ABSTRACT
INTRODUCTION: Hypertension is the most common disorder that occurs during pregnancy and one of the main causes of maternal mortality worldwide. Among the hypertensive disorders that affect pregnancy, preeclampsia (PE) is the major cause of maternal mortality, maternal morbidity, perinatal death, prematurity and intrauterine growth restriction. The acute cerebral complications in PE account for at least 75% of maternal death. Central nervous system hemodynamic modifications in PE are a controversial issue. Neurological involvement in PE-eclampsia syndrome fulfills the criteria of posterior reversible encephalopathy syndrome (PRES). The pathophysiology of PRES is still under investigation. Assessment of cerebral circulation is challenging. Noninvasive techniques, especially transcranial Doppler sonography, are becoming more widely used to evaluate cerebral flow. Ophthalmic artery Doppler is a noninvasive examination used to study central vascular flow that has been shown to be a promising method in the evaluation of pregnant women with hypertension. OBJECTIVES: The aim of this study was to compare the ophthalmic artery Doppler indices observed in singleton pregnant women complicated by hypertension (study group) and to correlate the indices observed in hypertensive pregnant women with those observed in normal pregnant women (control group). METHODS: Ophthalmic artery Doppler indices of 30 mild and 30 severe pre-eclamptic women and 30 pregnant women with chronic hypertension (CH) at 20-40weeks of gestational age (GA) were compared. The control group consisted of 289 healthy pregnant women. Resistance index (RI), pulsatility index (PI), and peak ratio (PR) were determined in the right eye. The mean and SD were calculated for each group. Analysis of variance (ANOVA) was used to compare Doppler indexes means between groups. As significant differences were determined by ANOVA analysis, each group was compared by the Tukey method. Receiver operating characteristics (ROC) curves were used to determine the predictive power of ophthalmic artery Doppler indexes for the identification of severe pre-eclamptic women. P<0.05 was considered statistically significant. RESULTS: Significant differences were found between the values obtained for RI, PI, and PR in severe PE women compared to the other groups (study and control). The mean and SD for IR, IP and PR in mild PE, severe PE and CH groups were respectively 0.73 (±0.06), 1.63 (±0.35) and 0.65 (±0.10); 0.63 (±0.09), 1.13 (±0.31) and 0.89 (±0.12); 0.73 (±0.07), 1.66 (±0.49) and 0.66 (±0.14). The mean and SD for IR, IP and PR in normotensive pregnant women were 0.75 (±0.05), 1.88 (±0.43), 0.52 (±0.10). The optimal cut-off values for IR, IP and PR for the identification of severe pre-eclamptic women determined by roc curves was 0.657, 1.318, 0.784 (sensitivity and specificity were 0.633 and 0.919, 0.733 and 0.888, 0.833 and 0.974, respectively). The area under the ROC curve for IR was 0.787(95% CI: 0.68-0.89), for IP was 0.797 (95% CI: 0.69-0.90) and for PR was 0.886 (95% CI: 0.80-0.96). CONCLUSION: Ophthalmic Doppler is a useful method in the identification of severe PE. PR was best ophthalmic Doppler index at discriminating between severe PE and pregnant women with mild PE or chronic hypertension as determined by roc curve.
ABSTRACT
We carried out a phylogenetic and population study in Alouatta caraya and Alouatta belzebul based on cytochrome b DNA sequence data. Maximum Parsimony and Median-Joining analyses grouped A. caraya from different localities showing a population structure in accordance with geographic distribution. The relation between A. caraya haplotypes could be explained with respect to the species range in the Cerrado, one of the most ancient morphoclimatic domains of South America, and the Chaco. Conversely, A. belzebul from the Amazonas and Atlantic forests grouped in a paraphyletic arrangement without an evident geographic pattern. Recent geologic events resulting in the separation of A. belzebul might explain why these geographically distant groups shared similar haplotypes and why ancestral polymorphisms might have been maintained in this species. Time of divergence estimates indicated that the splitting of the Alouatta lineage leading to A. caraya occurred some 4.58 MYA while the lineage leading to A. belzebul emerged 4.14 MYA.