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SUMMARYThis study was undertaken to determine the effect of micromolar concentrations of delta-9-tetrahydrocannabinol (Delta-9-THC) on herpes simplex virus type 2 (HSV-2) replication in vitro. Virus-infected Vero cells pretreated for 24 h with 10 -5 M-or 10 -6 MDelta-9-THC yielded 100-fold increases in infectious extracellular virus. Transmission electron microscopy of drug-treated cells revealed plasma membrane dissolution, distension of the smooth and rough endoplasmic reticulum, and the appearance of macrovacuoles in the cytoplasm containing aggregates of virus. These results suggest that Delta-9-THC enhances the release of HSV-2 by perturbing cellular membranes in virus-infected cells.

The effect of delta-9-tetrahydrocannabinol (delta-9-THC) on the growth kinetics and morphology of rat B103 neuroblastoma cells was assessed. Delta-9-THC in doses ranging from 10(-4) to 10(-7) M inhibited cellular growth in a dose-dependent fashion as evidenced by delay in doubling time, decrease in saturation density, and decrease in efficiency of plating. The inhibition in cellular growth was paralleled by dose-related alterations in cell morphology. Modifications included rounding of cells, retraction of neurites, blebbing of the cell surface, and exfoliation of the plasma membrane. Cytoplasmic alterations included distension of the endoplasmic reticulum, Golgi apparatus, and perinuclear space, and macrovacuolization. Intracytoplasmic laminated inclusions and vesicular clusters were suggestive of membrane repair in drug-treated cells. These morphological changes were accompanied by cytoskeletal rearrangement in the absence of significant alteration in the concentration of total cytoskeletal protein. Autoradiographic examination of the intracellular fate of 3H-delta-9-THC demonstrated that the drug was confined to the cytoplasmic compartment and often associated with macrovacuoles. These results suggest that delta-9-THC interacts with cellular membranes, thereby altering neuroblastoma cell growth and behavior.

There is a growing need for creating life-like virtual human simulations that can conduct a natural spoken dialog with a human student on a predefined subject. We present an overview of a spoken-dialog system that supports a person interacting with a full-size hologram-like virtual human character in an exhibition kiosk settings. We also give a brief summary of the natural language classification component of the system and describe the experiments we conducted with the system.

The effect of micromolar concentrations of delta-9-tetrahydrocannabinol (delta-9-THC) on the in vitro replication and biosynthesis of herpes simplex virus type 2 (HSV2) was determined. A 100-fold increase in extracellular virus was recorded for infected Vero cells pretreated with 10(-6) M or 10(-5) M drug when compared to infected vehicle-treated controls. However, no significant differences were observed in the production of total infectious virus for any of the vehicle or drug-treated cultures. Immunofluorescence of virus-infected cells revealed that delta-9-THC did not alter the intracellular compartmentalization of virus-specified proteins. Analytical sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography of isotopically labeled, cell-associated virus-specified proteins revealed that delta-9-THC had no major effect on the production of early nonstructural proteins but decreased the synthesis of late structural proteins. Scanning electron microscopy and light microscopy revealed blebs on the surface and macrovacuoles in the cytoplasm of both infected and uninfected cells treated with drug. These results suggest that delta-9-THC at micromolar concentrations selectively targets the host cell with the consequence of perturbation of cellular membranes. The alteration of cellular membranes may account for the enhanced virus release and for the decreased expression of virus-specified, cell-associated late structural proteins.