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Biomedical subjects

F V Plapp

Publications and source records attributed to F V Plapp.

At least 37 records · Page 2Linked to original sources
PubMed1983

Profound neutropenia associated with benzylpenicillin.

A 31-year-old white man with suspected aspiration pneumonia complicated by multiple pulmonary abscesses had profound neutropenia during a course of high-dose benzylpenicillin therapy for suspected bacterial endocarditis. Antigranulocyte antibodies were identified in the patient's serum. Leukopenia is an uncommon but potentially serious complication of therapy with this drug. We recommend weekly monitoring of blood counts during prolonged therapy with any beta-lactam antibiotic.

Adult↗
PubMed1983

The Rhesus D antigen. A dicyclohexylcarbodiimide-binding proteolipid.

Previous studies on the human Rhesus D antigen revealed several similarities between the D antigen and proteolipids. Proteolipids are a family of low-molecular-weight, hydrophobic proteins that are soluble in chloroform/methanol. In addition, many proteolipids bind dicyclohexylcarbodiimide (DCCD), an ATPase inhibitor. For determination of whether the D antigen was a proteolipid, the chloroform/methanol solubility and DCCD binding of the antigen were investigated. DCCD specifically inhibited the binding of anti-D IgG to Rh-positive red blood cells and to partially purified D antigen as determined by enzyme-linked immunoassays. The antigen was not only soluble in chloroform/methanol but was purified to apparent homogeneity by extraction with these solvents and subsequent discontinuous sucrose gradient centrifugation. The antigen's chloroform/methanol solubility, DCCD binding, low molecular weight, and previously reported phospholipid dependence allow classification of the D antigen as a proteolipid. The discovery that the D antigen is a proteolipid provides further clues to the antigen's cellular function.

Antigen-Antibody Reactions↗
PubMed1982

Steroid receptor proteins in human meningiomas.

Steroid receptor assays play an important role in determining the efficiency of endocrine therapy for patients with breast cancer. Other tumors could also be hormonally dependent and patients with these tumours might also benefit from endocrine manipulation. Thus, patients with meningiomas were tested for the presence or absence of estrogen and progesterone receptors. The results showed that a majority of meningiomas lacked estrogen receptors but contained large amounts of progesterone receptor. Therefore, it should be possible to use antiprogestin therapy in cases where complete surgical resection of meningiomas is not possible.

Adult↗
PubMed1982

Identification of Rho(D) antigen in polyacrylamide gels by an enzyme-linked immunoassay.

Human erythrocyte membranes were solubilized in sodium dodecyl sulfate at 100 degree C and subjected to polyacrylamide gel electrophoresis. The gels were sliced into segments and each segment was incubated with anti-Rho(D) IgG, washed, and then incubated with goat anti-human IgG covalently linked to alkaline phosphatase. Para-nitrophenyl phosphate was added to each slice and the absorbance of the solution surrounding each slice was measured at 405 nm. This technique demonstrated that the Rho (D) antigen is a protein with a mol, wt between 13, 000 and 30,000. This method should be applicable to the investigation of other membrane-bound antigens.

Electrophoresis, Polyacrylamide Gel↗
PubMed1981

Different ionic forms of estrogen receptor in rat uterus and human breast carcinoma.

Estrogen receptors from rat uterus and human breast carcinoma were analyzed by diethylaminoethyl-cellulose chromatography. Cytosols which had been incubated for short periods of time demonstrated a single discrete elution peak, indicating a single ionic form, while cytosols incubated for longer periods of time generated a second ionic form of receptor. Addition of cations to cytosols also promoted the rapid appearance of this second ionic form of receptor. Either leupeptin, a protease inhibitor, or sodium molybdate prevented the appearance of this second ionic form of estrogen receptor. The estrogen receptor from rat uterine cytosol incubated without leupeptin or molybdate had a smaller apparent molecular weight than did estrogen receptor from cytosols incubated with leupeptin or molybdate. Altogether, these experiments suggested that a cation-dependent protease present in the cytosols from both tissues was degrading the estrogen receptor to a second smaller species during extended incubation times.

Animals↗
PubMed1979

Partial purification of Rho (D) antigen from Rh positive and negative erythrocytes.

A rapid method is described for partial purification of Rho(D) antigen from sodium deoxycholate-solubilized erythrocyte membranes by affinity chromatography on a column coupled with anti-Rho(D) IgG. The Rho(D) antigen is a low molecular weight membrane protein that comigrates with the lipid zone of erythrocytes during sodium dodecyl sulfate/polyacrylamide gel electrophoresis. Similar quantities of Rho(D) antigen were present in Rh positive and negative erythrocytes. However, in the latter erythrocytes the antigen may not be exposed to the external cell surface, explaining why these cells are not agglutinated by anti-Rho(D) antiserum. LW antigen was also present in the fraction containing Rho(D) antigen. The genetic implications of these findings are discussed.

Antigens↗
PubMed1976

Electrophoresis of human multiple myeloma and Waldenström's macroglobulinemia sera in sodium dodecyl sulfate polyacrylamide gels.

Sera from normal persons and patients with IgA, IgD, IgG, and IgM monoclonal gammopathies were electrophoresed in polyacrylamide gels containing sodium dodecyl sulfate. The gels were stained with Coomassie blue or were used for immunodiffusion. By this method IgG multiple myeloma and IgM Waldenström's macroglobulinemia sera were readily distinguished by electrophoresis alone, whereas IgA and IgD myeloma sera were distinguished by further immunodiffusion against anti-alpha-chain antibody and anti-delta-chain antibody.

Electrophoresis, Polyacrylamide Gel↗
PubMed1975

Characterization of monosomes produced by aflatoxin B1.

A single injection of 1.5 mg aflatoxin B1 per kg body weight produced approx. 70% disaggregation of rat liver polysomes into monosomes within 18 h. Isolated monosomes dissociated into 40 S subunits during centrifugation in linear sucrose gradients containing 0.3 M KCI. The 4 S to 5 S molar RNA ratio of the monosomes was calculated to be 0.6, indicating 0.6 tRNA and/or aminoacyl tRNA molecule per ribosome; no peptidyl tRNA was present. These results suggest that a single injection of affatoxin B1 produces monosomes which resemble runoff ribosomes.

Aflatoxins↗