The normal fetal Cavum Septum Pellucidum in MR imaging - New biometric data

BACKGROUND AND PURPOSE

The cavum septum pellucidum (CSP) is an important landmark in the evaluation of the fetal neural axis. A deviation from the ultrasonic normal values may be associated with unfavorable outcomes, and a normal CSP provides reassurance of normal central forebrain development. Today, there is biometric data regarding the normal values for the width of the CSP in fetal ultrasound, but there is no such data for fetal MRI. The aim of this study was to determine the normal values for the measurements of the fetal CSP on MRI.

MATERIALS AND METHODS

We retrospectively examined 307 MRI scans of fetuses between 25 and 41 weeks gestation. Data was collected from the electronic charts of patients who underwent fetal MR imaging at a single tertiary Medical Center. The width and length of the CSP were measured in the axial plane, and the width and height were measured in the coronal plane.

RESULTS

The width and height of the CSP in fetuses tend to decrease starting from the 27th week of gestation onwards. High levels of intraobserver and interobserver agreements were calculated. The sex of the fetus does not appear to influence the biometry of the CSP.

CONCLUSION

This study provides MRI reference values for the dimensions of the CSP starting from the 25th week of gestation. Knowing the normal values for MRI could provide valuable information for researchers and in the decision-making process in patient's consultations.

Fetal brain biometry in isolated mega cisterna magna: MRI and US study

OBJECTIVE

To characterize the biometric parameters in ultrasound and brain MRI of fetuses with isolated mega cisterna magna (MCM).

METHODS

Cross-sectional historical cohort study conducted at a single tertiary medical center between 2011 and 2018. All fetuses underwent US and brain MRI scans. Matching analysis was performed according to gender and gestational age.

RESULTS

The study included a total of 103 fetuses; 44 fetuses with isolated MCM in the study group, and a control group of 59 fetuses with normal CNS. The study group had larger biparietal diameter (BPD) (86 vs. 79.8 mm, p = .001) and head circumference (HC) (318 vs. 292 mm, p < .001) on ultrasound. On MRI, study group had larger occipitofrontal diameter (OFD) (99 vs. 92 mm, p < .001) and BPD (77 vs. 72 mm, p < .001). Male fetuses' prevalence was higher in the study group (77.3% vs. 47.5%). After matching 20 fetuses from each group, the study group had larger HC (310.1 versus 300.7 mm, p = .029) and OFD (113.4 versus 108.3 mm, p = .009) on ultrasound, and larger OFD (97.4 versus 94.6, p = .013) on brain MRI.

CONCLUSIONS

Isolated MCM may be related to other large fetal CNS biometric measurements in both ultrasound and MRI and might be influenced by fetal gender.

Fetal Exposure to MR Imaging: Long-Term Neurodevelopmental Outcome

BACKGROUND AND PURPOSE

Very few studies have investigated long-term neurodevelopment of children exposed to MR imaging antenatally. Thus, the purpose of our study was to evaluate long-term neurodevelopmental outcomes of children exposed to MR imaging during pregnancy.

MATERIALS AND METHODS

We conducted a historical prospective cohort study in a single tertiary medical center. Women exposed to 1.5T noncontrast MR imaging for maternal or fetal indications were matched to unexposed controls. Long-term neurodevelopmental outcomes were evaluated of their children, 2.5 to 6 years of age, according to the Vineland-II Adaptive Behavior Scale. The Vineland-II Adaptive Behavior Scale assesses communication, daily living skills, socialization, and motor skills. A composite score summarizes these 4 domains.

RESULTS

A total of 131 exposed women matched our inclusion criteria and were included in the study group, and 771 unexposed women, in the control group. No difference was identified in the Vineland-II Adaptive Behavior Scale composite score between the children of the study and control groups (mean, 110.79 versus 108.18; P = .098). Differences were also not observed between the children of the 2 groups in 3 of the 4 questionnaire domains: communication (108.84 versus 109.10; P = .888), daily living skills (109.51 versus 108.28; P = .437), and motor skills (105.09 versus 104.42; P = .642). However, the socialization score was favorable for the study group (112.98 versus 106.47; P < .001).

CONCLUSIONS

Exposure to 1.5T noncontrast MR imaging during pregnancy had no harmful effects on long-term neurodevelopmental outcomes. This study contributes to understanding the safety of MR imaging during pregnancy.

