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1.
Ultraschall Med ; 37(3): 297-302, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27093520

ABSTRACT

The early fetal ultrasound assessment at 11 - 13(+6) weeks of gestation remains the cornerstone of care despite the progress in diagnosing fetal chromosomal defects using cell-free fetal DNA (cffDNA) from the maternal circulation. The measurement of nuchal translucency (NT) allows the risk calculation for the fetal trisomies 21, 18 and 13 but also gives information on those fetal chromosomal defects which are at present unable to be detected using cffDNA. Nuchal translucency is the only auditable parameter at 11 - 13(+6) weeks and gives thus information on the quality of the first trimester anomaly scan. In addition it gives indirect information on the risks for fetal defects and for cardiac anomalies. Also the chances for a healthy live baby can be estimated. As experience with first trimester anomaly scanning increases, and the resolution of the ultrasound equipment has increased substantially, more and more details of the fetal anatomy become accessible at the first trimester scan. Therefore fetal anatomical defects and complex anomalies have become amenable to examination in the first trimester. This guideline describes compulsory and optional parameters for investigation at the first trimester scan and outlines a structured method of examining a first trimester fetus at 11 - 13(+6) weeks of gestation.


Subject(s)
Pregnancy Trimester, First , Quality Assurance, Health Care/standards , Ultrasonography, Prenatal/standards , Biometry , Chromosome Aberrations/embryology , Endosonography , Female , Humans , Nuchal Translucency Measurement/standards , Pregnancy , Pregnancy Trimester, Second , Societies, Medical , Ultrasonography, Doppler/standards
2.
Prenat Diagn ; 35(3): 228-35, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25346419

ABSTRACT

OBJECTIVE: The aim of this article is to study secondary cranial signs in fetuses with spina bifida in a precisely defined screening period between 18 + 0 and 22 + 0 weeks of gestation. METHOD: On the basis of retrospective analysis of 627 fetuses with spina bifida, the value of indirect cranial and cerebral markers was assessed by well-trained ultrasonographers in 13 different prenatal centres in accordance with the ISUOG (International Society of Ultrasound in Obstetrics and Gynecology) guidelines on fetal neurosonography. RESULTS: Open spina bifida was diagnosed in 98.9% of cases whereas 1.1% was closed spina bifida. Associated chromosomal abnormalities were found in 6.2%. The banana and lemon signs were evident in 97.1% and 88.6% of cases. Obliteration of the cisterna magna was seen in 96.7%. Cerebellar diameter, head circumference and biparietal diameter were below the 5th percentile in chromosomally normal fetuses in 72.5%, 69.7% and 52%, respectively. The width of the posterior horn of the lateral ventricle was above the 95th percentile in 57.7%. The secondary cranial and cerebral signs were dependent on fetal chromosome status and width of the posterior horn. Biparietal diameter was also dependent on the chromosome status with statistical significance p = 0.0068. Pregnancy was terminated in 89.6% of cases. CONCLUSION: In standard measuring planes, lemon sign, banana sign and an inability to image the cistern magna are very reliable indirect ultrasound markers of spina bifida. © 2014 John Wiley & Sons, Ltd.


Subject(s)
Cerebellum/diagnostic imaging , Cerebrum/diagnostic imaging , Cisterna Magna/diagnostic imaging , Pregnancy Trimester, Second , Skull/diagnostic imaging , Spina Bifida Cystica/diagnostic imaging , Spina Bifida Occulta/diagnostic imaging , Abnormalities, Multiple/diagnostic imaging , Adolescent , Adult , Chromosome Disorders/complications , Cohort Studies , Female , Germany , Humans , Pregnancy , Retrospective Studies , Spina Bifida Cystica/complications , Spina Bifida Occulta/complications , Ultrasonography, Prenatal , Young Adult
3.
Ultraschall Med ; 36(1): 40-6, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25255236

