[Screening for fetal chromosome aberrations. Ultrasonic measurement of nuchal translucency thickness is most efficient].
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Chromosome Aberrations↗
Biomedical subjects
L Valentin
Publications and source records attributed to L Valentin.
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.
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.
Adnexa Uteri↗
Maternal anxiety in late pregnancy and fetal hemodynamics.
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.
Adolescent↗
A numerical study of persistence length effects on DNA conformation in sequencing electrophoresis.
We have developed a program to evaluate the influence of DNA stiffness on molecular mobility and conformation during electrophoresis. This (currently) two-dimensional numerical study models DNA as a chain of uniformly charged beads connected to one another by elastic segments, of finite mean size, in the presence of fixed obstacles representing gel fibers. Contrary to the standard biased reptation model (BRM), our Langevin-type dynamics for the chain are microscopic and warrant studies of fine effects such as inner chain orientation. Using this model, we show that the introduction of a persistence length decreases the (saturated) mobility at high electric fields, providing strong evidence that the gel generates a friction force and not only a (dissipation-free) constraint force. We also show that the persistence length leads to an increase of the chain orientation in the field direction. This suggests that DNA stiffness causes the saturation plateau value to be reached for smaller chain sizes than those predicted by the BRM model.
DNA↗
Uteroplacental and luteal circulation in normal first-trimester pregnancies: Doppler ultrasonographic and morphologic study.
OBJECTIVE: Our purpose was to establish reference data representative of normal findings at transvaginal color and spectral Doppler ultrasonographic examination of the uteroplacental and luteal circulation in the first trimester and to relate the Doppler findings to morphologic data. STUDY DESIGN: A cross-sectional study was performed of 64 uncomplicated pregnancies of 5 to 11 completed gestational weeks terminated by legal abortion for psychosocial reasons. Doppler examinations of the main uterine arteries, subchorionic arteries, intrachorionic area, and corpus luteum were performed. Abortion material was examined morphologically. RESULTS: In the uterine and subchorionic arteries blood flow velocity increased and pulsatility index values decreased with advancing gestation. Arterial or venous Doppler shift spectra were recorded from the intrachorionic area in 91% (58/64) of the pregnancies. Intrachorionic arterial blood flow velocities and pulsatility index values were low and did not change with advancing gestation; the mean time-averaged maximum velocity, peak systolic velocity, and pulsatility index values were 4.6 cm/sec, 6.0 cm/sec, and 0.47, respectively. Morphologic examination showed trophoblast plugs in the spiral arteries to consistently manifest multiple spaces containing red blood cells at the choriodecidual junction. CONCLUSION: Blood flow velocity in the uteroplacental arteries increases and pulsatility index values decrease with advancing gestation, indicating a steady increase in uterine perfusion during the first trimester. Our findings suggest intervillous flow to be present as early as the first trimester.
Adolescent↗
A novel rat tyrosine hydroxylase mRNA species generated by alternative splicing.
Tyrosine hydroxylase (TH) catalyzes the first and rate-limiting step in the biosynthesis of catecholamines. Among the various mechanisms implicated in the regulation of TH activity, alternative splicing of TH primary transcript has been described as a characteristic of higher primates and Drosophila. We investigated whether there is such a regulatory mechanism in the rat. Reverse transcriptase-PCR experiments were performed with RNA from PC12 cells. A new TH mRNA species was evidenced, resulting from the use of an alternative donor site in exon 2. RNase protection assays and in situ hybridization experiments detected this mRNA species in the adrenal medulla but not in the main catecholaminergic nuclei of the CNS. The corresponding putative protein lacks 33 amino acids in the N-terminal regulatory domain. A recombinant protein was produced in E. coli. Its in vitro specific activity was similar to that of the previously identified TH protein.
Adrenal Medulla↗
Transvaginal ultrasonography of the endometrium in women with postmenopausal bleeding--a Nordic multicenter study.
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.
Adult↗
Effect of a prostaglandin E1 analogue (gemeprost) on uterine and luteal circulation in normal first trimester pregnancies. A Doppler velocimetry study.
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.
Abortion, Induced↗
Reproducibility of Doppler measurements of blood flow velocity in the uterine and ovarian arteries in premenopausal women.
