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Of all gynecologic malignancies, epithelial ovarian cancer (EOC) is the most frequent cause of death, both in the United States (1) and in Europe (2). The relative absence of a [...], The prognosis in advanced-stage ovarian cancer remains poor. Tumor-specific intraoperative fluorescence imaging may improve staging and debulking efforts in cytoreductive surgery and thereby improve prognosis. The overexpression of folate receptor-α (FR-α) in 90-95% of epithelial ovarian cancers prompted the investigation of intraoperative tumor-specific fluorescence imaging in ovarian cancer surgery using an FR-α-targeted fluorescent agent. In patients with ovarian cancer, intraoperative tumor-specific fluorescence imaging with an FR-α-targeted fluorescent agent showcased the potential applications in patients with ovarian cancer for improved intraoperative staging and more radical cytoreductive surgery.

The best-studied cytoskeletal system is the inner surface of the erythrocyte membrane, which provides an erythrocyte with the structural support needed to be stable yet flexible as it passes through the circulation. Current structural models predict that the spectrin-actin-based cytoskeletal network is attached to the plasma membrane through interactions of the protein ankyrin, which binds to both spectrin and the cytoplasmic domain of the transmembrane protein band 3. The crystal structure of the cytoplasmic domain of band 3 predicted that the ankyrin binding site was located on a [beta]-hairpin loop in the cytoplasmic domain. In vitro, deletion of this loop eliminated ankyrin affinity for band 3 without affecting any other protein-band 3 interaction. To evaluate the importance of the ankyrin-band 3 linkage to membrane properties in vivo, we generated mice with the nucleotides encoding the 11-aa [beta]-hairpin loop in the mouse SIc4a1 gene replaced with sequence encoding a diglycine bridge. Mice homozygous for the loop deletion were viable with mildly spherocytic and osmotically fragile erythrocytes. In vitro, homozygous Id/Id erythrocytes were incapable of binding ankyrin, but contrary to all previous predictions, abolishing the ankyrin- band 3 linkage destabilized the erythrocyte membrane to a lesser degree than complete deficiencies of either band 3 or ankyrin. Our data indicate that as yet uncharacterized interactions between other membrane proteins must significantly contribute to linkage of the spectrin-actin-based membrane cytoskeleton to the plasma membrane. cytoskeleton | membrane | transgenic | spherocytosis

In this report, we describe the development of a quartz crystal microbalance biosensor for detection of folate binding protein (FBP). Using a simple folate--BSA conjugate adsorbed onto a Au-coated quartz sensor, a detection limit of 30 nM was achieved. Binding of FBP to the sensor surface could be blocked at concentrations as high as 1 [micro]M with a 100-fold excess of folic acid, indicating the specificity of the folate--FBP interaction and the absence of nonspecific binding to the functionalized surface. Moreover, capture could be achieved in the presence of blood serum, making the assay amenable to the analysis of bodily fluids. Further signal enhancement based on an anti-FBP antibody and protein-A-coated gold nanosphere sandwich assay extended the detection limit to 50 pM (~3 orders-of-magnitude improvement). Given the overexpression of FBP in certain malignancies and inflammatory disorders, we expect the methodology described here to be useful to detect FBP as a possible biomarker for disease diagnosis.

The cantilever arrays are investigated for real-time detection of Bacillus subtilis spores in liquid medium. The results show that real-time detection of multiple pathogenic organisms is realized by using peptide-functionalized microcantilever arrays.

