Fatal familial insomnia with an unusual prion protein deposition pattern: an autopsy report with an experimental transmission study.

We recently performed a post-mortem examination on a Japanese patient who had a prion protein gene mutation responsible for fatal familial insomnia (FFI). The patient initially developed cerebellar ataxia, but finally demonstrated insomnia, hyperkinetic delirium, autonomic signs and myoclonus in the late stage of the illness. Histological examination revealed marked neuronal loss in the thalamus and inferior olivary nucleus; however, prion protein (PrP) deposition was not proved in these lesions by immunohistochemistry. Instead, PrP deposition and spongiform change were both conspicuous within the cerebral cortex, whereas particular PrP deposition was also observed within the cerebellar cortex. The abnormal protease-resistant PrP (PrP(res)) molecules in the cerebral cortex of this case revealed PrP(res) type 2 pattern and were compatible with those of FFI cases, but the transmission study demonstrated that a pathogen in this case was different from that in a case with classical FFI. By inoculation with homogenate made from the cerebral cortex, the disease was transmitted to mice, and neuropathological features that were distinguishable from those previously reported were noted. These findings indicate the possibility that a discrete pathogen was involved in the disease in this case. We suggest that not only the genotype of the PrP gene and some other as yet unknown genetic factors, but also the variation in pathogen strains might be responsible for the varying clinical and pathological features of this disease.

Cladospolide D, a new 12-membered macrolide antibiotic produced by Cladosporium sp. FT-0012.

A new antibiotic termed cladospolide D was isolated along with the known cladospolides A and B from the fermentation broth of Cladosporium sp. FT-0012 by solvent extraction, ODS column chromatography and preparative HPLC. The structure of cladospolide D was deduced to be (E)-2-dodecen-5-hydroxy-11-olide-4-one. Cladospolide D showed antifungal activity against Pyricularia oryzae and Mucor racemosus.

Pathophysiology of early coronary angioplasty with stenting on non-Q-wave vs Q-wave myocardial infarction.

This study was undertaken to evaluate the pathophysiologic and clinical effects of the early application of percutaneous transluminal coronary angioplasty (PTCA) supported by stenting on non-Q-wave myocardial infarction (MI). Ninety-four patients with non-Q-wave MI and 316 patients with Q-wave MI were studied. Early PTCA with provisional stenting (40%) was performed in all of them. A history of MI (22% vs 12%, p=0.018), preinfarction angina < or = 24 hours before the onset of MI (60% vs 33%, p<0.001), and patent infarct-related vessels (83% vs 21%, p<0.001) were significantly more common in non-Q-wave MI than in Q-wave MI. As predictors of the occurrence of non-Q-wave MI, preinfarction angina (p=0.001) and previous MI (p=0.021) were significant variables. Clinical outcomes showed more improvement in in-hospital death (0.0% vs 5.0%, p=0.036) and long-term event-free curves for death and/or MI (p=0.035) in non-Q-wave MI than Q-wave MI when patients with previous MI were excluded. There was no significant difference in clinical outcome between the two groups when patients with previous MI were included. The high incidence of patent infarct-related vessels and preinfarction angina as well as the improved outcome obtained by early PTCA/stenting suggest instability of coronary occlusion and culprit coronary lesions in non-Q-wave MI. In conclusion, non-Q-wave MI constitutes a characteristic feature of MI induced by unstable coronary lesions, and early interventional therapies are presumed to result in improved outcomes by stabilizing the unstable culprit lesions.

Deacetylravidomycin M, a new inhibitor of IL-4 signal transduction, produced by Streptomyces sp. WK-6326. I. Taxonomy, fermentation, isolation and biological activities.

Streptomyces sp. WK-6326, a soil isolate, was found to produce an inhibitor of interleukin (IL)-4 signal transduction. Two structurally related compounds, a novel one designated deacetylravidomycin M and the known deacetylravidomycin, were isolated from the culture broth by solvent extraction, silica gel column chromatography and HPLC. Deacetylravidomycin M inhibited IL-4-induced CD23 expression in U937 cells without any cytotoxic effect, whereas deacetylravidomycin showed no inhibitory activity.

Deacetylravidomycin M, a new inhibitor of IL-4 signal transduction, produced by Streptomyces sp. WK-6326. II. Structure elucidation.

The structure of deacetylravidomycin M, an inhibitor of interleukin-4 signal transduction, was elucidated to be 6H-benzo[d]naphtho[1,2-b]pyran-6-one, 4-[3,6-dideoxy-3-(dimethylamino)-alpha-altropyranosyl]-1-hydroxy-10,12-dimethoxy-8-methyl- by spectroscopic studies including NMR measurements.

