Dopamine transporter density in the basal ganglia in obsessive-compulsive disorder, measured with [123I]IPT SPECT before and after treatment with serotonin reuptake inhibitors

It has been suggested that dopamine as well as serotonin are associated with the pathophysiology of obsessive-compulsive disorder (OCD). 5-Hydroxytryptophan inhibits dopamine release in healthy persons as well as in patients with OCD, and serotonin tonic inhibition affects dopamine function in basal ganglia, indicating a close relationship between serotonin and the dopamine system. Using iodine-123-labeled N-(3-iodopropen-2-yl)-2 beta-carbomethoxy-3beta-(4-chlorophenyl) tropane ([(123)I]IPT) single photon emission computed tomography (SPECT), we investigated the dopamine transporter (DAT) density in the basal ganglia of patients with OCD. The test consists of two measurements before and after treatment with serotonin reuptake inhibitors (SRIs). Ten patients with OCD before and after treatment with SRIs were included. We performed brain SPECT 2 h after intravenous administration of [(123)I]IPT using a dual-head SPECT camera (Vertex, ADAC, Calif., USA) and analyzed the SPECT data, reconstructed for the assessment of the specific/nonspecific DAT binding ratio in the basal ganglia. We then examined the correlation between the scores of OCD symptom changes, assessed with the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), and DAT binding ratio. Patients with OCD after treatment with SRIs showed a significantly decreased DAT binding ratio in the right basal ganglia compared with baseline. A significant correlation was found between the total scores and compulsion score changes of the Y-BOCS and the changes of the DAT binding ratio of the right basal ganglia. These findings suggest that the dopaminergic neurotransmitter system of the basal ganglia could play an important role in the symptom improvement of OCD patients.

Anterior cingulotomy for refractory obsessive-compulsive disorder

OBJECTIVE

This study was designed to prospectively investigate the efficacy and cognitive adverse effects of stereotactic bilateral anterior cingulotomy as a treatment for refractory obsessive-compulsive (OCD) patients for 12 months.

METHOD

Patients were eligible if they had severe OCD and rigorous treatments had been unsuccessful. Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Clinical Global Impression (CGI) and neuropsychological tests were used to assess the efficacy and cognitive changes of cingulotomy before and 12 months after operation.

RESULTS

The mean improvement rate of the Y-BOCS scores achieved from baseline was 36.0%. Out of 14 patients six met responder criteria; 35% or higher improvement rate on Y-BOCS and CGI improvement of very much or much better at 12-month follow-up. There was no significant cognitive dysfunction after cingulotomy.

CONCLUSION

Anterior cingulotomy shows few cognitive adverse effects, with about half of the OCD patients demonstrating significant symptomatic improvement.

Effects of risperidone on information processing and attention in first-episode schizophrenia

Risperidone appears to have a beneficial effect in several areas of cognitive function in schizophrenic patients. In previous studies, however, the clinical characteristics of the subjects differed between studies, and were heterogeneous even in single study. Most of the subjects were previously exposed to different kinds of neuroleptics and some of them were treatment-resistant. The aim of this study is to evaluate the effect of risperidone on attention and information processing in a homogeneous subgroup of schizophrenic patients, i.e. drug-naïve first-episode inpatients. In the patient group (n=17), cognitive tests and clinical assessments were performed before and after 8 weeks of risperidone treatment. The same cognitive tests were administered to the control group (n=24). The delay between test and retest was 8 weeks. Before treatment, the patient group performed significantly worse than control group on the tests measuring continuous attention, vigilance, and the speed of information processing. After treatment (the average dose of risperidone was 7.3mg/day), in spite of significant improvement of the clinical symptoms, the patients did not show any significant improvement or worsening in most of the items of these tests. The control group did not show any practice effect. These results suggest that first-episode schizophrenic patients have deficits in sustained attention and vigilance to visual stimuli, as well as the speed of information processing to visual and auditory stimuli, and these deficits are unrelated to clinical symptoms and remain stable during the early phase of treatment. This study did not receive pharmaceutical company financial support.

Differential regulation of NO availability from macrophages and endothelial cells by the garlic component S-allyl cysteine

Garlic has been used as a traditional medicine for prevention and treatment of cardiovascular diseases. However, the molecular mechanism of garlic's pharmacological action has not been clearly elucidated. We examined here the effect of garlic extract and its major component, S-allyl cysteine (SAC), on nitric oxide (NO) production by macrophages and endothelial cells. The present study demonstrates that these reagents inhibited NO production through the suppression of iNOS mRNA and protein expression in the murine macrophage cell line RAW264.7, which had been stimulated with LPS and IFNgamma. The garlic extract also inhibited NO production in peritoneal macrophages, rat hepatocytes, and rat aortic smooth muscle cells stimulated with LPS plus cytokines, but it did not inhibit NO production in iNOS-transfected AKN-1 cells or iNOS enzyme activity. These reagents suppressed NF-kappaB activation and murine iNOS promoter activity in LPS and IFNgamma-stimulated RAW264.7 cells. In contrast, these reagents significantly increased cGMP production by eNOS in HUVEC without changes in activity, protein levels, and cellular distribution of eNOS. Finally, garlic extract and SAC both suppressed the production of hydroxyl radical, confirming their antioxidant activity. These data demonstrate that garlic extract and SAC, due to their antioxidant activity, differentially regulate NO production by inhibiting iNOS expression in macrophages while increasing NO in endothelial cells. Thus, this selective regulation may contribute to the anti-inflammatory effect and prevention of atherosclerosis by these reagents.

