Erika D. J. Timmer

MON-150, a versatile monoclonal antibody against involucrin: characterization and applications

SummaryA monoclonal antibody, designated MON-150, was found serendipitously to react strongly with the granular layer of normal human epidermis and with the upper spinous layers of psoriatic epidermis. From analysis by flow cytometry of cultured human keratinocytes, it appeared that the percentage of MON-150-positive cells strongly increased when the cells reached confluence and the growth fraction declined. To identify the antigen recognized by MON-150, a lysate of human keratinocytes was subjected to affinity chromatrography using a MON-150 Sepharose column. This yielded a single protein of approximately 350 kDa as measured on Superose 6 FPLC gel permeation chromatography using nondenaturing conditions. In Western blot analysis under denaturing and reducing conditions, a 140-kDa protein was detected. The subcellular localization and the molecular weight of the antigen recognized by MON-150 suggested that the antigen involved might be involucrin. This was confirmed using a commercial polyclonal antiserum against involucrin. We conclude that MON-150 is a new, versatile antibody against human involucrin.

Expectations of gains in the second half of life: a study of personal conceptions of enrichment in a lifespan perspective

This research focuses on cognitive representations of the personal future during the second half of life. To investigate the developmental perspectives of people growing older, the anticipation of possible gains is studied. The participants of this study took part in the German Aging Survey and the sample comprises 2,934 subjects aged 40–85 years. To assess their anticipated ‘gains’, we selected the future-related items from the SELE-questionnaire, a sentence completion instrument administered for the Survey. We assumed that many would anticipate further enrichment by new social and societal activities in retirement, but the most frequently-mentioned gains referred to changes in life style and leisure activities, especially travelling. Plans and wishes feature a predominantly leisure-oriented life style. Among the anticipations, those concerned with generativity – caring for others, societal commitment, vocational ambitions – substantially decrease at about the age of 50 years. It was hypothesised that age, gender, living in the former East or West Germany, health, education, income, and perceived control would influence the cognitive representation of the future. To examine the effects of these personal and situational factors on gain anticipations, multiple regression analyses were performed. With respect to all independent variables, differences in the kinds of expected gains were found. The outcomes are discussed with reference to lifespan developmental theory and the role of older people in society.

A comparison of NSP-reticulons with conventional neuroendocrine markers in immunophenotyping of lung cancers

Neuroendocrine‐specific protein (NSP)‐reticulons are endoplasmic reticulum‐associated protein complexes, which have been identified as markers for neuroendocrine differentiation. In this study, the expression of two members of the family of NSP‐reticulons, NSP‐A and NSP‐C, have been investigated in different types of lung cancer and compared with the expression patterns of five conventional neuroendocrine markers, the neural cell adhesion molecule (NCAM), synaptophysin, chromogranin A, Leu‐7, and neurofilament proteins. NSP‐A and NSP‐C antibodies were reactive with most carcinoid tumour and small cell lung carcinoma (SCLC) cases, while atypical carcinoid tumours showed a variable expression. In the total group of neuroendocrine tumours, a high concordance of expression was found between NSP‐A and NSP‐C, while their expression correlated well with NCAM and synaptophysin positivity. Chromogranin A, Leu‐7, and neurofilament proteins were shown to be expressed to a limited extent in these neuroendocrine tumours. In a selected group of non‐SCLCs known to exhibit neuroendocrine features, NSP‐A expression was detected at much higher frequency than NSP‐C. In virtually all NSP‐A positive cases, this expression was associated with one or more of the other neuroendocine markers. NSP‐A expression showed a stronger correlation with conventional neuroendocrine markers than NCAM. In detecting neuroendocrine differentiation in non‐SCLC, NSP‐A is more sensitive than synaptophysin, chromogranin A, Leu‐7, and neurofilament proteins. It is concluded that NSP‐reticulons are valuable markers in the diagnosis of neuroendocrine differentiation in non‐SCLC and should be used in conjunction with NCAM.

Application of recombinant DNA technology in epitope mapping and targeting. Development and characterization of a panel of monoclonal antibodies against the 7B2 neuroendocrine protein.

