Presynaptic local signaling by a canonical wingless pathway regulates development of the Drosophila neuromuscular junction.

Wnt/wingless signaling contributes to the development of neuronal synapses, including the Drosophila neuromuscular junction. Loss of wg (wingless) function alters the number and structure of boutons at this model synapse. Examining Wnt/wingless signaling mechanisms, we find that a distinct pathway operates presynaptically in the motoneuron and can account for many of the effects of wingless at this synapse. This pathway includes the canonical elements arrow/LRP (low-density lipoprotein receptor-related protein), dishevelled, and the glycogen synthase kinase shaggy (GSK3) and regulates the formation of microtubule loops within synaptic boutons as well as the number of synaptic boutons. This pathway, however, appears to be independent of beta-catenin signaling and the transcriptional regulation that is most frequently downstream of these components. Instead, inhibition of shaggy is likely to act locally. This pathway thus provides a parallel mechanism to the postsynaptic activation of frizzled receptors and indicates that synaptic development results from the bidirectional influence of wingless on both presynaptic and postsynaptic structures via distinct intracellular pathways.

Targeting coagulation factor XII provides protection from pathological thrombosis in cerebral ischemia without interfering with hemostasis.

Formation of fibrin is critical for limiting blood loss at a site of blood vessel injury (hemostasis), but may also contribute to vascular thrombosis. Hereditary deficiency of factor XII (FXII), the protease that triggers the intrinsic pathway of coagulation in vitro, is not associated with spontaneous or excessive injury-related bleeding, indicating FXII is not required for hemostasis. We demonstrate that deficiency or inhibition of FXII protects mice from ischemic brain injury. After transient middle cerebral artery occlusion, the volume of infarcted brain in FXII-deficient and FXII inhibitor-treated mice was substantially less than in wild-type controls, without an increase in infarct-associated hemorrhage. Targeting FXII reduced fibrin formation in ischemic vessels, and reconstitution of FXII-deficient mice with human FXII restored fibrin deposition. Mice deficient in the FXII substrate factor XI were similarly protected from vessel-occluding fibrin formation, suggesting that FXII contributes to pathologic clotting through the intrinsic pathway. These data demonstrate that some processes involved in pathologic thrombus formation are distinct from those required for normal hemostasis. As FXII appears to be instrumental in pathologic fibrin formation but dispensable for hemostasis, FXII inhibition may offer a selective and safe strategy for preventing stroke and other thromboembolic diseases.

Urethral hypermobility after anti-incontinence surgery - a prognostic indicator?

The aim of this study was to define the concept of hypermobility of the bladder neck and determine its effects on the cure rate and postoperative complications in patients undergoing colposuspension. In a retrospective study, 310 patients who underwent primary colposuspension for urodynamically proven genuine stress urinary incontinence were assessed by introital ultrasound before surgery and during follow-up for up to 48 months postoperatively. A total of 152 women completed 48 months of follow-up. Mobility of the bladder neck during straining was described as linear dorsocaudal movement (LDM) with LDM >15 mm being defined as hypermobility. The overall objective cure rate was 90.0% at 6-month follow-up vs 76.8% at 48-month follow-up (Kaplan-Meier estimators). Urge symptoms occurred in 12.6% (39/310) of the women and de novo urge incontinence in 2.3% (7/310). Bladder neck hypermobility was significantly reduced after anti-incontinence surgery, from 67.1% (208/310) before surgery to 5.5% (17/310) immediately after surgery (P<0.0001). Postoperative hypermobility was associated with a higher recurrence rate. In the hypermobility group, 52.9 and 34.0% of the patients were continent for up to 6 and 48 months, respectively, as opposed to 92.2 and 79.2% in the group without hypermobility (P<0.0001). Women with postoperative hypermobility had a 3.2-fold higher risk of recurrence within 48 months. Bladder neck hypermobility after surgery was also associated with postoperative voiding difficulty (P=0.0278). Patients in whom hypermobility of the bladder neck diagnosed before surgery persists after colposuspension have a higher risk of recurrence and are more likely to develop postoperative complications than those without this hypermobility.

Defective thrombus formation in mice lacking coagulation factor XII.

Blood coagulation is thought to be initiated by plasma protease factor VIIa in complex with the membrane protein tissue factor. In contrast, coagulation factor XII (FXII)-mediated fibrin formation is not believed to play an important role for coagulation in vivo. We used FXII-deficient mice to study the contributions of FXII to thrombus formation in vivo. Intravital fluorescence microscopy and blood flow measurements in three distinct arterial beds revealed a severe defect in the formation and stabilization of platelet-rich occlusive thrombi. Although FXII-deficient mice do not experience spontaneous or excessive injury-related bleeding, they are protected against collagen- and epinephrine-induced thromboembolism. Infusion of human FXII into FXII-null mice restored injury-induced thrombus formation. These unexpected findings change the long-standing concept that the FXII-induced intrinsic coagulation pathway is not important for clotting in vivo. The results establish FXII as essential for thrombus formation, and identify FXII as a novel target for antithrombotic therapy.

