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We describe a novel surgical technique in 31 women with histopathologically confirmed placenta accreta spectrum (PAS) disorders managed by a multidisciplinary team using a prophylactic infrarenal abdominal aortic cross-clamping technique during caesarean hysterectomy. We conclude that this new surgical procedure is a relatively safe technique to potentially control operative blood loss. Our work may stimulate others to develop protocols assessing this innovative technique to improve the surgical outcome of PAS disorders., (© 2020 John Wiley & Sons Ltd.)

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.

The NF-κB transcription factor has a central role in diverse processes, including inflammation, proliferation and cell survival, and its activity is dysregulated in diseases such as autoimmunity and cancer. We recently identified the TRE17/ubiquitin-specific protease 6 (USP6) oncogene as the first de-ubiquitinating enzyme to activate NF-κB. TRE17/USP6 is translocated and overexpressed in aneurysmal bone cyst (ABC), a pediatric tumor characterized by extensive bone degradation and inflammatory recruitment. In the current study, we explore the mechanism by which TRE17 induces activation of NF-κB, and find that it activates the classical NF-κB pathway through an atypical mechanism that does not involve IκB degradation. TRE17 co-precipitates with IκB kinase (IKK), and IKK activity is augmented in stable cell lines overexpressing TRE17, in a USP-dependent manner. Optimal activation of NF-κB by TRE17 requires both catalytic subunits of IKK, distinguishing its mechanism from the classical and non-canonical pathways, which require either IKKβ or IKKα, respectively. TRE17 stimulates phosphorylation of p65 at serine 536, a modification that has been associated with enhanced transcriptional activity and nuclear retention. Induction of S536 phosphorylation by TRE17 requires both IKKα and IKKβ, as well as the IKKγ/NEMO regulatory subunit of IKK. We further demonstrate that TRE17(long) is highly tumorigenic when overexpressed in NIH3T3 fibroblasts, and that inhibition of NF-κB significantly attenuates tumor formation. In summary, these studies uncover an unexpected signaling mechanism for activation of classical NF-κB by TRE17. They further reveal a critical role for NF-κB in TRE17-mediated tumorigenesis, and suggest that NF-κB inhibitors may function as effective therapeutic agents in the treatment of ABC.

Aneurysmal bone cyst (ABC) is an aggressive, pediatric bone tumor characterized by extensive destruction of the surrounding bone. Although first described over 60 years ago, its molecular etiology remains poorly understood. Recent work revealed that ABCs harbor translocation of TRE17/USP6, leading to its transcriptional upregulation. TRE17 encodes a ubiquitin-specific protease (USP), and a TBC domain that mediates binding to the Arf6 GTPase. However, the mechanisms by which TRE17 overexpression contributes to tumor pathogenesis, and the role of its USP and TBC domains, are unknown. ABCs are characterized by osteolysis, inflammatory recruitment and extensive vascularization, the processes in which matrix proteases have a prominent role. This led us to explore whether TRE17 regulates the production of matrix metalloproteinases (MMPs). In this study we show that TRE17 is sufficient to induce expression of MMP-9 and MMP-10, in a manner requiring its USP activity, but not its ability to bind Arf6. TRE17 induces transcription of MMP-9 through activation of nuclear factor-kappaB (NF-kappaB), mediated in part by the GTPase RhoA and its effector kinase, ROCK. Furthermore, xenograft studies show that TRE17 induces formation of tumors that reproduce multiple features of ABC, including a high degree of vascularization, with an essential role for the USP domain. In sum, these studies reveal that TRE17 is sufficient to initiate tumorigenesis, identify MMPs as novel TRE17 effectors that likely contribute to ABC pathogenesis and define the underlying signaling mechanism of their induction.

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.

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.

