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Biomedical subjects

Y C Wu

Publications and source records attributed to Y C Wu.

At least 19 recordsLinked to original sources
PubMed2001

Bullatacin, a potent antitumor annonaceous acetogenin, inhibits proliferation of human hepatocarcinoma cell line 2.2.15 by apoptosis induction.

Bullatacin, isolated from the fruit of Annona atemoya, is one of the most potentially effective antitumor annonaceous acetogenins. Bullatacin was studied here for its ability to inhibit the proliferation of 2.2.15 cells, hepatitis B virus (HBV) DNA transfected human hepatocarcinoma cell line. It was found that bullatacin induced cytotoxicity of 2.2.15 cells in a time- and dose-dependent manner. Fifty percent effective dose (ED50) on day 1 of exposure to bullatacin were 7.8 +/- 2.5 nM for 2.2.15 cells. [3H]-Thymidine incorporation assays showed almost the same results. Bullatacin-treatment also reduced concentrations of hepatitis B surface antigen (HBsAg) in the cultured medium released from 2.2.15 cells, coincident with the decrease in the cell proliferation. Analysis of mophological changes of bullatacin-treated 2.2.15 by inverted phase-contrast microscope and eletron microscopy revealed a possible model of action for bullatacin to inhibit proliferation of 2.2.15 cells by inducing apoptosis. Most of the bullatacin-induced cell death was found to be due to apoptosis, as determined by double staining with fluorescein-isothiocyanate (FITC)-labeled annexin V and propidium iodide (PI).

Annexin A5↗
PubMed2001

Minimal access thoracic surgery for esophageal hemangioma.

Esophageal hemangioma is a rare tumor. This report describes the case of a 69-year-old woman with an esophageal tumor at the middle portion of the esophagus. The patient was successfully treated with minimal access thoracic surgery, and at the 6 month follow-up, the patient was free of any symptoms or recurrence.

Aged↗
PubMed2001

Laparoscopic bipolar coagulation of uterine vessels: a new method for treating symptomatic fibroids.

OBJECTIVE: To evaluate the effects of laparoscopic bipolar coagulation of uterine vessels in treating symptomatic fibroids. DESIGN: Prospective clinical study. SETTING: University-affiliated tertiary referral center. PATIENT(S): Eighty-seven women with symptomatic fibroids warranting surgical treatment and wanting to retain their uteri. INTERVENTION(S): Laparoscopic bipolar coagulation of uterine arteries and anastomotic sites of uterine arteries with ovarian arteries. MAIN OUTCOME MEASURE(S): Percentage reduction in the dominant fibroid size and clinical response evaluation. RESULT(S): Eighty-five (97.7%) of 87 patients underwent technically successful laparoscopic coagulation of uterine vessels without intraoperative complications. The mean follow-up time was 10.2 months. Symptomatic improvement was reported in 76 (89.4%) of 85 patients, including 18 (21.2%) with complete resolution of symptoms. Significant reductions in the dominant fibroid size (average, 76%) and the uterine volume (average, 46%) were sonographically demonstrated. Two patients conceived 4 and 9 months, respectively, after treatment. Three (3.5%) premenopausal women became postmenopausal postoperatively. CONCLUSION(S): Laparoscopic bipolar coagulation of uterine vessels appears to be a promising new method for treating fibroid-related menorrhagia and pelvic pain.

Adult↗
PubMed2001

Successful treatment of symptomatic arteriovenous malformation of the uterus using laparoscopic bipolar coagulation of uterine vessels.

