Neonatal effects of the administration of meperidine and promethazine to the mother in labor. Double blind study

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UPPER CISURALIAN-LOWER GUADALUPIAN BRACHIOPODS FROM THE QARARI UNIT, BATAIN PLAIN, NORTHEAST OMAN: SYSTEMATICS, PALAEOECOLOGY AND CORRELATION

Permian brachiopods from Oman are well-known as valuable tools for correlation and palaeobiogeographical and palaeoclimatic reconstructions. Here, we describe a new brachiopod fauna from the Qarari Unit of the allochthonous Batain Group in northeast Oman. Brachiopods were collected from four localities: Wadi Khawr al Jaramah (WKJ), Jebel Qarari (JQ1), Jebel X (JX3) and Shiya (SH11). The age of the fossiliferous localities is wellconstrained to the late Kungurian-early Roadian by conodonts and fusulines, in agreement with the age suggested by the brachiopod ranges.The brachiopod fauna consists of 339 specimens belonging to 68 species of 8 orders, among which five species are here identified as new. Based on the taphonomic attributes and the analysis of the brachiopod life-styles, the assemblages from the Qarari Unit are interpreted as life assemblages thriving on varied substrates, with limited post-mortem exposure on the sea floor and rapid burial at depths around the storm wave base.Based on the generally high biodiversity indices (Shannon-Wiener and Margalef indices), the Qarari brachiopod fauna can be considered a biodiversity hotspot, only comparable, in term of biodiversity, to the coeval faunas from West Texas and South China. However, palaeobiogeographical affinities of the Qarari brachiopods with these faunas are scanty, as well as the affinities with coeval faunas from the northern Gondwana margin and the Cimmerian and Cathaysian blocks, except for some similarities with the upper Kungurian brachiopods of Myanmar. This may be explained by the fact that the Qarari succession was deposited in the Madagascan arm of Neo-Tethys, and thus rather isolated from the main Gondwanan margin

Doppler velocimetry : critical analysis of umbilical, cerebral and aortic reference values

Cross-sectional reference standards of the umbilical flow velocity waveforms were investigated from 18 to 38 weeks of gestation on 482 normal pregnancies. A significant decrease in the pulsatility index (PI) and systolic/diastolic (SD) ratio was observed during gestation. This phenomenon was confirmed in a longitudinal study on 150 patients of the same population. The two slopes of cross-sectional and longitudinal data were not significantly different. A bimodal distribution of PI and S/D ratio was observed. Six per cent of data fell above the vast majority of cases. The dimension of the population studied allowed us to consider these findings not as outliers but as an interesting transient phenomenon of very low end-diastolic velocities which can occur in normal fetuses, without concomitant variations on the thoracic aorta and middle cerebral artery. Cross-sectional reference ranges were studied for these vessels on the same population from 26 to 38 weeks of gestation. A significant decrease in the PI of the middle cerebral artery was observed versus a significant increase in the PI of the thoracic aorta. These latter indices could be used to obtain indirect information on the normla redistribution of blood flow in the human fetus in the third trimester of gestation. However, the great variability observed should warn against the risks of a simplistic clinical use of these observations

The correlation of biochemical monitoring versus umbilical flow velocity measurements of the human fetus

The pulsatility index of the fetal umbilical arteries was evaluated in 14 high-risk pregnant patients delivered by cesarean section between 30 and 35 weeks of gestation. Transabdominal cord sampling by ultrasonic guidance was performed on 10 of these patients. Umbilical arterial and venous blood was obtained in all patients from the doubly clamped cord at the time of cesarean section. The blood samples were analyzed for respiratory gases, acid-base balance, and lactate concentrations. A significant relationship was found between the pulsatility index and pH, PCO2, and lactate concentrations measured on umbilical venous blood sampled in utero. The pulsatility index also correlated with the same variables measured on venous and arterial blood sampled at cesarean section. Umbilical venous blood obtained transabdominally had a significantly higher oxygen content than blood obtained at cesarean section. No significant correlation was found between umbilical venous oxygen content obtained at transabdominal cord sampling and the pulsatility index. At a pulsatility index greater than 1.5, lactate concentrations in umbilical venous blood increased sharply. There would appear to be a curvilinear relationship between umbilical blood flow and these indices of fetal oxygenation, such that moderate increases in pulsatility index were not associated with a significant increase in fetal lactate concentrations