A case of fetal axillary hemangiolymphangioma coexisting with intralesional hemorrhage is presented. At 27 weeks' gestation, the fetus was found to have a 52 x 43-mm left axillary multilocular cystic mass which showed no signals on color Doppler. The mass was composed mostly of sonolucent spaces. At 29 weeks' gestation, an arterial flow signal (15 cm/s) was detected within the mass. In addition, two low-density echogenic cystic spaces with bidirectional flow waveforms were found, which raised the suspicion of intratumoral bleeding. Two weeks later, a fine-needle aspiration of the mass revealed both straw-colored and chocolate-colored fluid. The tumor size increased from 52 x 43 mm at 27 weeks to 100 x 79 mm at 37 weeks. Blood clots developed gradually in the hemorrhagic spaces. The pregnancy proceeded smoothly to term and at 38 weeks an elective Cesarean section was performed. After a surgical excision of the mass at the age of 4 days, a mixed cavernous hemangioma and cystic lymphangioma with secondary intralesional hemorrhage was confirmed histopathologically.

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.

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.

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.)

Ureteral injuries are uncommon but serious complications of laparoscopically-assisted vaginal hysterectomy. The ureter is particularly at risk for inadvertent injury when the cardinal-uterosacral ligament complex is coagulated and divided below the uterine vessels. We present two recent cases which describe the application of transabdominal ultrasound including color Doppler mapping in the diagnosis of ureteral injury after laparoscopically-assisted vaginal hysterectomy. Transabdominal ultrasound including color Doppler mapping has great diagnostic potential as a method for non-invasive evaluation of post-operative ureteral conditions. Ultrasonic triads (absence of a ureteric jet, ascites, and the presence or absence of hydronephrosis) are capable of differentiating diagnosis of complete, partial, or nonobstructive surgical ureteral injuries.

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.

Nausea, vomiting, and other dyspeptic symptoms are common in pregnancy. This hospital-based, cross-sectional study was designed to determine the role of Helicobacter pylori infection in gastrointestinal (GI) symptoms during pregnancy. Standardized verbal scales were used to evaluate the frequency and severity of GI symptoms in 54 women whose pregnancies were in the first 16 gestational weeks. H. pylori infection was defined as a positive serum immunoglobulin G result on an immunochromatographic assay. The H. pylori seropositivity rate was higher in the pregnant women (69%) than in the general population (approximately 50%-55%), but seropositivity did not correlate with clinical symptoms. Moreover, no specific patterns of GI symptoms were uncovered in the H. pylori-infected patients. Maternal age, body weight, parity, gestational week, and educational level were not associated with H. pylori infection; neither were the prevalence and severity of GI symptoms.

A case of mixed intrahepatic arteriovenous shunts in a fetus diagnosed at 35 weeks' gestation is presented. Color Doppler ultrasonography in the fetal liver demonstrated complicated vascular connections fed by the hepatic arterial branches and drained into the portal and middle hepatic veins. Pulsed Doppler ultrasonography identified a high cardiac output state by the detection of increased flow velocities of the great vessels. The contribution of Doppler ultrasonography to hemodynamic changes is highlighted. The management is briefly discussed.

Both the Rho family of low-molecular-weight GTP-binding proteins and protein kinases C (PKCs) mediate responses to a variety of extracellular and intracellular signals. They share many downstream targets, including remodeling of the actin cytoskeleton, activation of p70(S6) kinase and c-jun N-terminal kinase (JNK), and regulation of transcription and cell proliferation. We therefore investigated whether Rho family GTP-binding proteins bind to PKCs. We found that Cdc42 associates with atypical PKCs (aPKCs) PKCzeta and -lambda in a GTP-dependent manner. The regulatory domain of the aPKCs mediates the interaction. Expression of activated Cdc42 results in the translocation of PKClambda from the nucleus into the cytosol, and Cdc42 and PKClambda colocalize at the plasma membrane and in the cytoplasm. Expression of activated Cdc42 leads to a loss of stress fibers, as does overexpression of either the wild type or an activated form of PKClambda. Kinase-dead PKClambda and -zeta constructs acted as dominant negatives and restored stress fibers in cells expressing the activated V12 Cdc42 mutant, indicating that Cdc42-dependent loss of stress fibers requires aPKCs. Kinase-dead PKClambda and -zeta and dominant-negative N17 Cdc42 also blocked Ras-induced loss of stress fibers, suggesting that this pathway may also be important for Ras-dependent cytoskeletal changes. N17 Rac did not block Ras-induced loss of stress fibers, nor did kinase-dead PKClambda block V12 Rac-stimulated loss of stress fibers. These results indicate that Cdc42 and Rac use different pathways to regulate stress fibers.

