Characterization of type I 5 alpha-reductase activity in DU145 human prostatic adenocarcinoma cells

Each amino acid is represented by a vector of numerical measurements for the attributes of volume, area, hydrophilicity, polarity, hydrogen bonding, shape, and charge. Inter-residue distances are then calculated according to common metrics, and we introduce a new clustering objective function derived from information-theoretic considerations. The arguments of the function are the inter-object distances of the things to be clustered: in this case the amino acids. By means of approximating the solution of an integer programming problem, then, the residues are partitioned into clusters. The clusters obtained are compared with groups obtained in substitution/mutation studies and found to be similar. Thus, probably the strongest and most objective evidence to date is supplied for believing that physico-chemical properties account for the viability of substitutions and that the important similarities/differences are explained by a relatively small and simple set of properties.     

Chronic liver disease in Peru: role of viral hepatitis

Autologous or glutaraldehyde treated bovine pericardial valved patch was utilized for widening of the right ventricular outflow tract in 20 patients with tetralogy of Fallot (autologous pericardium group in 10 patients and bovine pericardium group in 10). Pericardial valve function of the both materials was evaluated by postoperative cardiac catheterization performed 1 year after the operation. There were no significant differences in pulmonary arterial and right ventricular pressures, and right ventricular ejection fraction and end-diastolic volume between the 2 groups. Pulmonary angiogram in the autologous pericardium group patients demonstrated the pulmonary regurgitation (PR) of grade 1 in 5 patients, grade 2 in 4 and grade 3 in 1. On the other hand, 1, 3 and 6 patients in the bovine pericardium group demonstrated no-PR, grade 1 PR and grade 2 PR, respectively. It was concluded that there were no significant differences between autologous and glutaraldehyde treated bovine pericardium as a material of valved patch for widening of the right ventricular outflow tract of tetralogy of Fallot.     

Flavopiridol: a cytotoxic flavone that induces cell death in noncycling A549 human lung carcinoma cells

Flavopiridol (NSC 649890, L86-8275), a potent inhibitor of cyclin-dependent kinase 1/p34cdc2 phosphorylation and kinase activity, is currently undergoing Phase I clinical testing as a potential antineoplastic agent. Previous studies have suggested that flavopiridol is cytostatic but not cytotoxic when applied to exponentially growing cells. In the present study, various human tumor cell lines were assayed for trypan blue exclusion and ability to form colonies after exposure to flavopiridol under a variety of growth conditions. When log phase A549 non-small cell lung cancer cells were examined 72 h after the start of a 24-h flavopiridol exposure, as many as 90% of the cells accumulated trypan blue. A 24-h exposure to 250-300 nM resulted in trypan blue uptake in 50% of A549 cells at 72 h and a 50% reduction in colony formation. Similar results were observed in HCT8 ileocecal adenocarcinoma, T98G glioblastoma, MCF-7 breast adenocarcinoma, and HL-60 leukemia cells. With A549 cells, identical results were obtained in actively growing logarithmic phase cells and growth-arrested confluent cells. Treatment with the DNA synthesis inhibitor aphidicolin only minimally affected the cytotoxicity of flavopiridol. In contrast, the RNA synthesis inhibitor 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole or the protein synthesis inhibitor cycloheximide reduced the cytotoxicity of flavopiridol. These results suggest that: (a) flavopiridol is not only cytostatic, but also cytotoxic to a variety of human tumor cell lines; (b) flavopiridol is equally active against cycling and noncycling A549 cells; and (c) RNA and protein synthesis appear to play a role in flavopiridol-induced cytotoxicity.     

Optical measurements of thermal diffusivity of a material

The measurement of thermal diffusivity of a material (in particular, a thin film) is important for various reasons, e.g., to predict the heat transfer in the solid subjected to a thermal process, to monitor surface composition or morphology, or to detect invisible subsurface defects like delaminations. This measurement can be done in a noncontact manner using various photothermal methods. Such methods typically involve pulsed heating of the surface by small amounts using a laser source; the decay of the surface temperature after this pulsed photothermal heating is then probed to provide the thermal diffusivity. Various probing methods have been developed in the literature, including the probing of reflection, refraction, and diffraction from the pulsed heated area, infrared thermal radiometry, and surface deformation. This paper provides an overview of such techniques and some examples of their applications.     

