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Biomedical subjects

K Shiomi

Publications and source records attributed to K Shiomi.

At least 73 records · Page 4Linked to original sources
PubMed1996

A polypeptide toxin in the sea anemone Actinia equina homologous with other sea anemone sodium channel toxins: isolation and amino acid sequence.

The sea anemone (Actinia equina) was newly established to contain a polypeptide toxin (named Ae I) having lethal activity to crabs, besides the well-known cytolytic toxins (equinatoxins) of proteinic nature. Ae I, with a minimum lethal dose against crabs of 25 micrograms/kg, was easily isolated by gel filtration on Sephadex G-50 and reverse-phase HPLC on Nucleosil 300-7C18. Its amino acid composition is characterized by the abundance of Gly, the absence of Ala and the presence of Met. The complete amino acid sequence of Ae I was determined. Ae I has high sequence homology with type 1 sea anemone neurotoxins. Interestingly, the polypeptide chain of Ae I comprises 54 amino acid residues, being 5-8 residues longer than the known type 1 toxins having 46-49 residues.

Amino Acid Sequence↗
PubMed1996

Cine-magnetic resonance imaging evaluation of communication between middle cranial fossa arachnoid cysts and cisterns.

Cine-magnetic resonance (MR) imaging examinations were performed in 10 patients with middle cranial fossa arachnoid cysts to evaluate communication between the cysts and the normal cerebrospinal fluid (CSF) space. Eight of 10 patients were evaluated by time of flight cine-MR imaging, and two by phase contrast cine-MR imaging. Two patients underwent membranectomy of the cysts, and were evaluated both pre- and postoperatively. Computed tomography cisternography was used to confirm communication between the cysts and the surrounding cisterns. Pulsatile fluid motion within the cysts was present in all patients. However, marked fluid motion and jet flow between the cysts and the surrounding cisterns were only observed in communicating cysts. In the two patients who underwent membranectomy, postoperative examination found greater fluid motion and jet flow not previously present. Cine-MR imaging demonstration of marked pulsatile fluid motion accompanied by jet flow suggests that a cyst communicates with the normal CSF space.

Adult↗
PubMed1996

Andrastins A-C, new protein farnesyltransferase inhibitors produced by Penicillium sp. FO-3929. I. Producing strain, fermentation, isolation, and biological activities.

New protein farnesyltransferase inhibitors, andrastins A-C, have been discovered in the cultured broth of Penicillium sp. FO-3929. Andrastins extracted from broth supernatant were purified by silica gel chromatography, ODS chromatography and HPLC. The IC50 of andrastins A, B, and C against protein farnesyltransferase were 24.9, 47.1, and 13.3 microM, respectively.

Alkyl and Aryl Transferases↗
PubMed1996

Andrastins A-C, new protein farnesyltransferase inhibitors produced by Penicillium sp. FO-3929. II. Structure elucidation and biosynthesis.

The structures of new protein farnesyltransferase inhibitors, andrastins A-C, were elucidated. The cyclopentane ring of andrastins exhibited keto-enol tautomerism, which made the structure hard to elucidate. Therefore, the structure of andrastin A was elucidated by INADEQUATE and 13C-13C couplings using 13C-labeled andrastin A. The absolute configuration of the p-bromobenzoyl derivative of andrastin A was elucidated by X-ray crystallographic analysis and its skeleton was shown to be ent-5 alpha,14 beta-androstane. The biosynthesis of andrastin A was also studied by the incorporation of 13C-labeled acetates. Though the andrastins had a common androstane skeleton, they were biosynthesized from a sesquiterpene and a tetraketide.

Alkyl and Aryl Transferases↗
PubMed1996

Herquline B, a new platelet aggregation inhibitor produced by Penicillium herquei Fg-372.

A new herquline analog, herquline B was isolated from the culture broth of Penicillium herquei Fg372. Herquline B contains one piperazine and two cyclohexenones. The pyrrolidine ring of herquline A was cleaved to yield herquline B. The IC50 value of herquline B against platelet aggregation induced by ADP and platelet-activating factor were 1.6 and 5.0 microM, respectively.

Alkaloids↗
PubMed1996

Arisugacins A and B, novel and selective acetylcholinesterase inhibitors from Penicillium sp. FO-4259. I. Screening, taxonomy, fermentation, isolation and biological activity.

An in vitro screening method for selective acetylcholinesterase (AChE) inhibitors was established. Inhibitory activity of AChE and butyrylcholinesterase (BuChE) was measured and the culture broths of microorganisms that showed selective inhibition against AChE were characterized. By using this method, a strain producing the novel and selective inhibitors of AChE, arisugacins A and B, was picked out among over seven thousand microorganisms tested. Arisugacins were obtained as white powders from the culture broth together with three known compounds, territrems B and C and cyclopenin that also showed selective inhibition against AChE. Arisugacins and territrems are members of the meroterpenoid compounds. They showed potent inhibitory activities against AChE with IC50 values in range of 1.0 approximately 25.8 nM. Furthermore, they showed greater than 2,000-fold more potent inhibition against AChE than BuChE.

