Falx Cerebri Ossification: CT and MRI Evaluation.

During the last three years, CT and MRI brain scans of 40 patients revealed falx cerebri partial ossification as an incidental finding. The patients had been admitted for brain CT and MRI for several reasons. In most cases, there was no problem in the differential diagnosis of falx cerebri ossification during interpretation of the cases. In a few cases, the lesion should be distinguished from calcified meningioma, small hematoma in the interhemispheric fissure and in one case there was also meningeal infiltration of breast cancer. In these cases both CT and MRI scans of the brain were evaluated and a definite diagnosis was made.

Spectral characterization of a novel near-infrared cyanine dye: a study of its complexation with metal ions.

The spectral features of the near-infrared (NIR) dye TG-170 in different solutions and its complexation with several metal ions were investigated. The absorbance maxima of the dye are at lambda=819, 805, and 791 nm in dimethyl sulfoxide (DMSO), methanol, and a buffer of pH 5.9, respectively. These values match the output of a commercially available laser diode (780 nm), thus making use of such a source practical for excitation. The emission wavelengths of the dye are at lambda(em) =822, 812, and 803 nm in DMSO, methanol, and the buffer, respectively. The molar absorptivity and fluorescence quantum yield increase accordingly. The addition of either an Al(III) ion or Be(II) ion resulted in fluorescence quenching of the dye. The Stern-Volmer quenching constant, K(SV), was calculated from the Stern-Volmer plot to be K(SV)=3.11x10(5) M(-1) for the Al(III) ion and K(SV)=1.17x10(6) M(-1) for the Be(II) ion. The molar ratio of the metal to the dye was established to be 1:1 for both metal ions. The stability constant, K(S), of the metal-dye complex was calculated to be 4.37x10(4) M(-1) for the Al-dye complex and 1.94x10(6) M(-1) for the Be-dye complex.

Design and development of a fiber-optic immunosensor utilizing near-infrared fluorophores.

The design and application of a fluorescent fiber-optic immunosensor (FFOI) are reported. The FFOI is utilized for the detection of antibody/antigen binding within the near-infrared (NIR) spectral region. The technique is developed through the combined use of fiber-optic, semiconductor laser-excitation, fluorescence detection, NIR dye, and immunochemical techniques. The antibody is immobilized on the FFOI and utilized as a recognition component for trace amounts of specific antigen. The FFOI is constructed to utilize an antibody sandwich technique. The assay involves the immobilization of the capture antibody on the sensing tip of the FFOI followed by the exposure of the immobilized sensing tip to the antigen. The antigen-coated FFOI is then introduced to a second antibody previously labeled with the NIR dye. Typical measurements are performed in about 15 min. A semiconductor laser provides the excitation (780 nm) of the immune complex. The resulting emission is detected by a silicon photodiode detector (820 nm). The intensity of the resulting fluorescence is directly proportional to the concentration of the antigen. The sensitivity of the analysis reaches 10 ng/ml and the response time is 10-15 min.