Gestational age-specific risk estimates are lowest between 38 and 40 weeks and should be included in the informed-consent process. The information should also be used to allow for appropriate preparation with respect to adequate staff and equipment. ECD is consistently associated with increased intrapartum and neonatal mortality, risk of admission, and respiratory morbidity compared with PVD and has no advantage over emergency CD in terms of mortality. Neonatal morbidities are lower after ECD than emergency CD only with term births. Our data provide evidence that ECD should not be performed before term.
Bovine papillomavirus type 2 (BPV-2) is an oncogenic virus infecting both epithelial and mesenchymal cells. Its life cycle, similar to other papillomaviruses (PVs), appears to be linked to epithelial differentiation. Human and bovine PVs have been known to reside in a latent, episomal form in PBMCs; therefore, it is believed that blood cells, like all mesenchymal cells, function as non-permissive carriers. Here, for the first time in veterinary and comparative medicine, the BPV-2 E5 oncoprotein and the major structural L1 capsid protein, known to be expressed only in productive infections, were shown to occur in defined subsets of PBMCs. E5 oncoprotein was detected in sorted T-and B-cells as well as in monocytes by flow cytometry and Western blot analysis. However, CD4 + and CD8 + lymphocytes appeared to be the main circulating targets of the virus, thus possibly representing the most important reservoir of active BPV-2 in blood. L1 protein was identified by flow cytometry in a population of blood cells recognized as lymphocytes by morphological scatter properties. Western blot analysis was performed on lysates obtained from the sorted subpopulations of PBMCs and detected L1 protein in CD4 + and CD8 + cells only. Thus, this study showed that CD4 + and CD8 + lymphocytes are permissive for BPV-2 and are new, hitherto unknown sites of productive PV infection. In light of these observations, the life cycle of PVs needs to be revisited to gain novel insights into the epidemiology of BPV infection and the pathogenesis of related diseases. INTRODUCTIONBovine papillomaviruses (BPVs) are a heterogeneous group of viruses responsible for tumours of the skin, genital and paragenital area, eye, upper gastrointestinal tract and urinary bladder (IARC, 2007). BPVs, like all other papillomaviruses (PVs), are usually strictly species specific. However, cases of cross-species infection are known to occur. BPV type 1 (BPV-1) and BPV-2, belonging to the genus Deltapapillomavirus (de Villiers et al., 2004), are responsible for infections in equids resulting in sarcoids (Chambers et al., 2003;Trenfield et al., 1985), as well as in bison and water buffaloes leading to warts (Literák et al., 2006;Silvestre et al., 2009). In addition, a variant of BPV-8, classified in the genus Epsilonpapillomavirus, also causes papillomas of the skin in bison (Tomita et al., 2007). More recently, it has been suggested that BPVs could be responsible for cutaneous sarcoids in cats and captive African lions (Munday & Knight, 2010;Orbell et al., 2010).BPV-1 and -2 are closely related serotypes (Shafti-Keramat et al., 2009) and can infect both epithelial and mesenchymal cells. Similar to other PVs, BPV-1/-2 replication and virion production are confined to the epithelial region of the lesions, whilst infection of mesenchymal cells appears to be non-productive (Campo, 2006;Shafti-Keramat et al., 2009).BPV-2 is known to play a central role in bladder carcinogenesis of adult cattle reared on pasturelands rich in bracken fern. In these animals, tumours of the u...
Papillomaviruses (PVs) are believed to be highly epitheliotropic as they usually establish productive infections within stratified epithelia. In vitro, various PVs appear to complete their entire life-cycle in different trophoblastic cell lines. In this study, infection by and protein expression of bovine papillomavirus type 2 (BPV-2) in the uterine and chorionic epithelium of the placenta has been described in four cows suffering from naturally occurring papillomavirus-associated urothelial bladder tumors. E5 oncoprotein was detected both by Western blot analysis and immunohistochemically. It appears to be complexed and perfectly co-localized with the activated platelet-derived growth factor ß receptor (PDGFßR) by laser scanning confocal microscopy. The activated PDGFßR might be involved in organogenesis and neo-angiogenesis rather than in cell transformation during pregnancy. The major capsid protein, L1, believed to be only expressed in productive papillomavirus infection has been detected by Western blot analysis. Immunohistochemical investigations confirmed the presence of L1 protein both in the cytoplasm and nuclei of cells of the uterine and chorionic epithelium. Trophoblastic cells appear to be the major target for L1 protein expression. Finally, the early protein E2, required for viral DNA replication and known to be expressed during a productive infection, has been detected by Western blot and immunohistochemically. Electron microscopic investigations detected viral particles in nuclei of uterine and chorionic epithelium. This study shows that both active and productive infections by BPV-2 in the placenta of pregnant cows can occur in vivo.
BackgroundPapillomaviruses (PVs) are highly epitheliotropic as they usually establish productive infections within squamous epithelia of the skin, the anogenital tract and the oral cavity. In this study, early (E) and late (L) protein expression of bovine papillomavirus type 2 (BPV-2) in the urothelium of the urinary bladder is described in cows and water buffaloes suffering from naturally occurring papillomavirus-associated urothelial bladder tumors.Methods and FindingsE5 protein, the major oncoprotein of the BPV-2, was detected in all tumors. L1 DNA was amplified by PCR, cloned and sequenced and confirmed to be L1 DNA. The major capsid protein, L1, believed to be only expressed in productive papillomavirus infection was detected by Western blot analysis. Immunohistochemical investigations confirmed the presence of L1 protein both in the cytoplasm and nuclei of cells of the neoplastic urothelium. Finally, the early protein E2, required for viral DNA replication and known to be a pivotal factor for both productive and persistent infection, was detected by Western blot and immunohistochemically. Electron microscopic investigations detected electron dense particles, the shape and size of which are consistent with submicroscopic features of viral particles, in nuclei of neoplastic urothelium.ConclusionThis study shows that both active and productive infections by BPV-2 in the urothelium of the bovine and bubaline urinary bladder can occur in vivo.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.