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Biomedical subjects

P H Cleveland

Publications and source records attributed to P H Cleveland.

33 records · Page 2Linked to original sources
PubMed1981

Rapid and efficient immobilization of soluble and small particulate antigens for solid phase radioimmunoassays.

A rapid method of antigen immobilization (10 min.) was developed using soluble antigens (bovine serum albumin, epidermal growth factor, and goat IgG) and small particulate antigens (Keyhole limpet hemocynanine and E. coli) by drying them on filter paper discs. This technique results in a high % of the soluble antigen remaining firmly bound, goat IgG (89%), bovine serum albumin (73%). All the antigens we tested retained their antigenicity after drying as detected by [125I] labeled staphylococcal protein A radioimmunoassay. This method of antigen immobilization was compared to adsorption to plastic wells and was found to be much faster (10 min vs 18 hrs) and was 5 times more efficient than adsorption to plastic wells. Using this technique, we were able to detect as little as 40 ng of bovine serum albumin. These characteristics suggest that this technique of soluble antigen immobilization may be useful in rapid detection of antibodies to many different antigens, as well as detecting ng amounts of the antigens directly.

Animals↗
PubMed1981

A rapid radioimmunoassay using 125I-labeled staphylococcal protein A for antibody to varicella-zoster virus.

A sensitive radioimmunoassay for serum antibody to varicella-zoster virus is described; it uses 125I-labeled staphylococcal protein A and a specially designed immunofiltration apparatus. The assay accurately distinguishes between individuals who are susceptible and those who are immune to infection with varicella-zoster virus. In addition, it can detect passive antibody in recipients of varicella-zoster immune globulin. This radioimmunoassay also detects the heterologous antibody responses that occasionally occur in patients infected with herpes simplex virus, which also have been detected by other antibody assays. The particular advantages of this assay are the use of noninfectious reagents, the speed of execution (less than 3 hr), the requirement for only small quantities of serum (30 microliters), the objectivity of end-point determination, and the capability of screening large numbers of sera. Consequently, this radioimmunoassay is especially useful for the rapid identification of susceptible individuals, which is essential for the appropriate management of patients and hospital personnel after exposure to varicella.

Acute Disease↗
PubMed1979

Tumor-associated antigens of chemically-induced murine tumors; the emergence of MuLV and fetal antigens after serial passage in culture.

Using radioiodinated Staphylococcus aureus protein A [125I]SPA to measure syngeneic, allogeneic and heterogeneic IgG bound to murine tumor cells, we performed a serological analysis of surface antigens of 8 solid tumors and 2 leukemias of BALB/c mice (3 chemically-induced colon carcinomas, 3 chemically-induced sarcomas, 1 murine leukemia virus (MuLV) induced leukemia, 1 irradiation induced leukemia, 1 spontaneous melanoma and 1 spontaneous sarcoma). We were able to detect and distinguish between at least five separate antigenic specificities on these tumors. Unique tumor-associated antigens were found on 3 of the tumors, MuLV related antigens on 8 tumors, fetal antigens on 7 tumors and two distinct common antigens on 7 tumors (common antigen 1 (CA-1) on 5 tumors and common antigen 2 (CA-2) on 2 tumors). Neither of the common antigens was found to be sarcoma, carcinoma or tissue-tupe specific. A number of tumors which did not originally express either MuLV or fetal antigens in primary cultures expressed these antigens after several serial passages in vitro.

Animals↗
PubMed1979

Immobilization of viral antigens on filter paper for a [125I]staphylococcal protein A immunoassay: a rapid and sensitive technique for detection of herpes simplex virus antigens and antiviral antibodies.

A new technique is described for the rapid detection and quantitation of herpes simplex virus (HSV) antigens and antiviral antibodies. It involves immobilization of HSV antigens on filter paper discs and subsequent analysis by 125I-labeled staphylococcal protein A (SPA) radioimmunoassay. A specially designed 96-well filtration device is employed which serves both as an incubation chamber and as a filtration manifold. It is rapid, simple, sensitive and specific, and requires only small volumes of antiserum and few target cells. The results may be readily and objectively quantitated. This technique permits the simultaneous assay of a large number of specimens in less than 1 h. Its sensitivity is considerably greater than that of other currently used immunologic techniques, and it is amenable to automation. These characteristics suggest that this [125I]SPA immunofiltration technique may be applicable to the rapid diagnosis of viral infections.