Relation between cholinesterase inhibitor and Pisa syndrome

We report two patients who developed Pisa syndrome after treatment with cholinesterase inhibitors--cognition-enhancing novel agents for patients with Alzheimer's disease. Cholinergic excess could be another factor in Pisa syndrome, especially in cholinergically-imbalanced Alzheimer's disease.

Selective tumor kill of cerebral glioma by photodynamic therapy using a boronated porphyrin photosensitizer

The prognosis for patients with the high-grade cerebral glioma glioblastoma multiforme is poor. The median survival for primary tumors is < 12 months, with most recurring at the site of the original tumor, indicating that a more aggressive local therapy is required to eradicate the unresectable "nests" of tumor cells invading into adjacent brain. Two adjuvant therapies with the potential to destroy these cells are porphyrin-sensitized photodynamic therapy (PDT) and boron-sensitized boron neutron capture therapy (BNCT). The ability of a boronated porphyrin, 2,4-(alpha, beta-dihydroxyethyl) deuteroporphyrin IX tetrakiscarborane carboxylate ester (BOPP), to act as a photosensitizing agent was investigated in vitro with the C6 rat glioma cell line and in vivo with C6 cells grown as an intracerebral tumor after implantation into Wistar rats. These studies determined the doses of BOPP and light required to achieve maximal cell kill in vitro and selective tumor kill in vivo. The data show that BOPP is more dose effective in vivo by a factor of 10 than the current clinically used photosensitizer hematoporphyrin derivative and suggest that BOPP may have potential as a dual PDT/BNCT sensitizer.

A comparative study on the pharmacokinetics and biodistribution of boronated porphyrin (BOPP) and sulfhydryl boron hydride (BSH) in the RG2 rat glioma model

Boron neutron capture therapy is a treatment modality for cancer that depends on the specific uptake of boron by the tumor cells. The infiltrative growth of malignant gliomas requires that boron reach and accumulate in migrating cells outside the margin of the tumor; thus, it is important that the biodistribution of new boron compounds is also studied in the surrounding healthy brain tissue. This study is undertaken in the present work, in which the biodistribution and pharmacokinetics of sulfhydryl boron hydride (BSH) and boronated porphyrin (BOPP) in the RG2 rat glioma model are investigated. This model mimics the characteristics of human glioma with cells migrating into the surrounding brain. The animals were infused intravenously with either BSH (25 micrograms or 175 micrograms of boron per gram of body weight) or BOPP (12 micrograms of boron per gram body weight). For the low dose of BSH, the maximum tumor-boron content was 8 ppm at approximately 9 hours after the infusion with a tumor-to-blood ratio of 0.6. At the higher dose, the corresponding figures were 15 ppm after 12 hours with a tumor-to-blood ratio of 0.5. For BOPP, a tumor-boron concentration of 81 ppm was achieved 24 hours after the infusion and sustained in that range for at least 72 hours. The tumor-to-blood ratio at 24 hours was slightly above 6, but continued to increase as the blood was cleared. These results indicate that both compounds are spread into the normal brain tissue following the same pathways as the migrating tumor cells and in this way can be taken up even in distant tumor cell foci.

Boronated metalloporphyrins: a novel approach to the diagnosis and treatment of cancer using contrast-enhanced MR imaging and neutron capture therapy

Porphyrins are a unique class of metal chelating agents that have shown specific affinity for neoplasms. The water-soluble free-base derivative, tetrakiscarborane carboxylate ester of 2,4-(alpha,beta-dihydroxyethyl) deuteroporphyrin IX (BOPP), an agent designed for neutron capture therapy, has previously demonstrated selective localization and retention in a C6 murine glioma. In the present work, the authors demonstrate that the manganese chelate of BOPP also selectively localizes in a rat 9L gliosarcoma and preferentially enhances the tumor-normal brain contrast of T1-weighted images for at least 92 hours. The data indicate a maximal enhancement of contrast between tumor and normal brain at 24 hours after injection, compared with 5 minutes for manganese (III) tetraphenylporphine sulfonate (TPPS4). The results also indicate that Mn-BOPP may have a slower uptake in the 9L glioma than Mn-TPPS4 but a longer retention in the tumor. Mn-BOPP is unique in that it represents, to the authors' knowledge, the first example of a single agent that can enhance contrast between tumor and normal tissue and be potentially effective as an agent for boron neutron capture therapy.

Selective tumor uptake of a boronated porphyrin in an animal model of cerebral glioma

The prognosis for patients with high-grade cerebral glioma is poor. Most treatment failures are due to local recurrence of tumor, indicating that a more aggressive local therapy could be beneficial. Adjuvant treatments such as porphyrin-sensitized photodynamic therapy (PDT) or boron neutron capture therapy (BNCT) have the potential to control local recurrence. The selective tumor uptake of a boronated porphyrin was studied in CBA mice bearing an implanted intracerebral glioma. Biopsy samples of tumor, normal brain, and blood were analyzed by a fluorometric assay following intraperitoneal and intravenous administration of boronated protoporphyrin (BOPP). This compound was selectively localized to tumor at ratios as high as 400:1 relative to normal brain. Confocal laser scanning microscopy of glioma cells in vitro and in vivo showed that BOPP was localized within mitochondria and excluded from the nucleus of these cells. This discrete subcellular localization was confirmed by density gradient ultracentrifugation after homogenization of mouse tumor biopsies. The selective discrete localization of these compounds within the tumor suggests that this compound may be used as a dual PDT/BNCT sensitizer.