Comparison of Different In Situ Hybridization Techniques for the Detection of Various RNA and DNA Viruses

In situ hybridization (ISH) is a technique to determine potential correlations between viruses and lesions. The aim of the study was to compare ISH techniques for the detection of various viruses in different tissues. Tested RNA viruses include atypical porcine pestivirus (APPV) in the cerebellum of pigs, equine and bovine hepacivirus (EqHV, BovHepV) in the liver of horses and cattle, respectively, and Schmallenberg virus (SBV) in the cerebrum of goats. Examined DNA viruses comprise canine bocavirus 2 (CBoV-2) in the intestine of dogs, porcine bocavirus (PBoV) in the spinal cord of pigs and porcine circovirus 2 (PCV-2) in cerebrum, lymph node, and lung of pigs. ISH with self-designed digoxigenin-labelled RNA probes revealed a positive signal for SBV, CBoV-2, and PCV-2, whereas it was lacking for APPV, BovHepV, EqHV, and PBoV. Commercially produced digoxigenin-labelled DNA probes detected CBoV-2 and PCV-2, but failed to detect PBoV. ISH with a commercially available fluorescent ISH (FISH)-RNA probe mix identified nucleic acids of all tested viruses. The detection rate and the cell-associated positive area using the FISH-RNA probe mix was highest compared to the results using other probes and protocols, representing a major benefit of this method. Nevertheless, there are differences in costs and procedure time.

A ratiometric fluorescent composite nanomaterial for RNA detection based on graphene quantum dots and molecular probes

We developed a novel fluorescent nanocomposite RNA probe HVC-6@GQDs based on graphene quantum dots. This unique probe has been successfully applied for the detection of RNA in living cells.

Placental Pathology of Zika Virus: Viral Infection of the Placenta Induces Villous Stromal Macrophage (Hofbauer Cell) Proliferation and Hyperplasia

Context.—The placenta is an important component in understanding the fetal response to intrauterine Zika virus infection, but the pathologic changes in this organ remain largely unknown. Hofbauer cells are fetal-derived macrophages normally present in the chorionic villous stroma. They have been implicated in a variety of physiological and pathologic processes, in particular involving infectious agents. Objectives.—To characterize the fetal and maternal responses and viral localization in the placenta following Zika virus transmission to an 11 weeks' gestation fetus. The clinical course was notable for prolonged viremia in the mother and extensive neuronal necrosis in the fetus. The fetus was delivered at 21 weeks' gestation after pregnancy termination. Design.—The placenta was evaluated by using immunohistochemistry for inflammatory cells (macrophages/monocytes [Hofbauer cells], B and T lymphocytes) and proliferating cells, and an RNA probe to Zika virus. The fetal brain and the placenta were previously found to be positive for Zika virus RNA by reverse transcription–polymerase chain reaction. Results.—The placenta demonstrated prominently enlarged, hydropic chorionic villi with hyperplasia and focal proliferation of Hofbauer cells. The degree of Hofbauer cell hyperplasia gave an exaggerated immature appearance to the villi. No acute or chronic villitis, villous necrosis, remote necroinflammatory abnormalities, chorioamnionitis, funisitis, or hemorrhages were present. An RNA probe to Zika virus was positive in villous stromal cells, presumably Hofbauer cells. Conclusions.—Zika virus placental infection induces proliferation and prominent hyperplasia of Hofbauer cells in the chorionic villi but does not elicit villous necrosis or a maternal or fetal lymphoplasmacellular or acute inflammatory cell reaction.

A two-photon fluorescent RNA probe screened from a series of oxime-functionalized 2,2′:6′,2′′-terpyridine ZnX2(X = Cl, Br, I) complexes

An oxime-functionalized terpyridine ZnCl2complex is a RNA two-photon fluorescent probe exhibiting RNA binding, fluorescence intensity enhancement and compatibility with Hoechst 33342.

Hg2+ detection using a phosphorothioate RNA probe adsorbed on graphene oxide and a comparison with thymine-rich DNA

Using phosphorothioate modified RNA probes adsorbed by graphene oxide, Hg2+ is detected sensitively with less interference.