82 results on '"Chou, M M"'
Search Results
52. Growth of M- and A-plane GaN on LiGaO2 by plasma-assisted MBE.
- Author
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Schuber, R., Chou, M. M. C., Vincze, P., Schimmel, Th., and Schaadt, D. M.
- Subjects
- *
GALLIUM nitride , *LITHIUM compounds , *MOLECULAR beam epitaxy , *ANNEALING of semiconductors , *PLASMA gases , *SEMICONDUCTOR films , *SURFACE chemistry - Abstract
We have performed non-polar M- and A-plane GaN growth on LiGaO2 (LGO) by plasma-assisted molecular beam expitaxy (MBE). We demonstrate that non-polar GaN growth on LGO yields high phase purity and flat surfaces. We find that annealing of the substrates prior to growth is a suitable method for avoiding a peeling off of the film from the substrate after growth. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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53. Termination of pathological pregnancy in second and early third trimesters with extraamniotic instillation of 16-phenoxy-omega-tetranor prostaglandin E~2 methylsulfonylamide
- Author
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Hwang, S. F., Chou, M. M., and Ho, E. S. C.
- Published
- 1994
- Full Text
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54. Characterization of coal chars from a flash pyrolysis process by cross polarization/magic angle spinning {sup}1{sup}3C NMR
- Author
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Chou, M. M., Dickerson, D. R., Frye, J. S., and McKay, D. R.
- Subjects
COAL ,NUCLEAR magnetic resonance - Published
- 1984
- Full Text
- View/download PDF
55. Authors' response Re: Some concerns regarding aortic cross-clamping in caesarean hysterectomy for placenta accreta spectrum (Re: Vascular control by infrarenal aortic cross-clamping in placenta accreta spectrum disorders: description of technique; something old, something new & something borrowed).
- Author
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Chou MM, Su HW, Chen MJ, Kung HF, Tseng JJ, Chen WC, Chen YF, and Yuan JC
- Subjects
- Aorta, Abdominal surgery, Cesarean Section, Constriction, Female, Humans, Hysterectomy, Pregnancy, Placenta Accreta surgery
- Published
- 2021
- Full Text
- View/download PDF
56. Authors' reply re: Vascular control by infrarenal aortic cross-clamping in placenta accreta spectrum disorders: description of technique.
- Author
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Chou MM, Su HW, Chen MJ, Kung HF, Tseng JJ, Chen WC, and Chen YF
- Subjects
- Cesarean Section, Constriction, Female, Humans, Pregnancy, Placenta Accreta diagnostic imaging, Placenta Accreta surgery, Placenta Previa
- Published
- 2021
- Full Text
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57. Anisotropic photoluminescence of nonpolar ZnO epilayers and ZnO/Zn 1-x Mg x O multiple quantum wells grown on LiGaO 2 substrate.
- Author
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Yan T, Trinkler L, Korsaks V, Lu CJ, Berzina B, Chang L, Chou MMC, and Ploog KH
- Abstract
The temperature-dependent polarized photoluminescence spectra of nonpolar ZnO samples were investigated by 263 nm laser. The degree of polarization (DOP) of m-plane quantum wells changes from 76% at 10 K to 40% at 300 K, which is much higher than that of epilayer. The strong anisotropy was presumably attributed to the enhanced confinement effect of a one-dimension confinement structure formed by the intersection of quantum well and basal stacking fault. The polarization of laser beam also has an influence on the DOP. It is assumed that the luminescence polarization should be affected not only by the in-plane strains but also the microstructural defects, which do modify the electronic band structure.
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- 2020
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58. Visfatin-induced expression of inflammatory mediators in human endothelial cells through the NF-kappaB pathway.
- Author
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Lee WJ, Wu CS, Lin H, Lee IT, Wu CM, Tseng JJ, Chou MM, and Sheu WH
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- Cells, Cultured, E-Selectin metabolism, Endothelial Cells metabolism, Endothelium, Vascular metabolism, Enzyme-Linked Immunosorbent Assay, Humans, Intercellular Adhesion Molecule-1 metabolism, Interleukin-6 metabolism, Interleukin-8 metabolism, NF-kappa B metabolism, Umbilical Veins cytology, Up-Regulation drug effects, Vascular Cell Adhesion Molecule-1 metabolism, Cell Adhesion Molecules metabolism, Endothelial Cells drug effects, Endothelium, Vascular drug effects, Inflammation Mediators metabolism, Nicotinamide Phosphoribosyltransferase pharmacology
- Abstract
Background: Visfatin is an adipokine that is highly expressed in visceral fat. Plasma levels of visfatin have been reported to be higher in subjects with obesity and/or type 2 diabetes mellitus. However, the role of visfatin in endothelial dysfunction has been largely unexplored., Objectives: We investigated the possible pathogenic role of visfatin in endothelial dysfunction, particularly focusing on its effect on inflammatory mediators., Design: Primary human umbilical vein endothelial cells (HUVECs) pretreated with visfatin (1, 10 and 50 ng ml(-1)) were used to study the relationship between visfatin and endothelium dysfunction. Expressions of adhesion molecules (ICAM-1, VCAM-1 and E-selectin) and cytokines (interleukin (IL)-6 and IL-8) affected by visfatin were investigated by enzyme-linked immunosorbent assay, flow cytometry and real-time PCR. Activity of nuclear factor (NF)-kappaB was examined by electrophoretic mobility shift assay., Results: At a visfatin concentration of 50 ng ml(-1), significant increases in IL-6, IL-8, ICAM-1, VCAM-1 and E-selectin gene expression along with increased IL-6, IL-8 and sE-selectin protein levels in the conditioned medium were detected. Flow cytometry showed that the addition of visfatin significantly increased ICAM-1 expression and VCAM-1 expression (10 and 50 ng ml(-1), respectively). Electrophoretic mobility shift assay confirmed that visfatin increased the DNA-binding activity of NF-kappaB. In addition, pretreatment with visfatin (10 and 50 ng ml(-1)) increased human monocyte cell line THP-1 adhesion to HUVECs., Conclusions: Our findings suggest that visfatin causes endothelial dysfunction by increasing inflammatory and adhesion molecule expression at least partly through the upregulation of NF-kappaB activity.