The effect of mode of delivery in twin pregnancies on the latency period between diagnosis of preterm labor and birth

Introduction: The optimal mode of delivery in twin pregnancies presenting with preterm labor is controversial. Current literature regarding these cases is based on observational studies, innately prone to bias. A possibly substantial, yet hitherto unexplored, source of bias is an effect of mode of delivery on the timing of delivery. The aim of our study is to examine whether the mode of delivery affects the latency period between preterm labor (PTL) presentation and actual delivery and to assess the possible effect of latency on neonatal outcome.Material and methods: A retrospective cohort study at a single tertiary center from the year 2011 to 2018. All twin pregnancies (dichorionic or monochorionic-diamniotic) between 24 and 36 weeks of gestation admitted due to PTL were included in the study.Results: A total of 469 twin deliveries met the study criteria, of them, 204 delivered by cesarean section and 265 delivered vaginally. Cesarean delivery significantly decreased the chances of reaching a latency period of 1 or more days (OR = 0.53, 95% CI = 0.33-0.84), 2 or more days (OR = 0.47, 95% CI = 0.27-0.82) and 3 or more days (OR = 0.28, 95% CI = 0.09-0.9). In a regression model adjusting for gestational age at delivery, mode of delivery was not associated with neonatal morbidity or mortality. However, in a regression model adjusting for gestational age at PTL presentation, thereby accounting for differences in the latency period, cesarean delivery was found to significantly increase the risk of respiratory distress syndrome (OR = 1.62, 95% CI = 1.04-2.54).Conclusions: In PTL of twin pregnancies, the latency period is significantly longer in vaginal deliveries compared to cesarean deliveries. The possibility of longer latency period in vaginal deliveries should be considered when counseling patients on the mode of delivery in preterm twin pregnancies.

Do poor-responder patients undergoing IVF benefit from splitting and increasing the daily gonadotropin dose?

We aim to retrospectively evaluate the role of increasing the gonadotropin daily dose from 450 IU/day to 300 IU twice a day on IVF-ET outcome in poor responder patients. All consecutive women admitted to our IVF unit and underwent COH consisting of daily gonadotropin dose of 450 IU, followed by an IVF cycle using 300 IU twice a day, were included. Ovarian stimulation characteristics, number of oocytes retrieved, number of embryo transferred and pregnancy rate was assessed. Twenty-three patients undergoing both cycles were evaluated. While there was no between-group difference in the duration of COH, number of 2PN embryos, fertilization rate and number of embryos transferred, patients receiving daily gonadotropin 300 IU twice a day achieved a significantly higher peak estradiol levels (3350.39 ± 2364.26 vs. 2223.74 ± 1299.91; p < .03, respectively), and yielded significantly higher number of follicles >15 mm in diameter on day of hCG administration (3.2 ± 2.4 vs 1.8 ± 1; p < .03, respectively) and higher number of oocytes retrieved (3.48 ± 2.54 vs 1.87 ± 1.1; p < .02, respectively) with an acceptable live birth rate (5%). To conclude, in poor responders undergoing COH a daily gonadotropin dose of 450 IU, increasing the dose to 300 IU twice daily may result in higher oocyte yield, with the possible improvement in IVF outcome.

Chemotherapeutic agents induce the expression and activity of their clearing enzyme CYP3A4 by activating p53

Cytochrome P450 (P450) enzymes are abundantly expressed in the human liver where they hydroxylate organic substrates. In a microarray screen performed in human liver cells, we found a group of eleven P450 genes whose expression was induced by p53 (CYP3A4, CYP3A43, CYP3A5, CYP3A7, CYP4F2, CYP4F3, CYP4F11, CYP4F12, CYP19A1, CYP21A2 and CYP24A1). The mode of regulation of four representative genes (CYP3A4, CYP3A7, CYP4F2 and CYP4F3) was further characterized. The genes were induced in a p53-dependent manner in HepG2 and Huh6 cells (both are cancer-derived human liver cells) and in primary liver cells isolated from human donors. Furthermore, p53 was found to bind to p53-responsive elements in the genes' DNA-regulatory regions and to enhance their transcription in a reporter gene assay. Importantly, when p53 was activated following the administration of either of three different anticancer chemotherapeutic agents (cisplatin, etoposide or doxorubicin), it was able to induce CYP3A genes, which are the main factors in systemic clearance of these agents. Finally, the p53-dependent induction of P450 genes following either Nutlin or chemotherapy treatment led to enhanced P450 enzymatic activity. Thus, in addition to the well-established role of p53 at the tumor site, our data unravels a novel function of hepatic p53 in inducing P450 enzymes and position p53 as a major factor in the hepatic response to xenobiotic and metabolic signals. Importantly, this study reveals a novel pathway for the induction of CYP3As by their substrates through p53, warranting the need for careful consideration when designing systemically administered chemotherapeutic regimens.

p53, a novel regulator of lipid metabolism pathways

BACKGROUND & AIMS

In this study we aimed at characterizing the regulation of hepatic metabolic pathways by the p53 transcription factor.