Gold nanorods excited at 830 nm on a far-field laser-scanning microscope produced strong two-photon luminescence (TPL) intensities, with a [cos.sup.4] dependence on the incident polarization. The TPL excitation spectrum can be superimposed onto the longitudinal plasmon band, indicating a plasmon-enhanced two-photon absorption cross section. The TPL signal from a single nanorod is 58 times that of the two-photon fluorescence signal from a single rhodamine molecule. The application of gold nanorods as TPL imaging agents is demonstrated by in vivo imaging of single nanorods flowing in mouse ear blood vessels. in vivo imaging | plasmon resonance | multiphoton | nonlinear optics

We present a method for detecting and localizing a fluorescing tumor obscured underneath several millimeters of a multiply scattering, homogeneous medium from fluorescence measurements made above the surface. Using a statistical model of the measurement system, we develop approaches for detection by use of a binary hypothesis testing approach and localization by use of maximum-likelihood estimation. We also compute the probability of tumor detection and the Cramer-Rao lower bound for the localization estimate error, which are performance metrics that could potentially be optimized in an experimental design. We validate the methods in an experimental study involving an excised mouse tumor tagged with a new folate-indocyanine dye and obscured under a tissue-simulating lipid suspension.

Several vital functions/physical characteristics of erythrocytes (including glycolysis, the pentose phosphate pathway, ion fluxes, and cellular deformability) display dependence on the state of hemoglobin oxygenation. The molecular mechanism proposed involves an interaction between deoxyhemoglobin and the cytoplasmic domain of the anion-exchange protein, band 3 (cdB3). Given that band 3 also binds to membrane proteins 4.1 and 4.2, several kinases, hemichromes, and integral membrane proteins, and at least three glycolytic enzymes, it has been suggested that the cdB3-deoxyhemoglobin interaction might modulate the pathways mediated by these associated proteins in an [O.sub.2]-dependent manner. We have investigated this mechanism by synthesizing 10-mer peptides corresponding to the N[H.sub.2]-terminal fragments of various vertebrate cdB3s, determining their effects on the oxygenation reactions of hemoglobins from the same and different species and examining binding of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase to the erythrocytic membrane of mouse erythrocytes. The cdB3 interaction is strongly dependent on pH and the number of negative and positive charges of the peptide and at the effector binding site, respectively. It lowers the [O.sub.2] association equilibrium constant of the deoxygenated (Tense) state of the hemoglobin and is inhibited by magnesium ions, which neutralize cdB3's charge and by 2,3-diphosphoglycerate, which competes for the cdB3-binding site. The interaction is stronger in humans (whose erythrocytes derive energy predominantly from glycolysis and exhibit higher buffering capacity) than in birds and ectothermic vertebrates (whose erythrocytes metabolize aerobically and are poorly buffered) and is insignificant in fish, suggesting that its role in the regulation of red cell glycolysis increased with phylogenetic development in vertebrates. allosteric interaction; erythrocyte; oxygen binding; glycolytic enzymes

Intravital two-photon microscopy was used to follow the uptake and trafficking of fluorescent conjugates of folic acid in the rat kidney. Intravenously administered folate-linked dye molecules quickly filled the plasma volume but not cellular components of the blood. Glomerular filtration occurred immediately and binding to proximal tubule cells was seen within seconds. Fluorescence from a pH-insensitive conjugate of folic acid, folate Texas red (FTR), was readily observed on the apical surface of the proximal tubules and in multiple cellular compartments, but little binding or uptake could be detected in any other kidney cells. Fluorescence from a pH-sensitive conjugate of folic acid, folate fluorescein, was seen only on the apical surface of proximal tubule cells, suggesting that internalized folate conjugates are localized to acidic compartments. The majority of the FTR conjugate internalized by proximal tubules accumulated within a lysosomal pool, as determined by colocalization studies. However, portions of FTR were also shown by electron microscopy to undergo transcytosis from apical to basal domains. Additional studies with colchicine, which is known to depolymerize microtubules and interrupt transcytosis, produced a marked reduction in endocytosis of FTR, with accumulation limited to the subapical region of the cell. No evidence of cytosolic release of either folate conjugate was observed, which may represent a key difference from the cytosolic deposition seen in neoplastic cells. Together, these data support the argument that folate conjugates (and, by extrapolation, physiological folate) bind to the apical surface of proximal tubule cells and are transported into and across the cells in endocytic compartments. proximal tubule cell

Research has been conducted on the red blood cells. The effect of common signal trunsduction pathway activation mediated via protein kinase C on calcium influx into red blood cells and phosphatidylserine exposure has been investigated and the results are discussed.