Aberrant expression of the p53 oncoprotein is a common feature of a wide spectrum of human malignancies.

Accumulation of the p53 protein was analysed in 212 human malignant lesions. Immunohistochemical staining with new polyclonal (CM-1) and monoclonal antibodies (BP 53-12 and BP53-24) to p53 on methacarn-fixed paraffin sections showed positive staining in 161 (76%). The positive tumours were found across a wide range of human malignancies including breast, colon, stomach, bladder and testis carcinomas, soft-tissue sarcomas and melanomas.

Effect of sodium chloride on transport of bacteria in a saturated aquifer material.

Determinations were made of the influence of NaCl concentration, cell density, and flow velocity on the transport of Pseudomonas sp. strain KL2 through columns of aquifer sand under saturated conditions. A pulse-type boundary condition was used.

Localization of type X collagen in canine growth plate and adult canine articular cartilage.

Type X collagen was extracted from ends of canine growth plates by pepsin digestion after 4 M guanidine hydrochloride extraction, purified by stepwise salt precipitation (2.0 M NaCl in 0.5 M acetic acid), and chromatographed on a Bio-Gel A1.

An antibiotic-free medium for the xenic cultivation of Entamoeba gingivalis.

Diamond's TYI-S-33 (Trypticase-Yeast Extract-Iron-Serum) medium was used as the basis for a new antibiotic-free medium for xenic growth of Entamoeba gingivalis. Nutritional requirements of the oral protozoan were determined in an effort to optimize growth. TYI-S-33 medium did not support E.

Protein synthesis required to anchor a mutant p53 protein which is temperature-sensitive for nuclear transport.

The p53 protein is rendered temperature-sensitive by a point mutation. Rat cells transformed by this mutant p53 and an activated ras oncogene grow well at 37 degrees C but cease DNA synthesis and cell division when shifted to 32 degrees C. Immunostaining demonstrates that the mutant p53 protein is in the nucleus of the arrested cells at 32 degrees C but in the cytoplasm of the growing cells at 37 degrees C.

Environmental mutagens that induce the adaptive response to alkylating agents in Escherichia coli.

Many microorganisms exhibit an adaptive response to mutagenic alkylation damage. In Escherichia coli the response is regulated by the inducible Ada protein. A sensitive immunoassay employing two anti-Ada monoclonal antibodies has been developed here to monitor low levels of induction of the Ada protein.

Effects of in vitro electrical stimulation on enhancement and suppression of malignant lymphoma cell proliferation.

The suppression and enhancement of proliferation of mouse EL4 lymphoma cells varied significantly when the cells were electrically stimulated within a narrow range of low-level direct current. With the use of platinum electrodes, the suppression characteristics were observed over a narrow range, or window, of direct currents centered at approximately 17 microA. Enhancement characteristics were observed over a broad range of low-level direct currents (approximately 0.

Relationship between Cell Surface Properties and Transport of Bacteria through Soil.

A study was conducted to relate the properties of Enterobacter, Pseudomonas, Bacillus, Achromobacter, Flavobacterium, and Arthrobacter strains to their transport with water moving through soil. The bacteria differed markedly in their extent of transport; their hydrophobicity, as measured by adherence to n-octane and by hydrophobic-interaction chromatography; and their net surface electrostatic charge, as determined by electrostatic interaction chromatography and by measurements of the zeta potential. Transport of the 19 strains through Kendaia loam or their retention by this soil was not correlated with hydrophobicities or net surface charges of the cells or the presence of capsules.

Identification, location and analysis of contamination problems associated with cell/tissue preparation, stimulation and measurement techniques.

Any time a cell suspension or tissue sample is handled, chemically treated and prepared or measured with electrical or electrochemical probes, some level of contamination will occur. Often, the level and type of contamination can lead to serious misinterpretation of experimental results. A number of specific contamination problems have been consistently observed with certain preparation, stimulation and measurement techniques utilized in cell biology, histology, microbiology and pharmacology.

p53 mutations in colorectal cancer.

Immunohistological staining of primary colorectal carcinomas with antibodies specific to p53 demonstrated gross overexpression of the protein in approximately 50% of the malignant tumors examined. Benign adenomas were all negative for p53 overexpression. To determine the molecular basis for this overexpression we examined p53 protein expression in 10 colorectal cancer cell lines.

Genetic and immunochemical analysis of mutant p53 in human breast cancer cell lines.

The expression of the tumour suppressor gene p53 was analysed in 11 human breast cancer cell lines by immunohistochemistry, immunoprecipitation and cDNA sequencing. We used a panel of anti-p53 monoclonal antibodies for cell staining and found abnormalities in every case. Eight of the cell lines produce a form of p53 which can be immunoprecipitated by the monoclonal antibody PAb240 but not by PAb1620.