ABSTRACT

PURPOSE: To examine combined first trimester screening (FTS), noninvasive prenatal testing (NIPT) and a two-step policy that combines FTS and NIPT in screening for aneuploidy. MATERIALS AND METHODS: Retrospective study involving 21,052 pregnancies where FTS was performed at the Praxis Praenatal.de in Duesseldorf, Germany. In each case, the sum risk of trisomy 21, 18 and 13 was computed. We assumed that NIPT detects 99 %, 98 %, 90 % and 99 % of cases with trisomy 21, 18, 13 and sex chromosomal abnormalities and that the false-positive rate is 0.5 %. The following screening policies were examined: NIPT or FTS with sum risk cut-offs of 1 in 50 and 1 in 250 in all patients or a two-step-policy with FTS in all patients followed by NIPT in the intermediate sum risk group. For the intermediate risk group, sum risk cut-offs of 1 in 50 and 1 in 1000 and 1 in 150 and 1 in 500 were used. RESULTS: There were 127, 34, 13 and 15 pregnancies with trisomy 21, 18, 13 and sex chromosomal abnormalities. 23 fetuses had other chromosomal abnormalities with an increased risk for adverse outcome that are not detectable by NIPT. 20,840 pregnancies were classified as normal as ante- and postnatal examinations did not show any signs of clinically significant chromosomal abnormalities. FTS with a sum risk cut-off of 1 in 50 and 1 in 250 detects 81 % and 91 % for all aneuploidies. NIPT detects 88 % of the respective pregnancies. The 2-step approach with sum risk cut-offs of 1 in 50 and 1 in 1000 detects 94 % of all aneuploidies. With sum risk cut-offs of 1 in 150 and 1 in 500, the detection rate is 93 %. CONCLUSION: A 2-step policy with FTS for all patients and NIPT in the intermediate risk group results in the highest detection rate of all aneuploidies.


Subject(s)
Chromosome Aberrations , Pregnancy Trimester, First , Prenatal Diagnosis , Ultrasonography, Prenatal , Adult , Chromosome Disorders/diagnostic imaging , Chromosome Disorders/embryology , Chromosomes, Human, Pair 13/diagnostic imaging , Chromosomes, Human, Pair 18/diagnostic imaging , Down Syndrome/diagnostic imaging , Down Syndrome/embryology , Female , Germany , Humans , Predictive Value of Tests , Pregnancy , Pregnancy Outcome , Retrospective Studies , Sex Chromosome Aberrations/embryology , Trisomy , Trisomy 13 Syndrome , Trisomy 18 Syndrome
4.
Ultraschall Med ; 35(3): 229-36, 2014 Jun.
Article in German | MEDLINE | ID: mdl-24764214

ABSTRACT

In the last decades, prenatal screening for aneuploidy has become increasingly effective. While first trimester combined screening is considered to be the current gold standard, the use of cell-free fetal DNA (cffDNA), which is also called noninvasive prenatal testing (NIPT), will result in a change of paradigm. Respective studies indicate that in screening for trisomy 21, the detection and false-positive rates are 99 % and 0.1 %, respectively. For trisomies 18 and 13, there is less evidence but recent studies report detection rates of 98 % and 86 %. Despite the excellent results in screening for trisomy 21, NIPT should not be considered as a diagnostic test. Due to the costs of NIPT, it is unlikely that NIPT will be applied in the near future in population-based screening for trisomy. In addition, the scope of the current approach in first trimester screening exceeds the screening for aneuploidy as it is possible to assess the risk for various pregnancy complications. Therefore, a combination of both NIPT and first trimester combined screening seems reasonable. Both examinations could be applied in a contingent model where the latter is offered to everyone and NIPT is restricted to women with an intermediate risk after first trimester combined screening. Such a policy would result in a detection rate of about 97 % for a false-positive rate of about 1 %. While NIPT currently focuses on screening for trisomy 21, 18, 13 and sex chromosomal abnormalities, the scope of NIPT will soon become broader. In this respect, some study groups have managed to examine the whole fetal genome within the course of the pregnancy. However, moral and ethical considerations need to be taken into account.


Subject(s)
Cell-Free System , Chromosome Aberrations , DNA/genetics , Genetic Testing/methods , Pregnancy Trimester, First , Prenatal Diagnosis , Aneuploidy , Chromosome Disorders/diagnosis , Chromosome Disorders/genetics , Chromosomes, Human, Pair 13/genetics , Chromosomes, Human, Pair 18/genetics , Down Syndrome/diagnosis , Down Syndrome/genetics , Female , Humans , Predictive Value of Tests , Pregnancy , Trisomy/diagnosis , Trisomy/genetics , Trisomy 13 Syndrome , Trisomy 18 Syndrome
5.
Rev Sci Instrum ; 95(9)2024 Sep 01.
Article in English | MEDLINE | ID: mdl-39287481

