| 1. |
- Brodszki, Jana, et al.
(författare)
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Reproducibility of ultrasonic fetal volume blood flow measurements
- 1998
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Ingår i: Clinical Physiology. - : Wiley. - 1365-2281 .- 0144-5979. ; 18:5, s. 479-485
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Tidskriftsartikel (refereegranskat)abstract
- The intraobserver reproducibility of ultrasonic volume blood flow measurements in the human fetus was evaluated in this study. A new approach, simultaneous measurement of the vessel diameter and the flow velocity with a pulsed-wave Doppler ultrasound synchronized with a real-time ultrasound phase-locked echo-tracking system, was used to estimate volume blood flow (VBF) in the fetal descending aorta. Measurements were performed in a longitudinal study on 20 normally grown fetuses. Intraobserver reproducibility of repeated estimations of mean blood flow velocities throughout gestation was very good, with high values of intraclass correlation coefficient (IntraCC 0.80-0.91) and low values of coefficient of variation (CV 4-11%). The IntraCC of repeated vessel diameter measurements throughout gestation was low (0.30-0.68), whereas the values of CV were acceptable (< 12%), with the exception of the period between 140 and 167 gestational days (CV > 12%). The lower reproducibility of vessel diameter measurement contributed directly to the relatively low reproducibility of VBF estimations overall (IntraCC 0.25-0.70; CV 17-28%), as these are calculated from a formula using both flow velocity and vessel diameter. Nevertheless, the synchronized approach gives absolute values of vessel diameter, flow velocity and VBF comparable with values reported in the human fetus previously. The new method provides, by taking the vessel wall pulsations into consideration and by measuring diameter and velocity simultaneously, a more complete information on fetal haemodynamics and fetal physiology.
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| 2. |
- Ley, David, et al.
(författare)
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Respiratory distress syndrome in infants with impaired intrauterine growth
- 1997
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Ingår i: Acta Pædiatrica. - : Wiley. - 1651-2227 .- 0803-5253. ; 86:10, s. 1090-1096
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Tidskriftsartikel (refereegranskat)abstract
- The recently introduced intrauterine growth curve, based on ultrasonically estimated foetal weights, was retrospectively applied to an inborn population of 883 infants born before 33 gestational weeks at the University Hospital of Lund, during 1985-94. The estimation of birthweight deviation resulted in 630 (71.3%) infants with a birthweight appropriate for gestational age (AGA), 244 (27.6%) infants with a birthweight small for gestational age (SGA) and 9 (1.1%) infants with a birthweight large for gestational age. Birthweight deviation was associated with an increased mortality [odds ratio (OR) adjusted for gestational age 1.29 per SD (12%) change in birthweight for gestational age, 95% CI: 1.10-1.50; p = 0.002]. At gestational age 25-28 weeks, SGA-infants had an increased incidence of respiratory distress syndrome (RDS) as compared to AGA-infants (OR adjusted for gestational age: 1.98, 95% CI: 1.12-3.52; p = 0.019). At gestational age 29-32 weeks, SGA-infants had a lower incidence of RDS as compared to AGA-infants (OR adjusted for gestational age: OR 0.52, 95% CI: 0.34-0.80; p = 0.003). After adjustment for confounding variables, infants born at gestational age 25-28 weeks from mothers with pre-eclampsia, appeared to be a high-risk group for RDS, whereas at the age of 29-32 gestational weeks, negative birthweight deviation had a protective effect against RDS. Antenatal corticosteroid administration appeared to have a less beneficial effect on mortality, RDS and cerebral haemorrhage in infants born SGA vs in those born AGA.
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| 3. |
- Gudmundsson, Saemundur, et al.
