F. Alfred Anderer

Slope analysis of the postoperative CEA time course and its possible application as an aid in diagnosis of disease progression in gastrointestinal cancer

Abstract The postoperative carcinoembryonic antigen (CEA) time courses of patients with histologically proven adenocarcinoma of the gastrointestinal tract were analyzed to establish a possible correlation with distinct types of disease progression. The diagnosis of tumor progression was obtained by second-look surgery, and in some cases by other clinical diagnostic procedures. In thirty-one of thirty-four patients studied, tumor progression correlated with increasing CEA levels. The calculation of the slopes of the CEA increase in the computerized CEA surveillance diagrams represented a parameter that discriminated between local tumor recurrence and widespread tumor dissemination. All localized tumor recurrences exhibited a flat slope in the range of 0.08 to 0.30 ng CEA increase/ml serum within ten days, with a mean value of 0.17 ng/ml in ten days. The CEA slopes in cases of liver metastases were relatively steep and ranged from 0.9 to 3.8 ng/ml in ten days, yielding a mean slope of 2.2 ng CEA increase/ml serum in ten days.

Eighty-four potential second-look operations based on sequential carcinoembryonic antigen determinations and clinical investigations in patients with recurrent gastrointestinal cancer

In our study of patients with resected primary gastrointestinal cancer, slope analysis of the post-operatively increasing carcinoembryonic antigen time courses signaled relapse in about 80 percent of the patients up to 12 months before positive clinical diagnosis. In 29 patients, clinical confirmation of the relapse could be obtained only after second-look surgery. Slope analysis generally differentiated localized from metastatic disease and therefore also predicted the site of relapse. A first evaluation of 84 patients with potential cases of second-look operations provided evidence for a significant increase in survival. Recently, the evaluation of individual carcinoembryonic antigen doubling times was used to derive an individual prognosis since doubling times strongly correlated with the survival of untreated patients. On this basis, it was clearly possible to show the benefit of second-look operation, since patients with resectable recurrences exhibited longer survival times compared with patients with similar carcinoembryonic antigen doubling times without treatment. Moreover, the introduction of monoclonal antibodies with increased specificity for malignant states, has facilitated the selection of patients for second-look operation because unspecific carcinoembryonic antigen elevations are less frequent and recurrent disease can be predicted more reliably due to the higher carcinoembryonic antigen increments associated with malignant growth.

PROPERTIES OF DIFFERENT ARTIFICIAL ANTIGENS IMMUNOLOGICALLY RELATED TO TOBACCO MOSAIC VIRUS.

Abstract Artificial antigens carrying hexa-, penta-, tetra- or tripeptides homologous to the C-terminal amino acid sequence of tobacco mosaic virus strain vulgare (common strain) as haptenic groups have been prepared. The antisera obtained cross-react with tobacco mosaic virus strain vulgare and tobacco mosaic virus strain dahlemense to significantly different extents. The capacity to neutralize tobacco mosaic virus vulgare was established for all antisera homologous to the artificial antigens.

The formation of sphingomyelin from phosphatidylcholine in plasma membrane preparations from mouse fibroblasts.

The enzymatic formation of radioactive sphingomyelin from [14C]choline-labeled phosphatidylcholine was demonstrated to reside exclusively in the plasma membrane fraction of mouse fibroblasts. This activity has several properties in common with the phosphatidylcholine ceramide phosphocholine transferase of mouse liver microsomes. The enzyme has little if any phospholipase C activity and isotope dilution experiments suggest that phosphatidylcholine is the substrate rather than it is converted to CDP choline, phosphocholine, free choline or glycerophosphocholine prior to the transfer reaction. The activity is stimulated by the addition of bovine serum albumin and MnCl2 to the incubation mixtures. The plasma membrane localization of the enzyme suggests that it may have a central role in the biosynthetic pathways for sphingomyelin in mouse fibroblasts.

Recent Studies on the Structure of Tobacco Mosaic Virus

Publisher Summary This chapter focuses on the chemical structure of the virus protein and virus ribonucleic acid (RNA). It explores that tobacco mosaic virus (TMV) is a popular tool for studying the correlation between chemical structure and biological function. The virus is a well-defined complex of a single RNA molecule and 2130 identical polypeptide chains. The RNA alone is responsible for the infectivity of the virus. The protein functions only to protect the RNA; however, it is the protein and not the RNA that determines macroscopic properties of the virus, such as morphology and serological specificity. Although study of gross morphology is helpful for an understanding of the virus structure, correlation between structure and function requires analysis of the chemical structure of the RNA and protein subunits. The stimulating success of Sanger and his colleagues (1956) in elucidating the structure of insulin showed that the analysis of the primary structure of a pure protein is experimentally feasible.

