A major concern associated with ZIKV infection is the increased incidence of microcephaly with frequent calcifications in infants born from infected mothers. To date, postmortem analysis of the central nervous system (CNS) in congenital infection is limited to individual reports or small series. We report a comprehensive neuropathological study in ten newborn babies infected with ZIKV during pregnancy, including the spinal cords and dorsal root ganglia (DRG), and also muscle, pituitaries, eye, systemic organs, and placentas. Using in situ hybridization (ISH) and electron microscopy, we investigated the role of direct viral infection in the pathogenesis of the lesions. Nine women had Zika symptoms between the 4th and 18th and one in the 28th gestational week. Two babies were born at 32, one at 34 and 36 weeks each and six at term. The cephalic perimeter was reduced in four, and normal or enlarged in six patients, although the brain weights were lower than expected. All had arthrogryposis, except the patient infected at 28 weeks gestation. We defined three patterns of CNS lesions, with different patterns of destructive, calcification, hypoplasia, and migration disturbances. Ventriculomegaly was severe in the first pattern due to midbrain damage with aqueduct stenosis/distortion. The second pattern had small brains and mild/moderate (ex-vacuo) ventriculomegaly. The third pattern, a well-formed brain with mild calcification, coincided with late infection. The absence of descending fibres resulted in hypoplastic basis pontis, pyramids, and cortico-spinal tracts. Spinal motor cell loss explained the intrauterine akinesia, arthrogryposis, and neurogenic muscle atrophy. DRG, dorsal nerve roots, and columns were normal. Lympho-histiocytic inflammation was mild. ISH showed meningeal, germinal matrix, and neocortical infection, consistent with neural progenitors death leading to proliferation and migration disorders. A secondary ischemic process may explain the destructive lesions. In conclusion, we characterized the destructive and malformative consequences of ZIKV in the nervous system, as reflected in the topography and severity of lesions, anatomic localization of the virus, and timing of infection during gestation. Our findings indicate a developmental vulnerability of the immature CNS, and shed light on possible mechanisms of brain injury of this newly recognized public health threat.

Controversy still exists over whether the benefits of the available HPV vaccines outweigh the risks and this has suppressed uptake of the HPV vaccines in comparison to other vaccines. Concerns about HPV vaccine safety have led some physicians, healthcare officials and parents to withhold the recommended vaccination from the target population. The most common reason for not administering the prophylactic HPV vaccines are concerns over adverse effects. The aim of this review is the assessment of peer-reviewed scientific data related to measurable outcomes from the use of HPV vaccines throughout the world with focused attention on the potential adverse effects. We found that the majority of studies continue to suggest a positive risk-benefit from vaccination against HPV, with minimal documented adverse effects, which is consistent with other vaccines. However, much of the published scientific data regarding the safety of HPV vaccines appears to originate from within the financially competitive HPV vaccine market. We advocate a more independent monitoring system for vaccine immunogenicity and adverse effects to address potential conflicts of interest with regular systematic literature reviews by qualified individuals to vigilantly assess and communicate adverse effects associated with HPV vaccination. Finally, our evaluation suggests that an expanded use of HPV vaccine into more diverse populations, particularly those living in low-resource settings, would provide numerous health and social benefits.

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Formalin-fixed, paraffin-embedded tissues are widely used in biomedical research but little is known about the effect of the age of the block or unstained slides on the in situ hybridization or immunohistochemistry signal. We compared the in situ-based and immunohistochemistry-based signals for cervical intraepithelial neoplasia samples that ranged from 0 to 15 years of age. There was a progressive and statistically significant decrease in the strength of the p16 signal when comparing tissues prepared from recent unstained slides (0 to 1 y old, mean score of 92%) to those of intermediate age (5 to 7 y old, mean score of 49%) to old unstained slides (cut 13 to 15 y ago, mean score of 10%). Equivalent, progressive, and significant decreases in the intensity of the signals for microRNAs, CD45, and human papillomavirus DNA were seen in tissues stored on slides from 5 to 7 years and 13 to 15 years, respectively. However, the diminution of signal was much less, although still statistically significant, if the sections from the 13- to 15-year-old paraffin blocks were prepared in 2012. The data likely does not represent degradation of the targets as extraction of several microRNA from the old blocks showed no detectable degradation, despite the markedly weakened in situ hybridization signal. It is concluded that in situ-based signal for DNA, microRNAs, and proteins in paraffin-embedded tissues are significantly reduced over time, especially when stored long term on glass slides which, in turn, can lead to a significant underestimation of the amount and presence of the nucleic acid or protein target.

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