Prenatal DNA diagnosis of Noonan syndrome in a fetus with massive hygroma colli, pleural effusion and ascites.

Prenatal molecular genetic diagnosis for Noonan syndrome I is reported. Noonan syndrome was suspected because of large cystic hygroma colli, massive pleural effusion and ascites at 23 weeks of gestation and normal karyotype (46,XX). DNA was prepared from amnion cells and screened for mutations in the PTPN11 gene. In exon 8, a missense mutation (S285F) was found. Delivery was induced at 33 weeks of gestation because of silent cardiotocography (CTG). Despite immediate drainage of the hydrothorax, mechanical ventilation was insufficient and the child died 9 h after birth due to severe pulmonary hypoplasia. Pleural punctate was enriched for small lymphocytes and thus was characterized as chylus. Prenatal ultrasound findings in Noonan syndrome usually are unspecific and rarely lead to a diagnosis. However, with the combination of cystic hygroma, pleural effusion, ascites and normal karyotype Noonan syndrome should be considered and DNA testing for PTPN11 mutations may be appropriate. Malformations of lymphatic vessels and/or chylothorax in Noonan syndrome seem to be more frequent than usually anticipated.

Targeted deletion of murine coagulation factor XII gene-a model for contact phase activation in vivo.

To analyze the biological role of factor XII (FXII, Hageman Factor) in vivo, we generated mice deficient for FXII using a gene targeting approach on two distinct genetic backgrounds, i.e. mixed C57Bl/6J X 129X1/SvJ and inbred 129X1/SvJ. Homozygous FXII knockout (FXII(-)/(-)) mice showed no FXII plasma activity and had a markedly prolonged activated partial thromboplastin time (aPTT). In contrast, coagulation factors XI, VIII, IX, X,VII, V, II and fibrinogen did not differ between FXII(-/-) mice and their wild-type littermates. Heterozygous matings segregated according to the Mendelian inheritance indicating that FXII deficiency does not increase fetal loss. Furthermore, matings of FXII(-/-) males and FXII(-/-) females resulted in normal litter sizes demonstrating that total FXII deficiency in FXII(-/-) females does not affect pregnancy outcome. Also, gross and histological anatomy of FXII(-/-) mice was indistinguishable from that of their wild-type littermates on both genetic backgrounds. Thus it appears that deficiency of murine FXII does not cause thrombophilia or impaired fibrinolysis in vivo. These results indicate that FXII deficiency does not affect hemostasis in vivo and we anticipate that the FXII(-/-) mice will be helpful to elucidate the biological role(s) of FXII in health and disease.

Prospective analysis of placenta growth factor (PlGF) concentrations in the plasma of women with normal pregnancy and pregnancies complicated by preeclampsia.

OBJECTIVE: The aim of this study was to analyze if levels of plasma PlGF in the second half of pregnancy have predictive value for the identification of women destined to develop preeclampsia or another complication of pregnancy. MATERIAL AND METHODS: A bank of 1.543 randomly collected plasma samples (22-29 weeks of gestation) was established and PlGF concentrations were quantitated in a prospective longitudinal study in all pregnant women who developed a complication of pregnancy in late gestation (177 of 1.543) and the same number of gestational age matched pregnancies with normal outcome. RESULTS: Plasma PlGF levels in pregnant women rise steadily throughout pregnancy from the level of nonpregnant women (< 50 pg/mL) to levels exceeding 500 pg/mL after 30 weeks of gestation. Just 7.3% of pregnant women with normal outcome of pregnancy had PlGF levels of less than 200 pg/mL beyond 22 weeks of gestation (3.7% beyond 25 weeks of gestation). The rise in plasma PlGF in the second half of pregnancy was significantly attenuated in pregnancies that were complicated by preeclampsia in late gestation. Of all women who developed preeclampsia, 27.3% (12 of 44) had plasma PlGF levels below 200 pg/mL. The attenuation of the rise in plasma PlGF was not evident in other complications of pregnancy (transient hypertension, fetal retardation, pregnancy diabetes, premature contractions, proteinuria without hypertension, infections during pregnancy). CONCLUSION: The rise in plasma PlGF levels observed in normal pregnancies is significantly attenuated in pregnancies complicated by preeclampsia. Yet, due to the low sensitivity and specificity, plasma PlGF levels in the second half of pregnancy have no predictive value for the identification of individual women destined to develop preeclampsia.

Analyzes of three common thrombophilic gene mutations in German women with recurrent abortions.

