Cocaine abuse and HIV-1 infection: epidemiology and neuropathogenesis

The epidemiology of cocaine abuse and potential relationships of cocaine withdrawal to human immunodeficiency virus type 1 (HIV-1)-associated dementia (HAD) are discussed. Neuroendocrinological changes in HIV-1 infection of the central nervous system (CNS) are discussed with the relevant impact of cocaine abuse. HIV-1 load in the brain tissue of infected substance users is described along with possible associations with neuropathology and HAD. Finally, the molecular epidemiology and sequence heterogeneity of HIV-1 and their implications for neuropathogenesis are summarized. The complex context of addressing cocaine abuse in the setting of HIV-1 infection appears more tractable when decomposed into its components.     

Expression of nucleolar protein p120 in human lung cancer: difference in histological types as a marker for proliferation

The function of proliferation-associated nucleolar protein p120 is unclear. A recent report that a yeast protein, NOP2, 67% homologous to human p120, is up-regulated during the onset of growth and influences the morphology of the nucleolus supports the notion that this protein could serve as a marker for proliferation in neoplastic cells. Lung cancer is characteristic in that different histological types show different biological features. We attempted to evaluate the levels of p120 expression in resected human lung cancer tissues of different histological types and the relation of p120 expression and cell proliferation using human lung cancer cell lines. When 37 frozen specimens of human lung cancer and normal lung were stained with a p120 monoclonal antibody, the nucleoli of cancer cells were positively stained, whereas a few macrophages in normal lung revealed only weak staining. The labeling index of p120 in squamous cell carcinoma (67.7 +/- 12.4%) was significantly higher than that in adenocarcinoma (35.3 +/- 12.6%) or in large cell carcinoma (30.1 +/- 17.3%; P < 0.01). In six human lung cancer cell lines and one normal lung fibroblast cell line cultured in vitro, there was a significant correlation between S-phase fraction and p120 mRNA (r = 0.851, P < 0.02)/p120 protein (r = 0.869, P < 0.01) or between doubling time and p120 protein (r = -0.928, P < 0.01). In the context of the reports that indicate higher [3H]thymidine incorporation and shorter doubling time in the squamous cell carcinoma, these results indicate that p120 can be a marker for proliferation in human lung cancer cells in vivo and in vitro, and that it has an important function in the cell cycle of tumor proliferation.     

Theoretical analysis of resonant waveguide optical second harmonicgeneration devices

Theoretical analysis of resonant waveguide SHG devices is presented. Mathematical expressions for SHG interaction in waveguides for arbitrary initial conditions were derived and applied to the analysis. Dependences of SHG efficiency on pump amplitude of singly and doubly resonant devices with various cavity mirror reflectivities, phase-mismatch, and propagation losses are compared with that of traveling-wave devices. It is shown that in resonant SHG devices much higher efficiency is obtained for low pumping power than in traveling-wave device. It is found, for the first time, that complete conversion can be attained for a finite input power in the doubly resonant devices. However, the efficiency is very sensitive to the propagation losses     

Beef texture characterization using internationally established texture vocabularies in ISO5492:1992: Differences among four different end-point temperatures in three muscles of Holstein steers

‘Tenderness’ has been an important sensory characteristic for beef, although ‘tenderness’ has not been commonly defined. On the other hand, ISO5492:1992 provides internationally established vocabularies for sensory analysis with simple definition. The aim of this study was texture characterization for three beef muscles cooked to four end-point temperatures using ISO5492:1992 texture terms in Japanese to develop objective sensory evaluation terms for beef texture other than ‘tenderness.’ Longissimus, semitendinosus, and psoas major muscles harvested from three Holstein steers were cooked to 45, 60, 72, and 92 °C end-point temperatures and evaluated by a trained sensory panel. Correspondence analysis indicated that the ‘chewiness’ and ‘hardness’ defined in ISO5492 were distinguished in each muscle. Changes in the ‘chewiness’ and ‘hardness’ qualities during cooking were different from each other. These findings suggest that both ‘chewiness’ and ‘hardness’ as defined in ISO5492:1992 should be evaluated simultaneously to determine the sensory texture of beef.     

Type-I Quasi-Phase-Matched Waveguide Device for Polarization-Entangled Twin Photon Generation

Quantum-entangled twin photons are expected to play an important role in future quantum communications and information processing. We propose and demonstrate a Type-I quasi-phase-matched (QPM) nonlinear-optic (NLO) LiNbO₃ waveguide device for high-efficiency polarization-entangled twin photon generation. The device consists of a Ti:LiNbO₃ channel waveguide, a ferroelectric domain-inverted grating for Type-I QPM, and a thin-film half-wave plate for polarization conversion at the center of the NLO interaction region. Generation of polarization-entangled twin-photons is demonstrated through quantum interference experiment.