Cholinesterase Inhibitors↗
PubMed1996

Arisugacins A and B, novel and selective acetylcholinesterase inhibitors from Penicillium sp. FO-4259. II. Structure elucidation.

The structures of new acetylcholinesterase inhibitors, arisugacins A and B, were elucidated by NMR study. Arisugacins have a (4aR,6aR,12aS,12bS)-4a,6,6a,12,12a, 12b-hexahydro-4a,12a-dihydroxy-4,4,6a,12b-tetramethyl-4H,11H -naphtho[2,1-b] pyrano[3,4-e]pyran-1,11(5H)-dione moiety in common and 3,4-dimethoxyphenyl or 4-methoxyphenyl residues are attached to C-9 of the moiety.

Cholinesterase Inhibitors↗
PubMed1996

Kurasoins A and B, new protein farnesyltransferase inhibitors produced by Paecilomyces sp. FO-3684. II. Structure elucidation and total synthesis.

The structures of new protein farnesyltransferase inhibitors, kurasoins A and B, were elucidated by NMR study. Kurasoins A and B are acyloin compounds having in common a 3-hydroxy-1-phenyl-2-butanone moiety, to which p-hydroxyphenyl and 3-indolyl moieties respectively, are connected at C-4. The structures were confirmed by total synthesis.

Alkyl and Aryl Transferases↗
PubMed1995

Isolation and sequence determination of 6- and 8-kDa precursors of human neutrophil peptides from bone marrow, plasma and peripheral blood neutrophils.

Human neutrophil peptides (HNPs) are 29 to 30 amino acid antimicrobial peptides localized in the azulophil granules in neutrophils. We isolated endogenous molecular forms of HNPs from normal human bone marrow, plasma and peripheral blood neutrophils and determined their primary structures to investigate their post-translational processing. HNPs initially are synthesized as 94 amino acid precursors that produce 75 amino acid pro-HNPs by cleavage of a signal peptide. The majority of pro-HNPs was processed to 56 amino acid intermediates by preaspartate proteolytic cleavage in the bone marrow then to mature HNPs in peripheral blood neutrophils. Part of pro-HNPs was released into the plasma, in which they constituted 25-30% of the HNP molecules. Pro-HNPs and their mRNAs were detected both in peripheral blood neutrophils and bone marrow. Identification of the post-translational processing products of HNPs should provide a better understanding of the biosynthesis of the peptides.

Adult↗
PubMed1995

Detection of a proteinaceous toxin in the brackishwater clam (Corbicula japonica).

Water extracts from the brackishwater clam (Corbicula japonica) were found to be lethal to mice upon i.v. injection. Muscular tissues (foot muscle, adductor muscle, mantle muscle, mantle and siphon) were all toxic while gill and viscera (mid-gut gland, testis and ovary) were nontoxic; the highest toxicity was observed with foot muscle. The toxin was judged to be a thermolabile, basic protein with a mol. wt. of about 13,000.

Animals↗
PubMed1995

[A study of defensins in bronchoalveolar lavage fluid in patients with diffuse panbronchiolitis].

We estimated defensins, antimicrobial and cytotoxic peptides localized in azurophil granules of neutrophils, in bronchoalveolar lavage fluid (BALF) in patients with diffuse panbronchiolitis (DPB). BALF from DPB patients contained a higher concentration of defensins than those from patients with idiopathic pulmonary fibrosis and healthy volunteers. A significant correlation was observed between the concentration of defensins and the number of neutrophils, the concentration of interleukin-8 or neutrophil elastase in BALF of DPB patients. An immunohistochemical defensins in neutrophils and mucinous exudates in the airways and in the surface of bronchiolar epithelial cells. After treatment with macrolide antibiotics, significant reductions in the concentrations of defensins, IL-8 and neutrophil numbers in BALF of DPB patients were observed. These findings suggest that the lung injury in DPB could be caused by defensins released by neutrophils accumulated in the airways.

Adult↗
PubMed1995

Phenopyrrozin, a new radical scavenger produced by Penicillium sp. FO-2047.

A new radical scavenger, named phenopyrrozin, was isolated from the culture broth of Penicillium sp. FO-2047. Phenopyrrozin was purified from whole broth solvent extraction, silica gel chromatography, and HPLC. The structure of phenopyrrozin was elucidated as 5,6,7,7a-tetrahydro-2-hydroxy-1-phenyl-3H-pyrrolizin-3-one. The IC50 of phenopyrrozin against lipid peroxidation induced by Cr2K2O7 was 73 micrograms/ml. Phenopyrrozin also reduced chromosomal aberrations induced by paraquat.

Animals↗