ABSTRACT

Sophisticated tools such as computer vision techniques in combination with 1D lineout type analyses have been used in automating the analysis of spectral data for high energy density (HED) plasmas. Standardized automation can solve the problems posed by the complexity of HED spectra and the quantity of data. We present a spectroscopic code written for automated and streamlined analysis of spatially resolved x-ray absorption data from the COAX platform on Omega-60. COAX uses radiographs and spectroscopic diagnostics to provide shock position and density information. We also obtain the more novel spectral-derived spatial profile of the supersonic radiation flow into a low-density foam. Considerable effort has been spent modernizing our previous spectroscopic analysis method, including the development of new tools characterized by a faster runtime and minimal user input to reduce bias and a testing suite for verifying the accuracy of the various functions within the code. The new code analyzes our spectroscopic images in 1-2 min, with added uncertainty and confidence.

6.
Ultraschall Med ; 34(2): 157-61, 2013 Apr.
Article in English | MEDLINE | ID: mdl-22161619

ABSTRACT

PURPOSE: To compare various gestational ages and thresholds for diagnosing bowel dilatation in fetuses with gastroschisis and to evaluate the prognostic value of bowel dilatation for predicting postnatal bowel atresia and neonatal outcomes. MATERIALS AND METHODS: This was a retrospective observational study conducted from March 1997 to September 2009 that included 78 pregnancies with fetal gastroschisis. The predictive value of prenatal bowel dilatation for neonatal bowel atresia and postnatal complications was investigated in three subgroups: those with bowel dilatations ≥ 10 mm at a gestational age < 27 + 0 weeks, ≥ 10 mm at a gestational age < 30 + 0 weeks and ≥ 18 mm at a gestational age ≥ 30 weeks. RESULTS: Prenatally, 6 %, 81 % and 13 % of the bowel malformations were identified in the first, second and third trimesters, respectively. There were three stillbirths and three neonatal deaths, and the mean gestational age at delivery was 35.4 weeks (range 31 + 4 to 41 + 6). Bowel atresia was significantly correlated with prenatal bowel dilatation in all three subgroups. Bowel dilatations of ≥ 10 mm before 30 + 0 gestational weeks achieved the best performance in predicting bowel atresia, with a sensitivity of 89 % (8 / 9) and a specificity of 79 % (30 / 38). A prenatal bowel diameter ≥ 10 mm through 30 completed weeks was also the best predictor of a prolonged neonatal hospital stay ≥ 8 weeks (sensitivity = 61.1, 11 / 18, p = 0.002). CONCLUSION: Fetuses with isolated gastroschisis successfully underwent postnatal surgery in most cases (93.2 %), except for one termination, one intrauterine death and 3 cases of neonatal death. A fetal bowel dilatation > 10 mm before 30 + 0 weeks had the highest predictive value for postnatal bowel complications.


Subject(s)
Gastroschisis/diagnostic imaging , Intestinal Atresia/diagnostic imaging , Intestines/diagnostic imaging , Pregnancy Trimester, First , Pregnancy Trimester, Second , Ultrasonography, Prenatal/methods , Dilatation, Pathologic , Female , Fetal Death , Gastroschisis/surgery , Humans , Infant, Newborn , Intensive Care Units, Neonatal , Intestinal Atresia/surgery , Intestines/pathology , Length of Stay , Male , Pregnancy , Prognosis , Sensitivity and Specificity , Statistics as Topic , Stillbirth , Young Adult
7.
Rev Sci Instrum ; 94(2): 023504, 2023 Feb 01.
Article in English | MEDLINE | ID: mdl-36859010

ABSTRACT

In many inertial confinement fusion (ICF) experiments, the neutron yield and other parameters cannot be completely accounted for with one and two dimensional models. This discrepancy suggests that there are three dimensional effects that may be significant. Sources of these effects include defects in the shells and defects in shell interfaces, the fill tube of the capsule, and the joint feature in double shell targets. Due to their ability to penetrate materials, x rays are used to capture the internal structure of objects. Methods such as computational tomography use x-ray radiographs from hundreds of projections, in order to reconstruct a three dimensional model of the object. In experimental environments, such as the National Ignition Facility and Omega-60, the availability of these views is scarce, and in many cases only consists of a single line of sight. Mathematical reconstruction of a 3D object from sparse views is an ill-posed inverse problem. These types of problems are typically solved by utilizing prior information. Neural networks have been used for the task of 3D reconstruction as they are capable of encoding and leveraging this prior information. We utilize half a dozen, different convolutional neural networks to produce different 3D representations of ICF implosions from the experimental data. Deep supervision is utilized to train a neural network to produce high-resolution reconstructions. These representations are used to track 3D features of the capsules, such as the ablator, inner shell, and the joint between shell hemispheres. Machine learning, supplemented by different priors, is a promising method for 3D reconstructions in ICF and x-ray radiography, in general.

