Timing of adjunctive therapy in the treatment of depression: a chart review.

INTRODUCTION: The objective of this study was to examine the evolution of antidepressant switch and adjunctive therapy. METHODS: This chart review was conducted at 6 primary psychiatric clinics or hospitals, in Tokyo, Japan. A chart review of longitudinal prescriptions was conducted regarding 633 outpatients with major depressive disorder for up to 2 years after their first visit. Patients who had already received antidepressants prior to the visit were excluded. RESULTS: 22.6% (N=143) of the patients completed or continued the outpatient treatment over the 2 years while 27 (4.3%), 23 (3.6%), and 439 (69.4%) patients discontinued it due to hospitalization, referral to another clinic, and loss to follow-up, respectively. A total of 597 episodes of antidepressant treatment were identified. Among them, 482 episodes (80.7%) were associated with the suggested dose ranges while antidepressant drugs were under-dosed in 19.3% (N=115) of the episodes. 50 patients (7.9%) received adjunctive therapy; it was employed after a median of only one antidepressant had been tried. CONCLUSION: Psychiatrists may be hasty in prescribing an adjunctive therapy in the treatment of depression.

Long-term expression driven by herpes simplex virus type-1 amplicons may fail due to eventual degradation or extrusion of introduced transgenes.

In gene therapy applications employing herpes simplex virus amplicon-based vectors, a prevailing problem is the down-regulation of transgene expression over time. We have applied a combined immunocytochemistry and fluorescent in situ hybridization method to determine whether down-regulation of transgene expression at the single-cell level correlates with loss of vector DNA from the host cell nucleus. Utilizing separate fluorescent labels (i.e., rhodamine, fluorescein, and 4',6'-diamidino-2-phenlindole), we were able to simultaneously detect transgenes, their products, and their locations relative to the nuclear compartment of a single cell. Detection of the reporter gene lacZ and its encoded protein beta-galactosidase (beta-gal) was accomplished in in vivo experiments of the dentate gyrus of rats. A time course study of the expression of the transgene post-stereotactic microinfusion up to 60 days was made. Expression reached maximal levels within 12-24 h after infection, and lacZ presence was reduced to less than 3% of its maximal levels within 36 h after infection. In comparing days 1 and 60 post-stereotactic microinfusion, only one-fifth of the original DNA was observed in the area of a 100-mm radius around the site of microinfusion at day 60. Moreover, by comparing the locations of the reporter gene in cells that expressed the encoded protein versus those that did not, we found that introduced transgenes were preferentially localized in the nuclear periphery of down-regulated host cells, compared to expressing host cells. These results suggest that nuclear compartmentalization may play a role in the down-regulation of our reporter gene by means of peripheralization, extrusion, and/or degradation.

Neuroprotective potential of a viral vector system induced by a neurological insult.

Gene transfer into neurons via viral vectors for protection against acute necrotic insults has generated considerable interest. Most studies have used constitutive vector systems, limiting the ability to control transgene expression in a dose-dependent, time-dependent, or reversible manner. We have constructed defective herpes simplex virus vectors designed to be induced by necrotic neurological insults themselves. Such vectors contain a synthetic glucocorticoid-responsive promoter, taking advantage of the almost uniquely high levels of glucocorticoids-adrenal stress steroids-secreted in response to such insults. We observed dose-responsive and steroid-specific induction by endogenous and synthetic glucocorticoids in hippocampal cultures. Induction was likely to be rapid enough to allow transgenic manipulation of relatively early steps in the cascade of necrotic neuron death. The protective potential of such a vector was tested by inclusion of a neuroprotective transgene (the Glut-1 glucose transporter). Induction of this vector by glucocorticoids decreased glutamatergic excitotoxicity in culture. Finally, both exogenous glucocorticoids and excitotoxic seizures induced reporter gene expression driven from a glucocorticoid-responsive herpes simplex virus vector in the hippocampus in vivo.

A novel means of drug delivery: myoblast-mediated gene therapy and regulatable retroviral vectors.

A potentially powerful approach to drug delivery in the treatment of disease involves the use of cells to introduce genes encoding therapeutic proteins into the body. Candidate genes for delivery include those encoding secreted factors that could have broad applications ranging from treatment of inherited single-gene deficiencies to acquired disorders of the vasculature or cancer. Myoblasts, the proliferative cell type of skeletal muscle tissues, are potent tools for stable delivery of a gene of interest into the body, as they become an integral part of the muscle into which they are injected, in close proximity to the circulation. The recent development of improved tetracycline-inducible retroviral vectors allows for fine control of recombinant gene expression levels. The combination of ex vivo gene transfer using myoblasts and regulatable retroviral vectors provides a powerful toolbox with which to develop gene therapies for a number of human diseases.

Immobilization of ligand-modified polyamidoamine dendrimer for cultivation of hepatoma cells.

Cationic polyamidoamine dendrimers are known to be highly branched cascade polymers. The core part of these polymers, tris(2-aminoethyl)amine, was immobilized onto polystyrene plates to which animal cells do not adhere. using photoreactive 4-(3-trifluoromethylazirino) benzoyl-N-succinimide (TDBA-OSu). Cells of a rat hepatoma cell line, H4-II-E-C3, adhered to a surface immobilized with a first-generation dendrimer probably through interactions between the terminal amino groups of the dendrimer and the cell membranes. The adhered cells were viable, could proliferate, and exhibited urea synthetic activity. The modification of the terminal amino groups with fructose increased the final number of cells obtained after 5 days of cultivation. Multigeneration dendrimers were prepared by repeated linkage of tris(2-aminoethyl)amine with the amino groups. Theoretically, the number of terminal amino groups available for ligand modification is twice as much for each generation of dendrimer growth. Cells cultivated on multigeneration fructose-modified dendrimers exhibited enhanced urea synthetic activity. The use of ligand-modified dendrimers is, therefore, considered to be very promising for the construction of bioartificial organs based on cultivation of the animal cells.

Effectiveness of polyamidoamine dendrimers modified with tripeptide growth factor, glycyl-L-histidyl-L-lysine, for enhancement of function of hepatoma cells.

Cationic polyamidoamine dendrimers are known to be highly branched cascade polymers. Tripeptide growth factor, glycyl-L-histidyl-L-lysine (GHK), was employed as a ligand for activation or attachment of cells from a rat hepatoma cell line, H4-H-E-C3, and immobilized at the terminus of the dendrimer (GHK-dendrimer) to develop a suitable surface for use as a culture substratum in the bioartificial liver support system (BAL). The growth of cells was inhibited by increasing the number of generations of GHK-dendrimers. On the other hand, urea synthesis and lidocaine clearance of the cells adhered on fifth generation GHK-dendrimers were enhanced much more than on first generation GHK-dendrimers. GHK was shown to act as a growth inhibitor and an activator of hepatoma cells. These properties of GHK are advantageous for the utilization of hepatoma cells in BAL. Ligand-modified dendrimers are very promising for the creation of a high-performance substratum for cell culture and high performance bioartificial organs, as well as for high-performance bioartificial liver systems. GHK may have the potential to be a highly useful ligand.