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.

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.

Fetal cardiac hemangioma is rarely diagnosed prenatally. We present here a fetus with such a tumor diagnosed at 28 weeks' gestation. With the use of fetal echocardiography, a mixed echogenic mass protruding outward from the right atrial wall was observed. Moderate amounts of pericardial effusion were also found. Although no apparent blood flow signal was detected in the mass, fetal echocardiography showed signs suggestive of a hemangioma. Differential diagnosis, management and prognosis are discussed.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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., (Copyright 1994 International Society of Ultrasound in Obstetrics and Gynecology)

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.

We have established the human nck sequence as a new oncogene. Nck encodes one SH2 and three SH3 domains, the Src homology motifs found in nonreceptor tyrosine kinases, Ras GTPase-activating protein, phosphatidylinositol 3-kinase, and phospholipase C-gamma. Overexpression of human nck in 3Y1 rat fibroblasts results in transformation as judged by alteration of cell morphology, colony formation in soft agar, and tumor formation in nude BALB/c mice. However, overexpression of nck does not induce detectable elevation of the phosphotyrosine content of specific proteins, as is observed for v-crk, another SH2/SH3-containing oncogene. Despite this fact, we demonstrate that Nck retains the ability to bind tyrosine phosphorylated proteins in vitro, using a fusion protein of Nck with glutathione-S-transferase (GST). Moreover, when incubated with lysates prepared from v-src-transformed 3Y1 cells or the nck-overexpressing cell lines, GST-Nck binds to both p60v-src and serine/threonine kinases, respectively. Although phosphotyrosine levels are not elevated in the nck-expressing fibroblasts, vanadate treatment of these cells results in a phosphotyrosine pattern that is altered from the parental 3Y1 pattern, suggestive of a perturbation of indigenous tyrosine kinase pathways. These results suggest the possibility that human nck induces transformation in 3Y1 fibroblasts by virtue of its altered affinity or specificity for the normal substrates of its rat homolog and that Nck may play a role in linking tyrosine and serine/threonine kinase pathways within the cell.

A case of placenta previa/accreta was diagnosed at 23 weeks' gestation using color Doppler ultrasound. Imaging showed an unusually intense blood flow within the placental sonolucent spaces and the hypervascularization patterns within the placental and the non-placental tissues. Highly pulsatile venous flow patterns were detected within the placental blood lakes and the subplacental venous complex. A strong association between the lacunar flow pattern and the abnormally adherent placentation was confirmed by the color Doppler sonographic findings., (Copyright 1992 International Society of Ultrasound in Obstetrics and Gynecology)

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.

We present a case of type III fetal cystic adenomatoid malformation with bilateral total involvement of the lungs. The characteristic sonographic findings are echogenic homogeneous lung mass, fetal ascites and placentomegaly. The early diagnosis at 16 weeks' gestation allows the elective termination of pregnancy because of the likely fatal prognosis. To our knowledge, this is the earliest reported case of congenital cystic adenomatoid malformation of the lung that has been detected prenatally., (Copyright 1992 International Society of Ultrasound in Obstetrics and Gynecology)

We have examined the hydrophobicity component of signal peptide function using polymeric sequences in combination with cassette mutagenesis. Using homopolymeric units of either isoleucine, leucine, valine or alanine to replace the natural core segment of the Escherichia coli alkaline phosphatase signal peptide, the hydrophobicity requirements for export and processing were delineated. The transport properties of these mutants demonstrated that the net hydrophobicity determines the total extent of precursor processing, while a high mean hydrophobicity/residue is critical for complete, rapid processing and translocation. Moreover, alkaline phosphatase was converted from a periplasmic to an active membrane-anchored protein via a signal containing 20 leucine residues. This application of polymeric sequences allows systematic comparisons to be made, unambiguously revealing the hydrophobicity requirements governing specific steps in the transport process.