DNA flow cytometric analysis in patients with operable non-small cell lung carcinoma

Fresh surgical specimens of tumors from 60 patients with previously untreated non-small cell lung carcinoma (NSCLC) who underwent radical surgery between January 1991 and October 1992 were investigated by means of flow-cytometry. The nuclear DNA measurement was carried out using a Facscan (Becton, Dickinson, USA). Analysis of the DNA content was performed in all 60 patients whilst cell cycle analysis was possible in 41 cases (68.3%). Forty-two of the 60 cases (70%) were aneuploid and 18 (30%) were diploid. The overall mean value of DNA index was 1.5. Diploid NSCLC were compared with aneuploid tumors: no significant differences in age distribution, sex ratio, histology and staging were found between the two groups (P > 0.05). An S-phase proportion of more than 10% was found in 30 out of 41 patients (73.2%). Early cancer deaths were reported in four patients (6.6%): the aneuploidy rate was very close in these patients (75%) and in the remaining surviving patients (69.6%). An S-phase proportion of more than 10% was found in 100% of early cancer deaths and in 70.2% of the remaining cases; such a difference seems of some importance although it was not statistically significant (P = 0.071). In conclusion, flow-cytometry studies seem to be a useful tool in the understanding of the biological behavior of patients with NSCLC. In the present prospective report there were no significant correlations between DNA measurements and clinical outcome, however, these results suggest that a high S-phase proportion should be seen as a possible prognostic indicator.(ABSTRACT TRUNCATED AT 250 WORDS)     

Circuit Master: turnkey software for the introductory electricalengineering curriculum

A turnkey software system for the introductory electrical engineering curriculum is described in detail from a user's perspective. The system, Circuit Master, provides a structured, interactive, menu-driven environment that allows students to explore basic concepts in circuit and signal theory without requiring a background in computer programming. The system's interactive user interface and visual presentation format simultaneously display relationships between circuit components, pole-zero patterns. Bode plots, initial conditions, input/output signal waveforms, and input/output signal spectra for periodic and aperiodic signals. Simultaneous display of information for two sets of circuit components allows physical relationships, parametric changes, and sensitivity issues to be examined easily     

Rat preputial sebocyte differentiation involves peroxisome proliferator-activated receptors

We investigated the relationship between susceptibility to beta-lactam antibiotics and variation in the major outer membrane protein P2 (OmpP2; also called porin) of persistent nonencapsulated Haemophilus influenzae isolated from cystic fibrosis patients. Nine OmpP2 variants were selected from two distinct H. influenzae strains from two patients extensively treated with beta-lactam antibiotics. The variants differed in their susceptibilities to at least two beta-lactam antibiotics. By detergent extraction and column chromatography, OmpP2 was purified from two variants that were derived from strain 70 and that differed notably in their susceptibilities to beta-lactam antibiotics. The proteins were reconstituted into black lipid membranes for measurement of porin function. OmpP2 from the more resistant isolate (isolate 70b) had a smaller channel conductance than OmpP2 of the more susceptible isolate (isolate 70f). DNA sequencing of ompP2 of these isolates revealed single nonsynonymous base differences; there were changes in the amino acid sequence corresponding to surface-exposed loops 4, 5, 6, and 8. Changes in loops 4, 5, and 6 were previously shown to result in antigenic differences. Beside these mutations, variants of strain 70 showed additional mutations in loop 1 and nonexposed loop 3. Taken together, our results suggest that in variants of strain 70, nonsynonymous point mutations accumulated both in the sequences of ompP2 coding for antigen-variable loops and in other loops, notably, loops 1 and 3. The latter changes are suggested to affect the permeability of the porin channel.