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- 2009
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59. Differential expression of vascular endothelial growth factor, placenta growth factor and their receptors in placentae from pregnancies complicated by placenta accreta.
- Author
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Tseng JJ, Chou MM, Hsieh YT, Wen MC, Ho ES, and Hsu SL
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- Female, Humans, Immunohistochemistry, Ki-67 Antigen metabolism, Placenta Growth Factor, Pregnancy, Pregnancy Proteins genetics, RNA, Messenger genetics, RNA, Messenger metabolism, Receptors, Vascular Endothelial Growth Factor genetics, Vascular Endothelial Growth Factor A genetics, Gene Expression Regulation, Placenta Accreta metabolism, Pregnancy Proteins metabolism, Receptors, Vascular Endothelial Growth Factor metabolism, Vascular Endothelial Growth Factor A metabolism
- Abstract
Placenta accreta is a pregnancy complication characterized by the presence of life-threatening uteroplacental neovascularization. The factors involving its development are unknown. Vascular endothelial growth factor (VEGF), placenta growth factor (PlGF) and their receptors (VEGFR) have important roles in vascular remodeling. We have investigated the differential expression of these proteins in placentae from placenta accreta (cases) and normal placentation (controls). Immunohistochemically, the expression of VEGFR-2 in the syncytiotrophoblast was significantly lower in cases than in controls during both the second and third trimesters (P = 0.005 and 0.002, respectively). However, VEGFR-2 expression in the cytotrophoblastic and extravillous trophoblastic cells and VEGFR-1, -3 and Ki-67 in the trophoblast populations were not significantly different between controls and cases (P > 0.05). Ki-67 immunostaining also showed that endothelial cells of the larger vessels were stained weaker in normal placenta than in placenta accreta. The majority of VEGFR-2 expression, as demonstrated by Western blot or reverse transcription polymerase chain reaction, was consistent with the immunohistochemical findings in the syncytiotrophoblast. Furthermore, enzyme-linked immunosorbent assay in the placental lysates showed that the women with placenta accreta demonstrated significantly higher VEGF (P = 0.001) and lower soluble VEGFR-2 (P = 0.015) concentrations than did women with normal pregnancy. PlGF and soluble VEGFR-1 levels did not show any significance in study groups (P > 0.05). These observations suggest that the participation of up-regulated VEGF and down-regulated VEGFR-2 (both membrane-bound and soluble forms) may be associated with the development of placenta accreta.
- Published
- 2006
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60. Caspase-mediated cleavage of the TIAM1 guanine nucleotide exchange factor during apoptosis.
- Author
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Qi H, Juo P, Masuda-Robens J, Caloca MJ, Zhou H, Stone N, Kazanietz MG, and Chou MM
- Subjects
- 3T3 Cells, Animals, Binding Sites, Blood Proteins chemistry, COS Cells, Cell Line, Cell Membrane metabolism, Ceramides metabolism, Ceramides pharmacology, Enzyme Activation, GTP Phosphohydrolases metabolism, Guanine Nucleotide Exchange Factors, Humans, Immunoblotting, JNK Mitogen-Activated Protein Kinases, Jurkat Cells, Luciferases metabolism, Mice, Microscopy, Fluorescence, Mitogen-Activated Protein Kinase 8, Mitogen-Activated Protein Kinases metabolism, Neoplasm Proteins, PC12 Cells, Phosphoproteins chemistry, Precipitin Tests, Protein Structure, Tertiary, Rats, Serum Response Factor metabolism, Signal Transduction, T-Lymphoma Invasion and Metastasis-inducing Protein 1, Time Factors, Tumor Cells, Cultured, rac GTP-Binding Proteins metabolism, Apoptosis, Caspases metabolism, Proteins metabolism
- Abstract
Rho family GTPases Rac and Cdc42 are pivotal regulators of apoptosis in multiple cell types. However, little is known about the mechanism by which these GTPases are regulated in response to apoptotic stimuli. Here, we demonstrate that TIAM1, a Rac-specific guanine nucleotide exchange factor, is cleaved by caspases during apoptosis. TIAM1 cleavage occurs in multiple cell lines in response to diverse apoptotic stimuli such as ceramide, Fas, and serum deprivation. Processing occurs at residue 993 of TIAM1 and removes the NH(2)-terminal of TIAM's two pleckstrin homology domains, leaving a stable fragment containing the Dbl homology and COOH-terminal pleckstrin homology domains. This leads to functional inactivation of TIAM1, as determined by failure of the cleavage product to stimulate GTP loading of Rac in vivo. Furthermore, this product is defective in signaling to two independent Rac effectors, c-Jun NH(2)-terminal kinase and serum response factor. Finally, we demonstrate that in cells treated with ceramide, cleavage of TIAM1 coincided with the inactivation of endogenous Rac. These results reveal a novel mechanism for regulating guanine nucleotide exchange factor activity and GTPase-mediated signaling pathways.
- Published
- 2001
61. Three-dimensional color power Doppler imaging in the assessment of uteroplacental neovascularization in placenta previa increta/percreta.