Intra- and interobserver reproducibility of Doppler measurements of the pulsatility index (PI) and time-averaged maximum velocity (TAMXV) in the uterine and ovarian arteries were evaluated in examinations of healthy premenopausal women. Each woman underwent reproducibility measurements once in the late follicular phase and once in the midluteal phase. Intraobserver repeatability was assessed in examinations of 12 women, three replicate Doppler measurements being made by one observer in the same vessel. Interobserver agreement was assessed by comparing the results of Doppler measurements made by two investigators in 11 women. The intraclass correlation coefficient (Intra-CC) was 0.78 for the TAMXV in the dominant uterine artery in the follicular phase and 0.82 for the PI in the wall of the dominant follicle. For all other measurements the Intra-CC was < 0.75, indicating poor reproducibility. The interclass correlation coefficient (Inter-CC) was > 0.75 (0.79 to 0.88) for the PI and TAMXV in the dominant uterine artery in the follicular phase and for the PI of both uterine arteries in the luteal phase. For all other measurements the Inter-CC was < 0.75.
Adult↗
Transvaginal gray-scale and Doppler ultrasound examinations of the uterus and ovaries in healthy postmenopausal women.
The aim of this study was to elicit reference data representative of normal findings at transvaginal gray-scale and Doppler ultrasound examination of the uterus and ovaries in postmenopausal women. A total of 144 asymptomatic postmenopausal women with normal findings at clinical gynecological examination were included in the study. They underwent transvaginal sonography including Doppler measurements of blood flow velocity in the uterine and ovarian arteries. Ninety-eight (68%) women had a normal uterus and normal or non-visible ovaries at ultrasound examination, 23 (16%) had small uterine myomas but normal or non-visible adnexa, 19 (13%) had small adnexal cysts but a normal uterus, and four (3%) had both small myomas and small adnexal cysts. The median time-averaged maximum velocity (TAMXV) and pulsatility index (PI) values for the right and left uterine artery of normal uteri (n = 117) were 10.4 cm/s (range 2.2-43.0) and 10.6 cm/s (2.9-30.8), and 2.33 (0.97-5.13) and 2.35 (0.98-4.58), respectively. Median volumes of the normal right (n = 93) and left ovaries (n = 90) were 1.3 cm3 (0.4-3.7) and 1.2 cm3 (0.4-3.0), respectively, and median TAMXV and PI values for the stromal arteries in the normal right (n = 53) and left ovaries (n = 54) were 2.1 cm/s (1.3-4.6) and 2.3 cm/s (1.1-7.3), and 1.31 (0.65-2.61) and 1.26 (0.63-1.85), respectively. Our results provide a basis for gray-scale and Doppler ultrasound studies of pathological conditions in the female pelvis after the menopause.
Blood Flow Velocity↗
Interobserver agreement in the results of Doppler examinations of extrauterine pelvic tumors.
The aim of this study was to evaluate interobserver agreement in the results of Doppler measurements of peak systolic velocity (PSV), time-averaged maximum velocity (TAMXV) and the color content of tumor scans in extrauterine pelvic tumors. The results of transvaginal color and spectral Doppler examinations of 66 extrauterine pelvic masses obtained by two observers experienced in ultrasonography were compared. Each observer aimed to obtain the highest possible Doppler shift from arteries in the wall, septa and solid parts of each tumor. Tumor vascularization was assessed in terms of the 'tumor color score', i.e. the color content of the Doppler scan as rated for the tumor as a whole by each observer on a visual analog scale. The tumors were classified according to arbitrarily chosen cut-off limits for the tumor color score, the highest tumor TAMXV and the highest tumor PSV. Inter-class correlation coefficient values for TAMXV and PSV were < or = 0.75, whereas that for tumor color score was 0.89. Interobserver agreement was complete for the detection of color in tumors (Kappa value 1.0), excellent for the recording of arterial Doppler shift spectra from tumors (Kappa value 0.82), and moderate or good for classifying tumors based on cut-off limits for TAMXV, PSV (Kappa values ranging from 0.44 to 0.67) and tumor color score (Kappa values ranging from 0.59 to 0.66).(ABSTRACT TRUNCATED AT 250 WORDS)
Cysts↗
Transvaginal Doppler examination for the differential diagnosis of solid pelvic tumors.
