Hydrocephalus and arthrogryposis in an immunocompetent mouse model of ZIKA teratogeny: A developmental study.

The teratogenic mechanisms triggered by ZIKV are still obscure due to the lack of a suitable animal model. Here we present a mouse model of developmental disruption induced by ZIKV hematogenic infection. The model utilizes immunocompetent animals from wild-type FVB/NJ and C57BL/6J strains, providing a better analogy to the human condition than approaches involving immunodeficient, genetically modified animals, or direct ZIKV injection into the brain. When injected via the jugular vein into the blood of pregnant females harboring conceptuses from early gastrulation to organogenesis stages, akin to the human second and fifth week of pregnancy, ZIKV infects maternal tissues, placentas and embryos/fetuses. Early exposure to ZIKV at developmental day 5 (second week in humans) produced complex manifestations of anterior and posterior dysraphia and hydrocephalus, as well as severe malformations and delayed development in 10.5 days post-coitum (dpc) embryos. Exposure to the virus at 7.5-9.5 dpc induces intra-amniotic hemorrhage, widespread edema, and vascular rarefaction, often prominent in the cephalic region. At these stages, most affected embryos/fetuses displayed gross malformations and/or intrauterine growth restriction (IUGR), rather than isolated microcephaly. Disrupted conceptuses failed to achieve normal developmental landmarks and died in utero. Importantly, this is the only model so far to display dysraphia and hydrocephalus, the harbinger of microcephaly in humans, as well as arthrogryposis, a set of abnormal joint postures observed in the human setting. Late exposure to ZIKV at 12.5 dpc failed to produce noticeable malformations. We have thus characterized a developmental window of opportunity for ZIKV-induced teratogenesis encompassing early gastrulation, neurulation and early organogenesis stages. This should not, however, be interpreted as evidence for any safe developmental windows for ZIKV exposure. Late developmental abnormalities correlated with damage to the placenta, particularly to the labyrinthine layer, suggesting that circulatory changes are integral to the altered phenotypes.

Fetal cerebral ventricle volumetry: comparison between 3D ultrasound and magnetic resonance imaging in fetuses with ventriculomegaly.

OBJECTIVES: The aim of this study was to evaluate feasibility of fetal lateral ventricle (LV) volumetry in fetuses with ventriculomegaly and to compare measurements performed by 3D sonographic method virtual organ computer-aided analysis (VOCAL) with those obtained by magnetic resonance imaging (MRI). METHODS: This cross-sectional study evaluated 30 fetuses with atrial width (AW) between 10 and 30 mm, from 20 to 36 gestational weeks. Fifty-nine ventricles were measured by two observers. Sonographic volumetric measurements using VOCAL 30° were performed with an ACCUVIX XQ machine (Medison, Korea) and MRI assessments with a Sonata system using ARGUS software (Siemens, Germany). Agreement between both techniques was assessed by intraclass correlation coefficient (ICC) calculation, and proportionate Bland-Altman plots were constructed. RESULTS: A high degree of reliability was observed between VOCAL and MRI measurements (ICC 0.928, 95%CI [0.876;0.958]). Bland-Altman plots confirmed the high correlation (mean of differences: 1.62 cm(3) and standard deviation: ± 8.41 cm(3)). CONCLUSION: Three-dimensional volumetry of fetal LVs by VOCAL method has good agreement with fetal MRI in fetuses with ventriculomegaly and may be used as an additional tool in patient counseling and prognosis prediction.

Fetal brain tumors.

INTRODUCTION: Fetal intracranial tumors are rare and their evolution is usually poor. With routine use of antenatal ultrasound imaging, a larger number of such tumors have been diagnosed. METHODS: During the period from January 1992 to January 2002, 18 cases diagnosed as intracranial tumors in the fetal stage were treated in the Neurosurgery and Obstetrics Departments of the Federal University of São Paulo and in the Fetal Medicine Service of the Maternity Hospital Santa Joana. RESULTS: The tumors most frequently found were those of the choroid plexus and teratomas. Out of those 18 cases, 11 patients presented with fetal hydrocephalus, and 5 of them, who were less than 34 weeks old (gestational age), underwent repeated cephalocenteses while awaiting better conditions for delivery. Two fetuses died while in utero before any intervention had taken place and 16 underwent craniotomy after birth. Twelve of those patients are still alive, 9 of whom are considered normal. The 3 others are slightly or moderately retarded.

Massive congenital intracranial teratoma: report of a case in an hydrocephalic foetus

A large intracranial teratoma which replaced the entire brain is described in an hydrocephalic foetus which was aborted at the 25th week of gestation. This very rare condition is reported for the first time in the Caribbean literature (AU)