Yoshio Ikeda

Region extraction and shape analysis in aerial photographs

Abstract A new system for the analysis of aerial photographs of suburban areas is presented. In this system, regions are characterized by various spectral and spatial features such as brightness, color, size, shape, texture, and spatial relationships with other regions. The analysis proceeds from a global survey of the picture to the detailed analysis of specific regions. The former process extracts several kinds of characteristic regions which are supposed to include specific objects by using knowledge-free picture processing programs. In the detailed analysis, several object-detection programs perform parallel analysis of extracted characteristic regions in detail to recognize objects such as crop fields, woods, roads, and houses. Then the properties of the recognized objects are used to aid in analysis of the rest of the picture which was left unrecognized at the first step of recognition. Experimental results show that this system is quite useful in analyzing aerial photographs of complex suburban areas.

Existence of Met-enkephalin-Arg6-Gly7-Leu8 with Met-enkephalin, Leu-enkephalin and Met-enkephalin-Arg6-Phe7 in the brain of guinea pig, rat and golden hamster

Abstract High performance liquid chromatography (HPLC) coupled with specific radioimmunoassays for methionine-enkephalin-Arg6-Gly7-Leu8 (Met-E-Arg6-Gly7-Leu8), methionine-enkephalin (Met-E), leucine-enkephalin (Leu-E) and methionine-enkephalin-Arg6-Phe7 (Met-E-Arg6-Phe7) has demonstrated that Met-E-Arg6-Gly7-Leu8 exists together with Met-E, Leu-E and Met-E-Arg6-Phe7 in the brain of guinea pig, rat and golden hamster. The content of Met-E-Arg6-Gly7-Leu8 was comparable to those of Leu-E and Met-E-Arg6-Phe7, whereas that of Met-E was the highest among the four opioid peptides. These results are compatible with the recent studies on the nucleotide sequence of cloned cDNA for preproenkephalin from bovine adrenal medulla, which reveal that this precursor molecule contains four copies of Met-E and one copy each of Leu-E, Met-E-Arg6-Phe7 and Met-E-Arg6-Gly7-Leu8. The co-existence of Met-E-Arg6-Gly7-Leu8 with Met-E, Leu-E and Met-E-Arg6-Phe7 suggests that their biosynthetic pathway in the brain is similar to that in the adrenal medulla.

Leumorphin is a novel endogenous opioid peptide derived from preproenkephalin B

Using synthetic leumorphin, we obtained antisera for leumorphin and set up two radioimmunoassays (RIAs) with different specificities. Gel exclusion chromatography coupled with the two RIAs showed the existence of a considerable amount of leumorphin-like peptide in water extracts from porcine neuro-intermediate pituitaries. Reverse phase high performance liquid chromatography revealed that leumorphin-like peptide in the water extracts was indistinguishable from synthetic leumorphin. These results along with potent opioid activity of leumorphin indicate that leumorphin is a novel endogenous opioid peptide derived from preproenkephalin B.

A novel opioid peptide, leumorphin, acts as an agonist at the κ opiate receptor

Abstract The primary structure of the common precursor of porcine β-neo-endorphin and dynorphin (preproenkephalin B) has shown the existence of a third leucine-enkephalin (leu-enkephalin) sequence with a C-terminal extension of 24 amino acids. This nonacosapeptide, named leumorphin, was approximately 70 times more potent than leuenkephalin in inhibiting the contraction of the myenteric plexus-longitudinal muscle preparation of the guinea pig ileum. This action of leumorphin, like those of β-neo-endorphin and dynorphin, was antagonized less effectively by naloxone than that of leuenkephalin, but more effectively by Mr2266, an antagonist relatively specific for the κ type opiate receptor. The inhibitory action of leumorphin or β-neo-endorphin on the contraction of the guinea pig ileum muscle strip was reduced in a dose-dependent manner by pretreatment with dynorphin and vice versa . Leumorphin as well as β-neo-endorphin and dynorphin inhibits the contraction of the rabbit vas deferens which is known to have only the κ type opiate receptor. This action was also effectively antagonized by Mr2266. It is concluded that leumorphin has potent opioid activity and acts at the κ receptor, like other opioid peptides derived from preproenkephalin B.

Biosynthesis and distribution of opioid peptides

Group III opioid peptides are derived from proenkephalin B. The processing of this precursor peptide is still only partly understood and we still do not know how many final products come from proenkephalin B and whether Leu-enkephalin is produced from Group III peptides. However, potent biologic activity of Group III opioid peptides and existence of opiate-receptors specific for these peptides (k receptors) strongly suggest that Group III opioid peptides are not precursors of Leu-enkephalin but bioactive substances per se. Further studies should clarify details of the processing of proenkephalin B.

Parallel distribution of methionine-enkephalin-arg6-gly7-leu8 with methionine-enkephalin, leucine-enkephalin and methionine-enkephalin-arg6-phe7 in human and bovine brains

Using specific radioimmunoassays(RIAs) for methionine-enkephalin(Met-Enk), leucine-enkephalin(Leu-Enk), methionine-enkephalin-Arg6-Gly7-Leu8 (Met-Enk-Arg-Gly-Leu) and methionine-enkephalin-Arg6-Phe7 (Met-Enk-Arg-Phe), we studied the regional distribution of these opioid peptides in human and bovine brains. Met-Enk-Arg-Gly-Leu was distributed in parallel with Met-Enk, Leu-Enk and Met-Enk-Arg-Phe in human and bovine brains. The ratios of molar concentrations of these peptides are almost constant in various regions of human and bovine brains and similar to the ratio of these peptides contained in preproenkephalin A. Gel exclusion chromatography and HPLC coupled with respective RIAs showed the existence of authentic peptides without any detectable high molecular weight forms. These results indicate the parallel distribution of Met-Enk-Arg-Gly-Leu with Met-Enk, Leu-Enk and Met-Enk-Arg-Phe in various regions of human and bovine brains and further suggest that these opioid peptides are derived from the same precursor as that in the adrenal medulla and that the processing of preproenkephalin A is almost complete in human and bovine brains.