To evaluate the ability of transvaginal Doppler examination to discriminate between different types of solid pelvic tumors, 55 women scheduled for laparotomy because of a solid pelvic mass underwent transvaginal sonographic examination, including color and spectral Doppler techniques. Arteries in the wall and core of each mass were examined. The histological diagnoses were as follows: uterine myoma (n = 28), malignant ovarian tumor (n = 19), and benign ovarian tumor (n = 8). Pulsatility index values tended to be highest in the malignant ovarian tumors, albeit with considerable overlap with respect to the other tumor types. The respective median pulsatility index values for arteries in the wall and core of the malignant ovarian tumors were 0.93 and 0.87, versus 0.65 and 0.51 in the benign ovarian tumors and 0.80 and 0.67 in the myomas. Time-averaged maximum velocity did not differ significantly among the three types of tumor. We conclude that Doppler measurement of blood flow velocity in tumor arteries does not add substantial information to the differential diagnosis between myomas and benign or malignant solid ovarian tumors.
Adult↗
Endometrial thickness and Doppler velocimetry of the uterine arteries as discriminators of endometrial status in women with postmenopausal bleeding: a comparative study.
OBJECTIVE: Our purpose was to compare the ability of transvaginal Doppler ultrasonographic examination with that of gray-scale ultrasonographic examination to discriminate between benign and malignant and between normal and pathologic endometrium in women with postmenopausal bleeding. STUDY DESIGN: One hundred thirty-eight consecutive women scheduled for curettage because of postmenopausal bleeding underwent transvaginal ultrasonography, including color and spectral Doppler techniques, within 8 days preceding the operation. The thickness of the endometrium was measured. Doppler signals of the maximum blood flow velocity obtained from the two main uterine arteries and subendometrial and intraendometrial arteries were evaluated for pulsatility index and time-averaged maximum velocity. The results of the examinations were compared with the histologic diagnosis of the curettage specimen. RESULTS: Receiver-operator characteristic curves showed endometrial thickness to be a better discriminator between normal and pathologic and between benign and malignant endometrium than any Doppler variable, 14 mm being the optimal threshold value for differentiating between benign and malignant endometrium (sensitivity 88%, specificity 81%). CONCLUSION: Measurement of endometrial thickness with transvaginal ultrasonography is a better method for discriminating between benign and malignant or normal and pathologic endometrium than is Doppler velocimetry of the uterine arteries.
Aged↗
"In situ" characterization of GnRH receptors: use of two radioimagers and comparison with quantitative autoradiography.
New radioimagers, the HRRI (high resolution radioimager) and the Phosphorimager (phosphor screen : PS), apt to display more ample linear dose-response scale than radio-sensitive films, were tested in comparison with quantitative autoradiography (QA). GnRH receptor saturation experiments were achieved on tissue sections (rat pituitary, rat brain, human ovary) with a iodinate GnRH agonist (125I-[D-Ala6,Des-Gly10]-LH-RH Ethylamide) for determination of affinity constant (Kd). In rat pituitary, comparable results were obtained with the 3 methods (Kd: 0.4 to 0.6 nM). Discrepancies occurred in the hippocampus and in the granulosa cell layer of the preovulatory follicle, due to low resolutive (PS) or short linear dose-response (films) performances. In the hippocampus GnRH receptor affinity was under-estimated with PS (Kd: 2.3 vs 0.5 and 0.6 nM for QA and HRRI respectively). In the follicular granulosa cell layer it was over-estimated by QA (0.5 vs 50 nM for the HRRI), while PS did not allow resolution of this thin cell layer. In conclusion, the HRRI is a very powerful tool for the quantification of in situ radioligand binding (binding sites study and in situ hybridization) in very discrete areas.
Adult↗
HRRI: a high resolution radioimager for fast, direct quantification in in situ hybridization experiments.
