We report the identification and characterization of p33, the product of Kaposi's sarcoma-associated herpesvirus (KSHV) open reading frame 69 (ORF69), a positional homolog of the conserved herpesvirus protein UL31. p33 is expressed upon induction of viral lytic cycle with early kinetics. Immunofluorescence analysis revealed that in infected cell lines, the protein is localized in the nucleus, both in dotted spots and along the nuclear membrane. Nuclear fractionation experiments showed that p33 partitions with the nuclear matrix, and both immunoblotting of purified virions and immunoelectron microscopy indicated that the novel protein is not a component of the mature virus. Following ectopic expression in KSHV-negative cells, the protein was never associated with the nuclear membrane, suggesting that p33 needs to interact with additional viral proteins to reach the nuclear rim. In fact, after cotransfection with the ORF67 gene, the KSHV positional homolog of UL34, the p33 intranuclear signal changed and the two proteins colocalized on the nuclear membrane. A similar result was obtained when ORF69 was cotransfected with BFRF1, the Epstein-Barr virus (EBV) positional homolog of UL34 and ORF67. Finally, upon cotransfection, ORF69 significantly increased nuclear membrane reduplications induced by BFRF1. The above results indicate that KSHV p33 shares many similarities with its EBV homolog BFLF2 and suggest that functional cross-complementation is possible between members of the gammaherpesvirus subfamily.A number of proteins are conserved among all herpesviruses and are designated "core proteins." Among these, UL34 and UL31 protein family members have been studied extensively in the alphaherpesviruses herpes simplex virus type 1 (HSV-1) (54, 41), HSV-2 (53), pseudorabies virus (15), and equine herpesvirus 1 (EHV) (37) and in the betaherpesviruses human cytomegalovirus (CMV) (10) and mouse CMV (35, 47). For gammaherpesviruses, we initially identified and characterized the product of the Epstein-Barr virus (EBV) homolog of UL34, BFRF1 (12, 13), which has subsequently been shown to interact with the UL31 homolog BFLF2 (16,26) and to play an essential role in viral envelopment at the nuclear membrane (14).In all cases analyzed, UL34 and UL31 formed a complex at the inner nuclear membrane referred to as the nuclear egress complex (NEC), which is essential for viral egress (reviewed in reference 31), by interacting with viral (22, 44) and cellular kinases (35, 39) or with nuclear lamins (3,16,34,43). These interactions contribute to the dismantling of the rigid nuclear lamina (35) and facilitate access of nucleocapids to the nuclear membrane for primary envelopment.Very little is known of the intracellular viral maturation pathway of the second human gammaherpesvirus, Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV-8), a lymphotropic herpesvirus detected in biopsies of all clinical and epidemiological forms of Kaposi's sarcoma and also linked to lymphoproliferative disorders, such as ...
Thirteen liver biopsies in which the delta antigen was detected by immunofluorescence were studied by electron microscopy and immune electron microscopy with peroxidase labelled IgG and F(ab1)2 fraction obtained from a human antiserum containing high-titre anti-delta antibodies. The findings were compared with those obtained in 11 HBcAg positive and in two HBsAg negative controls. Neither unique particulate morphology nor any HB virus ultrastructural component were visualised in the delta positive specimens; 20-23 nm naked core particles were observed in 10 of 11 biopsies displaying the HBcAg in immunofluorescence. Delta positive nuclei frequently contained dense round structures of diameter varying between 20 and 30 nm with a soft indistinct edge. These granules did not exhibit characteristic ultrastructural features which enabled them to be distinguished from other granular material observed occasionally in nuclei of normal and diseased livers. However, their association with the delta antigen has been proved by the deposition on identical structures of peroxidase labelled anti-delta antibody. These results suggest that the delta antigen is unrelated to the Dane particle, the putative HB virus. The granules observed in the delta positive nuclei are composed of an amorphous matrix, possibly insoluble aggregates of the delta antigen.
Purpose Arthroplasty registries have an important role in improving outcomes in joint surgery. As the demand for joint arthroplasty continues to increase, growing attention is being paid to the establishment of national registries, which contribute to the enhancement of the quality of patients' care. Indeed, providing postmarketing surveillance data in terms of safety and effectiveness of medical devices, registries contribute to the best orthopaedic practice and support public health decision making. In this context, a project aimed at implementing a national arthroplasty registry in Italy has appeared to be essential, and the activities performed in the last years have consolidated data collection of hip and knee replacements. Methods Based on a close cooperation among public health institutions, clinicians, and involved stakeholders, the architecture of the registry is built on three pillars: (1) data collected using Hospital Discharge Records (HDRs) integrated by an additional dataset, (2) implants identified and characterized in a dedicated medical devices library, and (3) a federation of regional registries coordinated by a public health institution, the Italian National Institute of Health. Results Besides the organizational structure, statistical analyses on joint arthroplasty from national HDR database (2001–2014) and Italian registry data (2014) are presented. Currently, the institutions participating in the registry on a voluntary basis show 80% of completeness for hip and 58% for knee, and represent approximately 18% of the national volume. Conclusion To make data collection effective, participation should be mandatory and ruled by a national law. Level of Study Level III, observational analytic study.
The single dose pharmacokinetics of flutoprazepam and its active N-desalkyl metabolite were determined in 8 normal subjects by using newly developed, highly sensitive, GC-MS and HPLC techniques. Following a 2 mg dose of the drug, the concentrations of unchanged flutoprazepam in serum were extremely low (below 5 ng/ml at 2 h) and declined rapidly to undetectable levels within 6-9 h after dosing. At all sampling times, the serum concentration of the N-dealkylated metabolite (N-desalkylflurazepam) was much greater than that of the parent compound. This metabolite appeared in serum rapidly (within 2 h), reached a peak between 2 and 12 h and declined slowly, with an elimination half-life of about 90 h on average. The serum concentration of two additional putative metabolites (3-hydroxy-flutoprazepam and N-desalkyl-3-hydroxy-flutoprazepam) was below the limit of detection (2 ng/ml) in all samples. Mild CNS effects (documented by prolonged choice reaction time) were present at 2 and 4 h but were no longer detectable at 9 h. It is suggested that unchanged flutoprazepam is unlikely to contribute significantly to clinical effects and that the drug exerts its therapeutic activity through conversion to the slowly eliminated N-desalkyl metabolite.
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.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.