Controversy and consensus regarding the use of cognitive ability testing in organizations.

Seven hundred three members of the Society for Industrial and Organizational Psychology indicated agreement or disagreement with 49 propositions regarding cognitive ability tests in organizations. There was consensus that cognitive ability tests are valid and fair, that they provide good but incomplete measures, that different abilities are necessary for different jobs, and that diversity is valuable. Items dealing with the unique status of cognitive ability were most likely to generate polarized opinions. A 2-factor model, classifying items as those reflecting societal concerns over the consequences of ability testing and those reflecting an emphasis on the unique status of "g," fit the data well, and these factors proved especially important for predicting responses to the more controversial items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eruption times of third molars in young rural Nigerians

The mechanical stability of proximal femoral osteotomies fixed by the tension band wire technique was studied in flexion-compression and torsion tests. The fixation consisted in crossing the section with two Kirschner wires and with a wire cerclage applied to the tension surface. The study was conducted in three steps. First, cyclinders of wood were cut either transversely or at 30 degrees of inclination in relation to the long axis of the specimen, and fixed with two Kirschner wires and a wire cerclage. We concluded that the inclination of the plane of section significantly increased the stability of fixation. No significant difference was observed when oblique sections were made in the reverse orientation. Second, 30 degrees subtrochanteric varus osteotomies were performed in dog femurs, so that the section plane was transverse in one group and oblique in another, after closing the osteotomy. In both groups the fixation was achieved by two Kirschner wires that crossed the osteotomy and a wire cerclage placed on the lateral cortex (tension surface). We concluded that inclination of the osteotomy plane increased the stability of osteosynthesis in bone specimens, as already seen with the wood pieces. Third, the stability of tension band wire fixation was compared with that provided by the AO/ASIF paediatric angled plate. Varus osteotomies (30 degrees) were created at the subtrochanteric level of paired dog femurs. On one side, the femur was fixed with Kirschner wires and a wire cerclage as described previously. For the other femur, the osteotomy was fixed with the angled plate. We found that both types of fixation presented the same stability in flexion-compression tests. However, under torsion the tension band wire fixation was 30%-50% less stable than the plate fixation.     

Characterization of mutated transforming growth factor-beta s which possess unique biological properties

Transforming growth factor-beta (TGF-beta) is a potent regulator of cell growth and differentiation. On the basis of the crystal structure of TGF-beta 2, we have designed and synthesized two mutant TGF-beta s, TGF-beta 1 (71 Trp) and TGF-beta 1 (delta 69-73). Although both of these molecules inhibited the growth of Mv1Lu mink lung epithelial cells and LS1034 colorectal cancer cells, which are affected equally by TGF-beta 1 and TGF-beta 2, TGF-beta 1 (delta 69-73) was much less potent than TGF-beta 1 or TGF-beta 1 (71 Trp) at inhibiting the growth of LS513 colorectal cancer cells which are growth-inhibited by TGF-beta 1 but not TGF-beta 2. Both TGF-beta 1 (71 Trp) and TGF-beta 1 (delta 69-73) increased levels of mRNAs for fibronectin and plasminogen activator inhibitor with Mv1Lu cells, whereas only TGF-beta 1 (71 Trp) and not TGF-beta 1 (delta 69-73) up-regulated the mRNA level of carcinoembryonic antigen in LS513 cells. The expression level of carcinoembryonic antigen mRNA in LS1034 cells was not altered by either wild-type or mutant TGF-beta s. Receptor labeling experiments demonstrated that TGF-beta 1 (71 Trp) bound with high affinity to the cell-surface receptors of Mv1Lu, LS1034, and LS513 cells while TGF-beta 1 (delta 69-73) bound effectively to the receptors of Mv1Lu and LS1034 cells but much less to the receptors on LS513 cells.(ABSTRACT TRUNCATED AT 250 WORDS)