Comparison of the action of putative endogenous κ-agonists, leumorphin and rimorphin in vitro

Abstract Leumorphin and rimorphin (dynorphin B) were nearly equipotent in inhibiting the contraction of the myenteric plexus-longitudinal muscle preparation of the guinea pig ileum and the rabbit vas deferens. Leumorphin had long duration of action in vitro after wash-out, whereas the duration of action of rimorphin was relatively shorter. These action of leumorphin and rimophin were antagonized less effectively by naloxone than by Mr2266, an antagonist relatively specific for the κ-receptor. Rimorphin as well as leumorphin inhibits the contraction of the rabbit vas deferens which contains soley κ- receptors. It is concluded that leumorphin and rimorphin have equipotent opioid activity and act at the κ-receptor, like other opioid peptides derived from preproenkephalin B.

Rimorphin (dynorphin B) exists together with α-neo-endorphin and dynorphin (dynorphin A) in human hypothalamus

Rimorphin (dynorphin B) has been demonstrated to exist together with alpha-neo-endorphin and dynorphin(1-17) (dynorphin A) in the human hypothalamus. The content of rimorphin was comparable to that of alpha-neo-endorphin and somewhat higher than that of dynorphin. This result is quite similar to the recent observations in bovine, porcine and rat neural tissues, suggesting that rimorphin is derived from preproenkephal in B together with alpha-neo-endorphin and dynorphin in man.

Met-enkephalin-Arg6-Gly7-Leu8 exists together with Met-enkephalin-Arg6-Phe7, Met-enkephalin and Leu-enkephalin in human stomach.

Studies on the nucleotide sequence of cloned DNA complementary to mRNA for preproenkephalin A from adrenal medulla and human pheochromocytoma have revealed that this precursor contains 4 copies of methionine-enkephalin(Met-Enk) and one copy each of leu-enkephalin (Leu-Enk), methionine-enkephalin-Arg6-Gly7-Leu8(Met-Enk-Arg6-Gly7-Leu8) and methionine-enkephalin-Arg6-Phe7(Met-Enk-Arg6-Phe7). We have demonstrated the existence of Met-Enk-Arg6-Gly7-Leu8 together with Met-Enk, Leu-Enk and Met-Enk-Arg6-Phe7 in human gastric antrum, using high performance liquid chromatography(HPLC) coupled with radioimmunoassays for these opioid peptides. The ratio of molar concentrations of these peptides in human gastric antrum is almost equal to the ratio of these peptides contained in preproenkephalin A. Furthermore, gel filtration studies on Sephadex G-50 showed that most of immunoreactivities of these peptides were eluted at the elution position of each synthetic peptide without any detectable immunoreactivities at high molecular weight positions. In addition, most of immunoreactivities of these four opioid peptides were detected in the muscular layer of the gastric antrum. These results indicate the presence of Met-Enk-Arg6-Gly7-Leu8 together with Met-Enk, Leu-Enk, and Met-Enk-Arg6-Phe7 in human gastric antrum and further suggest that these opioid peptides are derived from the same precursor as preproenkephalin A in the adrenal medulla and the processing of preproenkephalin A is almost completed in the human stomach.

Methionine-enkephalin, leucine-enkephalin, methionine-enkephalin-Arg6-Phe7 and methionine-enkephalin-Arg6-Gly7-Leu8 in human pheochromocytoma

Methionine-enkephalin(met-enkephalin)-, leucine-enkephalin(leu-enkephalin)-, methionine-enkephalin-Arg6-Phe7(met-enkephalin-Arg-Phe)- and methionine-enkephalin-Arg6-Gly7-Leu8(met-enkephalin-Arg-Gly-Leu)-like immunoreactivities(-LI) were studied in 16 pheochromocytomas by radioimmunoassays (RIAs) for these four opioid peptides. Met-enkephalin-Arg-Phe-LI and met-enkephalin-Arg-Gly-Leu-LI existed together with met-enkephalin-LI and leu-enkephalin-LI in 16 pheochromocytomas. Significant positive correlations were observed among contents of these four opioid peptides in 16 pheochromocytomas. The concentrations of these four opioid peptides in epinephrine producing pheochromocytomas were much higher than those in norepinephrine producing tumors. HPLC and gel exclusion chromatography followed by the RIAs showed the presence of met-enkephalin, leu-enkephalin, met-enkephalin-Arg-Phe and met-enkephalin-Arg-Gly-Leu together with their high molecular weight forms. These results indicate the co-existence of met-enkephalin, leu-enkephalin, met-enkephalin-Arg-Phe, met-enkephalin-Arg-Gly-Leu and their high molecular weight forms derived from preproenkephalin A in human pheochromocytomas and suggest the association of preproenkephalin A synthesis with epinephrine production in human pheochromocytomas.