- Author
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Chou MM, Tseng JJ, Ho ES, and Hwang JI
- Subjects
- Adult, Angiography, Digital Subtraction, Female, Humans, Placenta diagnostic imaging, Pregnancy, Uterus diagnostic imaging, Imaging, Three-Dimensional, Neovascularization, Pathologic diagnostic imaging, Placenta blood supply, Placenta Previa diagnostic imaging, Placenta Previa physiopathology, Ultrasonography, Doppler, Color, Uterus blood supply
- Abstract
A case of placenta previa increta/percreta was diagnosed at 18 weeks' gestation with the 3-dimensional color power Doppler imaging technique. Unusually extensive uteroplacental vascular network architecture was seen on the 3-dimensional angiohistogram. After appropriate counseling, the patient chose to terminate the pregnancy. A hysterectomy was performed with prophylactic preoperative embolization of internal iliac arteries at 21 weeks' gestation, and histopathologic examination revealed placenta previa increta/percreta. This new 3-dimensional angiohistogram technique allowed us to visualize all 3 orthogonal planes of the angioarchitectural information. It appears to be a useful complementary tool and is likely to play a more defining and clarifying role in assessing the quantification of abnormal uteroplacental neovascularization for patients with placenta previa increta/percreta.
- Published
- 2001
- Full Text
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62. In utero sonographic diagnosis of a communicating enteric duplication cyst in a giant omphalocele.
- Author
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Tseng JJ, Chou MM, and Ho ES
- Subjects
- Adult, Cysts diagnostic imaging, Cysts surgery, Diagnosis, Differential, Female, Fetal Diseases surgery, Hernia, Umbilical surgery, Humans, Ileal Diseases surgery, Infant, Newborn, Male, Pregnancy, Fetal Diseases diagnostic imaging, Hernia, Umbilical diagnostic imaging, Ileal Diseases diagnostic imaging, Ultrasonography, Prenatal
- Abstract
Enteric duplications are rare lesions, and relatively few cases have been diagnosed prenatally. We present, to our knowledge, the first case of an associated communicating ileal duplication cyst in a huge omphalocele diagnosed prenatally. The prenatal ultrasound findings revealed four features of the cystic lesion including peristaltic movements of the cystic wall, communication between the cyst and normal bowel lumen, intra-cystic echogenic contents, and echogenic mesenteric tissue (fat) close to the cyst. These distinct characteristics helped us to make a firm in utero diagnosis., (Copyright 2001 John Wiley & Sons, Ltd.)
- Published
- 2001
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63. Assays for monitoring p70 S6 kinase and RSK activation.
- Author
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Masuda-Robens J, Krymskaya VP, Qi H, and Chou MM
- Subjects
- Animals, Antibodies, Cells, Cultured, Immunoblotting, Oocytes, Phosphorylation, Precipitin Tests, Protein Kinases immunology, Protein Kinases metabolism, Recombinant Proteins genetics, Recombinant Proteins isolation & purification, Recombinant Proteins metabolism, Ribosomal Protein S6 Kinases immunology, Ribosomal Protein S6 Kinases metabolism, Xenopus laevis, rho GTP-Binding Proteins metabolism, Gene Expression Regulation, Enzymologic, Protein Kinases genetics, Ribosomal Protein S6 Kinases genetics, Signal Transduction
- Published
- 2001
- Full Text
- View/download PDF
64. Perinatal management of congenital complete heart block.
- Author
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Tseng JJ, Chou MM, and Ho ES
- Subjects
- Adult, Dexamethasone therapeutic use, Female, Heart Block diagnosis, Heart Block therapy, Humans, Infant, Newborn, Pregnancy, Retrospective Studies, Heart Block congenital
- Abstract
Background: The perinatal management of congenital complete heart block (CCHB) remains controversial. The purpose of this study was to present a therapeutic modality for CCHB., Methods: We collected retrospective cases of all pregnant women admitted to our hospital between January 1992 and June 1999 whose babies developed CCHB antenatally. After a series of examinations, maternal, fetal and neonatal data were analyzed., Results: Nine fetuses from six mothers (cases 1-6) in nine different pregnancies were studied. In case 1, both consecutive fetuses had CCHB and in case 2, all three consecutive fetuses had CCHB. The other mothers (cases 3-6) had only one fetus each with CCHB. Of the seven fetuses with isolated CCHB, four underwent observation only due to late-onset, or nonimmunologic CCHB, two received dexamethasone and/or intravenous immunoglobulin therapy because of the presence of hydropic signs, and one received dexamethasone at 23 weeks' gestation due to early-onset CCHB. Shortening fractions of the right ventricle had good compensation in four fetuses, without any treatment, and improving compensation in two of three fetuses receiving dexamethasone therapy. All seven fetuses were delivered smoothly and pacemakers were implanted shortly after birth. Two other fetuses had a poor outcome due to associated ventricular septal defect or hemoglobin Bart's disease. Furthermore, we gave dexamethasone (2 mg/day) instead of prednisolone (10 mg/day) for the next pregnancies of patients 3 to 5, beginning at 12 weeks of gestation. No fetal CCHB developed again., Conclusions: For pregnant women with previous fetal immunologic CCHB, early initiation of dexamethasone instead of prednisolone might be effective to cross the placenta and avoid recurrences. Dexamethasone is also effective for fetal CCHB of early onset, fetal hydrops or heart failure. Observation only is suggested for nonimmunologic CCHB and remote or late-onset immunologic CCHB. Other modalities were tried for very sick fetuses, but their effectiveness was not predictable.