BACKGROUND: Several etiological factors have been proposed as a cause for recurrent fetal abortions. Changes in blood coagulation during pregnancy may play an important role in the occurrence of recurrent abortions (RA). METHODS: The aim of this study was to investigate the prevalence of factor V Leiden, factor II prothrombin, and methylenetetrahydrofolate reductase (MTHFR) mutations in women with recurrent abortions (> or =2 abortions) in the German population. The mean number of abortions was 3 (range 2-8). RESULTS: Frequencies of the factor V Leiden mutation and the prothrombin G20210A mutation were equally high in the patient group compared with our control group (for factor V Leiden: 11/101 vs. 9/122; p-value: 0.348; for prothrombin G20210A: 2/101 vs. 3/122; p-value: 0.81). Moreover, in both the patient and control groups, 15 of the women were homozygous for the MTHFR C677T allele (15/101 vs. 15/122; p-value: 0.635). The occurrence of FV Leiden, FII and MTHFR mutations was not significantly increased in the patient group compared with our control group. CONCLUSION: The results of the present study reveal no relationship between these common three thrombophilic mutations and recurrent abortions for the German population, and further studies are essentially recommended on whether a thrombophilia evaluation should be performed in patients with recurrent abortions.

Factor XII deficiency is strongly associated with primary recurrent abortions.

OBJECTIVE: To evaluate factor XII deficiency in women with primary and secondary recurrent abortion. DESIGN: Prospective case-control study. SETTING: University hospital. PATIENT(S): Sixty-seven women with primary and 33 women with secondary recurrent abortion of unexplained nature and 49 healthy controls with no history of thrombotic disease or adverse pregnancy outcomes. MAIL OUTCOME MEASURE(S): Plasma factor XII activity, activated protein C resistance, factor V Leiden mutation analysis, protein C, protein S, antithrombin III, karyotyping, and anticardiolipin antibodies. RESULT(S): Ten of 67 women with primary recurrent abortion (14.9%) and 4 of 33 women (12.1%) with secondary recurrent abortion had reduced factor XII activity (<60%). These results are highly significant in the former group and showed a tendency toward significance in the latter group. All controls had normal factor XII activity. CONCLUSION(S): Factor XII deficiency is strongly associated with primary recurrent abortion, and women with secondary recurrent abortion show a tendency toward factor XII deficiency.

Incidence of fetal malformations in pregnancies complicated by oligo- and polyhydramnios.

Oligo- and polyhydramnios could be observed in 1%-7% of all pregnancies and are associated with an increased risk of fetal anomalies. We evaluated the fetal outcomes of 840 pregnancies with oligo- and polyhydramnios on the basis of ultrasonographic findings (oligohydramnios: single deepest pocket <2 cm, polyhydramnios: single deepest pocket >8 cm) between 12 and 42 weeks of gestation. We observed 734 pregnancies (752 fetuses) with oligohydramnios and 106 pregnancies (108 fetuses) with polyhydramnios. Of the 752 fetuses with oligohydramnios, 81% survived and 19% died in utero. Among the 108 fetuses of pregnancies with polyhydramnios, 72% of the babies survived and 28% died in utero. In polyhydramnios, 48% (52 of 108) of the fetuses had severe malformations, which is significant compared to the rate of 11.8% (89 of 752) of fetal malformations in oligohydramnios ( P-value<0.001). Oligohydramnios is predominantly associated with malformations of the urinary tract, whereas polyhydramnios is associated with anomalies of the gastrointestinal tract. In conclusion, measurement of single deepest pocket is a valuable screening method to evaluate pregnancies showing the complications of oligo- and polyhydramnios. Pregnancies with severe polyhydramnios have a poorer outcome and fetuses have a significantly higher risk of congenital malformations compared to pregnancies with oligohydramnios.

Recurrent pregnancy loss and its relation to FV Leiden, FII G20210A and polymorphisms of plasminogen activator and plasminogen activator inhibitor.

Thrombophilic disorders and hypofibrinolysis were demonstrated to be risk factors in a majority of women with recurrent pregnancy loss (RPL) and infertility. We investigated the association of FV G1691A mutation, F II G20210A gene polymorphism (PM), 4G/5G PAI-1 and Alu I/D tPA PM in 32 women with infertility and 49 women with at least 2 unexplained early abortions. FV Leiden mutation was significantly more common in women with RPL (10%, p = 0.02) and infertility (19%, p = 0.0005) compared with controls (2%). PAI-1 4G PM and t-PA Alu I PM, alone or in combination, were not associated with RPL or infertility. 9/49 women with RPL showed coagulation disorders with heterozygous FV Leiden mutation (5), FXII (1), protein C (1) or protein S (2) deficiency. However, due to the small number of patients studied, no definite conclusion can be drawn.