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Seismicity induced in geo-reservoirs can be a valuable observation to image fractured reservoirs, to characterize hydrological properties, or to mitigate seismic hazard. However, this requires accurate location of the seismicity, which is nowadays an important seismological task in reservoir engineering. The earthquake location (determination of the hypocentres) depends on the model used to represent the medium in which the seismic waves propagate and on the seismic monitoring network. In this work, location uncertainties and location inaccuracies are modeled to investigate the impact of several parameters on the determination of the hypocentres: the picking uncertainty, the numerical precision of picked arrival times, a velocity perturbation and the seismic network configuration. The method is applied to the geothermal site of Soultz-sous-Forêts, which is located in the Upper Rhine Graben (France) and which was subject to detailed scientific investigations. We focus on a massive water injection performed in the year 2000 to enhance the productivity of the well GPK2 in the granitic basement, at approximately 5 km depth, and which induced more than 7000 earthquakes recorded by down-hole and surface seismic networks. We compare the location errors obtained from the joint or the separate use of the down-hole and surface networks. Besides the quantification of location uncertainties caused by picking uncertainties, the impact of the numerical precision of the picked arrival times as provided in a reference catalogue is investigated. The velocity model is also modified to mimic possible effects of a massive water injection and to evaluate its impact on earthquake hypocentres. It is shown that the use of the down-hole network in addition to the surface network provides smaller location uncertainties but can also lead to larger inaccuracies. Hence, location uncertainties would not be well representative of the location errors and interpretation of the seismicity distribution possibly biased. This result also emphasizes that it is still necessary to properly describe the seismic propagation medium even though the addition of down-hole sensors increases the coverage of a surface network. [ABSTRACT FROM AUTHOR]

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Copyright of Zeitschrift für Herz-, Thorax- und Gefaesschirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chorioamniotic membrane separation (CMS) comprises cases of spontaneous and iatrogenic detachment between the amniotic and chorionic membranes, with various fetal outcomes due to possible complications, particularly the formation of constrictive amniotic bands and preterm rupture of membranes. In the absence of mandatory management standards conservative monitoring is the most reported approach. In the case we present here, close sonographic surveillance afforded us the opportunity to observe the process from CMS to amnion rupture with the formation of constrictive amniotic bands and threatened cord impairment via constrictive margins of the amniotic sac. Despite the complicated background of reduced membranous layers in ruptured CMS, we performed a successful fetoscopic intervention with band release at 24 weeks' gestation and the pregnancy was prolonged to 34 weeks under close monitoring. [ABSTRACT FROM AUTHOR]

FLT3 defines a promising target for the treatment of acute myeloid leukemia (AML). In contrast to their efficacy in cell lines, FLT3-specific inhibitors as single agents have only modest clinical activity in patients with AML. As demonstrated here, overexpression of anti-apoptotic proteins of the BCL2 family leads to resistance against FLT3 inhibitors in a hematopoietic cell line model with activating FLT3 mutations. The susceptibility to FLT3 inhibition could be restored by treatment with the novel BH3 mimetic ABT-737. Primary AML samples tested in our study showed a high expression of BCL2 protein, but not of BCL-xL or MCL1. BCL2 protein levels were not reduced after dephosphorylation of FLT3 and its downstream target STAT5 in patient samples with FLT3 internal tandem duplications. Interestingly, treatment with ABT-737 caused apoptotic cell death in all primary AML samples at submicromolar level and synergized efficiently with FLT3 inhibition in AML samples with activating FLT3 mutations. In contrast to AML cell lines, BCR-ABL transformed human cells showed resistance to ABT-737, which might be due to the induction of MCL1 by BCR-ABL. Inhibition of BCL2 family members might define a novel highly efficient and specific strategy in the combined or monotreatment of AML.Leukemia (2007) 21, 1763–1772; doi:10.1038/sj.leu.2404776; published online 7 June 2007 [ABSTRACT FROM AUTHOR]