Three mouse monoclonal antibodies (Moabs) have been obtained with specificity for the 7B2 protein, a proposed member of the granin family of neuroendocrine proteins. Bacterially produced hybrid proteins of 7B2 were used as immunogens. The Moabs were designated MON-100, MON-101, and MON-102. Furthermore, we report the construction of 35 deletion mutants of the glutathione S-transferase-7B2 (GST-7B2) fusion-gene using recombinant DNA technology. The hybrid proteins encoded by eleven of these mutants were used in epitope mapping experiments and the results of these studies strongly suggested that recognition of 7B2 by all three Moabs involved the same 16 amino acid region of 7B2 (from amino acid residue 128-135). This was further substantiated by the observation that MON-101 and MON-102 specifically recognized a conjugate between bovine serum albumin and the synthetic peptide Phe-Glu-Pro-Glu-His-Asp-Tyr-Pro-Gly-Leu-Gly-Lys based upon the deduced amino acid sequence of the predicted epitope region in 7B2. In an approach to generate a series of 7B2-specific Moabs targeted against another epitope region in the 7B2 protein, the hybrid protein encoded by deletion mutant pPV32 was used as the immunogen. This protein lacked the epitope region recognized by the first series of Moabs. A second series of three Moabs, designated MON-142, MON-143, and MON-144, was obtained and, in all three cases, the region of 7B2 from amino acid residue 64-94 appeared to be involved in specific recognition by the Moabs. The whole panel of six anti-7B2 antibodies appeared to be useful in immunoprecipitation and Western blot analysis of the 7B2 protein and specifically stained neuroendocrine cells in immunohistochemical experiments. Using a double determinant sandwich enzyme immunoassay, 7B2 protein levels in rat pituitary were determined as 20 ng/mg tissue.

“When Looking Back on My Past Life I Regret…”: Retrospective Regret in the Second Half of Life

ABSTRACT The study investigated the frequency, themes, and attributions for significant regrets in a random probability sample of 3,917 German and Dutch nationals between the ages of 40 and 85 years. It was found that 14% did not have any regrets in spontaneous memory, and that this increased with the age of the respondents. With respect to mentioned regrets, older people, women, and those living in the former East Germany were more likely to recall externally attributed events; younger participants, men, West Germans, and the Dutch recalled more internally attributed events. Largely, memories related to 4 major themes: (a) mistakes, behavior, and bad decisions in general; (b) hard times; (c) social relationships; and (d) missed educational opportunities. The importance of these themes, however, varied according to age, gender, and regional belonging. Differences in the kind of attribution and in the centrality of themes are discussed in terms of lifespan theory, death preparation, and cultural differences.

Cognitive representations of future gains, maintenance, and losses in the second half of life

The aim of this study is to explore three different developmental dimensions in an aging population. Based on sentence completion responses, the investigation examines personal anticipations of possible gains, maintenance, and losses. Additionally, the effects of age and other personal and situational factors are examined. The study sample consists of 2,934 participants ranging from 40 to 85 years of age, who participated in the German Aging Survey of 1996. Study findings indicate that, to a large extent, the anticipated gains include positive changes in the way of life and increased leisure projects while anticipated maintenance refer to physical and behavioral resources and to life style. Anticipated losses are related to concerns about external living conditions and physical decline. There is a strong association of anticipated gains and maintenance with age, while present health conditions are related to expectations of loss. The implications of the study results for lifespan expectations in the second half of life and for lifespan theory are discussed.

MONOCLONAL-ANTIBODY MON-114 - DETECTION OF A MARKER FOR NEUROENDOCRINE DIFFERENTIATION IN HUMAN LUNG-CANCER

Mouse monoclonal antibody MON-114 was generated upon immunization with a human small cell lung carcinoma cell line GLC-19. Immunohistochemical analysis of normal tissues with MON-114 showed staining of the adrenal gland, brain and peripheral nerves. With respect to human lung carcinomas, 7 out of 8 small cell lung carcinomas were positively stained as well as 5 out of 5 carcinoid tumors, whereas only 4 out of 31 squamous cell carcinomas and 3 out of 19 adenocarcinomas were weakly stained. Furthermore, 1 large cell carcinoma was negative for MON-114 staining. Apparently, MON-114 stains cells of neuroendocrine differentiation.