We found an observational evidence of the multiplicity of the discrete delay time on the order of 200 and 1000 years of the response of the solar total Irradiance variation to the solar magnetic cycle amplitude variation in the time profiles of the variations. We used the10Be data in the annual layers of the ice cores of the Greenland as a proxy of the solar magnetic field variation. We also used the land air temperature anomalies, reconstructed from tree-ring growth rates, as a proxy of the solar total Irradiance variation. The delay time of 1000 years means that the Medieval Warm Epoch of the Earth around the 13th and 14th centuries is a result of release of heat stored in the solar convection zone around the 3rd and 4th centuries when the solar magnetic activity was high.
By inspecting decadal components of the land air temperature anomalies of the Earth, measured instrumentally and reconstructed from tree-ring growth rates of northern North American continent and of eastern slopes of polar Urals in Siberia, and of the water level change of Lake Victoria in eastern central African continent, we argue that (i) the fundamental postulate in our study of the Sun-climate connection, that the temperature anomalies can be a good proxy of the solar total irradiance variation, is plausible on decadal time scale in extended time intervals when the temperature anomalies of different parts of the Earth behave in unison, that (ii) the period when the water level changed cyclically on decadal time scale in phase with the 11-year solar magnetic field (SMF) cycle from solar cycle 14 to solar cycle 15 was in such a time interval, and thatv (iii) the water level change is a strong evidence of the Sun-climate connection.
The mitochondrial-fusion promoting (mF) plasmid first found in the slime mold Physarumpolycephalum is a parasitic, selfish mitochondrial plasmid, and is capable of manipulating mitochondria behavior as indicated by its name. To investigate the origin of the mF plasmid, we collected many Physarum laboratory strains as are available at present throughout the world, and classified their origin on the basis of the results of mating-type analysis and restriction endonuclease analysis of their mtDNA. They include 8 plasmodial strains obtained from mating crosses with 22 different myxamoebal strains and two sclerotia. One of the two sclerotia is originated at W. Seifriz'z laboratory in the University of Pennsylvania, and is the oldest laboratory strain in the world. The mtDNA of each strain formed a single 80-90kbp band but the mF+ strains yielded a 14-16kbp mF plasmid band in addition to this main band. Southern hybridization using labeled plasmid DNA as the probe allowed the mF- strains to be classified into two categories: simple mF- having only an mID sequence and ΔmF having some part of the mF plasmid integrated into the mtDNA. The mID sequence is almost identical to a 475-bp sequence (pID) of the mF plasmid. To confirm this finding, we designed PCR primers for amplifying certain parts of the mF plasmid. This PCR system enabled us to determine whether apparent mF- strains and sclerotia possessed the free or integrated mF plasmids. The sclerotium derived from Seifriz's laboratory is simple mF-, but the other sclerotium, which was originally derived from the North Carolina Biological supply house is complete mF+. Moreover, except this derivative of North Carolina Biological, DP12×DP13, which derived from a stock at the University of Iowa is ΔmF. Such scattered distribution of mF+ and ΔmF suggests that the mitochondria occasionally acquired the mF plasmid after the establishment of P. polycephalum as a species.
Surface molecular motions of amorphous polymeric solids have been directly measured on the basis of lateral force microscopic (LFM), scanning viscoelasticity microscopic (SVM) and differential X-ray photoelectron spectroscopic (D-XPS) studies. SVM and LFM measurements of monodisperse polystyrene (PS) films revealed that, in the case of the number-average molecular weight, Mn less than ca. 30k, the surface was in a glass-rubber transition state at room temperature even though the bulk glass transition temperature, Tg was far above room temperature. The active molecular motion at the polymeric solid surface can be interpreted mainly in terms of excess free volume near the surface region induced by the surface segregation of chain end groups, which was confirmed by dynamic secondary ion mass spectroscopy (DSIMS). D-XPS measurement revealed that the surface Tg for the poly(styrene-block-methyl methacrylate) diblock copolymer films increased gradually with an increase in depth from the air/polymer interface.
Macrophages were obtained from the peritoneal cavities of mice and infected in vitro with Mycobacterium leprae. After three weeks, the multiplication of the bacteria was observed inside of the infected cells. Three weeks after the infection the medium was replaced and antibiotic free medium was added to culture flask which was incubated at 32°C. Three months later, amorphous turbidity was observed under the surface layer of the medium. This turbidity slowly progressed with time. Next the sample was centrifuged and CBA macrophages ingested. After 3 weeks Ziehl-Neelsen positive rods were observed in 0.2-0.6% of the cells. These observations not only indicated the release of M. leprae from infected macrophages, but also suggested the possibility of the micro-organism growing in the medium itself. With these observations and experiences accumulated over fifteen years of trial and error, I discuss various potential improvements for the medium and the environment to permit more efficient growth of M. leprae in vitro.
Mycobacterium leprae is cultured in vitro with a newly devised ML medium. Two different samples were tested, one M. leprae Thai- 53 strain which was passaged through nude mice in 1976, and another clinically isolated M. leprae K-1 strain. 108 cells from these samples were cultured with ML medium at 32°C in glass flasks, and the medium gradually become turbid (as measured by optical density (OD) at 510nm). The addition of ethylene oxide treated Cutina LE (Henkel, Germany) to the ML medium significantly increased the turbidity. The turbidity increase without Cutina LE was from 0.339 to 0.687 in 65 days, while the addition of Cutina LE resulted in OD change from 0.05 to 0.67 in 1 week. The observation of the surface of Cutina LE by phase-contrast microscope showed the adherent bacteria with apparent active multiplication. The identity of the turbidity was confirmed to be M. leprae by the use of Polymerase chain reaction.
The antitumor effect of indomethacin on Colon 26 was investigated in vivo and the telomerase activity in the tumor tissues was monitored under chronic indomethacin treatment. Tumor growth was significantly suppressed with indomethacin treatment compared to the controls. In addition, telomerase activity in the tumor tissues markedly declined in contrast to the telomerase activity in the testis and liver, which was not affected by indomethacin treatment. This is the first observation that indomethacin can suppress tumor growth in association with a preferential decrease in telomerase activity in tumor tissues. This study suggests a method to investigate the mechanism(s) of tumor suppression by indomethacin. Furthermore, this study suggests that telomerase activity in the tumor tissues might be a good index to estimate the effectiveness of antitumor agents.
The three-dimensional structure of an enzyme, 2-hydroxyl-6-oxo-6-phenylhexa-2, 4-dienoic acid (HPDA) hydrolase (conventionally called BphD) from Rhodococcus sp. strain RHA1 has been solved by X-ray crystal structure analysis. This enzyme hydrolyzes one of the highly reactive intermediates, the meta cleavage product of the reaction catalyzed by 2, 3-dihydroxybiphenyl dioxygenase, in the metabolic pathway degrading biphenyl compounds including the notorious environmental pollutant PCBs (polychlorinated biphenyls). By virtue of this and several other enzymes, the biphenyl compounds including PCBs are finally introduced into the tricarboxylic acid cycle. The BphD enzyme is an oligomeric enzyme made up of eight identical subunits each of 285 amino acid residues. The subunit consists of two domains, α/β domain and α domain, between which the active site is located.
A radioautographic study of [3H]-choline was performed in the motor endplate region of the frog. The incorporation of the radioactive ligand was detected in the motor nerve terminal, as already seen in previous experiments. A dense labeling was observed in fibrocytes of the motor endplate region. Such substantial incorporation of choline in the fibrocytes, which has not been reported so far, brings new suggestions concerning the role of non-neural cells in the cholinergic metabolism.