No abstract

Herpes simplex virus thymidine kinase (HSV tk) gene therapy combined with ganciclovir (GCV) medication is a potential new method for the treatment of malignant glioma. We have used both retrovirus-packaging cells (PA317/tk) and adenoviruses (Adv/tk) for gene therapy for malignant glioma. Retrovirus-packaging cells were used for eight tumors in seven patients and adenoviruses were used for seven tumors in seven patients. As a control group, seven tumors in seven patients were transduced with lacZ marker gene 4-5 days before tumor resection. Safety and efficacy of the gene therapy were studied with clinical evaluation, blood and urine samples, MRI follow-up, and survival of the patients. Four patients with adenovirus injections had a significant increase in anti-adenovirus antibodies and two of them had a short-term fever reaction. Frequency of epileptic seizures increased in two patients. No other adverse events possibly related to gene therapy were detected. In the retrovirus group, all treated gliomas showed progression by MRI at the 3-month time point, whereas three of the seven patients treated with Adv/tk remained stable (p < 0.05). Mean survival times for retrovirus, adenovirus, and control groups were 7.4, 15.0, and 8. 3 months, respectively. The difference in the survival times between the adenovirus and retrovirus groups was significant (p < 0.012). It is concluded that HSV tk gene therapy is safe and well tolerated. On the basis of these results further trials are justified, especially with adenovirus vectors.

Regional neuronal loss in the substantia nigra was studied in relation to extrapyramidal symptoms and dementia in 12 patients with idiopathic Parkinson's disease (PD) and in 18 control subjects. Four areas of the right substantia nigra were investigated at the level of the superior colliculus and caudal red nucleus. In Parkinson's disease, the percentages of neurons, from the medial to the lateral part of the substantia nigra, were reduced to 49%, 31%, 41%, and 25% of the control values. The number of neurons in the lateral part showed a negative correlation with the severity of rigidity and hypokinesia, whereas tremor was less noticeable in patients with few neurons. The degree of dementia of the patients had a significant correlation only with neuronal loss in the medial part of the substantia nigra, suggesting, in view of the topographical organization of the neurons in the substantia nigra, that intact projections to the caudate nucleus and limbic and cortical areas are a prerequisite for normal cognitive functioning and that their dysfunction leads to clinical dementia.

Both retro- and adenovirus-mediated gene therapy have been suggested as a novel approach to the treatment of malignant brain tumors. However, little information is available about the gene transfer efficiency in human malignant glioma in vivo. We compared the feasibility and safety of retrovirus- and adenovirus-mediated beta-galactosidase gene transfer in human malignant glioma. Beta-galactosidase gene was transferred to 10 patients with malignant glioma via a catheter inserted into the tumor. The catheter was left in place until the tumor resection. To maximize gene transfer efficiency, gene transfer vectors (BAG retroviruses, titer, 6 x 10(5) CFU; and adenoviruses, titer from 3 x 10(8) to 3 x 10(10) PFU) were injected into the tumor via the catheter once a day for three consecutive days, followed by tumor resection 1-2 days later. Tumor was resected in such a way that the catheter was still in place inside the tumor, which permitted accurate histological analysis of the transduced tumors. X-Gal staining for beta-galactosidase activity was used to study gene transfer efficiency and distribution of the marker gene. Beta-galactosidase gene transfer was well tolerated with both vectors. Except for two patients with clear increases in serum adenovirus antibody titers, no adverse tissue responses or systemic complications were noticed in any of the patients. Gene transfer was successful in all patients. Gene transfer efficiency varied between <0.01 and 4% with retroviruses and between <0.01 and 11% with adenoviruses. However, the transgene activity was not evenly distributed in the tumors. Both glioma cells and endothelium in the tumor blood vessels were transduced with retro- and adenovirus vectors. In conclusion, the safety and feasibility of in vivo gene transfer to human malignant glioma was established with retro- and adenovirus vectors. Adenoviruses were more efficient than retroviruses in achieving in vivo gene transfer. Transduction of endothelial cells may have important consequences for the proposed treatment strategies and selection of treatment genes. The results justify clinical gene therapy trials for malignant glioma.

The calcium-binding protein, parvalbumin, was localized immunohistochemically in the human amygdaloid complex. Neuronal cell bodies and fibers that are immunoreactive to parvalbumin were observed in most of the amygdaloid nuclei and cortical areas. Three types of immunoreactive aspiny neurons, ranging from small spherical cells (type 1) to large multipolar cells (type 2) and fusiform cells (type 3), were observed. The densities of the types of neurons that were parvalbumin-immunoreactive varied in the different regions of the amygdala. The highest densities of parvalbumin-immunoreactive neurons were observed in the lateral nucleus, in the magnocellular and intermediate divisions of the basal nucleus, in the magnocellular division of the accessory basal nucleus and in the amygdalohippocampal area. The regions containing the lowest density of parvalbumin-immunoreactive cells were the paralaminar nucleus, the parvicellular division of the basal nucleus, the central nucleus, the medial nucleus and the anterior cortical nucleus. In general, the distribution of immunoreactive fibers and terminals paralleled that of immunoreactive cells. Parvalbumin-immunoreactive varicose fibers formed basket-like plexi and cartridges around the unstained neurons, which suggests that parvalbumin is located in GABAergic basket cells and chandelier cells, respectively. The distribution of parvalbumin-immunoreactive profiles in the human amygdaloid complex was similar to, rather than different from that previously reported in the monkey amygdala (Pitkänen and Amaral [1993] J. Comp. Neurol. 331:14-36). This study provides baseline information about the organization of GABAergic inhibitory circuitries in the human amygdaloid complex.