- Published
- 2000
65. Prenatal diagnosis of placenta previa accreta by transabdominal color Doppler ultrasound.
- Author
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Chou MM, Ho ES, and Lee YH
- Subjects
- Abdomen, Adult, Cesarean Section, False Positive Reactions, Female, Gestational Age, Humans, Hysterectomy, Placenta Accreta complications, Placenta Accreta surgery, Placenta Previa complications, Placenta Previa surgery, Pregnancy, Pregnancy Outcome, Pregnancy Trimester, Second, Pregnancy Trimester, Third, Prospective Studies, Reproducibility of Results, Risk Factors, Sensitivity and Specificity, Placenta Accreta diagnostic imaging, Placenta Previa diagnostic imaging, Ultrasonography, Doppler, Color methods, Ultrasonography, Prenatal methods
- Abstract
Objective: The aim of this study was to evaluate the efficacy of transabdominal color Doppler ultrasound in diagnosing placenta previa accreta., Design: Eighty patients with persistent placenta previa underwent transabdominal B-mode and color Doppler ultrasound evaluation in the second and third trimesters because they had a high risk of placenta accreta. Color Doppler imaging criteria used included diffuse intraparenchymal placental lacunar flow; focal intraparenchymal placental lacunar flow; bladder-uterine serosa interphase hypervascularity; prominent subplacental venous complex; and loss of subplacental Doppler vascular signals. The color Doppler images were interpreted prospectively for signs of placenta previa accreta according to the exhibited color Doppler sonographic features., Results: Sixteen of the 80 patients exhibited characteristic color Doppler imaging patterns highly specific for placenta accreta according to the preceding criteria, and 14 of these had histopathological proof of placenta accreta. Two patients had false-positive color Doppler imaging evidence mistaken for interphase hypervascularity caused by bladder varices. Thirteen patients underwent hysterectomy in the group suspicious for accreta. Of the 64 patients with negative color Doppler imaging results, three had placenta accreta, while two required cesarean hysterectomy; the remaining patient underwent uterine artery ligation for bleeding from the lower uterine segment. The sensitivity of color Doppler imaging in the diagnosis of placenta previa accreta was 82.4% (14/17) and the specificity was 96.8% (61/63). The positive and negative predictive values were 87.5% (14/16) and 95.3% (61/64), respectively., Conclusions: Variable vascular morphological patterns of placenta previa accreta were exhibited and categorized by transabdominal color Doppler sonography in the antenatal period. The identification of these specific vascular patterns had a positive impact on the peripartum clinical management of the affected patients.
- Published
- 2000
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66. Term pregnancy in a noncommunicating rudimentary horn of an unicornuate uterus: a case report.
- Author
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Chou MM, Ho ES, Lin SK, Yang SJ, Lee YH, Huang PC, and Chang SM
- Subjects
- Adult, Female, Humans, Laparotomy, Pregnancy, Ultrasonography, Prenatal, Pregnancy Complications diagnosis, Uterus abnormalities
- Abstract
A case of full-term pregnancy in the noncommunicating rudimentary horn of unicornuate uterus is presented. A healthy female infant weighing 2,985 g was delivered by cesarean section at 37 weeks' gestation. The diagnosis was missed by prenatal ultrasonography and was made only at laparotomy. A retrospective analysis of our ultrasound studies revealed that the echo pattern of the nongravid uterus resembled a soft pelvic mass. Color Doppler imaging revealed prominent low-impedance uterine arcuate-radial arterial blood flow surrounding the periphery of the pelvic mass, as well as multiple areas of placental implantation with a pulsatile lacunar flow pattern. A high index of suspicion of rudimentary horn pregnancy should be borne in mind whenever late-pregnancy ultrasonography shows the above-mentioned characteristic ultrasonic findings.
- Published
- 1999
67. Regulation of protein kinase C zeta by PI 3-kinase and PDK-1.
- Author
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Chou MM, Hou W, Johnson J, Graham LK, Lee MH, Chen CS, Newton AC, Schaffhausen BS, and Toker A
- Subjects
- 3-Phosphoinositide-Dependent Protein Kinases, 3T3 Cells, Animals, Cell Line, Enzyme Activation, Mice, Phosphorylation, Phosphothreonine metabolism, Protein Kinase C genetics, Protein Processing, Post-Translational, Recombinant Fusion Proteins metabolism, Transfection, Phosphatidylinositol 3-Kinases physiology, Protein Kinase C metabolism, Protein Serine-Threonine Kinases physiology
- Abstract
Background: Protein kinase C zeta (PKC zeta) is a member of the PKC family of enzymes and is involved in a wide range of physiological processes including mitogenesis, protein synthesis, cell survival and transcriptional regulation. PKC zeta has received considerable attention recently as a target of phosphoinositide 3-kinase (PI 3-kinase), although the mechanism of PKC zeta activation is, as yet, unknown. Recent reports have also shown that the phosphoinositide-dependent protein kinase-1 (PDK-1), which binds with high affinity to the PI 3-kinase lipid product phosphatidylinositol-3,4,5-trisphosphate (Ptdins-3,4,5-P3), phosphorylates and potently activates two other PI 3-kinase targets, the protein kinases Akt/PKB and p70S6K. We therefore investigated whether PDK-1 is the kinase that activates PKC zeta., Results: In vivo, PI 3-kinase is both necessary and sufficient to activate PKC zeta. PDK-1 phosphorylates and activates PKC zeta in vivo, and we have shown that this is due to phosphorylation of threonine 410 in the PKC zeta activation loop. In vitro, PDK-1 phosphorylates and activates PKC zeta in a Ptdins-3,4,5-P3-enhanced manner. PKC zeta and PDK-1 are associated in vivo, and membrane targeting of PKC zeta renders it constitutively active in cells., Conclusions: Our results have identified PDK-1 as the kinase that phosphorylates and activates PKC zeta in the PI 3-kinase signaling pathway. This phosphorylation and activation of PKC zeta by PDK-1 is enhanced in the presence of Ptdins-3,4-5-P3. Consistent with the notion that PKCs are enzymes that are regulated at the plasma membrane, a membrane-targeted PKC zeta is constitutively active in the absence of agonist stimulation. The association between PKC zeta and PDK-1 reveals extensive cross-talk between enzymes in the PI 3-kinase signaling pathway.
- Published
- 1998
- Full Text
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68. The p35/Cdk5 kinase is a neuron-specific Rac effector that inhibits Pak1 activity.