OBJECTIVE: To report a case of symptomatic arteriovenous malformation (AVM) of the uterus that was successfully treated with laparoscopic bipolar coagulation of uterine vessels. DESIGN: Case report. SETTING: University-affiliated tertiary referral center. PATIENT(S): A 66-year-old woman with symptomatic AVM of the uterus. INTERVENTION(S): Laparoscopic bipolar coagulation of uterine vessels. MAIN OUTCOME MEASURE(S): Clinical symptoms, color Doppler sonographic examination, and pelvic magnetic resonance imaging. RESULT(S): Remarkable shrinkage of the lesion size, obvious decrease in all of the impedance measurements (pulsatility, resistance, velocity indexes [systolic/diastolic]), and freedom from symptoms. CONCLUSION(S): This modality is a new alternative method for the management of patients with symptomatic AVM of the uterus who do not respond to conservative treatment.

Aged↗
PubMed2001

Four alkaloids from Annona cherimola.

Four alkaloids, annocherine A, annocherine B, cherianoine, and romucosine H, along with one known alkaloid, artabonatine B, were isolated from the MeOH extract of the stems of Annona cherimola. Their structures were identified on the basis of both analysis of their spectral data and from chemical evidence.

Alkaloids↗
PubMed2001

Antiplatelet activity of N-methoxycarbonyl aporphines from Rollinia mucosa.

Bioassay-directed fractionation of the stems of Rollinia mucosa led to the isolation of new N-methoxycarbonyl aporphine alkaloids, romucosine A (1), romucosine B (2), romucosine C (3), and romucosine D (4), along with the known alkaloid, N-methoxylcarbonyl-nornuciferine (5). Alkaloids 1 and 4 exhibited significant inhibition of collagen, arachidonic acid, and platelet activating factor-induced platelet aggregation, and alkaloid 3 also showed an inhibitory effect on arachidonic acid induced platelet aggregation.

Alkaloids↗
PubMed2001

Vaginal expulsion of submucous myomas after laparoscopic-assisted uterine depletion of the myomas.

STUDY OBJECTIVE: To determine the safety and side effects that may be caused by laparoscopic-assisted uterine depletion (LAUD) of submucous myomas. DESIGN: Retrospective chart review and follow-up (Canadian Task Force classification II-2). SETTING: University-affiliated tertiary referral center. PATIENTS: Five hundred twenty women with symptomatic myomas warranting surgical treatment, who wished to retain their uteri. INTERVENTION: Laparoscopic bipolar coagulation of uterine arteries and anastomotic sites of uterine arteries with ovarian arteries. MEASUREMENTS AND MAIN RESULTS: Postoperative sonographs showed submucous myomas in 53 (10.2%) women. During follow-up for a mean of 8.6 months very few complications occurred; however, nine women (1.7%) experienced vaginal expulsion of myomas from 2 weeks to 5 months postoperatively. Four of them were readmitted within 43 days with high fever and fetid discharge, and cervical cultures revealed heavy growth of Escherichia coli in three. Vaginal myomectomy was performed in six patients, and one woman passed the myoma spontaneously. Histopathologic studies of these nine specimens showed that two had infarction, three had coagulative necrosis, and four had degeneration. After treatment, all nine women had normal menstruation and their symptoms resolved during follow-up of at least 3 months. CONCLUSION: In our experience LAUD led to satisfactory symptomatic improvement and reduction in myoma volume and few complications. If vaginal expulsion of submucous fibroids can be viewed as a side effect, we should pay close attention to women with submucous myomas, especially within 2 months of LAUD. Otherwise, more dangerous complications could occur.

Adult↗
PubMed2001

C. elegans CED-12 acts in the conserved crkII/DOCK180/Rac pathway to control cell migration and cell corpse engulfment.

We have identified and characterized a novel C. elegans gene, ced-12, that functions in the conserved GTPase signaling pathway mediated by CED-2/Crkll, CED-5/DOCK180, and CED-10/Rac to control cell migration and phagocytosis of apoptotic cells. We provide evidence that ced-12 likely acts upstream of ced-10 during cell migration and phagocytosis and that CED-12 physically interacts with CED-5 and forms a ternary complex with CED-2 in vitro. We propose that the formation and localization of a CED-2-CED-5-CED-12 ternary complex to the plasma membrane activates CED-10, leading to the cytoskeletal reorganization that occurs in the polarized extension of cell surfaces in engulfing cells and migrating cells. We suggest that CED-12 counterparts in higher organisms regulate cytoskeleton dynamics, as CED-12 does in C. elegans.

