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- Akoka, S, et al.
(författare)
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Cerebral MRI on fetuses submitted to repeated cocaine administration during the gestation: an ovine model
- 1999
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Ingår i: European Journal of Obstetrics, Gynecology, and Reproductive Biology. - 0301-2115. ; 85:2, s. 185-190
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to determine the role of Magnetic Resonance Imaging (MRI) in investigating fetal cerebral lesions induced by long term exposure to cocaine during sheep pregnancy. Cerebral Magnetic Resonance Imaging was performed on two groups of fetuses at 125 days of gestation (normal gestation: 145 days). The control group consisted of eight fetuses of four pregnant ewes. The study group consisted of eight fetuses of four pregnant ewes receiving daily 140 mg/kg injection of cocaine from day 60 until delivery. The following MR sequences were applied: T1-weighted FLASH, and T2-weighted Fast-Spin-Echo. Cerebral images were evaluated semi quantitatively using the following criteria: Heterogenicity, contrast between grey and white matter, contours irregularity, hyposignal, lateral ventricle sizes. The brightness distribution and homogenicity of the images were analysed by means of edge pair distributions using a new computerized method originally designed for ultrasound images analysis developed by Ultrasight inc (USA). (1) Flash T1: Heterogenic areas and irregular contours were more frequent in cocaine exposed fetuses. The contrast between grey and white matter was more important in the cocaine group. Hyposignal was found only in the cocaine group. Enlarged lateral ventricle occurred more frequently in the cocaine group. (2) Spin echo T2: The contrast between grey and white matter was higher and the contours of the brain more irregular in the cocaine group. Heterogenicity and hyposignal were also more frequent in this group but the difference with the control group was not significant. The computerized analysis of the contrast density on the cerebral images showed that 88% of the areas exceeding the reference level concerned the cocaine group, while only 14% of the areas exceeding the reference level concerned the control group. Long term exposure to cocaine induces cerebral tissue modifications, in favor of an advanced maturation and the development of hypoxic lesions. The histology of the brains confirmed in the cocaine group, the existence of hypoxic lesions with gliosis, perivascular edema and hemorrhages, and neuronal death.
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- Sjöström, Karin, et al.
(författare)
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Maternal anxiety in late pregnancy and fetal hemodynamics
- 1997
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Ingår i: European Journal of Obstetrics, Gynecology, and Reproductive Biology. - 0301-2115. ; 74:2, s. 149-155
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate if fetal circulation is affected by maternal anxiety. 37 nulliparous women were studied prospectively in the third trimester of pregnancy, with self-rate tests of anxiety (STAI). Doppler ultrasound examination of the umbilical artery and fetal middle cerebral artery was performed at 37-40 gestational weeks. The pulsatility index (PI) was calculated and corrected for heart rate. The women were divided into groups of increasing levels of anxiety. The fetuses of women with high trait anxiety scores had significantly higher PI values in the umbilical artery (p = 0.0056), significantly lower PI values in the fetal middle cerebral artery (p = 0.0029) and significantly lower cerebro-umbilical PI ratios (p = 0.0002), suggesting a change in blood distribution in favor of brain circulation in the fetuses. Maternal weight, weight-increase, height, age, marital status, smoking habits, drinking habits and socio-economic factors known to affect fetal well-being did not interfere with these findings. No significant differences in birth-weight, length and head circumference were found between infants born to mothers with higher trait anxiety levels compared to mothers with lower trait anxiety levels. Our results suggest that maternal stress, in terms of trait anxiety, influences fetal cerebral circulation.
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| 4. |
- Valentin, Lil
(författare)
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Gray scale sonography, subjective evaluation of the color Doppler image and measurement of blood flow velocity for distinguishing benign and malignant tumors of suspected adnexal origin
- 1997
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Ingår i: European Journal of Obstetrics, Gynecology, and Reproductive Biology. - 0301-2115. ; 72:1, s. 63-72
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To compare the capacity of transvaginal Doppler ultrasound examination with that of gray scale sonography as an aid in distinguishing benign and malignant pelvic tumors of suspected adnexal origin. STUDY DESIGN: One hundred and fifty-one women scheduled for laparotomy or laparoscopic surgery because of a pelvic mass of suspected adnexal origin underwent ultrasound examination including color and spectral Doppler techniques within 8 days preceding the operation. Based on the gray scale ultrasound image, each tumor was classified as being either a unilocular cyst, a multilocular cyst, a unilocular cyst with solid parts, a multilocular cyst with solid parts or a solid tumor. Tumor vascularization was visualized with the color Doppler technique, each tumor being characterized by the color content of the scan, as rated subjectively on a visual analogue scale ('tumor color score'). Blood flow velocity waveforms were obtained by placing the Doppler gate over the colored area with the tumor. The blood flow velocity waveform with the highest time averaged maximum velocity was used to characterize the tumor . The results of gray scale imaging and Doppler ultrasound examination were compared with the histology of the specimen. RESULTS: Ultrasound morphology correctly identified all the malignant tumors, with a false-positive rate of 61%; none of the 49 unilocular or multilocular cysts without solid parts was malignant, whereas 24% (24/102) of the tumors with solid components were. Among multilocular cysts with solid parts, both tumor color scores and time average maximum blood flow velocities were significantly higher in malignant than in benign tumors, but among solid tumors there was complete overlap in Doppler results between the malignant and benign subgroups. Using Doppler examination to discriminate between benign and malignant multilocular cysts with solid parts and ultrasound morphology for differentiation of the remaining tumors, all the malignancies in the study were detected with a false-positive rate of 32 or 38% depending on which Doppler variable was used. CONCLUSION: The present technique of Doppler ultrasound examination is helpful only in the differential diagnosis of multilocular cysts with solid parts. Therefore, the degree to which Doppler examination can contribute to the differential diagnosis of pelvic tumors will depend on the proportion of multilocular cysts with solid parts in the population studied: the greater this proportion, the greater the potential of the Doppler examination to improve diagnostic accuracy.
