Biomedical subjects
Publications and source records attributed to H Fields.
A controlled investigation was conducted in which 50 sets of dentures were processed with different investing mediums. The most accurate results in maintaining the vertical dimension of occlusion of dentures during processing were obtained with artificial stone and a layer of silicone rubber.
A controlled investigation was conducted to compare the increase in vertical dimension of complete dentures after processing using acrylic resin and porcelain teeth. The smallest increase in vertical dimension was obtained using acrylic resin teeth.
An investigation was conducted to evaluate eight disclosing media for the detection of binding or interference regions on removable partial denture frameworks. The aerosol spray media were judged to be the most acceptable of those tested because they are easy to use and afford minimal waste; they also adhere well to removable partial denture metals and while easily removed, they are not washed away by excess saliva.
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A method of treatment that combines the advantages of both a removable partial denture and a fixed partial denture is described. The indications, contraindications, advantages, and special considerations are discussed. The procedures necessary for treatment of patients are described. Our observations indicate that this is an acceptable mode of treatment for those patients in need of this type of prosthesis.
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Explore the source record for details and available documents.
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To define more exactly the epidemiology of delta virus infection and confirm its role in causing fulminant Labrea hepatitis in the Amazon Basin, we studied the prevalence of delta virus infection among persons with acute and chronic hepatitis B virus infection in the Boca do Acre district of the southern Amazon Basin. Delta virus infection was found in 24% of asymptomatic hepatitis B virus carriers, 29% of acute nonfulminant hepatitis B cases, 74% of fulminant hepatitis B cases, and 100% of chronic hepatitis B cases. Chronic delta virus infection occurred primarily in older children and adults, while acute and fulminant delta virus infection occurred in young children as well. In fulminant hepatitis cases, delta virus superinfection of hepatitis B virus carriers was the most common serological pattern; histopathologic examination showed features identical to those described in fulminant hepatitis cases of similar etiology in Colombia and Venezuela. Delta virus infection is highly endemic in the southern Amazon Basin and is the principal cause of Labrea hepatitis.
Localization of virus and viral antigen in cell cultures infected with a rapidly replicating isolate of strain HM-175 of hepatitis A virus (HAV; pHM-175) was accomplished by using immunogold probes. Cells infected under one-step growth curve conditions were prefixed with 2% paraformaldehyde and 0.1-0.001% saponin at appropriate times postinfection for detection of maximum virus and viral antigen. An indirect labeling technique was employed using monoclonal antibody to HAV followed by 5 nm gold-antimouse IgG conjugate. Cells were then fixed by standard electron microscopy techniques and thin sectioned. This prefixation technique allowed penetration of the immunogold probes and moderate preservation of ultrastructure. Within infected cell cytoplasm, numerous antigenic sites were labeled with six to 200 gold particles. Two types of cells were infected with HAV and somewhat different results were obtained with the two cell types. In BS-C-1 cells, where a cytopathic effect (CPE) was not observed, myelin figures were immunogold labeled or frequently were located near immunogold-labeled sites. Vesicles containing viruslike particles (14-22 nm) were also observed. A significant observation in infected FRhK-4 cells was the presence of multivesicular bodies labeled with immunogold. Microfilaments were commonly seen near the multivesicular bodies. Our results demonstrate that the choice of prefixation method for immunogold labeling should be empirically determined for the cell type and condition.
Hepatitis B core antigen, antibody to core antigen, and DNA polymerase activity were measured in sera from a select group of post-transfusion hepatitis B patients who had been followed prospectively following blood transfusion. Preliminary results of this study have revealed (1) that RIA testing of blood would not eliminate but would reduce post-transfusion hepatitis B infections by about 50 per cent; (2) that infection with HB virus is modified or aborted in the presence of pre-existing antibody to HB surface antigen; and (3) that transfusion of blood containing anti-HBs does not increase the risk of post-transfusion hepatitis B. HBc Ag and/or DNA polymerase activity were observed in the sera of all recipients tested who developed liver enzyme abnormalities along HBs Ag and anti-HBc. DNA polymerase activity usually occurred in the early stages of incubation before the transaminase became abnormal, whereas HBc Ag was more often associated with increasing enzymatic evidence of liver damage, suggesting release of core structures from the hepatocytes. The presence of DNA polymerase without detectable HBc Ag may be due to the presence of intact Dane particles in the sera, preventing recognition of the core antigen. No serological evidence of hepatitis B was observed in the sera of 24 other recipients who developed abnormal transaminases. Immunoelectron microscopy of these same sera revealed evidence of exposure to hepatitis A antigen following transfusion in at least two recipients.
One week before their first dental visit, 36- to 60-month-old children were shown a videotape to model their behavior in the dental situation. The behavior was then rated for three visits. The children who had been modeled did not behave significantly better than either children who had no previous contact with the dental setting or children who had visited the reception room one week before their first dental visit.
The education and training of health service professionals and non-professionals is set to be driven by a market-place philosophy which will exert and endorse competition and control via rapidly evolving change and reform. Helen Field's article seeks to provide an outline of such reform within the National Health Service education and training arena. In particular, it considers how the education of nurse professionals will fare in a system which focuses more accurately on efficiency, cost effectiveness, quality and marketing of educational provision.