8.
Ultrasound Obstet Gynecol ; 37(4): 444-9, 2011 Apr.
Article in English | MEDLINE | ID: mdl-20645398

ABSTRACT

OBJECTIVE: To examine the prevalence of reversed a-wave in the ductus venosus, tricuspid regurgitation and absent nasal bone, in a second-trimester population undergoing amniocentesis, after exclusion of major fetal defects and to estimate the performance in screening for trisomy 21 based on maternal age and these markers in a general population. METHODS: This was a retrospective study involving pregnancies undergoing amniocentesis due to increased risk for trisomy 21, mainly because of advanced maternal age. Before the invasive procedure, an ultrasound examination was carried out to exclude major fetal defects and to examine the ductus venosus, tricuspid blood flow and the presence of the fetal nasal bone. Modeling techniques were used based on 20 000 euploid pregnancies and 20 000 pregnancies with trisomy 21 to assess the screening performance in a general population. RESULTS: The study population consisted of 3613 euploid pregnancies and 35 cases with trisomy 21. In the euploid group, reversed flow in the ductus venosus, tricuspid regurgitation and an absent nasal bone was observed in 1.7%, 1.5% and 0.1% of cases, respectively. In the trisomic group, these markers were found in 14.3%, 11.4% and 14.3% of cases, respectively. For a 5% false-positive rate, the detection rate in screening for trisomy 21, based on maternal age and either ductus venosus, tricuspid blood flow or nasal bone would be 33.8%, 32.4% or 31.4%, respectively. Screening by maternal age alone would detect 29.0% of the fetuses with trisomy 21. Receiver-operating characteristics curve analysis showed a slight but significant improvement in screening performance for trisomy 21 based on the inclusion of these markers. CONCLUSION: Second-trimester ultrasound screening for trisomy 21 based on maternal age with additional assessment of the ductus venosus, tricuspid blood flow and the fetal nasal bone in otherwise normal-appearing fetuses is only marginally better than is screening by maternal age alone.


Subject(s)
Down Syndrome/diagnostic imaging , Nasal Bone/diagnostic imaging , Umbilical Veins/diagnostic imaging , Vena Cava, Inferior/diagnostic imaging , Adult , Amniocentesis , Biomarkers/analysis , Chorionic Gonadotropin, beta Subunit, Human/analysis , Female , Humans , Maternal Age , Nasal Bone/abnormalities , Nasal Bone/embryology , Nuchal Translucency Measurement , Pregnancy , Pregnancy Trimester, Second , Pregnancy-Associated Plasma Protein-A/analysis , Regional Blood Flow/physiology , Retrospective Studies , Tricuspid Valve Insufficiency/diagnostic imaging , Tricuspid Valve Insufficiency/physiopathology , Ultrasonography, Prenatal , Umbilical Veins/physiopathology , Vena Cava, Inferior/physiopathology
9.
J Nanosci Nanotechnol ; 11(10): 9175-80, 2011 Oct.
Article in English | MEDLINE | ID: mdl-22400319

ABSTRACT

In order to verify two microscopic models of the molecular nanomagnet Cr7Cd we analyze a number of thermodynamic quantities calculated for two sets of parameters. The first model, with only single ion anisotropy, was established on the basis of the thermodynamic properties (by fitting susceptibility and magnetization) whereas the second, with single ion and bond-dependent exchange anisotropies, was based on the inelastic neutron scattering and EPR spectra. The calculations are performed by means of non-perturbative, numerically exact quantum transfer matrix technique on large scale parallel computers. We demonstrate that the predictions of the models are consistent in the region of small magnetic fields which do not exceed 10 T and differ significantly in higher fields. Comparison with the experiment leads to a conclusion that better modeling of magnetic torque requires more complex microscopic model with single ion and bond-dependent exchange anisotropies.