(författare)
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Factors affecting color Doppler energy ultrasound recordings in an in-vitro model
- 1998
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Ingår i: Ultrasound in Medicine and Biology. - 0301-5629. ; 24:6, s. 899-902
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Tidskriftsartikel (refereegranskat)abstract
- Compared to conventional color Doppler ultrasound imaging, the new color Doppler modality "color Doppler energy" (CDE) has improved the possibility of visualizing blood vessels having low blood-flow velocities, but appears to be influenced by the settings of the ultrasound instrument and motion artefacts. The aim of this methodological study was to evaluate the effects of the different factors on the CDE signal. The CDE mode of a commercially available ultrasound system (Acuson 128 XP) was tested in an in vitro study. The effect of depth, angle of insonation, flow velocity, instrument power output, gain and other instrument settings were evaluated. The CDE signals obtained were stored on videotape and subsequently subjected to off-line computer analysis. The CDE signal intensity was found to be influenced mainly by fluid flow velocity, but was also affected by depth and instrument settings. Gain and power had, however, limited influence in this setting. Thus, the intensity of the CDE signal is influenced by several factors. Our results emphasize the need for optimum fixed preinstalled instrument settings when attempting to quantify organ perfusion by use of this new technique.
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| 4. |
- Karlsson, Bengt, et al.
(författare)
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Transvaginal ultrasonography of the endometrium in women with postmenopausal bleeding--a Nordic multicenter study
- 1995
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Ingår i: American Journal of Obstetrics and Gynecology. - : Elsevier BV. - 1097-6868 .- 0002-9378. ; 172:5, s. 1488-1494
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The purpose of this study was to use transvaginal ultrasonographic measurements to find the thickness of the endometrium below which the risk of endometrial abnormality in women with postmenopausal bleeding is low. STUDY DESIGN: This multicenter study was carried out at eight clinics in four Nordic countries. The study included 1168 women with postmenopausal bleeding scheduled for curettage Before the curettage was performed, the thickness of the endometrium was measured with transvaginal ultrasonography. The measurement included both endometrial layers (double-layer technique). The transvaginal ultrasonographic measurement was compared with the histopathologic diagnosis of the curettage specimens. RESULTS: In women with atrophic endometrium the mean endometrial thickness (+/- SD) was 3.9 +/- 2.5 mm. The corresponding figures for women with endometrial cancer were 21.1 +/- 11.8 mm. No malignant endometrium was thinner than 5 mm. In 30 women (2.8%) it was not possible to measure the thickness of the endometrium; one of these women had endometrial cancer. The 95% confidence limit for the probability of excluding endometrial abnormality was 5.5% when the endometrial thickness was < or = 4 mm as measured by transvaginal ultrasonography. CONCLUSION: The risk of finding pathologic endometrium at curettage when the endometrium is < or = 4 mm as measured by transvaginal ultrasonography is 5.5%. Thus in women with postmenopausal bleeding and an endometrium < or = 4 mm it would seem justified to refrain from curettage.
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| 5. |
- Laurini, Ricardo, et al.
(författare)
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Placental histology and fetal blood flow in intrauterine growth retardation
- 1994
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - 1600-0412. ; 73:7, s. 529-534
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE. To define the histological lesions in the placenta associated with abnormal blood flow findings and to evaluate their possible clinical significance. DESIGN. A prospective blind study. SETTING. A clinical study at a teaching hospital, Malmo General Hospital, University of Lund, Sweden, morphological studies of placentas being performed at the Institute of Pathology, University of Lausanne, Switzerland. MATERIAL. Thirty-seven pregnancies where intrauterine growth retardation (IUGR) was suspected. METHODS. Blood velocimetry of the fetal descending aorta, umbilical artery and vein, and the maternal arcuate artery, using 2.5 MHz pulsed wave Doppler ultrasound. Histological examination of at least five random samples from each placenta. MAIN OUTCOME MEASURES. Frequency of small-for-gestational age (SGA) newborns (birth weight < or = mean -2 s.d.) and of operative delivery for fatal distress. RESULTS. Only the presence of placental infarction was significantly associated with IUGR and with intrauterine findings of abnormal blood velocity in the fetal descending aorta and umbilical artery. CONCLUSION. Placental infarction would seem to be a valuable morphological marker of uteroplacental vascular disease related to IUGR and impaired fetal and umbilical blood flow.