Amino Acid Sequence↗
PubMed2001

Cytotoxic constituents of the fruits of Cananga odorata.

A new guaipyridine sesquiterpene alkaloid, cananodine (1), and two new eudesmane sesquiterpenes, cryptomeridiol 11-alpha-L-rhamnoside (2) and gamma-eudesmol 11-alpha-L-rhamnoside (3), along with gamma-eudesmol (4), were isolated from the fruits of Cananga odorata. The structures of compounds 1-3 were established on the basis of NMR and MS methods. In addition, compounds 1-4 and four previously reported alkaloids, cleistopholine (5), N-trans-feruloyltyramine (6), (+)-ushinsunine-beta-N-oxide (7), and lyscamine (8), were evaluated for cytotoxicity against two human hepatocarcinoma cell lines.

Acetylation↗
PubMed2001

Novel cytotoxic annonaceous acetogenins from Annona muricata.

Seven new annonaceous acetogenins, muricins A-G (1-7), as well as five known compounds, a mixture of muricatetrocin A (8) and muricatetrocin B (9), longifolicin (10), corossolin (11), and corossolone (12), were isolated from the seeds of Annona muricata. The structures of all isolates were elucidated and characterized by spectral and chemical methods. These acetogenins showed significantly selective in vitro cytotoxicities toward the human hepatoma cell lines Hep G(2) and 2,2,15.

Antineoplastic Agents, Phytogenic↗
PubMed2001

The alkaloids of Artabotrys uncinatus.

A novel type of alpha,beta-butenolide alkaloid, uncinine (1), two novel oxoaporphines, artabonatine C (2) and artabonatine D (3), a new oxazoloaporphine, artabonatine E (4), and a new 7,7'-bisdehydroaporphine, artabonatine F (5), along with 25 known alkaloids, were isolated from Artabotrys uncinatus. The structures of 1-5 were determined using NMR and mass spectral data. Atherospermidine and squamolone exhibited cytotoxicity against hepatocarcinoma cancer cell lines (Hep G(2) and 2,2,15), and the activity of some of the alkaloids in an antithrombin assay is also discussed.

Alkaloids↗
PubMed2001

Mechanical effects of liriodenine on the left ventricular-arterial coupling in Wistar rats: pressure-stroke volume analysis.

1. In a recent in vivo study, liriodenine, an aporphine alkaloid, has been identified as a prominent anti-arrhythmic agent that can prevent rats' sudden deaths, even at the dose as low as 10(-7) g kg(-1). The aim of this study was to determine whether liriodenine at its effective anti-arrhythmic dose of 10(-7) g kg(-1) had effects on the left ventricular (LV)-arterial coupling in Wistar rats. 2. LV pressure and ascending aortic flow signals were recorded to construct the ventricular and arterial end-systolic pressure-stroke volume relationships to calculate LV end-systolic elastance (E(es)) and effective arterial volume elastance (E(a)), respectively. The optimal afterload (Q(load)) determined by the ratio of E(a) to E(es) was used to measure the optimality of energy transmission from the left ventricle to the arterial system. 3. Liriodenine at the dose of 10(-7) g kg(-1) showed no significant changes in basal heart rate (HR), cardiac output (CO), LV end-systolic pressure (P(es)), E(a), E(es), and Q(load). 4. By contrast, liriodenine at the dose of 10(-6) g kg(-1) produced a significant fall of 2.0% in HR and a significant rise of 5.8% in CO, but no significant change in P(es). Moreover, liriodenine administration of 10(-6) g kg(-1) to rats significantly decreased E(es) by 8.5% and E(a) by 10.6%, but did not change Q(load). 5. We conclude that liriodenine at the dose of 10(-7) g kg(-1) has no effects on the mechanical properties of the heart and the vasculature and the matching condition for the left ventricle coupled to its vasculature in rats. Even at 10 times the effective anti-arrhythmic dose, liriodenine shows no effects on the efficiency of energy transferred from the left ventricle to the arterial system.

