An electron microscopic study on differences in the fine structures of motor endplate in red, white and intermediate muscle fibers of rat intercostal muscle. A preliminary study

An electron microscopic study on the fine structural differences of motor endplates among the red, white and intermediate muscle fibers of the rat intercostal muscles was made and the following results were obtained. 1. In the motor endplate of the red fiber, the junctional folds were poorly developed and their number was small. 2. In the motor endplate of the white fiber, the junctional folds were well developed and their number was far more numerous than those in the red fiber. 3. The fine structure of the motor endplate of the intermediate fiber was of an intermediate character between the red and white fiber.</p

A cytological study of the effect of reinnervation and cross-innervation on rat striated muscle

The changes of rat muscle fiber structure and fiber types after the reunification of the nerve and cross-innervation between the nerve to M. soleus (SOL) and M. extensor digitorum longus (EDL) were cytologically studied and the following results were obtained: 1. After the reunification of the nerve, the tendency toward grouping to a single fiber type was observed, although in normal muscle, the red, white and intermediate fibers were distributed in mosaic pattern. 2. After the cross innervation, the changes of fiber types occurred; namely, in SOL, normally composed of red and intermediate fibers, the three types of fibers appeared after the cross- innervation with the nerve to EDL, which originally was composed of the red, white and intermediate muscle fibers, and vice versa. These changes were observed not only in histochemical sections, but also in the ultrastructural level by electron microscope.</p

Measurement of Electron Density and Temperature in a Pulsed Argon Ion Laser

This paper is concerned with some results of experiment and analysis on plasma of pulsed argon ion laser. A long pulsed discharge was brought about with varied discharge voltages of 2～5kV at pressures from 10 to lOOm Torr. Laser oscillations of 6 argon ion lines were observed in the pressure range from 10 to 30m Torr. The change of electron density during the discharge was measured with a He-Ne laser interferometer and a double probe, giving the value of the order of 10¹4cm⁻³ for the above discharge conditions. The time variation of electron temperature was also determined with a double probe and by the measurement of plasma electrical resistivity. Temperature of 4.5～7×10⁴ °K was obtained. From the analysis of the measured plasma parameters it is concluded that the free fall model of Tonks-Langmuir is valid in the laser plasma except in the early period of the pulsed discharge. Further, observed laser oscillations and spontaneous emissions are analized and three-level model is supported for the pumping of excited levels of argon ion lines in the quasi-CW oscillation region, i.e. the later period, of the laser discharge

Mimivirus reveals Mre11/Rad50 fusion proteins with a sporadic distribution in eukaryotes, bacteria, viruses and plasmids

<p>Abstract</p> <p>Background</p> <p>The Mre11/Rad50 complex and the homologous SbcD/SbcC complex in bacteria play crucial roles in the metabolism of DNA double-strand breaks, including DNA repair, genome replication, homologous recombination and non-homologous end-joining in cellular life forms and viruses. Here we investigated the amino acid sequence of the Mimivirus R555 gene product, originally annotated as a Rad50 homolog, and later shown to have close homologs in marine microbial metagenomes.</p> <p>Results</p> <p>Our bioinformatics analysis revealed that R555 protein sequence is constituted from the fusion of an N-terminal Mre11-like domain with a C-terminal Rad50-like domain. A systematic database search revealed twelve additional cases of Mre11/Rad50 (or SbcD/SbcC) fusions in a wide variety of unrelated organisms including unicellular and multicellular eukaryotes, the megaplasmid of a bacterium associated to deep-sea hydrothermal vents (<it>Deferribacter desulfuricans</it>) and the plasmid of <it>Clostridium kluyveri</it>. We also showed that R555 homologs are abundant in the metagenomes from different aquatic environments and that they most likely belong to aquatic viruses. The observed phyletic distribution of these fusion proteins suggests their recurrent creation and lateral gene transfers across organisms.</p> <p>Conclusions</p> <p>The existence of the fused version of protein sequences is consistent with known functional interactions between Mre11 and Rad50, and the gene fusion probably enhanced the opportunity for lateral transfer. The abundance of the Mre11/Rad50 fusion genes in viral metagenomes and their sporadic phyletic distribution in cellular organisms suggest that viruses, plasmids and transposons played a crucial role in the formation of the fusion proteins and their propagation into cellular genomes.</p

Histochemical studies of hydrolytic and oxidative enzymes in the human intestinal tumors