Membrane relocation but not tight binding of human immunodeficiency virus type 1 Gag particles myristoylated in Escherichia coli.

Expression of human immunodeficiency virus Gag protein and the N-terminal matrix (MA) domain in Escherichia coli yielded spherical structures in the cytoplasm. When human N-myristoyltransferase was coexpressed, both Gag and MA were fully myristoylated and spherical structures were relocated in close proximity to the cytoplasmic membrane. However, neither myristoylated Gag nor MA exhibited tight binding to E. coli membrane, suggesting that myristoylation in E. coli did not confer membrane affinity on Gag despite the relocation. Our data also suggest that the morphogenetic pathway of Gag particles in prokaryotic cells differs from that in eukaryotic cells despite biochemical similarities of in the form of Gag expressed.

Instability of coronary lesions in unstable angina assessed by C-reactive protein values following coronary interventions.

The instability of coronary lesions was evaluated in 30 patients with stable angina and 60 patients with unstable angina. The grade of instability of coronary lesions as predicted by the increases in C-reactive protein induced by PTCA and/or stenting was closely correlated with Braunwald's classification of unstable angina.

Chlorogentisylquinone, a new neutral sphingomyelinase inhibitor, produced by a marine fungus.

Chlorogentisylquinone, a new inhibitor of neutral sphingomyelinase activity, was purified from the culture broth of a fungal strain FOM-8108 isolated from a marine environment by solvent extraction, silica gel chromatography and Sephadex LH-20 chromatography. Its chemical structure was elucidated by spectroscopic studies including 1H, 13C, DEPT, HMQC and HMBC NMR experiments. Chlorogentisylquinone inhibited neutral sphingomyelinase activity of rat brain membranes with an IC50 value of 1.2 microM.

Lactacystin, a proteasome inhibitor: discovery and its application in cell biology.

Lactacystin was isolated from the culture broth of Streptomyces lactacystinaeus as an inducer of neurite outgrowth in Neuro 2a cells (a mouse neuroblastoma cell line). The structure of lactacystin, elucidated by spectroscopic analyses including NMR and X-ray crystallography, possesses a non-peptide skeleton consisting of two alpha-amino acids, N-acetylcysteine and a novel pyroglutamic acid derivative. Extensive studies on its mode of action revealed that lactacystin inhibits proteasome, a high molecular weight, multicatalytic protease complex responsible for most non-lysosomal intracellular protein degradation, by binding covalently to the active site N-terminal threonine residue in certain beta-subunits of proteasome. Lactacystin and its cell-permeable beta-lactone form, later designated omuralide by Prof. E. J. Corey, which are structurally different from the synthetic peptide aldehydes, are much more specific proteasome inhibitors. The demonstration of this lactacystin action gave decisive understanding of proteasome as a novel threonine protease. Since then, specific inhibitors have allowed researchers to simplify studies of proteasome functions, leading to many unexpected findings about the importance of the ubiquitin-proteasome pathway in various cellular processes, such as cell cycle, apoptosis, antigen presentation and the degradation of regulatory or membrane proteins. In this review, potential biomedical applications are also described.

Changing features of stent-supported primary angioplasty for acute myocardial infarction: impact of new flexible stents.

Although primary coronary stenting for acute myocardial infarction (AMI) has been reported to be superior to primary percutaneous transluminal coronary angioplasty (PTCA), cautious entry criteria resulted in low-risk populations in these studies. This study was undertaken to delineate factors that have not been clarified by randomized multicenter studies and is based on the results of stent-supported primary PTCA for AMI using second-generation new stents. In 1994-1998, 355 AMI patients were studied < 12 hours after onset. The patients were divided into two groups: group 1 (n = 175) was treated in 1994-1996 and group 2 (n = 180) in 1997-1998. In group 1, bailout stenting was performed in 17% of the patients for acute coronary dissection or occlusion with use of Palmaz-Schatz stents. In group 2, stenting was performed in 62% of the patients for suboptimal coronary dilatation and dissection or occlusion, using second-generation flexible stents with excellent radial force in 65% of them (Multilink, GFX, and NIR). In-hospital death and reinfarction occurred in 7.4% of group 1 and 5.0% of group 2 patients, and follow-up death and reinfarction in 4.0% of group 1 and 0.6% of group 2 patients (p < 0.05). In-hospital target vessel revascularization was performed in 8.6% of group 1 and 3.3% of group 2 patients (p < 0.05), and follow-up target vessel revascularization in 21.1% of group 1 and 11.7% of group 2 patients (p<0.02). Thus, the total adverse clinical event rates were 36.0% in group 1 and 18.3% in group 2 (p < 0.01). In conclusion, outcomes of stent-supported coronary intervention in nonselected AMI patients have improved along with the availability of second-generation flexible stents, approaching the outcomes of primary stent studies in highly selected patients.