Background: Adequate visualization of the placenta or umbilical cord during fetoscopic procedures in complicated monochorionic twin pregnancies may be difficult because of placental position and spatial constraints, as well as stained amniotic fluid. Partial amniotic carbon dioxide insufflation (PACI) has made it possible to overcome these obstacles in other fetoscopic procedures, but its value has not yet been reported in monochorionic twins.Methods: Partial amniotic carbon dioxide insufflation was carried out in five expectant women with complicated monochorionic twin pregnancies between 19 + 6 to 29 + 4 weeks of gestation when adequate fetoscopic visualization of pathological placental surface vessels or the umbilical cord was impossible because of stained or too little amniotic fluid. In four cases, five fetoscopic laser ablations of pathological placental vessels in twin-to-twin transfusion syndrome (TTTS) were performed. In one discordant twin pregnancy with TTTS, PACI was carried out in order to achieve umbilical cord ligation in a recipient with omphalocele and cardiac malformation.Results: Partial amniotic carbon dioxide insufflation offered superior visualization and did not result in any acute maternal or fetal complications. After fetoscopic laser coagulation, three women delivered one fetus at 27 + 5, two fetuses at 28 + 6, and two fetuses at 35 + 4 weeks of gestation, respectively. One set of twins with TTTS was lost. Following umbilical cord ligation, the surviving twin was delivered at 37 + 2 weeks of gestation.Conclusions: Partial amniotic carbon dioxide insufflation may facilitate fetoscopic procedures in complicated monochorionic twin pregnancies when conventional fetoscopic approaches within amniotic fluid meet difficulties. Further studies are required to allow assessment of benefits, risks, and safety margins of the new approach before it can generally be recommended. [ABSTRACT FROM AUTHOR]

Background: In order to minimize maternal trauma from current techniques for temporary fetoscopic tracheal occlusion, we tried to develop a percutaneous fetoscopic technique in sheep.Methods: In nine ewes between 77 and 128 days of gestation, the amniotic cavity was entered percutaneously. Each fetus was positioned and the feasibility of fetal laryngoscopy and percutaneous fetoscopic tracheal balloon occlusion was assessed.Results: Percutaneous intraamniotic access, fetal positioning, oropharyngeal sheath insertion, and fetoscopic laryngoscopy were achieved in all nine fetal sheep. Following some technical modifications to the working channel of the fetoscope, percutaneous fetoscopic tracheal balloon occlusion was successfully achieved in the last seven sheep.Conclusion: Percutaneous fetoscopic balloon occlusion of the fetal trachea can effectively and safely be achieved in sheep. Because intraamniotic spatial relationships, fetal position, and umbilical cord length are technically less favorable in sheep, our operative techniques might be feasible in humans even if difficult intraamniotic conditions are encountered. [ABSTRACT FROM AUTHOR]

Background: In order to minimize maternal trauma from open fetal surgery for prenatal coverage of fetal myelomeningoceles in humans, we assessed the feasibility of a percutaneous fetoscopic approach in sheep.Methods: In seven ewes between 90 and 100 days of gestation, the amniotic cavity was entered percutaneously. Each fetus was postured and a full-thickness skin lesion was created in the lumbosacral region. Then, the feasibility of covering this lesion with a patch and fetal skin by standard endoscopic suturing techniques (n = 3) or robot assistance (n = 4) was assessed.Results: Percutaneous fetoscopic patch and skin coverage of the full-thickness skin lesion was achieved in six of the seven fetal sheep. Five fetuses survived gestation and were delivered healthy.Conclusions: Percutaneous fetoscopic posturing and patch coverage of lumbosacral full-thickness skin lesions can effectively and safely be achieved in sheep. This approach promises to provide a substantial reduction of maternal trauma from fetal surgery for myelomeningoceles. [ABSTRACT FROM AUTHOR]

Abnormal flow profiles in the ductus venosus during early pregnancy may aid in diagnosing chromosomopathies, malformations, congenital heart disease, and twin-twin transfusion syndrome in monochorionic twins. Whereas reference values of ductus venosus flow velocities and waveform indices for the late first and early second trimester have been reported in singletons, similar reference values for multiple pregnancies have not been established in this age group. Therefore, the aim of the present ultrasound study in 119 multichorionic and 14 monochorionic multiples in human fetuses between 10–14 weeks of gestation was to establish reference values for ductus venosus flow waveform indices for multiple pregnancies. Data in multiples were compared with those of 607 singletons. Analysis of the ductus venosus (DV) flow velocity waveforms consisted of the calculation of the pulsatility index (PIV) and peak velocity index (PVIV) for veins. Comparing the data of singletons and multichorionic multiples, no statistically significant differences were observed between the two groups in any of the assessed Doppler parameters. The DV Doppler parameters of the 14 monochorionic twins that were analysed separately in order to avoid any potential bias from preclinical twin-twin transfusion syndrome were also found within the normal ranges. In the study population fetal heart rate did neither significantly correlate with PIV nor with PVIV. PIV and PVIV decreased from 10 to 14 weeks gestation. A 2.9% rate of absent or reverse flow during atrial contraction in normal fetuses at 10–14 weeks gestation was found and needs to be taken into consideration when this pattern is defined abnormal in screening tests for fetal chromosomopathies or congenital heart disease. [ABSTRACT FROM AUTHOR]

