Halo sign in fetal cytomegalovirus infection: cerebral imaging abnormalities and postmortem histopathology in 35 infected fetuses.

OBJECTIVE: To evaluate the correlation of periventricular echogenic halo (halo sign) with histopathological findings and its association with other brain imaging abnormalities in fetuses with cytomegalovirus (CMV) infection. METHODS: This was a retrospective study of fetuses diagnosed with severe CMV infection based on central nervous system (CNS) abnormalities seen on ultrasound, which had termination of pregnancy (TOP) or fetal demise at a single center from 2006 to 2021. All included cases had been evaluated by conventional complete fetal autopsy. A maternal-fetal medicine expert reanalyzed the images from the transabdominal and transvaginal neurosonography scans, blinded to the histological findings. The halo sign was defined as the presence of homogeneous periventricular echogenicity observed in all three fetal brain orthogonal planes (axial, parasagittal and coronal). Cases were classified according to whether the halo sign was the only CNS finding (isolated halo sign) or concomitant CNS anomalies were present (non-isolated halo sign). An expert fetal radiologist reanalyzed magnetic resonance imaging (MRI) examinations when available, blinded to the ultrasound and histological results. Hematoxylin-eosin-stained histologic slides were reviewed independently by two experienced pathologists blinded to the neuroimaging results. Ventriculitis was classified into four grades (Grades 0-3) according to the presence and extent of inflammation. Brain damage was categorized into two stages (Stage I, mild; Stage II, severe) according to the histopathological severity and progression of brain lesions. RESULTS: Thirty-five CMV-infected fetuses were included in the study, of which 25 were diagnosed in the second and 10 in the third trimester. One fetus underwent intrauterine demise and TOP was carried out in 34 cases. The halo sign was detected on ultrasound in 32 (91%) fetuses (23 in the second trimester and nine in the third), and it was an isolated sonographic finding in six of these cases, all in the second trimester. The median gestational age at ultrasound diagnosis of the halo sign was similar between fetuses in which this was an isolated and those in which it was a non-isolated CNS finding (22.6 vs 24.4 weeks; P = 0.10). In fetuses with a non-isolated halo sign, the severity of additional ultrasound findings was not associated with the trimester at diagnosis, except for microencephaly, which was more frequent in the second compared with the third trimester (10/18 (56%) vs 1/8 (13%); P = 0.04). With respect to histopathological findings, ventriculitis was observed in all fetuses with an isolated halo sign, but this was mild (Grade 1) in the majority of cases (4/6 (67%)). Extensive ventriculitis (Grade 2 or 3) was more frequent in fetuses with a non-isolated halo sign (21/26 (81%)) and those without a periventricular echogenic halo (2/3 (67%); P = 0.032). All fetuses with an isolated halo sign were classified as histopathological Stage I with no signs of brain calcifications, white-matter necrosis or cortical injury. On the other hand, 25/26 fetuses with a non-isolated halo sign and all three fetuses without a periventricular echogenic halo showed severe brain lesions and were categorized as histopathological Stage II. Among fetuses with a non-isolated halo, histological brain lesions did not progress with gestational age, although white-matter necrosis was more frequent, albeit non-significantly, in fetuses diagnosed in the second vs the third trimester (10/15 (67%) vs 3/11 (27%); P = 0.06). CONCLUSIONS: In CMV-infected fetuses, an isolated periventricular echogenic halo was observed only in the second trimester and was associated with mild ventriculitis without signs of white-matter calcifications or necrosis. When considering pregnancy continuation, detailed neurosonographic follow-up complemented by MRI examination in the early third trimester is indicated. The prognostic significance of the halo sign as an isolated finding is still to be determined. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

OMENTAL INFARCTION: SURGICAL or CONSERVATIVE TREATMENT? A CASE REPORTS and CASE SERIES SYSTEMATIC REVIEW.