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| 6. |
- Lövgren, Janita, et al.
(författare)
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Measurement of prostate-specific antigen and human glandular kallikrein 2 in different body fluids
- 1999
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Ingår i: Journal of Andrology. - 0196-3635. ; 20:3, s. 348-355
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Tidskriftsartikel (refereegranskat)abstract
- It has been demonstrated that prostate-specific antigen (PSA), in spite of its name, can be detected in body fluids and tumors from a variety of organs. Investigations have shown that human glandular kallikrein 2 (hK2), a related prostate-secreted protease, can activate the zymogen form of PSA, suggesting that the two enzymes might work as a functional unit, with hK2 as the activator molecule and PSA as the effector molecule. If this is true, then hK2 should be found together with PSA in body fluids other than seminal plasma, as well. Recently, a sensitive and specific assay was devised for hK2, enabling its measurement in picogram quantities. With this assay, the concentration of hK2 was determined in samples of seminal plasma, amniotic fluid, breast milk, and saliva. Simultaneously, the samples were assayed for molecular forms of PSA. In seminal plasma, the mean PSA concentration was 0.82 mg/ml, while the hK2 level was around two orders of magnitude lower: mean value, 6.4 microg/ml. Approximately the same ratio of PSA to hK2 as in seminal plasma was found in amniotic fluid and breast milk, but in most samples, the hK2 values were too low for direct measurements and had to be concentrated prior to analysis. Measurable levels of PSA, all in the free form, were detected in amniotic fluid at the thirteenth week of gestation and then gradually increased to levels around and over 1 microg/L from the twentieth week. Significant levels of PSA were detected in amniotic fluid collected at delivery, also. Measurable levels of mammary PSA were primarily detected in colostrum, with a range from less than 0.03 microg/L to 2.1 mg/L. Around half of the molecules were in complex with protease inhibitor. Most surprisingly, determinations on saliva samples showed that none of them had detectable PSA levels but had measurable concentrations of hK2 with a mean value, 0.09 microg/L. The presence in saliva suggests that hK2 can be the human equivalent to one of the mouse salivary kallikreins with important biological function, like the epidermal growth factor-binding protein or the gamma subunit of nerve growth factor. However, this was ruled out, as a phylogenetic analysis showed that the human and mouse glandular kallikreins evolved independently from a common precursor after the separation of the primate and rodent lineages. In conclusion, the measurements show that in addition to the previously known secretion in seminal plasma, hK2 is secreted in amniotic fluid, breast milk, and saliva. Furthermore, the concerted expression of PSA and hK2 in seminal plasma, amniotic fluid, and breast milk suggests that the two proteases might form a functional unit but not always as demonstrated by the sole presence of hK2 in saliva.
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| 7. |
- Maesel, A, et al.
(författare)
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Fetal cerebral blood flow velocity during labor and the early neonatal period
- 1994
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 4:5, s. 372-376
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Tidskriftsartikel (refereegranskat)abstract
- This study was performed to elucidate circulatory changes in the fetal cerebral circulation during uncomplicated labor and in early neonatal life. Eighteen healthy term singleton fetuses were followed longitudinally during labor. Using the transabdominal approach, and the color Doppler technique, the middle cerebral artery was identified and Doppler flow velocity waveforms recorded between and during uterine contractions. Neonatal recordings were made by insonating the middle cerebral artery from the temporal region before and immediately after the cutting of the umbilical cord, and at 1 hour and 1 day after birth. The recorded Doppler signals were evaluated for pulsatility index, heart rate, peak systolic flow velocity, end-diastolic flow velocity and time-averaged maximum velocity. There was no change in the pulsatility index between and during contractions (1.39 +/- 0.36 and 1.40 +/- 0.39, respectively, mean +/- SD). A significant decrease in the pulsatility index compared to fetal values was seen 4 min after birth (1.06 +/- 0.30, p < 0.01). One hour after birth, the pulsatility index values increased significantly (1.52 +/- 0.25, p < 0.001), to fall again between I hour and 1 day after birth (0.95 +/- 0.26, p < 0.001). Mechanical compression of the skull, blood gas changes and a decrease in ductal shunting may all have contributed to these changes. The present study has shown physiological neonatal circulatory adaptation and onset of breathing to cause manifest changes in cerebral blood flow velocity.