- Author
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Nikolic M, Chou MM, Lu W, Mayer BJ, and Tsai LH
- Subjects
- Animals, COS Cells, Cell Membrane metabolism, Cyclin-Dependent Kinase 5, Enzyme Inhibitors metabolism, GTP Phosphohydrolases metabolism, Histones metabolism, Neurites enzymology, Phosphorylation, Signal Transduction, Transfection, p21-Activated Kinases, rac GTP-Binding Proteins, Cyclin-Dependent Kinases, GTP-Binding Proteins metabolism, Nerve Tissue Proteins metabolism, Neurons enzymology, Protein Serine-Threonine Kinases antagonists & inhibitors, Protein Serine-Threonine Kinases metabolism
- Abstract
Cyclin-dependent kinase 5 (Cdk5) and its neuron-specific regulator p35 are essential for neuronal migration and for the laminar configuration of the cerebral cortex. In addition, p35/Cdk5 kinase concentrates at the leading edges of axonal growth cones and regulates neurite outgrowth in cortical neurons in culture. The Rho family of small GTPases is implicated in a range of cellular functions, including cell migration and neurite outgrowth. Here we show that the p35/Cdk5 kinase co-localizes with Rac in neuronal growth cones. Furthermore, p35 associates directly with Rac in a GTP-dependent manner. Another Rac effector, Pak1 kinase, is also present in the Rac-p35/Cdk5 complexes and co-localizes with p35/Cdk5 and Rac at neuronal peripheries. The active p35/Cdk5 kinase causes Pak1 hyperphosphorylation in a Rac-dependent manner, which results in down-regulation of Pak1 kinase activity. Because the Rho family of GTPases and the Pak kinases are implicated in actin polymerization, the modification of Pak1, imposed by the p35/Cdk5 kinase, is likely to have an impact on the dynamics of the reorganization of the actin cytoskeleton in neurons, thus promoting neuronal migration and neurite outgrowth.
- Published
- 1998
- Full Text
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69. Second trimester selective termination in a dizygotic twin pregnancy with discordancy for Down's syndrome: a case report.
- Author
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Chou MM, Ho YP, and Ho ES
- Subjects
- Adult, Female, Humans, Infant, Newborn, Male, Pregnancy, Pregnancy Trimester, Second, Abortion, Induced, Diseases in Twins, Down Syndrome, Twins, Dizygotic
- Abstract
A 34-year-old woman with a twin pregnancy underwent genetic amniocentesis in a local hospital at 18 weeks' gestation. Fetal chromosome analysis showed a boy without abnormal findings (46, XY) and another boy with trisomy 21 (47, XY, +21). Sonography showed a fetal nuchal translucency thickness for the normal twin of 4.4 mm, and of 8.0 mm for the affected twin. The affected twin was terminated by ultrasonographically guided intracardiac injection of 2.5 ml (5 mEq) potassium chloride solution at 21 weeks' gestation. Serial ultrasound scans and coagulopathy tests were unremarkable. Labor was induced at 39 weeks' gestation. A healthy 3,080 g male infant was born vaginally with Apgar scores of 8 and 9 at one and five minutes, respectively. At the time of writing (one month after delivery), the mother and baby continue to do well. To our knowledge, this is the second successful case in Taiwanese literature of selective birth in twins with discordancy for Down's syndrome.
- Published
- 1998
70. Recombinant human relaxin as a cervical ripening agent.
- Author
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Brennand JE, Calder AA, Leitch CR, Greer IA, Chou MM, and MacKenzie IZ
- Subjects
- Administration, Intravaginal, Adult, Cervix Uteri physiology, Dose-Response Relationship, Drug, Double-Blind Method, Female, Gels, Humans, Labor Stage, First, Pregnancy, Recombinant Proteins administration & dosage, Recombinant Proteins adverse effects, Cervix Uteri drug effects, Labor, Induced methods, Oxytocics administration & dosage, Oxytocics adverse effects, Relaxin administration & dosage, Relaxin adverse effects
- Abstract
Objective: The aim of this study was to investigate the efficacy and safety of recombinant human relaxin (rhRIx) as a cervical ripening agent in women with an unfavourable cervix before induction of labour at term., Design: A multi-centre, double-blind, placebo-controlled trial performed in Edinburgh, Glasgow and Oxford. Women were treated with 0, 1, 2 or 4 mg of rhRIx in a gel vehicle administered intravaginally. Analysis of variance tests were performed on all continuous variables, and Cochran Mantel-Haenszel tests employed for all discrete variables., Participants: Ninety-six women at 37 to 42 weeks of gestation with a singleton pregnancy and a modified Bishop score of < or = 4 were recruited., Results: There was no significant difference in the change in modified Bishop score between the four treatment groups. The lengths of the first and second stages of labour were similar in all 4 groups. PGE2 and oxytocin requirements were similar in all groups, as was the mode of delivery. There was no evidence that relaxin was absorbed systemically when given in this way., Conclusion: Recombinant human relaxin 1 to 4 mg, administered as an intravaginal gel, has no effect as a cervical ripening agent before induction of labour at term.
- Published
- 1997
- Full Text
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71. Severe limb reduction defects after uterine lavage at 7-8 weeks' gestation.
- Author
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Chou MM, Lin SK, and Ho ES
- Subjects
- Adult, Female, Humans, Infant, Newborn, Limb Deformities, Congenital, Male, Pregnancy, Pregnancy Outcome, Pregnancy Trimester, First, Sex Determination Analysis, Therapeutic Irrigation adverse effects, Fetal Diseases etiology, Prenatal Diagnosis adverse effects, Uterus cytology
- Abstract
A 35-year-old multiparous Chinese woman underwent a uterine lavage procedure for prenatal sex determination at 7-8 weeks' gestation. The baby was delivered by elective Caesarean section because of breech presentation at 38 weeks' gestation. The child weighed 2425 g and had severe reduction defects of all four limbs. This case warrants advising prospective patients of a possible association and encouraging practitioners to mount a careful prenatal ultrasonography and postnatal follow-up of all pregnancies investigated by prenatal diagnostic uterine lavage.