Background: Recent efforts to develop procedures for fetoscopic fetal cardiac interventions have been prompted by the development of severe secondary damage to the fetal heart due to semilunar valvar obstructions and the poor outcome of therapy-refractory fetal arrhythmias. The purpose of our manuscript is to analyze and share our experience with the creation of an operative setup for these procedures in sheep.Methods: We studied a total of 48 fetal sheep between 81 and 106 days of gestation (term, 145 days). After entering the amniotic cavity by a percutaneous approach, we performed various fetoscopic fetal cardiac procedures. We analyzed the success of percutaneous fetal access, methods of trocar support, the incidence and management of trocar dislodgement or accidental insertion into the chorioamniotic space, problems related to amniotic insufflation and trocar placement, as well as techniques for fetal posturing and uterine closure.Results: Percutaneous fetal access was achieved in all sheep. The use of resterilizable trocars substantially decreased the costs of our procedures. Utilizing a percutaneous transuterine purse-string suture for trocar support helped to minimize the number of nonabsorbable T-fasteners remaining inside the uterus postoperatively. As complications such as trocar dislodgement, insertion of the trocar into the chorioamniotic space, and problems with intraamniotic insufflation and gas loss were mastered, conversion to an open operative approach was never required. A novel strategy that we devised for percutaneous fetal posturing permitted adequate fetal posturing with ease and minimal trauma to the fetal skin.Conclusion: As operative techniques have become more refined, the feasibility of performing fetoscopic fetal cardiac interventions in human fetuses now depends mainly on technical improvements in imaging and interventional catheters, as well as advances in pacemaker equipment. [ABSTRACT FROM AUTHOR]

Background: Maternal morbidity and preterm labor from fetal surgery might be minimized by a percutaneous technique for fetal access and uterine closure.Methods: In each of 16 ewes, we inserted three trocars percutaneously into the amniotic cavity using ultrasound and fetoscopic guidance. In six ewes, percutaneous uterine closure after the procedure was attempted. We assessed feasibility and acute complications of our technique during surgery and at autopsy.Results: We achieved percutaneous fetal access in 14 ewes and closed the uterus percutaneously in all six ewes attempted. Fetal injury was related to amnioinfusion or fixation of chorioamniotic membranes. Other complications were trocar dislodgment and damage to uterine wall and chorioamniotic membranes. The latter complication was prevented using balloon-tipped trocars.Conclusions: Percutaneous intraamniotic access and uterine closure for fetoscopic surgery can be achieved reliably with little maternal and fetal morbidity in sheep. Minor modifications are desired to apply this approach in humans. [ABSTRACT FROM AUTHOR]

Background: Cardiac procedures in exteriorized fetuses or assisted by fetoscopy require monitoring capabilities not attended by conventional maternal transabdominal echocardiography.Methods: We, therefore, assessed the potential of fetal transesophageal echocardiography (TEE) utilizing an intravascular ultrasound catheter (IVUC) for fetal cardiac monitoring. We inserted a 10-F-10-MHz IVUC into the esophagus in 12 exteriorized fetal sheep and by a fetoscopic approach in 4 fetal sheep. Cardiac events were observed. Heart rate, cardiac rhythm, patency of the foramen ovale and ductus arteriosus, and the width of the branch pulmonary arteries could be assessed in all fetuses. Ventricular contractility could be assessed only in fetuses weighing less than 2.5 kg. Larger fetuses did not allow adequate imaging of the apical portion of the ventricles because of limited tissue penetration of the IVUC. Fetal TEE permitted placing small guide wires in the cardiac atria and left ventricle. Short-lived premature beats following intracardiac manipulations of these wires could be observed by fetal TEE in all cases.Results: At autopsy, no complications from IVUC insertion were observed in the exteriorized fetuses. Fetoscopic placement of the IVUC resulted in minor perioral skin erosion in two nonexteriorized fetuses.Conclusions: In conclusion, fetal TEE can be achieved with minor fetal injury and may provide useful information during open and fetoscopic cardiac procedures. Further improvements in IVUC design will permit the application of this technique to monitor human fetal cardiac procedures. [ABSTRACT FROM AUTHOR]