László Orosz

Assessment of cerebrovascular reserve capacity in asymptomatic and symptomatic hemodynamically significant carotid stenoses and occlusions.

BACKGROUND Cerebrovascular reactivity measurements are believed to be a helpful tool for selecting patients who are at higher risk for hemodynamic strokes. The aim of this study was to compare cerebral vasoreactivity among patients suffering from internal carotid artery stenosis of different severity (asymptomatic stenosis, asymptomatic occlusion, symptomatic stenosis, symptomatic occlusion). METHODS Sixty-two patients with asymptomatic and symptomatic internal carotid artery stenoses and occlusions underwent transcranial Doppler-acetazolamide tests. Absolute velocities of the middle cerebral arteries (MCAV), percent increases of the MCAV at different time points of the test (cerebrovascular reactivity, CVR) and maximal percent increase after administration of acetazolamide (cerebrovascular reserve, CRC) were compared on the affected and non-affected sides. Asymmetry indices (CRC (affected side)/CRC (non-affected side)) were compared between the groups of different severity of obstructive lesion. RESULTS Resting MCAV was similar on both sides in all groups. A significant side-difference of the MCAV values after acetazolamide was observed only in the symptomatic groups. Difference of cerebrovascular reserve capacity between the affected and non-affected side was statistically significant only in the symptomatic groups (CRC symptomatic stenosis 36.6 +/- 20.9% vs. 71.1 +/- 27.9%, CRC symptomatic occlusion: 31.2 +/- 24.6% vs. 64.5 +/- 29.7%). Asymmetry index of the CRC was near to 1 in the asymptomatic stenosis group only, while in all the other groups this index referred to a significant hemispheric asymmetry of the vasoreactivity. CONCLUSIONS Although in general cerebrovascular reserve capacity is compromised in cases of hemodynamically significant carotid lesions, there is a large individual variability within the subgroups. Further randomized studies are needed to clarify whether the clinical efficiency of carotid endarterectomy and extra-intracranial bypass may be improved by selecting the patients using hemodynamic criteria.

In utero incarceration of congenital diaphragmatic hernia.

In utero diagnosis of incarcerated congenital diaphragmatic hernia has never been reported. In our case, congenital diaphragmatic hernia presented at 34 weeks of gestation with dilated bowel loops, pleural effusion, and ascites on fetal ultrasound. Preterm delivery and emergency exploration revealed a tight posterolateral diaphragmatic defect with extensive bowel infarction.

Clinical applicability of a mathematical model in assessing the functional ability of the communicating arteries of the circle of Willis

BACKGROUND The brain collateral blood supply, which is essential in patients suffering from significant stenoses or occlusions of the extracranial arteries, remains difficult to assess accurately in practice. We compared data obtained from transcranial color-coded duplex sonography (TCCD) combined with carotid compression tests to morphometric autopsy data and to results given by a mathematical model of the cerebral macrocirculation. METHODS AND RESULTS In 16 moribund patients, anterior and posterior communicating arteries of the circle of Willis were divided into functional and non-functional based on the results of the TCCD combined with carotid compression tests. After death of the patients diameters and lengths of the main intracranial arteries were measured at autopsy and these values were treated with a mathematical model for calculating blood flow and blood pressure in all the segments of the arterial network. The diameters and the blood flows through the communicating arteries were found to be significantly higher in the group of functional arteries than in that of non-functional ones. However, blood flow was also shown to be dependent on other parameters such as the pressure difference between the two ends of the vessel. CONCLUSION Our data indicate that functional ability of the Willisian collaterals depends on morphological and functional parameters, and is therefore better assessed by a functional method, such as TCCD, than by a solely morphological one, such as cerebral angiography. Mathematically based circulation modeling, when it will be possible, could be a more comprehensive tool for delineating patients at a higher risk for hemodynamic cerebrovascular insufficiency.

Measuring expression levels of small regulatory RNA molecules from body fluids and formalin-fixed, paraffin-embedded samples

MicroRNAs are involved in the regulation of various pathophysiological processes such as immune regulation and cancer. Next-generation sequencing methods enable us to monitor their presence in various types of samples but we need flexible methods for validating datasets generated by high-throughput methods. Here we describe the detailed protocols to be used with our MiRNA Primer Design Tool assay design system. The presented methods allow the flexible design of the oligonucleotides needed for the RT-qPCR detection of any variant of small regulatory RNA molecules from virtually any species. This method can be used to measure miRNA levels from formalin-fixed, paraffin-embedded (FFPE) samples and various body fluids. As an example, we show the results of the hsa-miR-515-3p, hsa-miR-325, and hsa-miR-155 quantification using a specific UPL probe (Universal Probe Library) and a stem-loop RT-qPCR assay. The small nucleolar RNA RNU43 is used as endogenous control for normalization of the results. Urine from healthy pregnant women and FFPE samples from patients diagnosed with colorectal cancer and treated with antibody-based anti-EGFR monotherapy were used as samples.

Integrated systems biology approach identifies novel maternal and placental pathways of preeclampsia

Preeclampsia is a disease of the mother, fetus, and placenta, and the gaps in our understanding of the complex interactions among their respective disease pathways preclude successful treatment and prevention. The placenta has a key role in the pathogenesis of the terminal pathway characterized by exaggerated maternal systemic inflammation, generalized endothelial damage, hypertension, and proteinuria. This sine qua non of preeclampsia may be triggered by distinct underlying mechanisms that occur at early stages of pregnancy and induce different phenotypes. To gain insights into these molecular pathways, we employed a systems biology approach and integrated different “omics,” clinical, placental, and functional data from patients with distinct phenotypes of preeclampsia. First trimester maternal blood proteomics uncovered an altered abundance of proteins of the renin-angiotensin and immune systems, complement, and coagulation cascades in patients with term or preterm preeclampsia. Moreover, first trimester maternal blood from preterm preeclamptic patients in vitro dysregulated trophoblastic gene expression. Placental transcriptomics of women with preterm preeclampsia identified distinct gene modules associated with maternal or fetal disease. Placental “virtual” liquid biopsy showed that the dysregulation of these disease gene modules originates during the first trimester. In vitro experiments on hub transcription factors of these gene modules demonstrated that DNA hypermethylation in the regulatory region of ZNF554 leads to gene down-regulation and impaired trophoblast invasion, while BCL6 and ARNT2 up-regulation sensitizes the trophoblast to ischemia, hallmarks of preterm preeclampsia. In summary, our data suggest that there are distinct maternal and placental disease pathways, and their interaction influences the clinical presentation of preeclampsia. The activation of maternal disease pathways can be detected in all phenotypes of preeclampsia earlier and upstream of placental dysfunction, not only downstream as described before, and distinct placental disease pathways are superimposed on these maternal pathways. This is a paradigm shift, which, in agreement with epidemiological studies, warrants for the central pathologic role of preexisting maternal diseases or perturbed maternal–fetal–placental immune interactions in preeclampsia. The description of these novel pathways in the “molecular phase” of preeclampsia and the identification of their hub molecules may enable timely molecular characterization of patients with distinct preeclampsia phenotypes.