Surface complex of ZnTMPyP4 metalloporphyrin with double-stranded Poly(A)-Poly(U).

This communication presents synthesis and spectral characterization of metalloporphyrin [Zn(X)TMPyP4] (TMPyP4 is 5,10,15,20-tetrakis (N-methylpyridinium-4-yl)porphyrin), and studies its binding onto anionic surface sites of synthetic double stranded polynucleotide Poly(A)-Poly(U). [Zn(X)TMPyP4] binding with Poly(A)-Poly(U) was monitored by UV-Vis absorbance spectroscopy, two fluorescence spectroscopies and 1H NMR in a working aqueous medium of 0.15M ionic strength, pH7.0 and at 25°C. The evidence provided by spectroscopic measurements and multivariate data analysis suggests the use of this metalloporphyrin as a probe for investigation of the polynucleotide surface. In contrast to TMPyP4 intercalation, an outside adsorption of [Zn(X)TMPyP4] induces an attenuation of luminescence intensity and has little influence on the shape of luminescence band. Special attention was paid to the quantitative description of the interaction between neighboring ligands on the Poly(A)-Poly(U) surface. The intrinsic binding constant to an isolated binding site lgKin 5.8±0.1, the cooperativity parameter ω 1.8±0.2, and number of monomers occupied by a ligand n=2 (25°C; pH7.0) were calculated based upon the recently proposed non-linear least-squares fitting procedure. The discovered cooperativity of binding of [Zn(X)TMPyP4] metalloporphyrin to Poly(A)-Poly(U) is significantly lower as compared to free porphyrin TMPyP4, reflecting minimal mutual influence between the nearest neighboring ligands bound with functional PO4(-) groups of the polynucleotide surface.

Cognitive performance and cerebrohemodynamics associated with the Persian Gulf Syndrome.

The Persian Gulf Syndrome generally manifests as a set of nonspecific complaints with emphasis on central nervous system impairment. The purpose of this study was to determine if cognitive performance and middle cerebral artery blood flow velocity (MCABFV) were altered in symptomatic Gulf War veterans (sGWVs) and asymptomatic Gulf War veterans (aGWVs) by exposure to low levels of acetone. MCABFV was assessed in male aGWVs (n = 8) and sGWVs (n = 8) during cognitive challenges while breathing 1) clean air, 2) a clean air placebo, and 3) a mixture of air and 40 parts per million (ppm) acetone. Pulmonary function was also evaluated. Pulmonary function tests showed no statistical differences between aGWVs and sGWVs while breathing clean air or 40 ppm acetone in air. Cognitive performance was similar during the clean air, placebo, and acetone test conditions for sGWVs and aGWVs. Data pooled across test conditions for each group indicated a statistically significant (P < 0.05) poorer performance primarily in memory and executive function tasks by sGWVs. sGWVs had a 34.2% higher baseline MCABFV than aGWVs (P < 0.05). Increases in MCABFV for aGWVs (averaged over all cognitive tasks for each test condition) ranged between 7.8% and 8.8%, and were not statistically significant. Increases for sGWVs ranged between 0.3% and 4.8%, averaged over all cognitive tasks for each test condition. No significant differences were noted between the clean air and placebo test conditions but both were significantly different to the acetone condition. Differences in MCABFV increases for each of the test conditions between aGWVs and sGWVs were also statistically significant. sGWV did not appear to demonstrate pulmonary dysfunction following exposure to acetone. They did, however, appear to have generally lower cognitive function as compared to aGWVs. sGWVs appeared to have a significant degree of autoregulatory disruption in cerebral perfusion, resulting in reduced cognitive reserve capacity and potentially impaired ability to handle complex cognitive tasks.

Three-dimensional laser imaging system for measuring wound geometry.

BACKGROUND AND OBJECTIVE: A low cost laser imager was designed and fabricated for measurement of wound geometry. METHODS: The accuracy of the imager was validated using reference depressions of known dimensions. Perimeter, area, and volume were compared to planimetric and packing techniques on simulated wound models. RESULTS: Wound tracing and alginate measurement methods required approximately 20 times longer for the reference standards, and 11 times longer for the simulated wounds than with the laser scanning method (LSM). LSM consistently overestimated the reference perimeter by 0.73+/-0.20 cm and the area by 0.98+/-0.62 cm2. Volume estimates were not statistically different. The tracing method underestimated the perimeter by 0.34+/-0.27 cm and the area by 1.07+/-1.09 cm2. Volume measurements by the alginate method were not statistically different. The perimeters of the simulated wounds averaged 1.29+/-0.27 cm greater using the LSM than obtained by the tracing method, and areas greater by 2.02+/-1.30 cm2. Volume scans averaged 1.04+/-0.61 cm3 greater than by the alginate method.