The distribution and activities of five hydrolytic and eight oxidative enzymes were histochemically studied in 60 different tumors of the human intestines. Benign polyp showed similar activities of most enzymes as those in normal crypt cells of large intestine with exception of higher activity of succinic dehydrogenase in benign polyp than in crypt cells. Malignant polyp had higher activities of most oxidative enzymes. Reticulo-sarcoma had weak activities of all enzymes. Carcinoid had strong activities of glucose-6-phosphate dehydrogenase and isocitric dehydrogenase while very weak of succinic dehydrogenase. Carcinoma showed varying degrees of the activity of all enzymes. Alkaline phosphatase and aminopeptidase were almost negative in all cells but in the stromal elements their weak activities were sporadically observed. Most enzymes were decreased in the central area of the carcinoma cell nestle, while in the infiltrating area or in the margin of cell nestle they were not decreased and sometimes increased.</p

DNAsynthesis and cell renewal in small and large intestines of mouse

DNA synthesis and cell renewal of mouse intestinal epithelium were studied with radioautography after injection of thymidine-H&#179; to know the difference of the mode of epithelial cell generation relating to the different frequency of cancer developement in several parts of small and large intestines. Succinic dehydrogensase activity was also observed by histochemical method. Renewal time of the intestinal epithelium of mouse is about three days throughout the intestine with somewhat longer time in rectum and anus, and relatively shorter one in ileum compared to the other parts of the intestine. Daily regenerating rate was low in large intestine, especially in rectum and anus. Strong activity of succinic dehydrogenase appeared in the bottom of crypt and seems to be correlated to the active cell division. Epithelial cells in large intestine move very slowly upward and few of them seem to move to the opposite side or stay long time at one place. Intermitotic time is about 27 hours in small intestine and about 40 hours in large intestine. These suggest some relations between the mode of the epthelial cell renewal and cancer development. Because in human the frequency of cancer development is very high in large intestine, rectum and anus, and the epithelial renewal of these areas is supposed to be delayed similarly as in mice.</p

A histochemical study of hydrolytic and oxidative enzymes in an eosinophilic granuloma of parotid gland region

We experienced a case of eosinophilic granuloma in soft tissue, and demonstrated its patterns of hydrolytic and oxidative enzymes histochemically. Neutrophils were rich in acid phosphatase and glucose-6-phosphate dehydrogenase. Eosinophils had much acid phosphatase and less other hydrolytic and oxidative enzymes. Lymphocytes showed weak reaction in all enzymes. Lymph follicles and histiocytes or fibrocytes had moderately oxidative enzymes. Small blood vessels and collagen fibers were rich in alkaline phosphatase and had a moderate amount of oxidative enzymes and acid phosphatase.</p

Effect of chlorine dioxide gas of extremely low concentration on absenteeism of school children

Gas-generating devices of chlorine dioxide (ClO 2 ) are used as deodorant of rooms. We happened to use a commercial tabletop deodorant canister that releases extremely low-concentration ClO 2 gas in a school classroom as deodorant. We found retrospectively and unexpectedly that during a period of 38 consecutive school days the rate of school children absent from the school was markedly lower (1.5%) in a classroom where the ClO 2 device was placed than that (4.0%) in a classroom where it was not placed. The percentages of absenteeism between these classrooms (1.5% vs. 4.0%) were significantly (p &lt; 0.00001) different. The predominant causes of absenteeism during the period were common cold and influenza. Judging from the known virucidal activity of ClO 2 , our unexpected finding in the school classrooms strongly suggests the usefulness of extremely low-concentration ClO 2 gas to prevent respiratory viral diseases in semi-closed areas, such as theaters, hospitals and aircraft, without necessitating evacuation

Histochemical studies on enzyme activities of gastric carcinoma. II. Dehydrogenases

With gastric carcinomas the activities of eight dehydrogenases; succmlC, lactic, malic, &#945; glycerophosphate, glutamic, &#946;-hydroxybutyric, glucose-6-phosphate and isocitric dehydrogenase were statistically estimated. Principal findings may be briefly summarized as follows. These enzymatic activities differed considerably even in the same classification of carcinomas and generally ranged from strong to weak in the following order: lactic, malic, glucose-6-phosphate, isocitric, succinic, &#945;-glycerophosphate, glutamic and &#946;-hydroxybutyric dehydrogenase. The activities of adenocarcinomas were stronger than those in simple ones, and these were not related appreciably to cell differentiation in adenocarcinomas except succinic, glutamic, glucose-6-phosphate and isocitric dehydrogenase. As for succinic dehydrogenase and NAD-linked dehydrogenases except for lactic dehydrogenase, the activities were strongest in intestinal metaplasia and early mucosal carcinomas, the next being in benign adenomatous polyps and weakest in the other carcinomas. As for NADP-linked dehydrogenases and lactic dehydronase, the activities were also strongest in intestinal metaplasia and early carcinomas, the second in the other carcinomas and the third in the benign polyps. Generally, these dehydrogenase activities were strongest in free carcinoma cells in blood and lymph vessels and in actively growing part of several carcinomas and weakest in the central area of tumors, especially almost negative in the central necrotic area.</p