The role of endogenous phosphatidylcholine and ceramide in the biosynthesis of sphingomyelin in mouse fibroblasts

The intracellular location of sphingomyelin formation via the cholinephosphotransferase reaction from both endogenous an exogenous phosphatidylcholine and ceramide substrates has been studied in the subcellular membrane fractions prepared from mouse fibroblasts. The enzyme was found to be located in both the plasma membrane and the Golgi fractions. Activity in the Golgi fraction was stimulated to a greater extent by the addition of exogenous ceramide than was the activity in the plasma membrane fraction. It is concluded that endogenous phosphatidylcholine is available to the cholinephosphotransferase at saturating concentration and, therefore, is not rate-limiting. In contrast, the very low concentration of endogenous ceramide seems to limit the reaction rate, necessitating supplementation with exogenous material Both endogenous substrates are shown to be utilized in an intramembranous rather than an intermembranous reaction. The capacity of the plasma membrane fraction to synthesize sphingomyelin from endogenous phosphatidylcholine and ceramide was found to be sufficiently high to account for the rate of net synthesis of plasma membrane-bound sphingomyelin observed in the logarithmically multiplying cell culture. In contrast, the Golgi fraction displayed only 26% of the expected capacity, but it was stimulated 6-fold by the addition of exogenous ceramide. These results demonstrate that the total cellular sphingomyelin of the mouse fibroblasts can be provided via the cholinephosphotransferase pathways and that the plasma membrane and the Golgi fraction are most probably the intracellular sites of sphingomyelin biosynthesis.

Studies on mouse leukemia viruses: I. Isolation and characterization of a group-specific antigen

Abstract An antigen specific for mouse leukemia viruses (MLV) was isolated in highly pure form from Friend virus after Tween 80-ether treatment. Its purity was demonstrated by electrophoresis, analytical ultracentrifugation, and serological tests. Serologically identical antigens are present in Rauscher virus as well as Gross virus and a mouse leukemia virus contained in L cell cultures. The group-specific antigen of Friend virus is a strongly basic protein, having a molecular weight of about 26,000 daltons. The amino acid composition of this component was likewise determined.

Phosphoprotein pp135 is an essential component of the nucleolus organizer region (NOR)

The association of phosphoproteins pp135 and pp105 with distinct substructures of the nucleolus was studied by cytochemical and immunological methods at the light microscopic and electron microscopic level. Both phosphoproteins exhibited a very high affinity for silver and Giemsa staining compared to other nucleolar proteins. Immunolocalization of pp135 and pp105 during mitosis by light microscopy revealed a tight association of pp135 with the silver staining nucleolus organizer region (NOR), whereas pp105 (cross-reacting with C23) appeared to be only partially associated with the NOR, exclusively at telophase. At the immunoelectron microscopic level the distribution of pp135 and pp105 was investigated in interphase nucleoli. Phosphoprotein pp135 was located in the fibrillar shell and pp105 in the fibrillar shell and the granular zone. The fibrillar centers were essentially free of both phosphoproteins..

Isolation and characterization of phosphoprotein pp 105 from simian virus 40-transformed mouse fibroblasts

Investigation of the cellular distribution of a 105 kDa phosphoprotein (pp 105) in transformed mouse fibroblasts, showed that only a minor amount was located on the surface of logarithmically grown suspension cells. More than 90% of total pp 105 was contained in the cytosolic fraction representing about 0.2% of total cytosolic proteins. Surface and cytosolic pp 105 had identical phosphopeptide patterns. Cytosolic pp 105 was highly purified by ammonium sulfate precipitation followed by three chromatographic steps and gel electrophoresis. The purified pp 105 was capable of weak autophosphorylation. In the stationary growth phase of suspension cells, the amount of pp 105 detectable by endogenous phosphorylation was only 10-15% of that observed during logarithmic growth. pp 105 was also detected in normal mouse tissue and its distribution determined.

Antigenic properties of proteins cross-linked by multidiazonium compounds.

Abstract The antigenic properties of cross-linked proteins were examined. Cross-linking was performed by coupling proteins to the diazonium groups of a mixed polycondensate of aromatic amino carboxylic acids. The resulting cross-linked protein samples were soluble under physiological conditions. The immunogenic capacity was determined without the use of adjuvants by intravenous injection. The cross-linked proteins have been found to give a greatly enhanced antibody response compared with the original proteins. The antisera obtained after immunization with cross-linked proteins cross-reacted with the original protein monomers (kallikrein inactivator, ribonuclease, human chorionic gonadotropin) and neutralized their biological activity.