Analysis of Variance↗
PubMed2001

Duodenal reflux induces cyclooxygenase-2 in the esophageal mucosa of rats: evidence for involvement of bile acids.

BACKGROUND & AIMS: Reflux of duodenal contents including bile acids is believed to contribute to esophageal injury and Barrett's esophagus. Cyclooxygenase (COX)-2, an inducible form of COX, has been implicated in both inflammation and carcinogenesis. In this study, we investigated the effects of bile acids and duodenal reflux on COX-2 expression in cultured esophageal cells and tissue, respectively. METHODS: Immunoblotting and Northern blotting were used to assess the effects of bile acids on COX-2 expression in esophageal cell lines. Immunoblotting and immunohistochemistry were performed to evaluate the effects of duodenal reflux on COX-2 expression and cell proliferation in esophageal tissue. RESULTS: Unconjugated bile acids were about fivefold more potent inducers of COX-2 messenger RNA, COX-2 protein, and prostaglandin synthesis than conjugated bile acids. Acidifying the culture medium sensitized esophageal cells to bile acid-mediated induction of COX-2. The induction of COX-2 by bile acids was mediated by phosphatidylinositol-3 kinase and extracellular signal-regulated kinase 1/2 mitogen-activated protein kinases. In experimental animals, duodenoesophageal reflux led to esophagitis, marked thickening of the esophageal mucosa, and enhanced expression of COX-2. Increased immunoreactivity for Ki-67 and cyclin D1 indicated that enhanced cell proliferation contributed to mucosal thickening. CONCLUSIONS: Reflux of duodenal contents into the esophagus led to increased COX-2 expression and mucosal thickening. Bile acids are likely to contribute to these effects.

Animals↗
PubMed2001

Flow cytometry compared with indirect immunofluorescence for rapid detection of dengue virus type 1 after amplification in tissue culture.

Dengue virus (DV) was detected early in infected mosquito C6/36 cells by using indirect immunofluorescence (IF) in conjunction with flow cytometry. Three fixation-permeabilization methods and three DV serotype 1 (DEN-1)-specific monoclonal antibodies, 8-8 (anti-E), 16-4 (anti-NS1), and 15F3-1 (anti-NS1), were evaluated for the detection of DEN-1 in infected C6/36 cells. We found that these three monoclonal antibodies were capable of detecting DV in C6/36 cells as early as 24 h postinoculation by using a conventional indirect IF stain. Both 8-8 and 16-4 detected DV earlier and showed a greater number of DV-positive cells than 15F3-1. In flow cytometry, 3% paraformaldehyde plus 0.1% Triton X-100 with 16-4, the best fixation-permeabilization method for testing DV, showed higher sensitivity (up to 1 PFU) than indirect IF stain. The higher sensitivity of 16-4 in detecting DEN-1 was found with both IF and flow cytometry. Flow cytometry, which had a sensitivity similar to that of nested reverse transcription-PCR, was more sensitive in detecting DV in the infected mosquito cells 10 h earlier than the conventional IF stain. When clinical specimens were amplified in mosquito C6/36 cells and then assayed for DV using flow cytometry and conventional virus isolation at day 7 postinfection, both methods had 97.22% (35 out of 36) agreement. Moreover, among 12 positive samples which were detected by conventional culture method, the flow cytometry assay could detect DV in 58.33% (7 out of 12) of samples even at day 3 postinfection. In conclusion, both monoclonal antibodies 8-8 and 16-4 can be used for the early detection of DEN-1-infected C6/36 cells, with 16-4 (anti-NS1) being the best choice for the rapid diagnosis of DV by both the IF staining and flow cytometry methods.

