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Biomedical subjects

R D Aach

Publications and source records attributed to R D Aach.

At least 37 records · Page 2Linked to original sources
PubMed1980

Post-transfusion hepatitis: current perspectives.

Viral hepatitis is still the most serious post-transfusion complication. Despite the routine screening of donor blood for the hepatitis type B surface antigen in the United States, post-transfusion hepatitis develops in approximately 7% of blood recipients. Type B hepatitis accounts for only 10% to 15% of cases; non-A, non-B hepatitis constitutes the remainder. Non-A, non-B hepatitis is usually asymptomatic and anicteric but often runs a prolonged course manifested by persistent or intermittent elevations of alanine aminotransferase levels. The risk of developing non-A, non-B hepatitis is increased considerably when blood from paid rather than volunteer donors is transfused. Although there are currently no definitive preventive measures that can be used to reduce the attack rate, the possibility of developing a serologic test fot the non-A, non-B agent is under active investigation.

Blood Donors↗
PubMed1979

A partial characterization of hepatitis B e antigen.

Partially purified hepatitis B e antigen (HBeAG) was prepared by ultracentrifugation, ammonium sulfate precipitation, and molecular sieve chromatography of sera obtained from asymptomatic carriers of hepatitis B surface antigen. The antigenic specificity of the HBeAG preparations was investigated further with affinity chromatography. The results indicated that HBeAG is distinct and separable from DNA polymerase activity. Columns coupled with either goat IgG prepared from antiserum to human IgG or antibody to HBeAg bound all detectable HBeAg and bound 31% and 100% of the IgG, respectively, from a partially purified HBeAg preparation. Rate zonal sucrose sedimentation and molecular sieve and ion-exchange chromatography indicated a variability in molecular weight and charge; this finding suggested a heterogenous population of immunoreactivities containing HBeAg. Our preliminary results suggest the existence of an HBeAg-IgG complex.

Carrier State↗
PubMed1979

Hepatitis B e antigen, DNA polymerase activity, and infection of household contacts with hepatitis B virus.

To determine if the presence of hepatitis B e antigen (HBeAg) and elevated DNA polymerase activity in the serum of chronic HBeAg carriers indicate increased contagiousness in a household setting, the household contacts of 74 carriers were prospectively evaluated for serologic evidence of hepatitis B infection. Thirty of the HBsAg carriers had HBeAg and 44 had anti-HBe. Twenty-eight HBeAg-positive carriers regularly demonstrated elevated DNA polymerase when serially drawn serum samples were analyzed. None of the anti-HBE-positive carriers demonstrated elevation of DNA polymerase activity. Both household contacts of HBeAg-positive and anti-HBe-positive carriers demonstrated serologic evidence of hepatitis B infection (HBsAg, anti-HBs, and anti-HBc). However, infection was significantly more frequent among spouses and sexual partners of carriers who had either HBeAg (P less than 0.001) or elevated DNA polymerase activity (P less than 0.001). Thus, the data indicate that a particular subpopulation of spouses and sexual partners of hepatitis B carriers are at significantly greater risk for acquiring infection.

Adult↗
PubMed1978

Filtration and immunoprecipitation in the elimination of DNA polymerase activity associated with bacterial contamination of sera positive for hepatitis B e antigen and its corresponding antibody.

Samples of serum inoculated with Escherichia coli and serum that became contaminated with bacteria after exposure to a laboratory atmosphere demonstrated elevated DNA polymerase activity. The levels of activity were well within the range of values found in hepatitis B e antigen (HBeAg)-positive samples. The bacterial polymerase activity was markedly reduced by a single passage of serum samples through a 0.22-micron Millipore filter prior to analysis. Repeated filtration did not result in a substantial further decrease in polymerase activity. In sera that were heavily contamined with E. coli, however, filtration was not successful in reducing bacteria-associated polymerase activity to a base-line uncontaminated level. In such instances double antibody immunoprecipitation proved effective in elimination of bacterial activity. When bacterial contamination of serum samples is a possibility, specimens should be subjected to either Millipore filtration or immunoprecipitation prior to analysis, particularly when correlation of DNA polymerase activity with HBeAg and its corresponding antibody is attempted.

Antibodies, Viral↗
PubMed1978

Anticore antibody screening of transfused blood.

Aliquots of 130 HB8Ag negative units of blood which were administered to 26 recipients were tested under code for anti-HBc by a solid phase radioimmunoassay technqiue. 14 of the 26 recipients developed posttransfusion hepatitis (PTH), including 6 cases of hepatitis B. Anti-HBc was detected in 7 or 5.3% of 130 donor units. Of the 14 patients acquiring PTH, 6 received a unit of anti-HBc-positive blood. Type B hepatitis occurred in 4 of the 7 anti-HBc recipients, and non-type B hepatitis in 2. Only 1 of 12 recipients who failed to develop PTH had received a unit containing anti-HBc.

Antibodies, Viral↗
PubMed1978

Non-A, non-B hepatitis transmission in chimpanzees: a project of the transfusion-transmitted viruses study group.

Experimental transmission of non-A, non-B hepatitis was apparently accomplished in 5 chimpanzees following inoculation with presumably infectious human sera. Administration of sera from implicated donors with normal alanine aminotransferase (ALT) values, as well as from those with abnormal ALT levels, resulted in the development of ALT abnormalities in the inoculated chimpanzees. Transmission from donors with normal ALT values implies that healthy carriers of non-A, non-B virus exist. Evidence is presented which indicates that a period of viremia precedes the clinical illness by at least 12 days.

Alanine Transaminase↗
PubMed1977

Discordant e antigen, DNA polymerase activity, and Dane particle responses in two patients representing an index case-contact case pair with hepatitis B virus infection.

Discordant results for e antigen, DNA polymerase activity, and Dane particle frequency were noted in the sera of two patients representing an index case-contact case pair with chronic aggressive hepatitis B. The lack of correlation between presence of e antigen and the infecting viral strain, as well as the strong relationship of e antigen to persistent and significant viremia, emphasize the role of the host's immune response in the expression of this antigen.

Adult↗
PubMed1975

Enzymatic activation and trapping of luminol-substituted peptides and proteins. A possible means of amplifying the cytotoxicity of anti-tumor antibodies.

Glutathione and glucose oxidase (EC 1.1.3.4) conjugates containing covalently bound luminol were prepared as prototypes for peptides and proteins with latent, enzyme-activatable chemical reactivity. In the presence of small quantities of activated horseradish peroxidase, conjugated luminol molecules were oxidized to unstable free radicals which reacted rapidly with soluble proteins and cells. These observations are of interest in regard to possible sequential localization reactions in which a few molecules of cell-bound antibody-horseradish peroxidase would be used to catalytically alter and trap many molecules of a second (luminol-substituted) enzyme, toxin, or hapten in the same area, as might be desirable in promoting selective cell destruction.

Antibodies, Anti-Idiotypic↗
PubMed1975

Angiosarcoma of the liver associated with Fowler's solution (potassium arsenite).

A patient with an angiosarcoma of the liver associated with the chronic ingestion of Fowler's solution (potassium arsenite) is described. The patient's clinical course was characterized by upper gastrointestinal hemorrhage, recurrent hemoperitoneum, hepatic failure, and, subsequently, the appearance of an angiosarcoma of the skin. Selective angiography demonstrated features consistent with both hepatoma and cavernous hemangioma. The hepatic toxicity and the carcinogenicity of arsenic are reviewed, with particular reference to Fowler's solution, which previously has been widely used for the treatment of psoriasis. The long latency period for the development of the malignancies is emphasized.

Adult↗