10.
Ultraschall Med ; 32 Suppl 2: E108-14, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21877317

ABSTRACT

PURPOSE: The purpose of this study was to compare the prenatal detection of four congenital heart defects (CHDs) and the image quality of five corresponding ultrasound planes among obese, overweight and normal-weight women. MATERIALS AND METHODS: This was a retrospective cohort study of 54,846 pregnancies undergoing fetal echocardiography between 18 and 37 weeks of gestation in the years from 2000 to 2007. The women were categorized according to pre-pregnancy body mass index (BMI) as normal-weight (BMI < 25), overweight (BMI 25 - 29.9) and obese (BMI ≥ 30). Image quality and prenatal detection of atrioventricular septal defect (AVSD), double outlet right ventricle (DORV), tetralogy of fallot (TOF) and dextro transposition of the great arteries (D-TGA) were evaluated in the BMI strata. RESULTS: 108 cases with one of the considered CHDs were identified. The prevalence was significantly higher (relative risk = 2.04) in overweight or obese women (57/19,404 vs. 51/35,442, p < 0.0002) than in normal-weight women. In total 86.1% of CHDs were correctly identified prenatally (93/108, CI: 79.6%-92.6%), 84.3% (43/51) in the normal weight group, 88.6% (39/44) in the overweight group and 84.6% (11/13) in the obese group. The rate of insufficient ultrasound images increased from 6.4% in normal-weight patients to 17.4% in obese women within the 108 CHD cases. CONCLUSION: The prenatal detection of fetal AVSD, DORV, TOF and D-TGA was also satisfactory in overweight and obese patients, but image quality substantially decreases with an increasing maternal BMI. If there is a BMI-associated difference in the detection rate, it probably will not exceed 20%.


Subject(s)
Echocardiography/methods , Heart Defects, Congenital/diagnostic imaging , Image Enhancement , Obesity/diagnostic imaging , Obesity/physiopathology , Overweight/diagnostic imaging , Overweight/physiopathology , Pregnancy Complications/diagnostic imaging , Pregnancy Complications/physiopathology , Ultrasonography, Prenatal/methods , Adult , Body Mass Index , Cohort Studies , Double Outlet Right Ventricle/diagnostic imaging , Female , Heart Septal Defects/diagnostic imaging , Humans , Pregnancy , Retrospective Studies , Sensitivity and Specificity , Tetralogy of Fallot/diagnostic imaging , Transposition of Great Vessels/diagnostic imaging
12.
Ultraschall Med ; 32 Suppl 2: E134-40, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22161617

ABSTRACT

PURPOSE: To assess the spectrum of underlying diseases in cases of fetal anemia in which the cause was unknown at the time of first and second transfusion or thereafter. MATERIALS AND METHODS: All patients who underwent intrauterine transfusion were identified in the perinatal databases of two tertiary referral centers for prenatal medicine and treatment between 2002 and June 2010. RESULTS: 82 fetuses received intrauterine transfusion in the study period. A total of 356 transfusions were performed in these patients. The causes of fetal anemia in our cohort were alloimmunization (32), parvovirus infection (23), feto-fetal transfusion syndrome (9), sacrococcygeal teratoma (2) and cytomegalovirus infection (1). In the remaining 15 cases, the cause of fetal anemia was unknown at the time of first and second transfusion, and could only be ascertained in the further course of pregnancy, in the postnatal period or was ultimately left in doubt. In all cases markedly elevated peak systolic velocities in the middle cerebral artery accurately predicted fetal anemia. The final diagnosis in these cases was fetomaternal hemorrhage (4), Blackfan-Diamond anemia (1), diffuse neonatal hemangiomatosis with chorangioma (1), kaposi-like hemangioendothelioma (1), elliptocytosis (1), neonatal hemochromatosis (1), mucopolysaccharidosis type VII (1) and in 5 cases the cause of fetal anemia remained unexplained. The latter 5 cases had an uneventful postnatal course and did not require further transfusions in infancy. CONCLUSION: In cases of fetal anemia with negative indirect Coombs test and TORCH serology, rare causes of anemia have to be considered. Fetal studies should therefore include reticulocyte count, parameters of hemolysis, peripheral blood smear and fetal liver function tests. Maternal studies should involve a search for fetal red cells using flow cytometry rather than Kleihauer-Betke test.