Animals↗
PubMed2001

A novel mutation in the calcium-sensing receptor gene in a Chinese subject with persistent hypercalcemia and hypocalciuria.

Familial hypocalciuric hypercalcemia (FHH) is an autosomal dominant disorder characterized by high penetrance of relatively benign, lifelong persistent hypercalcemia and hypocalciuria. By contrast, neonatal severe hyperparathyroidism represents a life-threatening form of hypercalcemia that can cause the early newborn mortality if immediate intervention is not undertaken. Both disorders are due to inactivation mutation of the human calcium-sensing receptor (CaSR) gene on chromosome 3q21-24. Up to now, more than 30 mutations in the CaSR gene associated with FHH have been described. In this study, we analyzed one 79-yr-old male with hypocalciuric hypercalcemia without siblings or children to compare with an additional group of 50 normal Chinese subjects in Taiwan. DNA sequence analysis of the CaSR gene was performed. The result showed that the proband had a heterozygous nonsense mutation in exon 7 of the CaSR gene at codon 648 (CGA-->TGA/Arg-->Ter). This mutation, located in the COOH-terminal of the first intracellular loop of the CaSR, predicts a markedly truncated protein. We have identified a novel R648X mutation in the CaSR gene in one patient with FHH in Taiwan

Aged↗
PubMed2001

UCN-01 suppresses E2F-1 mediated by ubiquitin-proteasome-dependent degradation.

E2F-1 regulates the transcription of genes required for DNA synthesis. Previously, we have reported that UCN-01 suppresses E2F-1 protein expression without any noticeable effect on its mRNA level in gastric cancer cell line SK-GT5 (Clin. Cancer Res., 4: 2201-2206, 1998). In this study, we investigated the mechanism responsible for the suppression of E2F-1 expression by UCN-01 in SK-GT5 cells. After 24-h exposure to 1 microM UCN-01, E2F-1 protein expression was decreased by >99%. The suppressive effect of UCN-01 could be reversed by ubiquitin-dependent proteasome inhibitors such as calpain inhibitor I and lactacystin. Transfection experiments using expression plasmids encoding full-length E2F-1 or truncated E2F-1 with deletion of the COOH-terminal region (which is required for eliciting ubiquitination and protein degradation) revealed that the expression of truncated E2F-1 was not affected by UCN-01. Other cell-cycle-related and ubiquitin-proteasome-regulated proteins such as p21, p27, and cyclin B1 were not repressed by UCN-01 in E2F-1-overexpressing cells. In vitro-translated, full-length E2F-1 degraded more rapidly upon incubation with extracts from UCN-01-treated cells when compared with truncated E2F-1. Taken together, these data indicate that UCN-01 suppresses E2F-1 protein expression mediated by the ubiquitin-proteasome pathway in a specific manner.

Acetylcysteine↗
PubMed2000

NUC-1, a caenorhabditis elegans DNase II homolog, functions in an intermediate step of DNA degradation during apoptosis.

One hallmark of apoptosis is the degradation of chromosomal DNA. We cloned the Caenorhabditis elegans gene nuc-1, which is involved in the degradation of the DNA of apoptotic cells, and found that nuc-1 encodes a homolog of mammalian DNase II. We used the TUNEL technique to assay DNA degradation in nuc-1 and other mutants defective in programmed cell death and discovered that TUNEL labels apoptotic cells only during a transient intermediate stage. Mutations in nuc-1 allowed the generation of TUNEL-reactive DNA but blocked the conversion of TUNEL-reactive DNA to a subsequent TUNEL-unreactive state. Completion of DNA degradation did not occur in the absence of cell-corpse engulfment. Our data suggest that the process of degradation of the DNA of a cell corpse occurs in at least three distinct steps and requires activities provided by both the dying and the engulfing cell.

Animals↗