- Published
- 1997
72. A Drosophila gene structurally and functionally homologous to the mammalian 70-kDa s6 kinase gene.
- Author
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Watson KL, Chou MM, Blenis J, Gelbart WM, and Erikson RL
- Subjects
- 3T3 Cells, Amino Acid Sequence, Androstadienes pharmacology, Animals, COS Cells, Drosophila embryology, Embryo, Nonmammalian, Enzyme Inhibitors pharmacology, Gene Expression Regulation, Developmental, Gene Expression Regulation, Enzymologic, Humans, Mammals, Mice, Molecular Sequence Data, Polyenes pharmacology, Protein Serine-Threonine Kinases chemistry, Recombinant Proteins biosynthesis, Recombinant Proteins chemistry, Ribosomal Protein S6 Kinases, Sequence Homology, Amino Acid, Sirolimus, Transfection, Wortmannin, Drosophila enzymology, Drosophila genetics, Genes, Insect, Protein Serine-Threonine Kinases biosynthesis, Protein Serine-Threonine Kinases genetics
- Abstract
cDNAs encoding the Drosophila 70-kDa S6 kinase (S6K) were isolated by low-stringency hybridization with mammalian p70S6k probes. Conceptual translation of S6k cDNA sequences yields a product containing all of the canonical features typical of serine/threonine kinases and has 78% amino acid identity in the catalytic domain with the human p70S6k homologue. The S6k gene, located at polytene chromosome site 65D, gives rise to two predominant transcripts of 3.0 and 5.0 kb and at least two smaller transcripts (< 3.0 kb) that are found in whole-animal RNAs at all stages of development. Blood cells derived from the hematopoietic organs of ribosomal protein S6 (RpS6air8) mutant animals express higher levels of the smaller S6k transcripts, suggesting tissue- or genotype-specific differences in the regulation of the S6k gene. Drosophila S6K expressed in COS or NIH 3T3 cells phosphorylates mammalian RPS6 in a mitogen-dependent wortmannin- and rapamycin-sensitive manner, suggesting that its regulation is similiar to mammalian p70S6k.
- Published
- 1996
- Full Text
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73. The 70 kDa S6 kinase complexes with and is activated by the Rho family G proteins Cdc42 and Rac1.
- Author
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Chou MM and Blenis J
- Subjects
- 3T3 Cells cytology, 3T3 Cells enzymology, Alleles, Androstadienes pharmacology, Animals, Antifungal Agents pharmacology, Bacterial Proteins genetics, Calcium-Calmodulin-Dependent Protein Kinases physiology, Cell Cycle Proteins antagonists & inhibitors, Cell Cycle Proteins metabolism, Enzyme Activation drug effects, Enzyme Activation physiology, Epidermal Growth Factor antagonists & inhibitors, GTP Phosphohydrolases antagonists & inhibitors, GTP Phosphohydrolases genetics, GTP Phosphohydrolases metabolism, GTP-Binding Proteins antagonists & inhibitors, GTP-Binding Proteins metabolism, GTP-Binding Proteins physiology, Gene Expression physiology, Growth Substances physiology, Guanine Nucleotide Exchange Factors, Guanine Nucleotides metabolism, Guanosine Triphosphate metabolism, Isomerism, JNK Mitogen-Activated Protein Kinases, Mice, Mutation physiology, Phosphatidylinositol 3-Kinases, Phosphorylation, Phosphotransferases (Alcohol Group Acceptor) physiology, Plant Proteins antagonists & inhibitors, Plant Proteins genetics, Plant Proteins metabolism, Platelet-Derived Growth Factor antagonists & inhibitors, Polyenes pharmacology, Protein Serine-Threonine Kinases antagonists & inhibitors, Protein Structure, Tertiary, Retroviridae Proteins, Oncogenic genetics, Ribosomal Protein S6 Kinases, Signal Transduction physiology, Sirolimus, Wortmannin, cdc42 GTP-Binding Protein, Saccharomyces cerevisiae, p38 Mitogen-Activated Protein Kinases, rac GTP-Binding Proteins, rhoA GTP-Binding Protein, Bacterial Toxins, Cell Cycle Proteins genetics, Escherichia coli Proteins, GTP-Binding Proteins genetics, Membrane Proteins, Mitogen-Activated Protein Kinases, Protein Serine-Threonine Kinases metabolism
- Abstract
The 70 kDa ribosomol S6 kinase (pp70S6k) plays an important role in the progression of cells through G1 phase of the cell cycle. However, little is known of the signaling molecules that mediate its activation. We demonstrate that Rho family G proteins regulate pp70S6k activity in vivo. Activated alleles of Cdc42 and Rac1, but not RhoA, stimulate pp70S6k activity in multiple cell types. Activation requires an intact effector domain and isoprenylation of Cdc42 and Rac1. Coexpression of Dbl, an exchange factor for Cdc42, also activates pp70S6k. Growth factor-induced activation of pp70S6k is abrogated by dominant negative alleles of Cdc42 and Rac1. In addition, Cdc42 and Rac1 form GTP-dependent complex with the catalytically inactive form of pp70S6k in vitro and in vivo, suggesting a mechanism by which these G proteins activate pp70S6k.
