Optimality criteria for the design of 2-color microarray studies

We discuss the definition and application of design criteria for evaluating the efficiency of 2-color microarray designs. First, we point out that design optimality criteria are defined differently for the regression and block design settings. This has caused some confusion in the literature and warrants clarification. Linear models for microarray data analysis have equivalent formulations as ANOVA or regression models. However, this equivalence does not extend to design criteria. We discuss optimality criterion, and argue against applying regression-style D-optimality to the microarray design problem. We further disfavor E- and D-optimality (as defined in block design) because they are not attuned to scientific questions of interest.     

The shape of the thorax based on data of fluorographic studies]

Five thoracic types were distinguished on the basis of 3 transverse sizes between the 4th, 7th, and 10th ribs, detected on the thoracic fluorograms of 1116 men and 1460 women: cylindrical, narrow conical, conical, wide conical, and egg-shaped. A subtype of a cylindrical thorax--cylindrical with a waist--was distinguished in women. In men conical chests occurred in 48.9% of cases, wide conical in 24%, whereas in women narrow conical chests occurred in 41.8% and cylindrical in 27.5% of cases. The examinees were grouped in accordance with the thoracic shape and their physical parameters and the parameters of the chests were compared. The chest proportions represent the most comprehensive characterization of the skeletal index: the ratio between the transverse size between the 7th ribs and the vertical size in per cent. The skeletal index directly correlates with body mass, thoracic circumference, transverse and longitudinal sizes of the heart and is in inverse correlation with body length, angle of inclination of the 8th rib and angle of inclination of the heart axis to the horizontal line.     

Analytical methodologies for metallomics studies of antitumor Pt-containing drugs

Pt-containing drugs are nowadays essential components in cancer chemotherapy. However, drug resistance and side effects limit the efficiency of the treatments. In order to improve the response to Pt-based drugs, different administration strategies or new Pt-compounds have been developed with little success. The reason for this failure could be that the mechanism of action of these drugs is not completely understood. In this way, metallomics studies may contribute to clarify the interactions of Pt-containing drugs within the organism. This review is mainly focused on the role of Analytical Chemistry on the study of the interactions between Pt-based drugs and biomolecules. A summary of the analytical techniques and the most common sample treatment procedures currently used in metallomics studies of these drugs is presented. Both are of paramount importance to study these complex samples preserving the drug-biomolecule interaction. Separation and detection techniques must be carefully selected in order to achieve the intended goals. The use of multidimensional hyphenated techniques is usually necessary for a better understanding of the Pt-based drugs interactions in the organism. An overview of Pt-drugs biological interactions is presented, considering the different sample matrices and the drugs course through the organism. Samples analysed in the included studies are blood, urine, cell cytosol, DNA as well as the drugs themselves and their derivatives. However, most of these works are based on in vitro experiments or incubations of standards, leading in some cases to contradictory results depending on the experimental conditions used. Though in vivo experiments represent a great challenge due to the high complexity and the low concentrations of the Pt-adducts in real samples, these studies must be undertaken to get a deeper understanding of the real interactions concerning Pt-containing drugs.     

Analytical studies on crotamine hydrochloride.

The neurotoxin crotamine, which is a basic low molecular weight protein, was isolated, in the form of its hydrochloride, from a South Brazilian rattlesnake (Crotalus durissus crotaminicus, Crotalus durissus terrificus) venom.Disc electrophoresis, carried out in 7% acrylamide by the method of Reisfeld, at pH 4.5, showed a single band for the purified toxin.The toxin showed the following amino acid composition: Asx₂, Ser₃, Glx₂, Pro₃, Gly₅, Cys₅, Met₁, Ileu₁, Leu₁, Tyr₁, Phe₂, Trp₂, Lys₉, His₂, and Arg₂, which corresponds to a minimum molecular weight of 4760. This assignment of minimum molecular weight is supported by the recovery of 1.0 mole of N-terminal $\text{Tyr}\text{5800}\text{g}$ of crotamine by the Sanger dinitrophenol (DNP) method, 1.0 mole of $\text{Tyr}\text{4880}\text{g}$ by the Udenfriend method, and by uv analysis, which gave a value of 4820. The odd number of half-cystine residues ($\text{5}\text{4760}\text{g}$) cannot be explained on the basis of available analytical data.Tyrosine was the only amino-terminal residue detectable by the Sanger DNP method. Glycine was identified as the only carboxyl-terminal residue by the hydrazinolysis method of Akabori and by release upon treatment with yeast carboxypeptidase.The H⁺ electrometric and Cl^? complexometric titrations of crotamine hydrochloride showed that about 13 moles of HCl are bound per 4760 g of the free base.     

Analytical studies on migrating movement of the pseudo-plasmodium ofDictyostelium discoideum

Summary Migrating movement of a pseudoplasmodium (slug) of the cellular slime mouldDictyostelium discoideum was analyzed using a time-lapse video tape recorder. Since slugs usually migrated with repeated interruptions of advance, migrating velocities were measured only within a period of forward movement. On the basis of some known facts and assumptions, a dynamical model for slug movement was formulated, which consists of motive force generated by slug cells against their intrinsic resistance and resistance of slime sheath at the tip. The migrating velocity of a slug depended neither on its width nor its volume, but solely on its length. Under any experimental conditions tested, a linear relationship always held between reciprocals of the two variables. The results were in good agreement with predictions of the model. Quantitative analyses of experimental results by the use of the model lead to the conclusions that a decrease in velocity at a low temperature is due to an increase in resistance of slime sheath at the tip, but that a decrease in velocity during prolonged migration is due to a decrease in motive force of constituent cells. An anterior isolate dissected from a slug migrated at a velocity greater than that of an intact slug of the same length. This was interpreted by the model to be due to the fact that the anterior cells have greater motive forces and intrinsic resistances than the posterior cells. The heterogeneous distributions of the two variables in the cell mass is discussed in reference to the mechanism of sorting out of cells.     

Analytical ultracentrifugation studies on chloroplastic fructose bisphosphatase

Analytical ultracentrifugation studies performed on spinach chloroplast fructose bisphosphatase show that the tetrameric oxidized (inactive) or reduced (active) enzyme dissociates into inactive dimers and monomers at alkaline pH. The dissociation process is, at least, partially reversible if the enzyme is dimeric. Moreover, the oxidized inactive tetrameric enzyme is less prone to dissociation into dimers and monomers than the reduced active tetramer. The irreversibility of the dissociation process may be explained by a sulfhydryl-disulfide interchange. Together with the findings from previously published sulfhydryl group titration experiments (J. Pradel et al., Eur. J. Biochem., 113 (1981) 507), the above results suggest that the activation of the oxidized tetramer involves the reduction of two inter-protomeric disulfide bonds.     

Objective criteria for determining the degree of radiation injury of nerve cells in a cerebral syndrome

The automatized morphometric technique was used to estimate the degree of injury to spinal nervous cells of rats exposed to 360 Gy radiation. It was shown that the compression coefficient and the volume of neuron nuclei considerably diminished as the CNS-syndrome developed, and the geometrical dimensions of the nervous cells themselves underwent phase changes.     

Dosimetric criteria for the intestinal form of acute radiation injury in man. An empirical model

On the basis of the results of radiobiological studies on acute nonuniform irradiation of the animal's abdomen a dose dependence has been found for the duration of the injury to barrier properties of the small intestine epithelium, T(D). With relative coordinates x = D/LD50 and y = T (D)/T(LD50), this dependence may be represented by a single function for various animal species.