Local changes in cerebral glucose utilization during the postictal phase of amygdaloid-kindled generalized seizures were studied with the quantitative autoradiographic 2-[14C]deoxyglucose method in conscious rats. Measurement was initiated either just after termination of a behavioral seizure (GS-I) or 30 s after seizure termination (GS-II) to determine dynamic metabolic changes in the postictal phase. Although glucose utilization of the neocortex was remarkably depressed in both GS-I and GS-II, that of the hippocampus significantly increased in GS-I and then decreased in GS-II as compared with control. These changes of hippocampal glucose utilization were observed in all sectors of the pyramidal cell layer (CA 1-4) and in the molecular layer. Because metabolic changes associated with development of amygdaloid-kindled seizures begin in the limbic structures including the hippocampus, the transient increase in hippocampal glucose utilization observed in the early postictal phase indicates that the hippocampus is one of the key structures not only for initiating and maintaining but also for terminating kindled seizures.

Amygdala↗

PubMedDate not supplied

Spiral hyphae of Candida albicans formed in anaerobic culture.

Candida albicans from a patient with dental caries grew on minimal medium consisting of agar supplemented with magnesium chloride and sodium phosphate. Hyphal growth was observed when the yeast was cultured between 26 degrees C and 28 degrees C under aerobic conditions, and typical chlamydospores were formed. However, when the yeast was cultured at the same temperature under anaerobic conditions, curly hyphae developed on the surface of the medium, but no chlamydospores were formed. This phenomenon was also observed if the culture was started under aerobic conditions but was continued under anaerobic conditions.

Anaerobiosis↗

PubMedDate not supplied

Transplantation of xenogeneic cells secreting beta-endorphin for pain treatment: analysis of the ability of components of complement to penetrate through polymer capsules.

The permeation of component of complement and secreted peptides through polymer capsules (PM30, K6305, and K5708) were examined. To analyze permeability by complement, the degree of hemolysis of sensitized sheep erythrocytes (EA) (1 x 10(9)/ml) enclosed in each type of capsule was examined after 24-h incubation in culture medium containing 10% human serum. PM30 and K6305 prevented the permeation of complement well, while K5708 did not. EA suspended in alginate prevented hemolysis even in K5708. Peptide permeation through the capsules was assessed by measuring the concentration of ACTH secreted by proopiomelanocortin (POMC)-gene-transfected-Neuro2A in the culture medium on days 4, 7, 14, 21, and 28 after encapsulation. The ACTH levels in the culture medium remained high until day 28. Alginate appeared to prevent the secretion, because ACTH levels decreased in alginate-suspended cells after day 14. The PM30-K6306 double capsules containing cell lines, Neuro2A, BHK21 (hamster fibroblasts), L929 (mouse fibroblasts), and HF-SKFII (human fibroblasts) were transplanted into the cerebrospinal fluid (CSF) space of the monkeys in the lumber region. The morphological examination showed the partial survival of Neuro2A, and BHK21 and HF-SKFII, which were cells concordant with the monkeys. On the other hand, L929 cells, which were discordant with the monkeys, could not survive at all. Because these results suggest that the complement components penetrate the polymer capsules, concordant cells are preferable for xenografting with polymer capsules into the CSF space.

Adrenocorticotropic Hormone↗

PubMedDate not supplied

Long-term functional assessment of encapsulated cells transfected with Tet-On system.

In our previous study, xenogeneic mouse neuroblastoma cells bearing the POMC gene, the precursor of ACTH and beta-endorphin, were implanted within polymer capsules into the CSF space of rats. Although ACTH and beta-endorphin were secreted, we were not able to control the amounts or times of hormone release. A promoter that is inducible by administration of tetracycline derivatives (Tet) was linked to the POMC gene to control its gene expression (Neuro2A-Tet-On-POMC; NTP). The results showed that POMC gene expression in the implanted encapsulated NTP cells could be regulated in a dose-dependent manner by Tet administration to the hosts. However, no analysis of gene control with the Tet-On system over a long period has been performed. In this study, encapsulated NTP cells were treated in vitro with doxycycline (Dox) (1.0, 10, 100, 1000 ng/ml) continuously for a month. On day 4, the amount of ACTH secretion was dependent on the Dox dose. But in the course of the experiment, the difference of ACTH secretion among those treated with Dox 10, 100, and 1000 ng/ml was eliminated. On the other hand, NTP cells, which were treated with Dox (1000 ng/ml) just on days 7, 14, 21, and 28, secreted almost the same amount of ACTH in 24 h. From these results, for clinical use, an NTP cell line that secretes enough opiate to reduce pain sensitivity without Dox should be established, and Dox could then be administered if necessary.

Adrenocorticotropic Hormone↗