Activating mutations in p53 produce a common conformational effect. A monoclonal antibody specific for the mutant form.

Point mutations in the p53 gene are the most frequently identified genetic change in human cancer. They convert murine p53 from a tumour suppressor gene into a dominant transforming oncogene able to immortalize primary cells and bring about full transformation in combination with an activated ras gene. In both the human and murine systems the mutations lie in regions of p53 conserved from man to Xenopus.

A new medium containing antibiotics for the xenic cultivation of Entamoeba gingivalis.

Diamond's trypticase-yeast extract-serum-gastric mucin (TYSGM-9) medium was studied for its suitability to support the xenic growth of the oral protozoan Entamoeba gingivalis. Amoebic growth was found to be best when the inoculum for transfer was 0.1 ml, the incubation temperature was 35 degrees C, and the interval between transfers was 48 h.

Interactions between SV40 T antigen and DNA polymerase alpha.

Simian virus 40 large T antigen is the only viral protein required for SV40 DNA synthesis in vivo and in vitro. This complex protein recruits the cellular DNA replication apparatus to the SV40 origin and provides a good model for the initiation of cellular DNA replication. The interaction between SV40 large T antigen (TAg) and DNA polymerase alpha has been shown previously to be inhibited by murine p53, the nuclear protein product of a cellular anti-oncogene.

Growth studies on xenic cultures of Entamoeba gingivalis using established media.

Wantland's egg medium, modified Shaffer-Frye (MSF) medium and Tryptose-Trypticase-Yeast Extract-Serum-Blood (TTY-SB) medium were compared with variations of the latter two media for their ability to support xenic growth of Entamoeba gingivalis. Wantland's egg medium was unsuitable for growth of E. gingivalis.

Clinical survey of Entamoeba gingivalis by multiple sampling in patients with advanced periodontal disease.

A clinical survey of Entamoeba gingivalis was conducted in patients with advanced periodontal disease. A total of 100 specimens were taken from 10 patients (four females and six males) who were each sampled at 10 disto-facial random sites. The oral hygiene of the persons scored from good to fair to poor and very poor.

Studies on the microflora associated with xenic cultures of Entamoeba gingivalis.

The microflora associated with xenic stock cultures (ATCC 30927) of Entamoeba gingivalis, the major protozoan of the human oral cavity, were isolated and identified as Citrobacter diversus, Yersinia enterocolitica, Acinetobacter anitratus and Pseudomonas maltophilia. In studies to determine whether the bacterial isolates were able to utilize rice starch as a sole carbon source, Y. enterocolitica exhibited excellent growth in rice starch minimal medium and TYSGM-9 medium (with rice starch), but growth was weak in TYSGM-9 medium (without rice starch).

Host proteins that bind to or mimic SV40 large T antigen: using antibodies to look at protein interactions and their significance.

The papovavirus SV40 is able to induce tumours in susceptible hosts and will transform cells in vitro. Its major early protein, large T antigen, is required for viral DNA synthesis, both in vivo and in vitro, and is also responsible for the oncogenic action of the virus. We have made use of an extensive library of anti-T monoclonal antibodies to investigate the cellular effects of T.

Structure and function of SV40 large-T antigen.

The small eukaryotic DNA tumour virus, SV40, has long provided a very useful model for the study of eukaryotic DNA replication and cellular transformation. The viral gene product, large-tumour (large-T) antigen, is essential for the initiation of viral DNA replication and the initiation and maintenance of SV40-virus-mediated cellular transformation. The large-T antigen is a complex multifunctional protein, and to delineate its activity more precisely in viral DNA replication and cellular transformation, small functional domains of the protein have been expressed in Escherichia coli and analysed by using a very extensive library of anti-T monoclonal antibodies.

p53 and DNA polymerase alpha compete for binding to SV40 T antigen.

The large T antigen (T) of simian virus 40 is a multifunctional protein required for both viral DNA replication and cellular transformation. T antigen forms specific protein complexes with the host protein p53 in both virus-infected and transformed cells. p53 has recently been shown to be an oncogene, but its normal function is not clear.

A data-based approach to diet questionnaire design and testing.

A self-administered diet history questionnaire has been developed for epidemiologic and clinical use. Both the food list and the nutrient values to be associated with it were developed using dietary data from 11,658 adult respondents to the Second National Health and Nutrition Examination Survey (NHANES II). Food items were selected on the basis of their contribution to total population intake of energy and each of 17 nutrients in the NHANES II data, and represent over 90% of each of those nutrients.