METHODS

Analysis of gene expression following alteration of p53 status in several human- and mouse-derived cells using microarray analysis, quantitative real-time PCR, chromatin immunoprecipitation, and reporter gene assays. A functional assay was performed to determine lipid transfer activity.

RESULTS

We identified a novel role for the p53 protein in regulating lipid and lipoprotein metabolism, a process not yet conceived as related to p53, which is known mainly for its tumor suppressive functions. We revealed a group of 341 genes whose expression was induced by p53 in the liver-derived cell line HepG2. Twenty of these genes encode proteins involved in many aspects of lipid homeostasis. The mode of regulation of three representative genes (Pltp, Abca12, and Cel) was further characterized. In addition to HepG2, the genes were induced following activation of p53 in human primary hepatic cells isolated from liver donors. p53-dependent regulation of these genes was evident in other cell types namely Hep3B cells, mouse hepatocytes, and fibroblasts. Furthermore, p53 was found to bind to the genes' promoters in designated p53 responsive elements and thereby increase transcription. Importantly, p53 augmented the activity of secreted PLTP, which plays a major role in lipoprotein biology and atherosclerosis pathology.

CONCLUSIONS

These findings expose another facet of p53 functions unrelated to tumor suppression and render it a novel regulator of hepatic lipid metabolism and consequently of systemic lipid homeostasis and atherosclerosis development.

Mutant p53 facilitates somatic cell reprogramming and augments the malignant potential of reprogrammed cells

p53 deficiency enhances the efficiency of somatic cell reprogramming to a pluripotent state. As p53 is usually mutated in human tumors and many mutated forms of p53 gain novel activities, we studied the influence of mutant p53 (mut-p53) on somatic cell reprogramming. Our data indicate a novel gain of function (GOF) property for mut-p53, which markedly enhanced the efficiency of the reprogramming process compared with p53 deficiency. Importantly, this novel activity of mut-p53 induced alterations in the characteristics of the reprogrammed cells. Although p53 knockout (KO) cells reprogrammed with only Oct4 and Sox2 maintained their pluripotent capacity in vivo, reprogrammed cells expressing mutant p53 lost this capability and gave rise to malignant tumors. This novel GOF of mut-p53 is not attributed to its effect on proliferation, as both p53 KO and mut-p53 cells displayed similar proliferation rates. In addition, we demonstrate an oncogenic activity of Klf4, as its overexpression in either p53 KO or mut-p53 cells induced aggressive tumors. Overall, our data show that reprogrammed cells with the capacity to differentiate into the three germ layers in vitro can form malignant tumors, suggesting that in genetically unstable cells, such as those in which p53 is mutated, reprogramming may result in the generation of cells with malignant tumor-forming potential.

Modulated expression of WFDC1 during carcinogenesis and cellular senescence

Fibroblasts located adjacent to the tumor [cancer-associated fibroblasts (CAFs)] that constitute a large proportion of the cancer-associated stroma facilitate the transformation process. In this study, we compared the biological behavior of CAFs that were isolated from a prostate tumor to their normal-associated fibroblast (NAF) counterparts. CAFs formed more colonies when seeded at low cell density, exhibited a higher proliferation rate and were less prone to contact inhibition. In contrast to the general notion that high levels of α-smooth muscle actin serve as a marker for CAFs, we found that prostate CAFs express it at a lower level compared with prostate NAFs. Microarray analysis revealed a set of 161 genes that were altered in CAFs compared with NAFs. We focused on whey acidic protein four-disulfide core domain 1 (WFDC1), a known secreted protease inhibitor, and found it to be downregulated in the CAFs. WFDC1 expression was also dramatically downregulated in highly prolific mesenchymal cells and in various cancers including fibrosarcomas and in tumors of the lung, bladder and brain. Overexpression of WFDC1 inhibited the growth rate of the fibrosarcoma HT1080 cell line. Furthermore, WFDC1 level was upregulated in senescent fibroblasts. Taken together, our data suggest an important role for WFDC1 in inhibiting proliferation of both tumors and senescent cells. Finally, we suggest that the downregulation of WFDC1 might serve as a biomarker for cellular transformation.