- Published
- 1996
- Full Text
- View/download PDF
74. The p70S6K signalling pathway: a novel signalling system involved in growth regulation.
- Author
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Grammer TC, Cheatham L, Chou MM, and Blenis J
- Subjects
- Animals, Humans, Proto-Oncogene Mas, Ribosomal Protein S6 Kinases, Cell Division physiology, Protein Serine-Threonine Kinases physiology, Signal Transduction physiology
- Abstract
This chapter has outlined our current understanding of the regulation of p70S6K activity and its importance for cell growth and proliferation. Although incomplete at the moment, the picture of P70S6K activation reveals novel mechanisms for mitogenic signalling that closely link lipid phosphorylation and protein activation in ways previously unrecognized. Knowledge about the regulation of this signalling pathway is already proving crucial for the medical management of patients. The p70S6K regulating pathways appear to be involved in cell transformation by the polyomavirus. Rapamycin is a strong candidate for use as an immunosuppressant and is currently being tested in clinical trials. Analysis of the activation of the proto-oncogene, akt, demonstrates a possible link of the p70S6K activating pathway to carcinogenesis. Equally exciting is the recent connection between the p70S6K regulating system and IGF2 expression, which may prove crucial for the treatment of IGF2 secreting rhabdomyosarcomas. Certainly, future work will fill in the gaps in our understanding and most likely provide more surprises in the fields of cell biology and molecular oncology.
- Published
- 1996
75. Antenatal diagnosis and early surgery for choledochal cyst: a report of two cases.
- Author
-
Peng HC, Chen HC, Chang WT, Chou MM, and Hsieh WK
- Subjects
- Adult, Choledochal Cyst surgery, Female, Humans, Infant, Newborn, Male, Pregnancy, Choledochal Cyst diagnostic imaging, Ultrasonography, Prenatal
- Abstract
Since the advent of routine antenatal sonography to detect fetal abnormalities, two cases of choledochal cyst have been found prenatally in our hospital. The first presented when a choledochal cyst was demonstrated at 31 weeks of gestation, and a firm diagnosis established within 2 days of birth. Technetium 99m disofenin (DISIDA) cholescintigram revealed delayed visualization of the small bowel. The second case was found by ultrasound examination at 21 weeks of gestation to have a choledochal cyst, and diagnosis was confirmed within 3 days of birth. DISIDA scintigram demonstrated complete obstruction of the extrahepatic biliary tree. Both infants received early excision of the cyst at the ages of three and four days respectively. The postoperative course was quite smooth, and there were no abnormal symptoms after follow up of four and two years, respectively. Neonates with distal common bile duct obstruction in association with presumed choledochal cyst should have prompt surgical exploration, and early excision of the cyst is a safe procedure in the newborn.
- Published
- 1996
76. The 70 kDa S6 kinase: regulation of a kinase with multiple roles in mitogenic signalling.
- Author
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Chou MM and Blenis J
- Subjects
- Ribosomal Protein S6 Kinases, Signal Transduction drug effects, Mitogens pharmacology, Protein Serine-Threonine Kinases physiology, Signal Transduction physiology
- Abstract
The activation of the 70kDa S6 kinase, pp70S6k, is a well documented mitogenic response, yet until recently little was known of how pp70S6k is activated, or of the identities of its crucial targets. The past year has revealed the complexity of pp70S6k regulation, with the overriding theme being that enzymes which have proven or putative roles in phospholipid metabolism mediate its activation. Studies also indicate that pp70S6k may regulate many more pathways than previously recognized.
- Published
- 1995
- Full Text
- View/download PDF
77. Metobromuron/metolachlor ingestion with late onset methemoglobinemia in a pregnant woman successfully treated with methylene blue.
- Author
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Yang CC, Hwang SF, Chou MM, and Deng JF
- Subjects
- Adult, Cyanosis chemically induced, Female, Follow-Up Studies, Humans, Methemoglobinemia chemically induced, Pregnancy, Pregnancy Complications drug therapy, Suicide, Acetamides poisoning, Herbicides poisoning, Methemoglobinemia drug therapy, Methylene Blue therapeutic use, Phenylurea Compounds poisoning, Pregnancy Complications chemically induced
- Abstract
Metobromuron, a substituted urea herbicide, is widely used for control of grasses and broad-leaved weeds in Taiwan. Major systemic toxicity has not been reported following poisoning. A 22-year-old woman at 36 weeks of gestation was admitted to the emergency department three hours after ingestion of a mixture of 25% metobromuron and 25% metolachlor. Though stable initially, she developed central cyanosis 12 hours later. Emergent cesarean section was considered but administration of intravenous methylene blue readily reversed the cyanosis and prevented the operation. Recurrent cyanosis did not develop. Normal vaginal delivery occurred 17 days after the poisoning. Follow-up for four years revealed normal growth of the child. Metobromuron poisoning, like other urea herbicides, may cause methemoglobinemia via its hydrolysis products. Administration of methylene blue is effective treatment and should be considered in the treatment of methemoglobinemia following urea herbicide poisoning.
- Published
- 1995
- Full Text
- View/download PDF
78. A prospective, double-blind, randomized comparison of prophylactic intramyometrial 15-methyl prostaglandin F2 alpha, 125 micrograms, and intravenous oxytocin, 20 units, for the control of blood loss at elective cesarean section.
