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1.
Among the apoA-I-containing lipoproteins isolated by selected-affinity immunosorption from human serum and plasma, we have identified a subpopulation which, unlike the bulk of high density lipoproteins, has pre-beta electrophoretic mobility. This pre-beta subpopulation can be observed directly in fresh plasma by immunoelectrophoresis. It contains phospholipid and free and esterified cholesterol, but protein constitutes 90% of its mass. Apolipoprotein A-I is the predominant apolipoprotein in this subpopulation; apolipoprotein A-II and the B lipoproteins are not detected. The protein moiety of this subpopulation exhibits markedly lower helicity than that of high density lipoproteins isolated by ultracentrifugation. 相似文献
2.
Research has revealed that most chlorophyllous explants/plants in vitro have the ability to grow photoautotrophically (without
sugar in the culture medium), and that the low or negative net photosynthetic rate of plants in vitro is not due to poor photosynthetic
ability, but to the low CO2 concentration in the air-tight culture vessel during the photoperiod. Moreover, numerous studies have been conducted on improving
the in vitro environment and investigating its effects on growth and development of cultures/plantlets on nearly 50 species
since the concept of photoautotrophic micropropagation was developed more than two decades ago. These studies indicate that
the photoautotrophic growth in vitro of many plant species can be significantly promoted by increasing the CO2 concentration and light intensity in the vessel, by decreasing the relative humidity in the vessel, and by using a fibrous
or porous supporting material with high air porosity instead of gelling agents such as agar. This paper reviews the development
and characteristics of photoautotrophic micropropagation systems and the effects of environmental conditions on the growth
and development of the plantlets. The commercial applications and the perspective of photoautotrophic micropropagation systems
are discussed. 相似文献
3.
Methods of cell biology and electrophysiology using dissociated primary cultured neurons allow in vitro study of molecular functions; however, analysis of intact neuronal circuitry is often preferable. To investigate exogenous genes, viral vectors are most commonly injected using a pipette that is inserted from the top of the cortex. Although there are few reports that describe the success rate of injection in detail, it is sometimes difficult to locate the pipette tip accurately within the CA1 pyramidal cell layer because the pyramidal layer is only 0.1 mm thick. In the present study, we have developed a system to inject viral vectors accurately into the mouse hippocampal CA1 pyramidal cell layer using a stereotaxic injection system with simultaneous electrophysiological monitoring of theta oscillation. The pipette tip was positioned reliably based on integrated values of the theta oscillation in the hippocampal CA1 pyramidal cell layer. This approach allows accurate injection of solutions and provides an efficient method of gene transfer using viral vectors into the hippocampus, which can be a useful tool for studies involving the molecular mechanisms of neuronal functions. 相似文献
4.
Molecular and Cellular Biochemistry - The aims of this study were to investigate the impact of caloric restriction (CR) on cardiac senescence in an animal model of diabetes and examine the signal... 相似文献
5.
Motoo Shibata Masaru Uyeda Yutaka Kido Keiko Shigemori Yoko Aziki Toyoki Hirakawa 《Bioscience, biotechnology, and biochemistry》2013,77(9):1767-1771
From the results of taxonomic studies, Streptomyces sp. strain No. KT–151 isolated from a soil sample collected in Kumamoto City, was identified as a strain belonging to Streptomyces luteogriseus Schmitz, Deak, Crook and Hooper 1964. A new antibiotic, produced by this strain, was isolated as a leaflet crystal by ion-exchange chromatography and found to be an amino acid with the molecular formula, C5H12N2O2, and named antibiotic KT–151 (refered to as KT–151 hereinafter). The antibiotic showed antimicrobial activity against various Gram-positive and Gram-negative bacteria in a chemically defined medium but it was antagonized by several amino acids such as valine, leucine, isoleucine and threonine. 相似文献
6.
7.
Spectroscopic properties of single-stranded DNA/schizophyllan ternary complexes (ss-DNA2s-SPG), induced by addition of either complementary or noncomplementary strands, have been investigated. The addition of the complementary strands to ss-DNA2s-SPG induced the quick release of the bound ss-DNA to the complementary strands (both DNA and RNA), whereas the ternary complex was unaffected upon addition of noncomplementary strands. Our experiments imply that SPG has complexation properties indispensable to the gene carriers. As far as we know, there is no report on exploitation of such nonviral gene carriers that can accomplish an intelligent release of the bound ss-DNA toward the complementary strands. We believe, therefore, that SPG, a natural and neutral polysaccharide, has a great potential to become a new ss-DNA carrier. 相似文献
8.
Chu C Jin Q Kunitake T Kato K Nabekura T Nakazato M Kangawa K Kannan H 《Regulatory peptides》2002,105(1):29-34
Neuromedin U (NMU) is a brain-gut peptide, which peripherally stimulates smooth muscle, increases of blood pressure, alters ion transport in the gut, controls local blood flow, and regulates adrenocortical function. Although intracerebroventricular (i.c.v.) administration of NMU is known to decrease food intake and body weight, little is known about its effect on other physiological functions. We examined the effects of i.c.v. administration of NMU on mean arterial pressure (MAP), heart rate (HR), and plasma norepinephrine in conscious rats. Neuromedin U (0.05 and 0.5 nmol) provoked an increase in MAP (93.8 +/- 0.5 to 123.5 +/- 1.7 and 94.7 +/- 0.8 to 132.7 +/- 3.0 mm Hg, respectively) and HR (334.9 +/- 6.0 to 494.1 +/- 6.9 and 346.3 +/- 3.3 to 475.1 +/- 8.9 beats/min, respectively). In contrast, plasma norepinephrine increased only with a high dose of neuromedin U. Intravenously administered NMU (0.5 nmol) elicited a small and short lasting increase in MAP, compared to that by i.c.v. NMU. These results indicate that central neuromedin U regulates sympathetic nervous system activity and affects cardiovascular function. 相似文献
9.
Yulan?Xiao Yee?Hin?Lok Toyoki?KozaiEmail author 《In vitro cellular & developmental biology. Plant》2003,39(2):186-192
Summary Explants of sugarcane, a C4 plant, were cultured in vitro for 18d on Floridalite (a solid cube consisting of vermiculite and cellulose fibers) used as supporting material with sugar-free
Murashige and Skoog liquid medium with double-strength KH2PO4, MgSO4, FeSO4, and Na2-EDTA in the vessel with enhanced natural ventilation. CO2 concentration in the culture room was kept at 1500 μmol mol−1 (four times the atmospheric CO2 concentration) during the photoperiod. A factorial experiment was designed with two levels of photosynthetic photon flux
(PPF) and three levels of N (number of air exchanges of the vessel). The results were compared with those in the control treatment (photomixotrophic
culture using sugar-containing agar medium under low PPF and low N). PPF and N showed significant positive effects on the growth of sugarcane plantlets in vitro. In the photoautotrophic (using sugar-free medium) treatments with relatively high PPF (200–400 μmol m−2 s−1) and high N (2–10 h−1), the growth of plantlets was four to seven times greater than that in the control. Also, the culture period for multiplication
and rooting was shortened from 30 d in the control to 18 d or less in the photoautotrophic, high PPF, and high N treatments. Use of porous supporting material in photoautotrophic treatments promoted rooting and plantlet growth significantly. 相似文献
10.