FAST (Flexible Analysis by Software Tool) and CHAMP (CHemico-physical AMinoacidic Parameter data bank): a new tool to investigate protein structure

A flexible package designed to study protein structure is described.The package is devoted to the analysis of protein sequencesby drawing structural profiles of specific structure-relatedamino acid parameters. An Aminoacidic Parameters Data Bank (CHAMP)containing 32 different series of physico-chemical parametersof amino acids is available. Sequences can be loaded from anyASCII format data bank or from keyboard. The program possessesa routine which enables easy updating of the protein data bankand CHAMP Data Bank. FAST reads statistical correlations betweentwo plots in order to identify structural similarities. Plotscan be printed, saved or used for correlation, comparison orgraph overlap by using common spreadsheets (e.g. Lotus 123).Plots can be smoothed by a running mean or a running median.The program also has a special feature—a global flexibilityanalysis of proteins. The package runs on IBM or compatiblesand requires DOS 3.0 or later. Received on June 20, 1989; accepted on August 2, 1989     

Mechanisms by which EGF receptor and TGF alpha contribute to malignant transformation

Alterations affecting the epidermal growth factor/transforming growth factor alpha-responsive mitogenic pathway are frequently detected in malignancies. In particular, the epidermal growth factor receptor has been found overexpressed in a number of human tumors. Production and secretion of transforming growth factor type alpha has also been shown in several tumor cells but not in their normal counterparts. In this review we describe the establishment of in vitro model systems to study the transforming potential of these molecules and summarize our current understanding of the mechanisms involved in transformation by genes encoding a growth factor and a growth factor receptor.     

Characterization of a new and highly distinguishable HLA-A allele in a Spanish family

Correspondence to: J. L. Vicario.     

Morphometric stepwise discriminant analysis of three genetically identified species within Pseudoterranova decipiens (Krabbe, 1878) (Nematoda: Ascaridida)

Univariate and multivariate statistical analyses have been performed on 19 morphometric variables of adult male specimens belonging to three genetically identified species within Pseudoterranova decipiens (Nematoda: Ascaridida) parasitic in the digestive tract of seals. Two morphometric keys are proposed for the identification of the three species. One key, which uses two variables, determines a frequency of error of 3.8% (3/79). The second key, which uses two canonical discriminant functions based on seven variables previously selected with a stepwise procedure, gives 100% (76/76) accurate classification.     

Flow cytometric detection of mitotic cells using the bromodeoxyuridine/DNA technique in combination with 90 degrees and forward scatter measurements

Mitotic cells could be well discriminated from the cells in the G1-, S- and G2-phases of the cell cycle using pulse labeling of S-phase cells with bromodeoxy-uridine (BrdUrd) and staining of the cells for incorporated BrdUrd and total DNA content. Unlabeled G2- and M-phase cells could be measured as two separate peaks according to propidium iodide fluorescence. M-phase cells showed lower propidium iodide fluorescence emission compared to G2-phase cells. The fluorescence difference of M- and G2-phase cells was caused by the different thermal denaturation of their DNA. Best separation of M- and G2-phase cells was obtained after 30-50 min heat treatment at 95 degrees C. Mitotic index could be measured if no unlabeled S-phase cells were present in the cell culture. With additional measurements of 90 degree scatter and/or forward scatter signals, mitotic cells could be clearly discriminated from both unlabeled G2- and S-phase cells. The correct discrimination (about 99%) of mitotic cells from interphase cells was verified by visual analysis of the nuclear morphology after selective sorting. Unlabeled and labeled mitotic cells could be observed as pulse-labeled cells progressed through the cell cycle. We conclude that this modified BrdUrd/DNA technique using prolonged thermal denaturation and the simultaneous measurement of scatter signals may offer additional information especially in the presence of BrdUrd-unlabeled S-phase cells.     

Hints on the evolutionary design of a dimeric RNase with special bioactions.

Residues P19, L28, C31, and C32 have been implicated (Di Donato A, Cafaro V, D'Alessio G, 1994, J Biol Chem 269:17394-17396; Mazzarella L, Vitagliano L, Zagari A, 1995, Proc Natl Acad Sci USA: forthcoming) with key roles in determining the dimeric structure and the N-terminal domain swapping of seminal RNase. In an attempt to have a clearer understanding of the structural and functional significance of these residues in seminal RNase, a series of mutants of pancreatic RNase A was constructed in which one or more of the four residues were introduced into RNase A. The RNase mutants were examined for: (1) the ability to form dimers; (2) the capacity to exchange their N-terminal domains; (3) resistance to selective cleavage by subtilisin; and (4) antitumor activity. The experiments demonstrated that: (1) the presence of intersubunit disulfides is both necessary and sufficient for engendering a stably dimeric RNase; (2) all four residues play a role in determining the exchange of N-terminal domains; (3) the exchange is the molecular basis for the RNase antitumor action; and (4) this exchange is not a prerequisite in an evolutionary mechanism for the generation of dimeric RNases.     

Febrile Gastroenteritis Due to Salmonella thompson—Report of an Outbreak

Salmonella thompson, a common pathogen of poultry, has received scant attention as a cause of human gastroenteritis. At least 45 persons were infected with S thompson in Sacramento, California, after eating at a chicken restaurant and 38 became symptomatic. Ten required admission to hospital, and all were treated with antibiotics and improved. In 19 cases cultures of stool specimens for S thompson over a 60-day period showed slower but statistically insignificant differences in salmonellal elimination in 7 patients who received antibiotics when compared with 12 who were untreated. We report this outbreak to increase awareness of the virulence and prevalence of gastroenteritis due to S thompson.     

Malic acid production and consumption by selected of Saccharomyces cerevisiae under anaerobic and aerobic conditions

Summary Fermentation tests in clearly defined laboratory conditions were carried out with eight functionally selected strains of Saccharomyces cerevisiae. Analysis of the data showed that there were no significant differences in malic acid production between the strains when the acid was initially present. When it was initially absent, however, significant differences were observed two strains (Nos. 1141 and 1083) showing marked productive superiority. With malic acid as the sole C source, two strains (Nos. 1109 and 1141) showed less acid consumption.     

Evaluation of the antibacterial activity in vitro of various cephalosporins on different gram-negative bacterial species of recent clinical isolation

The Authors have compared the antibacterial activity "in vitro" of new cephalosporines (cephuroxim, cephoxitin and cephaclor) with other cephalosporines having an action which is already known (cephaloridine, cephazoline and cephalexine) on the Gram-negative bacterial strains of recent clinical isolation. The results show that the cephalosporines of last generation, having in their molecular nucleus a methoximinic group, realize a greater antibacterial protection than those cephalosporines of antecedent preparation.