Biomedical subjects
Publications and source records attributed to J Summers.
This issue's discussion has two goals. First, we shall examine the reasons clinical personnel gravitate to the Kantian concept of duty. Second, we shall examine a technique used within Kantian theory that will help you decide when an ethical dilemma obligates you to act regardless of the consequences.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A DNA virus with the characteristics of a herpesvirus has been isolated from woodchuck hepatocytes cultured in vitro. We refer to this virus as herpesvirus of marmots (HVM). Electron microscopy of thin sections of HVM-infected cells showed nucleocapsids with a hexagonal outline and a diameter of 80 nm. Enveloped virions were seen in cytoplasmic vacuoles and outside the cell. Negatively stained virus particles purified from cell supernatants were enveloped with the characteristic appearance of herpesviruses. The DNA was double-stranded with a molecular size of approximately 140 kb and a G + C content of 73%. The virus replicated with a lytic effect in kidney cells of owl monkeys and African green monkeys, baby hamster kidney cells, feline kidney cells and WCH-17, a cell line derived from a woodchuck hepatoma. An indirect immunofluorescence assay has shown the presence of antibody to HVM in seven out of 37 animals tested. An important reason for studying HVM lies in its possible role in infection or the disease produced by woodchuck hepatitis virus, an animal model for human hepatitis B virus.
Transfection of the human hepatocellular carcinoma cell line HuH7 with a plasmid containing a tandem copy of the duck hepatitis B virus DNA sequence resulted in transient replication of the virus. Viral particles secreted by transfected HuH7 cells exhibited physical properties similar to those of serum-derived duck hepatitis B virus and were infectious in primary duck hepatocyte cultures.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
We obtained two lines of evidence that monolayer cultures of primary woodchuck hepatocytes support replication of the genome of human hepatitis delta virus (HDV). (i) From a Northern (RNA blot) analysis of the HDV-related RNA in infected cultures, both genomic and antigenomic 1.7-kilobase RNA species were detected at 11 days after infection. The ratio of genomic RNA to antigenomic RNA was 2:1 to 10:1, comparable to that previously reported in studies of experimentally infected chimpanzees and woodchucks. (ii) Replication in culture was also demonstrated by in situ hybridization with a strand-specific probe. Such studies showed that only a small fraction of the cultured cells supported replication and that in such cells the relative and absolute levels of the HDV RNAs were comparable to those in liver cells infected in vivo. Furthermore, as with the in vivo studies, the HDV RNAs were predominantly localized to the nucleus. In summary, we demonstrated that cultured cells supported both the early events of HDV adsorption and penetration and the intermediate events of genome replication.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
We devised a simple method using inexpensive instrumentation for determination of accurate levels of radiation exposure. The method can be used by technologists in small hospitals, private practices, and other facilities that do not employ full-time or consulting physicists to provide these data.
Covalently closed circular (CCC) double-stranded DNA believed to be the transcriptional template for duck hepatitis B virus (DHBV) is amplified in aging primary cultures of hepatocytes from congenitally infected ducklings. Analysis of 5-bromodeoxyuridine-labeled heavy/light CCC DNA shows that the relaxed circular DNA synthesized in the cytoplasm by reverse transcription is the predominant precursor to the amplified pool of nuclear viral CCC DNA. In vitro infection of uninfected hepatocyte cultures with DHBV demonstrates that a similar 50-fold amplification of CCC DNA occurs during an early stage in the infection before virus production. This amplification allows the establishment of a pool of transcriptional templates in the cell without the need for semiconservative replication or multiple rounds of infection. This process may account for the ability of hepadnavirus-infected cells persistently to produce virus particles in the absence of stable integration of viral DNA.
Explore the source record for details and available documents.
Uncompensated cares poses considerable management, marketing and ethical challenges to health care managers. A variety of responses are examined which offer the possibility of reducing the need for inpatient care and the cost of that care as well as for the enhancement of the organization's positioning in the marketing and sales environment. Some of the programs will require support from local community agencies or employers, but others will be quite feasible without such support. Additionally, the programs build on sensitivity to the hospital mission as opposed to turning away from it.