BACKGROUND: Omental infarction (OI) is an infrequent cause of acute abdominal pain and there is no consensus on whether conservative or surgical treatment is the best strategy when performing positive CT diagnosis. OBJECTIVES: To assess which of the two treatments is the most commonly adopted and compare outcomes in terms of success rate in resolution of symptoms and hospital length of stay. ELIGIBILITY CRITERIA: Case report and case series of patients with abdominal pain and positive diagnosis by CT of omental infarction. DATA SOURCES: PubMed, Science Direct and Google Scholar in combination with cross-referencing searches and manual searches of eligible articles from January 2000 to June 2018. PARTICIPANTS: Patients older than 18 years of age. METHODS: Patient characteristics and results were summarized descriptively. Categorical variables were assessed by chisquare test or Fischer's exact test, and continuous variables by the Wilcoxon-Mann-Whitney or Kruskal-Wallis test. Risk factors for failure of the conservative management were identified using multivariate logistic regression. RESULTS: 90 articles were included in the final analysis (146 patients). 107 patients (73.3%) received conservative treatment with a failure rate of 15.9% (patients needing surgery) and 39 patients (26.7%) received surgery as first treatment. The mean hospital length of stay was 5.1 days for the conservative treatment group and 2.5 days for the surgery group with statistically significant differences (p = 0.00). Younger age and white blood cells count ≥12000/µl were predictive factors of conservative treatment failure. CONCLUSIONS: Although conservative treatment is effective in most patients, surgery has advantages in terms of hospital length of stay.

Historical demography of Mullerian mimicry in the neotropical Heliconius butterflies.

We compare the historical demographies of two Müllerian comimetic butterfly species: Heliconius erato and Heliconius melpomene. These species show an extensive parallel geographic divergence in their aposematic wing phenotypes. Recent studies suggest that this coincident mosaic results from simultaneous demographic processes shaped by extrinsic forces over Pleistocene climate fluctuations. However, DNA sequence variation at two rapidly evolving unlinked nuclear loci, Mannose phosphate isomerase (Mpi) and Triose phosphate isomerase (Tpi), show that the comimetic species have quite different quaternary demographies. In H. erato, despite ongoing lineage sorting across the Andes, nuclear genealogical estimates showed little geographical structure, suggesting high historical gene flow. Coalescent-based demographic analysis revealed population growth since the Pliocene period. Although these patterns suggest vicariant population subdivision associated with the Andean orogeny, they are not consistent with hypotheses of Pleistocene population fragmentation facilitating allopatric wing phenotype radiation in H. erato. In contrast, nuclear genetic diversity, theta, in H. melpomene was reduced relative to its comimic and revealed three phylogeographical clades. The pattern of coalescent events within regional clades was most consistent with population growth in relatively isolated populations after a recent period of restricted population size. These different demographic histories suggest that the wing-pattern radiations were not coincident in the two species. Instead, larger effective population size (N(e)) in H. erato, together with profound population change in H. melpomene, supports an earlier hypothesis that H. erato diversified first as the model species of this remarkable mimetic association.

A new report of mesomelic camptomelia, polydactyly and Dandy-Walker complex in siblings.

Two male siblings with several malformations are reported. The anomalies detected in both fetuses were mesomelic camptomelia, postaxial hexadactyly and Dandy-Walker complex. There was only one similar previous report in the literature. This combination could represent a specific pattern of malformation or a new syndrome, with different variants. The parents' consanguinity and the recurrence in a subsequent pregnancy suggest an autosomal recessive inheritance pattern.

Spectral narrowing in the propagation of chirped pulses in single-mode fibers.

A theoretical study of the nonlinear propagation of picosecond chirped pulses in single-mode fibers is presented. We show that, under appropriate conditions, spectral narrowing-rather than broadening, as is generally believed-is induced, owing to the interplay of self-phase-modulation and dispersion. For downchirped pulses at a wavelength of 0.9 microm and a peak power as low as 0.1 W, substantial spectral narrowing occurs.

Geometrical characterization of liquid core fibers by measurement of thermally induced mode cutoffs and interference.

Transmitted and scattered intensity in liquid core fibers have been measured as a function of temperature and v values of cutoff points obtained which are in good agreement with weakly guiding mode theory. We also report observation of oscillations in the transmitted intensity which we interpret to be caused by interference between modes. We show that measurement of the period of these oscillations can be used to make high-precision nondestructive measurements of core radius and core ellipticity along the fiber length.