Prognostic value of C-reactive protein levels within six hours after the onset of acute myocardial infarction.

BACKGROUND: Inflammation is an important feature of atherosclerotic lesions, and the vulnerability of coronary lesions in acute myocardial infarction (AMI) at the time of onset may be related to blood levels of C-reactive protein (CRP) on admission, before CRP levels are affected by myocardial damage. METHODS: A total of 234 patients with AMI in whom plasma CRP was measured within 6 hours after onset were studied. They were divided into 2 groups: group 1 (n = 49) with elevated CRP (>/=0.3 mg/dL) on admission within 6 hours after onset and group 2 (n = 185) with normal CRP (<0.3 mg/dL) within 6 hours after onset. All were treated by primary percutaneous transluminal coronary angioplasty with provisional stenting. RESULTS: There were no significant differences in baseline characteristics between the 2 groups. In-hospital adverse coronary events, including coronary reocclusion, reinfarction, target vessel revascularization, and death, were significantly more frequent in group 1 (22.4%) than in group 2 (4.3%, P <.005), and bailout stenting was performed significantly more frequently in group 1 (61. 2%) than in group 2 (37.8%, P <.005). In contrast, there were no significant differences between the 2 groups in parameters that represent myocardial damage, including peak creatine kinase and left ventricular ejection fraction. CONCLUSION: CRP levels within 6 hours after the onset of AMI reflect the vulnerability of culprit coronary lesions and predict adverse coronary events after primary PTCA/stenting.

Synthetic conversion of ACAT inhibitor to acetylcholinesterase inhibitor.

Natural product acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor pyripyropene A was synthetically converted to acetylcholinesterase (AChE) inhibitor via heterolitic cleavage of the 2-pyrone ring, followed by gamma-acylation/cyclization with several aroyl chlorides. The 4-pyridyl analogue selectively showed AChE inhibitory activity (IC50 7.9 microM) and no ACAT inhibitory activity IC50 = >1000 microM.

Effect of fungal metabolites cytochalasans on lipid droplet formation in mouse macrophages.

Effects of seven cytochalasans including cytochalasins B, D and E and novel phenochalasins A and B were tested on cytosolic lipid droplet formation and neutral lipid synthesis in mouse peritoneal macrophages. Phenochalasin A inhibited lipid droplet formation in a dose-dependent manner at least up to 20 microM without any morphological changes in macrophages. Cytochalasins D and E also inhibited lipid droplet formation only in a narrow range of concentrations, around 1 and 0.1 microM, respectively. At higher concentrations they gave morphological changes in macrophages. The other four cytochalasans only showed severe morphological changes in macrophages. Phenochalasin A and cytochalasins D and E inhibited cholesteryl ester (CE) synthesis specifically with IC50 values of 0.61, 2.4 and 0.20 microM, respectively, while the other cytochalasans inhibited both CE and triacylglycerol syntheses. Thus, among the cytochalasans tested, phenochalasin A showed very specific inhibition of CE synthesis and gave the lowest morphological changes in macrophages, resulting in the best inhibitor of lipid droplet formation in macrophages.

Reversal of multidrug resistance by 7-O-benzoylpyripyropene A in multidrug-resistant tumor cells.

7-O-Benzoylpyripyropene A (7-O-BzP), a semi-synthetic analog of pyripyropene, was investigated for its reversing effect on multidrug-resistant (MDR) tumor cells. 7-O-BzP (6.25 microg/ml) completely reversed resistance against vincristine and adriamycin in vincristine-resistant KB cells (VJ-300) and adriamycin-resistant P388 cells (P388/ADR), respectively. 7-O-BzP alone had no effect on the growth of drug sensitive and drug-resistant cells. 7-O-BzP (6.25 microg/ml) significantly enhanced accumulation of [3H]vincristine in VJ-300 cells and completely inhibited the binding of [3H]azidopine to the P-glycoprotein in VJ-300 cells and P388/ADR cells. The result suggests that 7-O-BzP effectively reverses P-glycoprotein-related MDR by interacting directly with P-glycoprotein in drug resistant VJ-300 and P388/ADR cells.