- Author
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Chou MM and MacKenzie IZ
- Subjects
- Adult, Carboprost adverse effects, Carboprost therapeutic use, Dose-Response Relationship, Drug, Double-Blind Method, Female, Hemorrhage etiology, Humans, Injections, Injections, Intravenous, Myometrium, Oxygen blood, Oxytocin adverse effects, Oxytocin therapeutic use, Pregnancy, Prospective Studies, Treatment Outcome, Carboprost administration & dosage, Cesarean Section adverse effects, Hemorrhage prevention & control, Oxytocin administration & dosage
- Abstract
Objective: Our purpose was to compare intramyometrial 15-methyl prostaglandin F2 alpha with intravenous oxytocin for controlling blood loss at elective cesarean section., Study Design: A double-blind, randomized trial was performed with intramyometrial 15-methyl prostaglandin F2 alpha, 125 micrograms, or intravenous oxytocin, 20 U, in 60 women undergoing elective lower segment cesarean section at 36 to 41 weeks' gestation. Subjective assessment of the operative blood loss and early lochial discharge and objective change in hemoglobin and hematocrit before and 24 hours after delivery and the incidence of side effects were compared by nonparametric statistical tests., Results: The mean estimated blood loss was similar in both groups, with 645 ml (SD 278, range 400 to 1500) in the 15-methyl prostaglandin F2 alpha group compared with 605 ml (SD 303, range 200 to 1750) in the oxytocin group. The mean fall in hemoglobin and hematocrit was greater in the 15-methyl prostaglandin F2 alpha group than in the oxytocin group, 0.98 gm/dl (SD 0.95) versus 0.65 gm/dl (SD 0.79) for hemoglobin and 2.58% (SD 2.96) versus 2% (SD 2.96) for hematocrit. None of these differences reached statistical significance. There were no differences in side effects and lochial discharge between the treatment groups. In both groups there was a decrease of approximately 1% in maternal arterial oxygen saturation., Conclusion: Routine intramyometrial 15-methyl prostaglandin F2 alpha, 125 micrograms, does not offer any obvious advantage over intravenous oxytocin, 20 U, in reducing operative blood loss at elective lower-segment cesarean section.
- Published
- 1994
- Full Text
- View/download PDF
79. Titration of protein transport activity by incremental changes in signal peptide hydrophobicity.
- Author
-
Doud SK, Chou MM, and Kendall DA
- Subjects
- Alkaline Phosphatase chemistry, Alkaline Phosphatase metabolism, Amino Acid Sequence, Amino Acids metabolism, Base Sequence, Biological Transport, Calorimetry, Escherichia coli enzymology, Genes, Bacterial, Molecular Sequence Data, Mutagenesis, Site-Directed, Oligodeoxyribonucleotides, Protein Conformation, Protein Sorting Signals chemistry, Protein Sorting Signals genetics, Restriction Mapping, Alkaline Phosphatase genetics, Escherichia coli genetics, Methionine metabolism, Protein Sorting Signals metabolism
- Abstract
A systematic series of mutants has been generated which provides a means for titrating the dependence of protein transport activity on signal peptide hydrophobicity. These mutants involve replacement of the hydrophobic core segment of the Escherichia coli alkaline phosphatase signal peptide while maintaining the natural amino- and carboxyl-terminal segments and the overall length. The new core regions vary in composition from 10:0 to 0:10 in the ratio of alanine to leucine residues. Thus, a nonfunctional polyalanine-containing signal peptide is titrated with the more hydrophobic residue, leucine. Using precursor processing to quantify transport activity, we observe a clear, nonlinear dependence on hydrophobicity. At ratios of alanine to leucine of less than or equal to 8:2, the signal peptide is essentially nonfunctional; at ratios greater than or equal to 3:7, the signal peptide functions efficiently. The midpoint is between alanine to leucine ratios of 6:4 and 5:5. Signal peptides with hydrophobicity just below the midpoint show substantial, additional precursor processing over time while the others do not. The data are consistent with a simple model involving a two-state equilibrium between the untransported and transported species and a change in the delta G of -0.85 kcal/mol for every alanine to leucine conversion.
- Published
- 1993
- Full Text
- View/download PDF
80. [Clinical experience of GDM screening program].
- Author
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Hsieh WK, Ho ES, and Chou MM
- Subjects
- Adult, Female, Glucose Tolerance Test, Humans, Pregnancy, Pregnancy Outcome, Diabetes, Gestational diagnosis
- Abstract
From Jan. 1985 to Jun. 1990, 2561 pregnant women attending our prenatal clinic were screened for gestational diabetes. A 50-gm, 1-hour glucose challenge test was given and 470 patients (18.4%) showed plasma glucose values greater than or equal to 140 mg/dl. These women were subjected to a further 3-hr 100-gm OGTT to diagnose diabetes using O'Sullivans' criteria. Of these 470 cases, 80 (3.1%) of total cases were shown to be diabetic. Strict glycemic control with a fasting plasma sugar under 105 mg/dl and postprandial sugar under 120 mg/dl was conducted using diet and insulin in all cases. We compared the perinatal outcome of GDM pregnant women with normal pregnant women. Statistically, there was no significant difference. This study clearly demonstrates that a GDM screening program should be recommended for every pregnant woman. Prompt glycemic control should be given for all diabetic mothers to optimize the perinatal outcome.
- Published
- 1992
81. Malignant germ cell tumors of ovary: a 15-year survey at V.G.H.
- Author
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Yuan CC, Ng HT, Chou MM, Chang MC, and Liu HC
- Subjects
- Adolescent, Adult, Biomarkers, Tumor blood, Child, Combined Modality Therapy, Female, Humans, Middle Aged, Prognosis, alpha-Fetoproteins analysis, Neoplasms, Germ Cell and Embryonal diagnosis, Neoplasms, Germ Cell and Embryonal therapy, Ovarian Neoplasms diagnosis, Ovarian Neoplasms therapy
- Published
- 1987
82. Preventing complications from lines and tubes.
- Author
-
MacDonald MG and Chou MM
- Subjects
- Humans, Infant, Newborn, Infant, Newborn, Diseases etiology, Intubation, Gastrointestinal adverse effects, Intubation, Intratracheal adverse effects, Thorax, Umbilical Arteries, Umbilical Veins, Catheterization adverse effects, Infant, Newborn, Diseases prevention & control, Intubation adverse effects
- Abstract
Rather than providing an exhaustive list of known complications of all tubes and lines used in the NICU, we have highlighted the potentially traumatic nature of their use and outlined general principles of prevention. Most complications of care are more easily avoided if we know about them in advance. Attention to simple details, while recognizing that use of indwelling tubes and lines has both benefits and hazards, should lessen some of these morbidities.
- Published
- 1986
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