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| 8. |
- Maesel, A, et al.
(författare)
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Mode of delivery and perinatal cerebral blood flow
- 1996
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Ingår i: Early Human Development. - 1872-6232. ; 44:3, s. 85-179
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To ascertain whether the perinatal cerebral blood flow velocity differed between vaginally delivered appropriate for gestational age (vag. AGA) term babies, AGA babies delivered by Caesarean section (C.s. AGA), and small for gestational age (C.s. SGA) babies also delivered by Caesarean section. STUDY DESIGN: Forty-five babies were examined by Doppler ultrasound of the middle cerebral artery prior to and immediately after delivery, and at 1 h and 24 h after birth. The pulsatility index (PI) and time-averaged maximum velocity (TAMXV) were calculated. RESULTS: No differences in TAMXV were found between the vag. AGA and C.s. AGA groups at any of the four recordings. A significantly higher PI value was found in the C.s. AGA group 1 h after birth. The C.s. SGA group had lower PI values before and just after birth, but did not differ significantly from the C.s. AGA group at 1 h or 24 h after birth. CONCLUSIONS: The results suggest mode of delivery to have a transitory effect on cerebral vascular resistance in healthy term AGA babies. The C.s. SGA group differed in the initial recording just after birth, but later manifested similar blood flow velocities in middle cerebral artery as the C.s. AGA group.
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| 9. |
- Malcus, Peter, et al.
(författare)
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Doppler blood flow changes and placental morphology in pregnancies with third trimester hemorrhage
- 1992
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 1600-0412 .- 0001-6349. ; 71:1, s. 39-45
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Tidskriftsartikel (refereegranskat)abstract
- Combined real-time ultrasound and pulsed Doppler ultrasound examinations were performed in 67 patients with third trimester hemorrhage and other symptoms related to placental abruption, starting from the onset of symptoms to delivery. In 52 of the cases, placental morphology was investigated by light microscopy. Thirteen patients were ultimately given the diagnosis abruptio placentae. None of the morphological placental changes considered had any statistical relationship to placental abruption. Patients with placental centrocotyledon hemorrhages and infarction more often had abnormal umbilical artery flow velocity waveforms at the onset of symptoms, and more frequent abnormal arcuate artery flow velocity waveforms were found among those with placental infarction alone. Abnormal flow velocity waveforms in the umbilical and arcuate arteries were associated with placental abruption, both at the onset of symptoms and at the final examination before delivery. The results indicate an increased risk for placental abruption if the arcuate and/or umbilical artery flow velocity waveforms are abnormal in patients with third trimester hemorrhage.
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| 10. |
- Malcus, Peter, et al.
(författare)
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Waveform Pattern Recognition – A New Semiquantitative Method for Analysis of Fetal Aortic and Umbilical Artery Blood Flow Velocity Recorded by Doppler Ultrasound
- 1991
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Ingår i: Ultrasound in Medicine and Biology. - 0301-5629. ; 17:5, s. 453-460
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Tidskriftsartikel (refereegranskat)abstract
- A semiquantitative computerized waveform pattern recognition system for analysis of the fetal descending aortic and umbilical artery Doppler flow velocity waveforms is presented. Based on empirically and manually selected clinical recordings from both vessels, 11 computerized and normalized standard curves for the aorta (type curves A to K), and 10 curves for the umbilical artery (type curves a to j) were constructed. The best match between the normalized waveform and the standard curve was based on either the degree of absent diastolic flow or, in cases with positive diastolic flow, on the calculation of the least square sum of the difference. The pattern recognition was tested against conventional waveform indices and our older semiquantitative Blood Flow Class (BFC) system in 472 clinical consecutive Doppler recordings. A good correlation was found. This new relatively simple computer-based method for waveform analysis is now prospectively applied in clinical studies.
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