During the search for polyketide synthase (PKS) in the genome of
Streptomyces halstedii HC34, we found clustered new genes which appeared to encode typical Type 1 PKSs beyond the cluster harboring ...the genes for the biosynthesis of antitumor antibiotic vicenistatin. The deduced domain configuration of these putative PKS genes allowed to predict a corresponding partial structure of polyketide, which was in turn materialized by isolation of new polyketide macrolactone halstoctacosanolides A and B from the fermentation broth of
S.
halstedii HC34. The structures of these metabolites were determined by spectroscopic means to have a novel 28-membered macrolactone structure. The partial structure deduced from the genetic data was completely compatible to the structures of halstoctacosanolides A and B. This success clearly demonstrates the present new approach of genome-inspired search for new antibiotics promising. Halstoctacosanolides A and B showed moderate antimicrobial activity against several microorganisms.
Genetically predicted polyketides were materialized by isolation of two new compounds, halstoctacosanolides A and B, from the fermentation broth of
Streptomyces halstedii HC34, and the structures were determined to have a novel 28-membered macrolactone.
The transformation of state of silica particles and inorganic salts during the calcination of solid mixtures of silica/potassium halide (KX) was investigated at temperatures below the melting point ...of either material. The (SiO2-Na2O)/KX solid was examined at high temperatures using thermal analysis, XRD and SEM. The data suggest the crystalline inorganic salt component transformed into an amorphous state about 100-200 C lower than its melting point, while the silica particle component coagulated, spontaneously separating the two components ("coagulation/phase separation"). Upon cooling, the inorganic salt was dispersed in water, resulting in porous silica with a narrow pore size distribution. However, at calcination temperatures above 800 C, formation of silica crystal existed as a separate domain without creating porous structures. 22 refs.
2′,5′-isoDNA mimic chiral peptide nucleic acid (isoPNA) monomers derived from
d- and
l-aspartic acids were synthesized. These novel monomers were incorporated in aminoethylglycine peptide nucleic ...acid (aegPNA) thymine dodecamers, and the hybridization properties to RNA and DNA were demonstrated by UV thermal denaturation.
The synthesis and hybridization properties of isogaPNA is reported.
Up to now, 10 planetary nebulae have been regarded as halo planetary nebulae (halo PNe). We obtained low‐ and moderate‐dispersion spectra of the spatially resolved halo planetary nebula H4‐1 in the ...wavelength region of 3700–6800 Å with the Cassegrain Spectrograph of the 74 inch telescope. At moderate dispersions, we were able to observe Oiii λλ4959, 5007 and Hα of H4‐1 at several position angles (P.A.). We assumed that the widths of these emission‐line profiles were due to Doppler broadening and that these emission lines were composed of several Gaussian components. Multiple Gaussian deconvolution analysis of such emission lines indicated H4‐1 has broad wing components (∼600 km s−1) at P.A. 135° and 180°. We think H4‐1 has a “bipolar flow” between P.A. 135° and 180°. From low‐dispersion spectra, we confirm that H4‐1 is a metal‐poor PN. In spite of the lack of spatially resolved images at present, we believe that H4‐1 has a bipolar flow and that its axis is almost parallel to the line of sight, with a small inclination angle.
Abstract Objectives This study sought to evaluate the diagnostic performance of optical frequency domain imaging (OFDI) for recognition of coronary plaque morphologies and to assess additive values ...of integrated backscatter intravascular ultrasound (IB-IVUS) in detection of vulnerable plaque. Background Precise diagnosis of coronary lesions susceptible to plaque rupture and thrombosis may serve to stratify the risk of future coronary events and to make decisions for appropriate treatment of choice. Methods Twenty-seven coronary arteries from 14 human autopsy hearts were interrogated ex vivo by OFDI and IB-IVUS. Imaged segments were sectioned at 3 mm intervals where a total of 360 pairs of cross-sectional images coregistered to histology were investigated. Results Overall, OFDI could depict various plaque components and structures such as fibrous tissue, sheet and nodular calcification, lipid, cholesterol crystals, and healed plaque rupture. OFDI could detect 14 of 18 thin-cap fibroatheroma (TCFA), however, the diagnostic accuracy was not high (positive predictive value PPV = 60.9%, κ = 0.664; area under the curve AUC: 0.88) mainly because of signal interference from macrophages. Further, we defined IB-IVUS–derived TCFA by recursive partitioning analysis as: 1) cross-sectional % lipid area >65.1%; 2) % lipid area >32.3 but <65.1% with plaque area >10.5 mm2 , where TCFA detection by IB-IVUS alone was marginal (PPV = 50.0%, κ = 0.545; AUC: 0.82). However, when IB-IVUS was combined with OFDI, all pseudo OFDI-derived TCFA (non-TCFA on histology) were excluded. Accordingly, PPV of TCFAs diagnosed by both OFDI and IB-IVUS was improved to 100.0% (κ = 0.704; AUC: 0.93). Conclusions OFDI could recognize detailed morphologies of human coronary plaque. However, diagnostic accuracy of both OFDI alone and IB-IVUS alone to identify TCFA is limited. Combination of IB-IVUS with OFDI improved the accuracy for TCFA detection, suggesting hybrid imaging or further development of novel devices will be required to identify coronary lesions responsible for future events.
Nightshift work, which is known to cause mental stress and disrupt normal biological diurnal rhythms, leads to endothelial dysfunction resulting in increased risk for cardiovascular disease. This ...study aimed to investigate the acute effect of night-shift work on coronary microcirculation through assessment of coronary flow reserve (CFR) by transthoracic Doppler echocardiography. This study consisted of 36 women nurses who underwent transthoracic Doppler echocardiographic examinations after working a nightshift and on a regular day without previous nightshift work. Flow velocity in the distal portion of the left anterior descending coronary artery was measured at baseline and during adenosine infusion. CFR was calculated as the ratio of hyperemic to basal mean diastolic flow velocity. CFR after night work was lower than that on a regular workday (3.8 ± 0.6 vs 4.1 ± 0.6, p <0.001). Degree of decreases in CFR after night work was correlated to Framingham risk score (r = 0.35, p = 0.036). In conclusion, this study demonstrated that coronary microcirculation was impaired after nightshift work in women nurses.
Background It remains unclear whether treatment of dyslipidemia with 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitors (statins) reduces the risk of developing hypertension. Objective In ...this post-hoc analysis of the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese Study, a large-scale primary prevention trial with pravastatin, we examined the preventive effect of pravastatin on the future development of hypertension in patients with hypercholesterolemia. Methods Of the overall Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese Study population, 3397 nonhypertensive patients at baseline were enrolled in this study. The patients were randomly assigned to either the diet alone group (n = 1722) or the diet plus pravastatin group (n = 1675) and then were followed-up for a median of 36 months to determine new-onset hypertension. Results During the follow-up period, 1595 patients developed hypertension (49.1% in the diet alone group and 44.7% in the diet plus pravastatin group). After adjusting for multiple covariates, the diet plus pravastatin group showed a 10% reduction in the risk of developing hypertension (hazard ratio 0.90, 95% confidence interval 0.81–0.998), compared with the diet alone group. Subgroup analyses revealed that the preventive effect of pravastatin on the development of hypertension was pronounced in patients aged ≥60 years, men, those with chronic kidney disease or diabetes mellitus and those without obesity. Conclusions Pravastatin reduced the risk of developing hypertension in Japanese patients with hypercholesterolemia. The risk reduction of cardiovascular disease with statins could be partly explained by their preventive effect on the development of hypertension.
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