Phenochalasins, inhibitors of lipid droplet formation in mouse macrophages, produced by Phomopsis sp. FT-0211.

Phomopsis sp. FT-0211, a soil isolate, was found to produce inhibitors of lipid droplet formation in mouse peritoneal macrophages. Structurally related new compounds designated phenochalasins A and B were isolated from the fermentation broth of the producing strain by solvent extraction, ODS column chromatography and preparative HPLC. Phenochalasin A caused a dose-dependent reduction in the number and size of lipid droplets in macrophages without any cytotoxic effect at least up to 20 microm. On the other hand, phenochalasin B showed inhibition of lipid droplet formation with a severe cytotoxic effect on macrophages.

Structure elucidation of fungal phenochalasins, novel inhibitors of lipid droplet formation in mouse macrophages.

The structures of phenochalasins A and B were elucidated by spectroscopic studies including various NMR measurements. Phenochalasins A and B have the cytochalasan skeleton of the 21,23-dioxa, 17,22-dione moiety containing unique phenyl and O-methyl phenyl residues at the C-10 position, respectively.

Roselipins, inhibitors of diacylglycerol acyltransferase, produced by Gliocladium roseum KF-1040.

Gliocladium roseum KF-1040, a marine isolate, was found to produce a series of new inhibitors of diacylglycerol acyltransferase (DGAT). Four active compounds, designated roselipins 1A, 1B, 2A and 2B, were isolated from the fermentation broth of the producing strain by solvent extraction, ODS column chromatography and preparative HPLC. The highest production of roselipins was observed when cultured in the medium containing natural sea water. Roselipins inhibit DGAT activity with IC50 values of 15 approximately 22 microM in an enzyme assay system using rat liver microsomes.

Differential inhibition of HMG-CoA synthase and pancreatic lipase by the specific chiral isomers of beta-lactone DU-6622.

A synthetic beta-lactone trans-DU-6622 (3-hydroxy-2-(hydroxymethyl)-5-[7-(methylcarbonyl)-naphthalen++ +-1-yl]pentanoic acid 1,3-lactone, a mixture of (2R, 3R)- and (2S, 3S)-beta-lactones) was found to inhibit HMG-CoA synthase (IC(50): 0. 15 microM) and pancreatic lipase (IC(50): 120 microM). The effects of the optically pure DU-6622 isomers on the two enzymes were compared. The (2R, 3R)-isomer was shown to be a highly specific inhibitor of HMG-CoA synthase (IC(50): 0.098 microM vs 270 microM for pancreatic lipase), while the (2S, 3S)-isomer markedly increased the specificity of lipase inhibition (IC(50): 27 microM vs 31 microM for HMG-CoA synthase). Furthermore, the (2R, 3R)-isomer strongly inhibited the binding of [(14)C]hymeglusin to HMG-CoA synthase, indicating that the isomer was bound to the same site of the synthase as hymeglusin. The (2R, 3R)-beta-lactone is responsible for the specific inhibition of HMG-CoA synthase, while the (2S, 3S)-beta-lactone is responsible for the inhibition of pancreatic lipase.

The effect of spatial frequency on chromatic and achromatic steady-state visual evoked potentials.

OBJECTIVE: Little is known about the physiological properties of the major components of steady-state visual evoked potentials (VEPs). Based on the hypothesis that isoluminant color and high contrast pattern differentially activate the parvo- and magnocellular pathways, we studied difference in spatial frequency function between chromatic and achromatic VEPs to sinusoidal gratings. METHODS: Steady-state VEPs to isoluminant chromatic (red-green) and high contrast (90%) achromatic (black-white) sinusoidal gratings with nine spatial frequencies (0.5 to 8.0 cycles/degrees (cpd)) at 4 Hz (8 reversals/s) were recorded in 13 normal subjects. VEPs were Fourier analyzed to obtain phase and amplitude of the second (2F) and fourth (4F) harmonic responses. RESULTS: The 2F amplitude of chromatic VEPs decreased above 4.0 cpd in a low-pass function while that of achromatic VEPs showed a band-pass function with a peak at 4.0 cpd. The 4F amplitude of chromatic VEPs was not affected significantly by spatial frequency whereas that of achromatic VEPs exhibited a high-pass function. The phases of 2F and 4F showed a non-monotonic function of spatial frequency in both chromatic and achromatic stimuli with peaks at middle spatial frequencies. CONCLUSION: Chromatic and achromatic visual stimuli differently affected 2F and 4F components, which thus suggests that 2F and 4F components are generated from different neuronal subgroups largely in the parvocellular pathway.