Repeated administration of opioids alters characteristics of membrane-bound phorbol ester binding in rat brain

Scatchard analysis of saturation binding data indicated that dissociation constant (KD) of [3H]phorbol 12,13-dibutyrate (PDB) binding to the membrane-bound protein kinase C of rat cortex and midbrain was significantly decreased following systemic repeated administration of morphine (mu-opioid receptor agonist) and butorphanol (mu/delta/kappa-mixed opioid receptor agonist). No change in the receptor density (Bmax) of [3H]PDB binding was found following repeated treatment with morphine and butorphanol. On the other hand, neither the Bmax nor KD values in pons/medulla were altered in these rats. These results suggest that systemic repeated opioid treatment, such as morphine and butorphanol leads to an increased affinity for phorbol ester binding to the membrane-bound protein kinase C in rat cortex and midbrain.     

Preparation and transplantation of photoreceptor sheets

PURPOSE: Photoreceptor (PR) transplantation may be a treatment for blindness secondary to PR degeneration. We studied different technical aspects of PR-sheet preparation. METHODS: Geographic variation in the thickness of the cat PR layer (from the outer segments to the outer plexiform layer) and inner retina (width of the remainder of the retina) was studied. PR sheets (cat and human) were prepared through gelatin embedding and subsequent vibratoming or excimer laser ablation. Cat PR sheets were evaluated after transplantation. RESULTS: The thickness of the cat PR layer and inner retina varied in different regions. The superior central retina, including the area centralis, was thickest (PR layer: 115-123 microm, entire retina: 225-230 microm, in fixed tissue). The peripheral retina was approximately 40% thinner than the center. Fresh retina was approximately 7.9% thicker than the fixed retina. Both vibratomy and excimer laser ablation removed the inner retina, leaving a PR-layer sheet with good morphology. To produce good quality PR sheets with vibratomy, use of different gelatin concentrations (2% to 35%) at various stages of sheet preparation was crucial. To produce PR sheets of uniform thickness with excimer laser ablation, control of fluid on the retinal surface was critical. Twenty-four hours after PR transplantation surgery, donor PR cells were well oriented and in close contact with host retinal pigment epithelial cells. Gelatin supporting the transplant dissolved as early as 100 min after surgery. CONCLUSIONS: We confirmed and expanded the work of previous investigators and showed that cat and human PR sheets can be manufactured using vibratomy or excimer laser ablation. This preparation provides a well oriented and organized PR cell layer after transplantation.     

Exploratory factor analysis of MRI brain structure measures in schizophrenia

Much of the literature shows various regional structural brain abnormalities in schizophrenia, but the complexity and variability of brain makes it difficult to determine how these regions are related. Statistical methods which estimate factors underlying patterns of covariance have not been widely used, but could be useful for analyzing such complex data. We applied exploratory and confirmatory factor analysis procedures to specific cortical and subcortical regional brain volume measures from MRI data in 60 normal and 44 schizophrenic subjects. Basal ganglia, heteromodal cortical gray, and medial temporal lobe factors were present in both the normal and the schizophrenia groups. The factor structure observed in the normal group showed a high degree of bilateral symmetry which is present but disrupted in the schizophrenia group. In the bilateral data, the disruption is most pronounced with medial and lateral temporal lobe structures including entorhinal cortex and anterior and posterior superior temporal gyri. There was a significant correlation between the basal ganglia factor and the heteromodal cortical gray factor in the normal group that was not present in the schizophrenia group. In the unilateral data, left posterior superior temporal gyrus did not load onto any factor in the schizophrenia group. Confirmatory factor analyses showed significant differences between the two groups in factor structure. A number of specific brain regions are affected in schizophrenia, and structural relationships between groups of regions also are abnormal. The results suggest that heteromodal dorsolateral prefrontal and superior temporal cortical gray regions are structurally related, whereas inferior parietal cortical gray is less so. These results should be viewed as preliminary as the ratio of parameters to subjects was relatively low, and replication is needed. However, the results demonstrate the potential utility of latent structure methods such as factor analysis in study of complex relationships in neuropsychiatric data.     

The action of reserpine on the concentration of 5-hydroxytryptamine, epinephrine and norepinephrine in the venous blood of migraine patients

Vasoactive amines, particularly 5-hydroxy-tryptamine (5-HT) have been implicated as the cause of migraine. Our study was a biochemical one on the effect of reserpine on the content of 5-HT, NE and E in migraneurs. The effect of one single infection of reserpine. 23 migrainous patients and 7 controls were given one i.m. injection of reserpine (1,5 mg/1.7 m2 surface). The content of 5-HT in blood platelets of 8 migraneurs and 7 controls 6 hours after the injection of reserpine decreased to comparable levels in both groups. The serotonin releasing effect of reserpine, however, is different from that of tyramine. The effect of prolonged reserpine medication. The effect of i.v. injection of reserpine over a period of 6 weeks on 5-HT, NE and E, was investigated. The doses of reserpine corresponded exactly to the doses already used by Nattero et al. (0.2 mg reserpine 3 times a week for 6 weeks). In correspondance with this work a double blind clinical examination was carried out by Nattero et al. (1975). Blood amine levels were measured weekly. The NE decreased to a minimum of 62% of basal mean value after 3-7 weeks of treatment. The decrease is significant from the third to the sixth week. Basal value was not reached until 6 weeks after withdrawal of reserpine. The concentration of 5-HT in blood platelets decreased to 5% of basal mean value and remained low during the reserpine treatment. The decrease is highly significant. A clinical improvement began 1-2 weeks after the introduction of reserpine treatment, continued during treatment and for 2-6 weeks after. In the open trial performed by us, we can confirm the results of Nattero et al. We demonstrated a marked decrease in concentration of blood amines corresponding to clinical improvement.     

Contraction of developing avian heart muscle

26 patients with at least one clinical symptom that could indicate a tear of the scapho-lunate interosseous ligament but normal static and dynamic radiographs were examined by arthroscopy. We found that a diagnosis of scapho-lunate instability could be established by dynamic manoeuvres during radio-carpal and mid-carpal arthroscopy. Five patients were found to have true scapholunate instability. Six tears of the interosseous ligament without instability were also detected but it was doubtful if the tear was the origin of the painful symptomatology. This experience suggests that dynamic manoeuvres during arthroscopy are superior to other methods in diagnosing scapholunate instabilities at the pre-radiographic stage.