Antibodies, Viral↗
PubMed1979

Immunogenicity of chemically induced murine colon cancers.

The antigenicity and immunogenicity of three colorectal carcinomas induced in BALB/c mice by 1,2-dimethylhydrazine or N-methyl-N-nitrosourethan were studied. All tumors were readily transplantable. Two of these tumors metastasized when transplants reached sufficient size. All tumors were found to be immunogenic in the strain of origin, and all tumors were shown to contain unique tumor-specific transplantation antigens in cross-protection experiments. The use of these tumors as an animal model for studies of adjuvant immunotherapy and chemoimmunotherapy is suggested.

Animals↗
PubMed1970

Effect of mengovirus replication on choline metabolism and membrane formation in novikoff hepatoma cells.

Infection of Novikoff rat hepatoma cells (subline NlSL-67) with mengovirus resulted in a two- to threefold increase in the rate of choline incorporation into membrane phosphatidylcholine at about 3 hr after infection, without affecting the rate of transport of choline into the cell or its phosphorylation. The time course of virus-stimulated phosphatidylcholine synthesis was compared with the time courses of other virus-induced processes during a single cycle of replication. The formation of viral ribonucleic acid (RNA) polymerase and of viral RNA commenced about 1 hr earlier than the virus-stimulated choline incorporation. Further, isopycnic centrifugation of cytoplasmic extracts indicated that the excess of phosphatidylcholine synthesized by infected cells is not located in the membrane structures associated with the viral RNA replication complex, but with structures of a lower density (1.08 to 1.14 g/cc). These membrane structures probably represent the smooth vesicles which accumulate in the cytoplasm of infected cells during the period of increased phosphatidylcholine synthesis between 3 and 5 hr after infection. They are formed with both newly synthesized phosphatidylcholine and phosphatidylcholine present prior to infection. However, concomitant protein synthesis is not required for the stimulated synthesis of membranes; the effect was not inhibited by treating the cells with inhibitors of protein synthesis at 3 hr after infection, although virus production was inhibited about 90% and virus-induced cell degeneration was markedly reduced and delayed. Production of mature virus began normally at about the same time as the stimulation of phosphatidylcholine synthesis. Treatment of infected cells with puromycin at 2 hr, on the other hand, completely inhibited the stimulation of phosphatidylcholine synthesis.

Animals↗
PubMedDate not supplied

Humoral and cell-mediated immunity in peripheral blood following introduction of antigen into the middle ear.

Serum levels of specific IgG and the sensitization of peripheral blood T-lymphocytes were measured in guinea pigs after single-dose antigenic sensitization by two routes: intratympanic and intradermal injection. Keyhole limpet hemocyanin (KLH) served as the antigen. Intratympanic injection of antigen resulted in much lower levels of circulating anti-KLH IgG than intradermal injection. When KLH was conjugated with alum to produce nonspecific inflammation and serve as adjuvant, the intratympanic route was considerably enhanced, but remained much less effective than the intradermal route. Development of an IgG response was also somewhat less rapid following intratympanic than following intradermal administration. Marked sensitization of circulating T-lymphocytes was seen after intradermal injection of alum-precipitated KLH. A much weaker, though still positive, response was seen after intradermal injection of KLH alone and with the intratympanic injection of alum-precipitated KLH. No T-lymphocyte sensitization could be detected after intratympanic injection of KLH alone. It was concluded that the afferent limb of both humoral (IgG) and cell-mediated immunity was operative in the middle ear. Therefore, the middle ear does not represent an immunologically "privileged" site. On the other hand, the afferent limb from the middle ear appears to operate less effectively and rapidly than that from the dermis. This observation is consistent with observations in other mucosal systems.

Animals↗