We present a high-speed, high-resolution beta imager. It has been developed to be used in in situ hybridization experiments, either instead of or in complement with autoradiographic film and emulsions that are currently used for these experiments. It allows the user to locate and perform quantitative analyses of (3H-, 14C-, 35S-, 32P-, 125I-) labeled molecules with a 15-microns spatial resolution on a 1.2 cm2 area. We have combined recent techniques (specific scintillator thin sheets and intensified charge-coupled device [CCD]) so that this imager offers a wide dynamic range and real-time acquisition. Several biological applications will be discussed.
Animals↗
Limited contribution of Doppler velocimetry to the differential diagnosis of extrauterine pelvic tumors.
OBJECTIVE: To compare the ability of transvaginal color and spectral Doppler and that of gray-scale ultrasound examination to discriminate between benign and malignant extrauterine pelvic tumors. METHODS: One hundred forty-nine consecutive women scheduled for laparotomy because of an extrauterine pelvic mass underwent ultrasound examination, including color and spectral Doppler techniques, within 8 days before a planned operation. Based on the gray-scale ultrasound image, each tumor was classified as a unilocular cyst, multilocular cyst, unilocular cyst with solid parts, multilocular cyst with solid parts, or solid tumor. Doppler signals of the maximum blood flow velocity of tumor vessels were evaluated for pulsatility index (PI) and peak systolic and time-average maximum velocity. The results of gray-scale imaging and Doppler velocimetry were related to the final diagnosis, which in most cases was based on histology of the specimen. RESULTS: None of the 88 unilocular or multilocular cysts without solid parts were malignant, compared to 28 malignancies (46%) among the 61 tumors with solid components. The PI was significantly lower, and the peak systolic and time-average maximum blood flow velocities significantly higher, in the malignant than in the benign tumors. However, this was true only of the multilocular cysts with solid parts; the PI and blood flow velocity results overlapped completely between benign and malignant solid tumors. According to receiver operating characteristic curves, the ultrasound morphology of the tumors was a better discriminator between benign and malignant tumors than any of the Doppler variables. Ultrasound morphology correctly identified all the malignant tumors, with a false-positive rate of 27%. Discrimination was slightly improved if PI and blood flow velocity were used for discriminating between benign and malignant multilocular cysts with solid parts. With this approach, all the malignant tumors were detected with a false-positive rate of 17-23%, depending on which Doppler variable and which cutoff level was used. CONCLUSION: The present technique of Doppler velocimetry has a limited contribution to the differential diagnosis of extrauterine pelvic tumors.
Adolescent↗
Clinical evaluation of the fetus and neonate. Relation between intra-partum cardiotocography, Apgar score, cord blood acid-base status and neonatal morbidity.
The relation between intra-partum cardiotocography (CTG), cord blood acid-base status, Apgar score and neonatal morbidity was studied in 1228 consecutively live-born babies and in a subgroup of 200 babies (148 babies with a 1 min Apgar score < or = 8 and 52 randomly selected babies with a 1 min Apgar score > or = 9). The scores for the individual components of the 1 min Apgar score were strongly associated with each other, whereas the scores for the individual components of the 5 min Apgar score were less strongly associated. At 1 min the scores for muscle tone, reflex irritability and respiration but not the scores for heart rate and skin colour were associated with arterial and venous cord blood pH (low scores being associated with low pH). Out of the individual components of the Apgar score, heart rate and reflex irritability at 1 min were the best discriminators between "healthy or relatively healthy" and "severely ill" babies. Intrapartum CTG, total Apgar score and cord blood acid-base status were only weakly related. Venous cord blood pH was the best predictor of the 1 min Apgar score. Intra-partum CTG (silent pattern), 5 min Apgar score and venous cord blood pH were the best predictors of severe neonatal morbidity.
Acid-Base Equilibrium↗
SOFI: a bidimensional detector for fast direct on-line quantification of beta particles on blots.
We present a high-speed, high-resolution beta imager developed to replace autoradiographic films currently used in molecular biology experiments. It allows the user to locate and make quantitative analyses of 32P-labeled molecules on a 25.6 x 25.6-cm flat surface. Combining new techniques--scintillating optical fibers and multianode photomultipliers--this fast imager offers several advantages when compared with recent gas detectors and flexibility for further improvements. Several biological applications will be discussed.
Animals↗