Color Doppler sonographic appearance of a Krukenberg tumor in pregnancy.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
M M Chou
Publications and source records attributed to M M Chou.
Second trimester selective termination in a dizygotic twin pregnancy with discordancy for Down's syndrome: a case report.
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.
Abortion, Induced↗
Prenatal diagnosis of placenta previa accreta with power amplitude ultrasonic angiography.
A case of placenta previa accreta was diagnosed at 28 weeks' gestation with use of power amplitude ultrasonic angiography, which showed an unusually intense blood flow within the placental sonolucent spaces and hypervascularity within the placental and surrounding tissues. High-velocity (> or = 15 cm/sec) turbulent venous-type flow was detected within the placental blood lakes, and prominent low-impedance (resistance index 0.24) arterial blood flow was detected within the uterine serosa-posterior bladder wall boundary zone. An uneventful cesarean hysterectomy was performed at 32 weeks' gestation, and histopathologic examination revealed placenta previa increta.
Adult↗
Recombinant human relaxin as a cervical ripening agent.
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.
Administration, Intravaginal↗
Severe limb reduction defects after uterine lavage at 7-8 weeks' gestation.
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.
Adult↗
A Drosophila gene structurally and functionally homologous to the mammalian 70-kDa s6 kinase gene.
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.
3T3 Cells↗
The 70 kDa S6 kinase complexes with and is activated by the Rho family G proteins Cdc42 and Rac1.
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.
3T3 Cells↗
Antenatal diagnosis and early surgery for choledochal cyst: a report of two cases.
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.
Adult↗
The p70S6K signalling pathway: a novel signalling system involved in growth regulation.
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.
Animals↗
Structural and functional analysis of pp70S6k.
The pp70/85-kDa S6 kinases, collectively referred to as pp70S6k, are thought to participate in transit through the G1 phase of the cell cycle. pp70S6k regulates the phosphorylation of the 40S ribosomal protein S6 and the transcription factor CREM tau. pp70S6k is regulated by serine/threonine phosphorylation, and although 1-phosphatidylinositol 3-kinase and phospholipase C have been implicated as upstream regulators, the mechanism of activation and identity of the upstream pp70S6k kinases remain unknown. To improve our understanding of how this mitogen-stimulated protein kinase is regulated by growth factors and the immunosuppressant rapamycin, we have initiated a structure/function analysis of pp70S6k. Our results indicate that both the N and C termini participate in the complex regulation of pp70S6k activity.
Androstadienes↗
A novel ligand for SH3 domains. The Nck adaptor protein binds to a serine/threonine kinase via an SH3 domain.
We have previously shown that overexpression of the SH2- and SH3-containing Nck adaptor protein causes transformation of mammalian fibroblast. To elucidate the mechanism by which it deregulates growth, we have sought to identify potential effectors for Nck. We report that a serine/threonine kinase, which we term NAK (for Nck-associated kinase), associates with Nck in vivo and in vitro. Using glutathione S-transferase fusion proteins generated with isolated domains of Nck, we demonstrate that NAK binds specifically to the second of Nck's three SH3 domains. NAK is complexed with Nck in a wide variety of cell types, including NIH3T3, A431, PC12, and Hela cells.
3T3 Cells↗
The 70 kDa S6 kinase: regulation of a kinase with multiple roles in mitogenic signalling.
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.
Mitogens↗
PDGF signalling is required for gastrulation of Xenopus laevis.
During Xenopus gastrulation, platelet-derived growth factor (PDGF) receptor-alpha is expressed in involuting marginal zone cells which migrate over ectodermal cells expressing PDGF-A. To investigate the role of PDGF signalling during this process, we have generated a novel point mutant of PDGF receptor-alpha analogous to the W37 mutation of c-kit. This molecule is a specific, potent, dominant inhibitor of PDGF signalling in vivo. Injection of RNA encoding this protein into Xenopus embryos prevents closure of the blastopore, leads to abnormal gastrulation and a loss of anterior structures. Convergent extension is not inhibited in these embryos, but rather, involuting mesodermal cells fail to adhere to the overlying ectoderm. PDGF may therefore be required for mesodermal cell-substratum interaction.
Animals↗
Metobromuron/metolachlor ingestion with late onset methemoglobinemia in a pregnant woman successfully treated with methylene blue.
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.
Acetamides↗
Prenatal diagnosis of placental chorioangioma: contribution of color Doppler ultrasound.
A case of placental chorioangioma was diagnosed at 35 weeks' gestation using color Doppler ultrasound. Color flow imaging showed an intraplacental hypoechoic mass fed directly by the anomalous chorionic tumor vessels arising from the insertion of the umbilical cord. Hypervascularization was present in some areas of the tumor. The diagnosis of typical 'angiomatous' type was confirmed by histopathological examination following delivery.
Journal Article↗
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.
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.
Adult↗
Termination of pathological pregnancy in second and early third trimesters with extraamniotic instillation of 16-phenoxy-omega-tetranor prostaglandin E2 methylsulfonylamide.
OBJECTIVES: To evaluate the efficacy, safety and influence on subsequent fertility of sulprostone, a prostaglandin E2 analog, in terminating pathological pregnancies via the extraamniotic route. METHODS: Forty pregnant women with intrauterine fetal death or major congenital anomalies were enrolled. Sulprostone was instilled into the extraamniotic space through a silicon Foley catheter. The instillation rate was 0.5-1 microgram/min. Instillation was discontinued when the catheter was expelled or when rupture of the membranes occurred. The duration of instillation and the time interval to completion of abortion was recorded. Information about subsequent fertility was collected by telephone or at outpatient clinic visits. RESULTS: The mean duration of instillation was 7.0 h and the mean dose of sulprostone was 314.8 micrograms. The mean induction-to-abortion interval (IAI) was 17.0 h. In two of the 40 patients, the cervix was not adequately ripened after 48 h and these pregnancies were ultimately terminated by alternative methods. The success rate of termination in 48 h was 92.5% (37/40). No severe side effects were encountered. CONCLUSION: To the best of our knowledge, this is the first report in the English literature of administration of sulprostone by extraamniotic instillation for termination of pathological pregnancies. The method is effective and safe and has an insignificant influence on subsequent fertility.
Abortifacient Agents, Nonsteroidal↗
Titration of protein transport activity by incremental changes in signal peptide hydrophobicity.
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.
Alkaline Phosphatase↗