Subject(s)
Anemia, Neonatal/etiology , Blood Transfusion, Intrauterine , Fetal Diseases/etiology , Ultrasonography, Prenatal , Anemia, Neonatal/epidemiology , Anemia, Neonatal/therapy , Causality , Coombs Test , Diagnosis, Differential , Female , Fetal Diseases/therapy , Gestational Age , Hemoglobinometry , Humans , Infant, Newborn , Pregnancy
13.
Rev Sci Instrum ; 92(3): 033532, 2021 Mar 01.
Article in English | MEDLINE | ID: mdl-33820092

ABSTRACT

Great strides have been made in improving the quality of x-ray radiographs in high energy density plasma experiments, enabled in part by innovations in engineering and manufacturing of integrated circuits and materials. As a consequence, the radiographs of today are filled with a great deal of detail, but few of these features are extracted in a systematic way. Analysis techniques familiar to plasma physicists tend toward brittle 1D lineout or Fourier transform type analyses. The techniques applied to process our data have not kept pace with improvements in the quality of our data. Fortunately, the field of computer vision has a wealth of tools to offer, which have been widely used in industrial imaging and, more recently, adopted in biological imaging. We demonstrate the application of computer vision techniques to the analysis of x-ray radiographs from high energy density plasma experiments, as well as give a brief tutorial on the computer vision techniques themselves. These tools robustly extract 2D contours of shocks, boundaries of inhomogeneities, and secondary flows, thereby allowing for increased automation of analysis, as well as direct and quantitative comparisons with simulations.

14.
Br J Cancer ; 103(1): 52-60, 2010 Jun 29.
Article in English | MEDLINE | ID: mdl-20531411

ABSTRACT

BACKGROUND: The current standard of care for pancreatic cancer is weekly gemcitabine administered for 3 of 4 weeks with a 1-week break between treatment cycles. Maximum tolerated dose (MTD)-driven regimens as such are often associated with toxicities. Recent studies demonstrated that frequent dosing of chemotherapeutic drugs at relatively lower doses in metronomic regimens also confers anti-tumour activity but with fewer side effects. METHODS: Herein, we evaluated the anti-tumour efficacy of metronomic vs MTD gemcitabine, and investigated their effects on the tumour microenvironment in two human pancreatic cancer xenografts established from two different patients. RESULTS: Metronomic and MTD gemcitabine significantly reduced tumour volume in both xenografts. However, K(trans) values were higher in metronomic gemcitabine-treated tumours than in their MTD-treated counterparts, suggesting better tissue perfusion in the former. These data were further supported by tumour-mapping studies showing prominent decreases in hypoxia after metronomic gemcitabine treatment. Metronomic gemcitabine also significantly increased apoptosis in cancer-associated fibroblasts and induced greater reductions in the tumour levels of multiple pro-angiogenic factors, including EGF, IL-1alpha, IL-8, ICAM-1, and VCAM-1. CONCLUSION: Metronomic dosing of gemcitabine is active in pancreatic cancer and is accompanied by pronounced changes in the tumour microenvironment.


Subject(s)
Adenocarcinoma/drug therapy , Antimetabolites, Antineoplastic/therapeutic use , Carcinoma, Pancreatic Ductal/drug therapy , Cell Hypoxia , Deoxycytidine/analogs & derivatives , Pancreatic Neoplasms/drug therapy , Adenocarcinoma/blood supply , Adenocarcinoma/pathology , Animals , Apoptosis/drug effects , Carcinoma, Pancreatic Ductal/blood supply , Carcinoma, Pancreatic Ductal/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Deoxycytidine/therapeutic use , Endothelial Cells/drug effects , Humans , Male , Mice , Pancreatic Neoplasms/blood supply , Pancreatic Neoplasms/pathology , Xenograft Model Antitumor Assays , Gemcitabine
15.
Ultrasound Obstet Gynecol ; 35(2): 183-90, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20101636

