entered the study between March 1999 and December 2001. Of these, 142 women (33.6%) were under the age of 40 years at the time of LBCUV, 36 of whom (36/142, 25.3%) were sexually active without contraception. In a prospective study of 142 patients (<40 years old) undergoing LBCUV for symptomatic myomas, 15 women became pregnant (17 total pregnancies) and were evaluated by physical and ultrasound examinations. RESULTS: The volume of the dominant myoma was 117.4 +/- 118.4 and 36.8 +/- 56.8 cm(3) before and after LBCUV respectively. Volume of the dominant myoma after pregnancy was 46.2 +/- 76.7 cm(3) (mean +/- SD). There was a significant difference in myoma volume before and after LBCUV (P = 0.002), but no significant difference in myoma volume when comparing post-partum size with post-LBCUV size (P = 0.269). Pregnancy outcomes included seven miscarriages in the first trimester and one premature rupture of membrane (PPROM). Although the other pregnancies were regarded as uncomplicated, only two women were delivered of normal neonates as the other seven pregnancies were terminated secondary to patient request. CONCLUSIONS: The pregnancy and term pregnancy rates in sexually active women without contraception were 41.6% (15/36) and 5.6% (2/36) respectively. Because a relatively high rate (7/17, 41.2%) of early miscarriages was observed, we recommend that this procedure be employed only for women who do not desire additional children.

Abortion, Induced↗
PubMed2003

[Analysis of serum insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 in benign prostatic hyperplasia].

OBJECTIVES: To determine changes of insulin-like growth factor-1 (IGF-1) and IGF binding protein-3 (IGFBP-3) in serum samples from benign prostatic hyperplasia (BPH) patients and to evaluate the value of these molecules as possible etiologic factors for BPH. METHODS: The serum IGF-1 and IGFBP-3 levels were measured with immunoradiometric assay(IRMA) in 64 cases of BPH and in 30 healthy subjects as controls. The cases of BPH were divided into 3 groups according to the prostate volume(PV). There were 18 cases(PV < or = 30 ml) in group A, 24 cases(PV31 approximately 50 ml) in group B, 22 cases(PV > or = 50 ml) in group C. RESULTS: There were no statistical differences between the levels of Both IGF-1 and IGFBP-3 in BPH groups and healthy groups (both P > 0.05), but there were statistical differences among three groups of BPH. Both IGF-1 and IGFBP-3 levels in group C of BPH were significantly higher than those in group A (both P < 0.05). A positive correlation between the serum levels of IGF-1 and PV displayed(r = 0.58), as well as IGFBP-3 (r = 0.48). CONCLUSIONS: Together these observations implicate IGF-1 and IGFBP-3 as important factors during the progression of BPH. It shows the value of non-operation treatment for this disease.

Aged↗
PubMed2002

Comparison of two procedures for laparoscopic-assisted vaginal hysterectomy of large myomatous uteri.

STUDY OBJECTIVE: To evaluate whether laparoscopic bipolar coagulation of uterine vessels (LBCUV) and supracervical amputation improve laparoscopic-assisted vaginal hysterectomy (LAVH). DESIGN: Prospective, randomized, longitudinal study (Canadian Task Force classification II-1). SETTING: Private practice, university-affiliated hospital. PATIENTS: Sixty-four women (age 31-52 yrs) with symptomatic myomatous uteri larger than 12 weeks on bimanual examination. INTERVENTIONS: LAVH with or without LBCUV and laparoscopic supracervical amputation followed by trachelectomy. MEASUREMENTS AND MAIN RESULTS: LBCUV and laparoscopic supracervical amputation followed by trachelectomy and removal of the specimen vaginally were performed successfully in 29 women (group A). Hysterectomy was performed successfully in 32 comparable patients (group B) with severing of the round ligament, ovarian ligament, or infundibulopelvic ligament, and preparation of the bladder flap in the laparoscopic phase, and severing of uterine vessels and cardinal-uterosacral ligament complex through the vagina. Average blood loss was 169.8 and 308.7 ml in groups A and B, respectively (p <0.05); average operating time was 126.4 and 152.8 minutes, respectively (p <0.05); hemoglobin decreased on average 0.9 and 1.7 g/100 ml, respectively (p <0.05). Conclusion. LBCUV and laparoscopic supracervical amputation followed by trachelectomy reduce operating time and blood loss in LAVH, and allow conversion of many abdominal procedures to laparoscopy.

Adult↗