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- vonSchoultz, B
(författare)
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HRT and breast cancer risk, what to advise?
- 1997
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Ingår i: European journal of obstetrics, gynecology, and reproductive biology. - 0301-2115. ; 71:2, s. 205-208
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Tidskriftsartikel (refereegranskat)
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| 21. |
- Valentin, Lil, et al.
(författare)
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Effect of a prostaglandin E1 analogue (gemeprost) on uterine and luteal circulation in normal first trimester pregnancies. A Doppler velocimetry study
- 1995
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Ingår i: European Journal of Obstetrics, Gynecology, and Reproductive Biology. - 0301-2115. ; 59:1, s. 25-34
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate the effects of gemeprost on utero-placental and luteal circulation and on the embryo/fetus in normal first trimester pregnancies. STUDY DESIGN: Sixty-seven women with a normal first trimester pregnancy requesting termination of pregnancy for psychosocial reasons were randomly allocated to pre-operative treatment with vaginal suppositories containing placebo or gemeprost. The women underwent transvaginal color and spectral Doppler ultrasound examination before the application of the suppository, 4 h after the application of the suppository but before the abortion, and on the seventh post-operative day. Blood flow velocities in the uterine and subchorionic arteries, the intrachorionic area and arteries in the wall of the corpus luteum and the embryonic/fetal heart rate were measured. RESULTS: The median value for pulsatility index (PI) in the dominant uterine artery was 2.4 before treatment with gemeprost and 8.5 4 h after treatment (P = 0.0006); the corresponding values for time-averaged maximum velocity (TAMXV) being 27 cm/s and 10 cm/s (P = 0.0006). Four (14%) of 28 embryos/fetuses in the gemeprost group were dead 4 h after treatment with gemeprost and the median heart rate of those still alive was significantly lower than before treatment (130 vs. 163 bpm; P = 0.003). In the placebo group, the results for the uterine arteries and the embryonic/fetal heart rate did not differ significantly between the first and second ultrasound examinations. The median values for PI and TAMXV in the arteries of the corpus luteum wall at the first ultrasound examination were 0.71 and 18 cm/s, respectively, in the placebo group and 0.71 and 20 cm/s, respectively, in the gemeprost group. These values remained almost unchanged at the second and third ultrasound examinations in both groups. CONCLUSION: Gemeprost has profound effects on utero-placental circulation in the first trimester and can induce embryonic/fetal bradycardia and sometimes embryonic/fetal demise. It has no unequivocal effect on luteal circulation.
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| 22. |
- Burström, Lage, et al.
(författare)
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The influence of shock-type vibrations on the absorption of mechanical energy in the hand and arm
- 1999
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Ingår i: International Journal of Industrial Ergonomics. - 0169-8141 .- 1872-8219. ; 23:5, s. 585-594
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Tidskriftsartikel (refereegranskat)abstract
- In recent years there has been a discussion as to whether shock-type vibration from hand tools has stronger effects on the hand-arm system in comparison with non-impulsive vibration. The purpose of the investigation is to compare the influence of these two types of vibration on the absorption of mechanical energy in the human hand and on the grip and feed forces applied by the subjects.The energy absorption has been measured by use of a specially designed laboratory handle. The grip and feed forces applied by the subject to the handle were measured simultaneously. In the study two different frequency weighted acceleration levels were used.The outcome showed that the vibration exposure levels made a significant contribution to the vibration absorption as well as to the strength of the grip and feed forces. Moreover, it was found that the hand forces decrease while the absorption of energy increases during the experiment. Furthermore, the influence of shock-type exposure gave a significantly higher hand forces and absorption of energy compared with the non-impulsive exposure. It was, therefore, concluded that the vibration response characteristics of the hand and arm differ, depending upon whether the exposure is of shock or non-impulsive type.Relevance to industryThe paper discusses the dynamic response of the hand and arm during exposure to shock and non-impulsive vibration. Whenever possible, a tool that requires low grip and feed forces should be used as well as tools that not generate shock-type excitation. This can be helpful in choosing the proper tool for the job.
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