ABSTRACT

OBJECTIVE: To evaluate the intrauterine course and outcome of tricuspid atresia detected in the fetus. METHODS: This was a retrospective review of all confirmed cases of tricuspid atresia detected prenatally between 1998 and 2006 in three tertiary referral centers in Germany. RESULTS: Fifty-four cases of tricuspid atresia were detected prenatally during the study period and confirmed postnatally: 28 (51.9%) cases had a concordant ventriculoarterial connection of which 14 also had pulmonary outflow obstruction; 25 (46.3%) cases had a discordant ventriculoarterial connection of which 14 also had aortic outflow obstruction, six had pulmonary outflow tract obstruction and two had other associated intracardiac anomalies; and one (1.9%) had a common arterial trunk. The peak velocity index for veins in the ductus venosus was significantly elevated in 19 of the 37 (51.4%) cases assessed; however, this finding did not correlate with adverse intrauterine outcome. There were associated extracardiac anomalies in 12 cases: five with chromosomal anomalies, two with VACTERL association, one with unilateral renal agenesis, one with hypospadia, one with hydrothorax, one with megacystis and one with agenesis of the ductus venosus. Seventeen of the 54 (31.5%) cases underwent termination of pregnancy, two (3.7%) died in utero, two (3.7%) died in infancy and 33 (61.1%) children survived with a median follow-up of 26 (range, 12-120) months. Prenatal echocardiography correctly anticipated the postnatal course and the need for neonatal intervention in 29/35 (82.9%) continued pregnancies; in the remaining six (17.1%) cases the right outflow tract obstruction had been underestimated. CONCLUSIONS: Tricuspid atresia and the frequently associated intracardiac anomalies can be diagnosed in the fetus with considerable accuracy. A thorough search for extracardiac malformations should be performed in order to rule out chromosomal anomalies and multiple malformation syndromes. Elevated pulsatility in the ductus venosus does not indicate cardiac failure. The short-term overall survival in continued pregnancies in our study exceeded 89%, with the greatest rate of loss being in the first year of postnatal life.


Subject(s)
Abnormalities, Multiple/diagnostic imaging , Fetal Diseases/diagnostic imaging , Fetal Heart/diagnostic imaging , Tricuspid Atresia/diagnostic imaging , Abnormalities, Multiple/genetics , Abnormalities, Multiple/mortality , Abortion, Induced , Female , Fetal Diseases/epidemiology , Fetal Diseases/genetics , Germany/epidemiology , Gestational Age , Humans , Infant, Newborn , Male , Pregnancy , Pregnancy Outcome , Retrospective Studies , Tricuspid Atresia/genetics , Tricuspid Atresia/mortality , Ultrasonography, Prenatal
16.
Rev Sci Instrum ; 91(7): 073102, 2020 Jul 01.
Article in English | MEDLINE | ID: mdl-32752842

ABSTRACT

Cubic spline interpolation is able to recover temporally and spectrally resolved soft x-ray fluxes from an array of K-edge filtered x-ray diodes without the need for a priori assumptions about the spectrum or the geometry of the emitting volume. The mathematics of the cubic spline interpolation is discussed in detail. The analytic nature of the cubic spline solution allows for analytical error propagation, and the method of calculating the error for radiation temperature, spectral power, and confidence intervals of the unfolded spectrally resolved flux is explained. An unfold of a blackbody model demonstrates the accuracy of the cubic spline unfold. Tests of cubic spline performance using spectrally convolved detailed atomic model simulation results have been performed to measure the method's ability to conserve spectral power to within a factor of 2 or better in line-dominated regimes. The unfold is also demonstrated to work when information from the x-ray diode array is limited due to high signal-to-noise ratios or the lack of signal due to over-attenuation or over-filtration of the x-ray diode signal. The robustness of the unfold with respect to background subtraction and raw signal processing, signal alignment between diode traces, limited signal information, and initial conditions is discussed. Results from an example analysis of a halfraum drive are presented to demonstrate the capabilities of the unfold in comparison with previously established methods.

17.
Sci Rep ; 10(1): 19218, 2020 11 05.
Article in English | MEDLINE | ID: mdl-33154474

ABSTRACT

To understand neurochemical brain responses to pain, proton magnetic resonance spectroscopy (1H-MRS) is used in humans in vivo to examine various metabolites. Recent MRS investigations have adopted a functional approach, where acquisitions of MRS are performed over time to track task-related changes. Previous studies suggest glutamate is of primary interest, as it may play a role during cortical processing of noxious stimuli. The objective of this study was to examine the metabolic effect (i.e., glutamate) in the anterior cingulate cortex during noxious stimulation using fMRS. The analysis addressed changes in glutamate and glutamate + glutamine (Glx) associated with the onset of pain, and the degree by which fluctuations in metabolites corresponded with continuous pain outcomes. Results suggest healthy participants undergoing tonic noxious stimulation demonstrated increased concentrations of glutamate and Glx at the onset of pain. Subsequent reports of pain were not accompanied by corresponding changes in glutamate of Glx concentrations. An exploratory analysis on sex revealed large effect size changes in glutamate at pain onset in female participants, compared with medium-sized effects in male participants. We propose a role for glutamate in the ACC related to the detection of a noxious stimulus.


Subject(s)
Glutamic Acid/metabolism , Glutamine/metabolism , Gyrus Cinguli/metabolism , Pain/metabolism , Adult , Female , Functional Neuroimaging , Gyrus Cinguli/diagnostic imaging , Humans , Magnetic Resonance Spectroscopy , Male , Pain/diagnostic imaging , Young Adult
19.
J Biomech ; 42(3): 349-54, 2009 Feb 09.
Article in English | MEDLINE | ID: mdl-19147144

ABSTRACT

UNLABELLED: Accurate measurement of cartilage deformation in loaded cadaver hip joints could be a valuable tool to answer clinically relevant research questions. MRI is a promising tool, but its use requires an understanding of cartilage deformation and recovery properties in the intact hip. Our objective was to answer the following questions: (1) How long does it take for hip cartilage to reach a deformed steady-state thickness distribution under simulated physiological load, and how much does the cartilage deform? (2) How long does it take for hip cartilage to return to the original cartilage thickness distribution once the load is removed? METHODS: Five human hip specimens were axially loaded to 1980N in a 7T MR scanner and scanned every 15min throughout loading. One specimen was scanned every hour throughout recovery from load. One repeatability specimen was loaded and scanned every day for 4 days. Hip cartilage was segmented as a single unit and thickness was measured radially. RESULTS: The hip cartilage reached a steady-state thickness distribution after 225min of load, and 16.5h of recovery. Mean strain after 225min of load was 30.9%. The repeatability specimen showed an average day-to-day change in mean cartilage thickness of 0.10mm over 4 days of data collection. The amount of deformation (0.96mm) was far greater than the image resolution (0.11mm) and error due to repeatability (0.10mm). CONCLUSION: Using an ex vivo model, this method has potential for assessing changes in hip cartilage strain due to injury or surgical intervention.


Subject(s)
Cartilage/anatomy & histology , Hip Joint/anatomy & histology , Hip Joint/physiology , Adult , Cartilage/physiology , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged
20.
Sci Rep ; 9(1): 6737, 2019 05 01.
Article in English | MEDLINE | ID: mdl-31043639

ABSTRACT

For years, the issues related to the origin of the Goths and their early migrations in the Iron Age have been a matter of hot debate among archaeologists. Unfortunately, the lack of new independent data has precluded the evaluation of the existing hypothesis. To overcome this problem, we initiated systematic studies of the populations inhabiting the contemporary territory of Poland during the Iron Age. Here, we present an analysis of mitochondrial DNA isolated from 27 individuals (collectively called the Mas-VBIA group) excavated from an Iron Age cemetery (dated to the 2nd-4th century A.D.) attributed to Goths and located near Maslomecz, eastern Poland. We found that Mas-VBIA has similar genetic diversity to present-day Asian populations and higher diversity than that of contemporary Europeans. Our studies revealed close genetic links between the Mas-VBIA and two other Iron Age populations from the Jutland peninsula and from Kowalewko, located in western Poland. We disclosed the genetic connection between the Mas-VBIA and ancient Pontic-Caspian steppe groups. Similar connections were absent in the chronologically earlier Kowalewko and Jutland peninsula populations. The collected results seem to be consistent with the historical narrative that assumed that the Goths originated in southern Scandinavia; then, at least part of the Goth population moved south through the territory of contemporary Poland towards the Black Sea region, where they mixed with local populations and formed the Chernyakhov culture. Finally, a fraction of the Chernyakhov population returned to the southeast region of present-day Poland and established the archaeological formation called the "Maslomecz group".


Subject(s)
Genetic Structures , Genetics, Population , Human Migration , White People/genetics , Archaeology , Chromosome Mapping , Cluster Analysis , Europe , Female , Genetic Markers , Genetic Variation , Geography , Haplotypes , Humans , Male
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