Lysis of Bacillus subtilis Cells by Glycerol and Sucrose Esters of Fatty Acids

The lytic action of glycerol and sucrose esters of fatty acids with different carbon chain lengths on the exponentially growing cells of Bacillus subtilis 168 was investigated. Of each series of esters, glycerol dodecanoate and sucrose hexadecanoate were the most active. Lysis at 1 h after the addition of 0.1 mM glycerol dodecanoate or 20 μg of sucrose hexadecanoate per ml was 81 or 79%, respectively, as evaluated by the reduction in optical density. During this treatment a great loss of viability occurred that preceded lysis. The results that were obtained suggest that autolysis is induced by these esters. The esters caused morphological changes in the cells, but a seeming adaptation of the cells to esters was seen.     

Thresholds of retinal and extraretinal photoreceptors measured by photobehavioral response in catfish,Silurus asotus

Summary Light thresholds of retinal and extraretinal photoreceptors in catfish were examined by the photobehavioral response using a method in which reflex body movements are recorded. Thresholds were determined in six groups, (A) intact, (B) ophthalmectomized, (C) pinealectomized, (D) ophthalmectomized + pinealectomized, (E) ophthalmectomized, pinealectomized and skinless over the brain (skinless fish) and (F) ophthalmectomized, pinealectomized and dorsally covered with aluminum foil over the brain (covered fish). All these fishes displayed short term activity to white light stimulation after being dark adapted for more than 5 h. The lowest threshold was obtained in the intact group (2.0×10^–4 W/cm²). The thresholds of lateral eyes and the pineal organ were 3.4×10^–3 and 1.5×10^–2 W/cm², respectively. Without lateral eyes and pineal organ, catfish still responded to light, indicating the possible existence of extraretinal nonpineal photoreceptors (ENPs). The threshold of ENPs was 3.3 W/cm². The localization of ENPs was assumed to be in the brain from the experiment with the combination of skinless and covered fish.Abbreviation ENP extraretinal nonpineal photoreceptor     

Decreased Fatty Acylation of Myelin Proteolipid Protein in the Twitcher Mouse

We examined chronological changes of myelin proteins of the brainstem and spinal cord of the twitcher mouse (15, 20, and 30 days old), a murine model of human globoid cell leukodystrophy caused by a genetic deficiency of galactosylceramidase I activity. The yield of myelin was normal until postnatal day 20, whereas galactosylsphingosine (psychosine) accumulated with age in myelin. The protein profiles of myelin and the activity of 2',3'-cyclic nucleotide 3'-phosphodiesterase in the myelin remained normal throughout the experimental period. Fatty acylation of proteolipid protein (PLP) was examined in a cell-free system by incubation of myelin with [3H]palmitic acid, CoA, and ATP, and was normal at postnatal day 15, but decreased after postnatal day 20. Decreased fatty acylation of PLP was also observed in the twitcher mouse at postnatal day 20 when the isolated myelin was incubated with [14C]palmitoyl-CoA in the absence of ATP and CoA, or the slices of brainstem and spinal cord were incubated with [3H]palmitic acid. The activity of fatty acid:CoA ligase was reduced in myelin. These data suggest that decreased acylation of PLP in twitcher mouse myelin is probably due to reduced activities for both activation and transfer of fatty acid into PLP and that metabolic disturbance is present in myelin because acylation of PLP has been shown to occur in myelin membrane. Although psychosine (200 microM) inhibited only 17% of the acylation in vitro, it may be responsible for the reduced acylation of PLP in vivo.     

Bacteriochlorophyll-protein complexes of aerobic bacteria,Erythrobacter longus and Erythrobacter species OCh 114

Bacteriochlorophyll(Bchl)-protein complexes were isolated from obligate aerobic bacteria, Erythrobacter longus and Erythrobacter species OCh 114. The apparent molecular weights, absorption spectra and polypeptide compositions of the light-harvesting complexes were, in general, similar to those of the light-harvesting Bchl-protein complexes of purple photosynthetic bacteria. The reaction center complexes of these bacteria also showed similar properties to those of the purple bacteria except for slightly altered polypeptides. However, the following characteristic features of the light-harvesting systems were found in these aerobic bacteria. Major carotenoids were not bound to the Bchl-protein complex in E. longus. In Erythrobacter sp. OCh 114, a new type of Bchl-protein complex which showed a single absorption band in the near infrared region at 806 nm was obtained. The reaction center of strain OCh 114 was associated with a c-type cytochrome.Abbreviations Bchl bacteriochlorophyll a - RC reaction center - SDS sodium dodecylsulfate - PAGE polyacrylamide gel electrophoresis     

Possibility of using salivary ultra‐weak chemiluminescence as a biomarker for feelings of anxiety in hospital settings

The aim of this study was to assess whether a particular value of noninvasive salivary ultra‐weak chemiluminescence (UCL) could be used as a biomarker of psychological stress. Our study covered two groups. Group 1 comprised six healthy volunteers who stayed in a hospital for one night and group 2 comprised 15 patients with lung cancer and 24 patients with respiratory diseases other than lung cancer who were in hospital for an extended stay. First, we evaluated the UCL of saliva from six healthy volunteers before and after one night in hospital. Immunoglobulin A (IgA) concentrations were also measured. The integrated intensity value of UCL was correlated with the IgA concentration (correlation coefficient 0.90). Second, in the case of a long hospital stay, we found that the maximum salivary UCL intensities were higher in patients with lung cancer than in those with respiratory diseases other than lung cancer or in 28 healthy controls. Copyright © 2016 John Wiley & Sons, Ltd.     

Rice phloem thioredoxin h has the capacity to mediate its own cell-to-cell transport through plasmodesmata

Rice (Oryza sativa L.) phloem sieve tubes contain RPP13-1, a thioredoxin h protein that moves around the plant via the translocation stream. Such phloem-mobile proteins are thought to be synthesized in the companion cells prior to being transferred, through plasmodesmata, to the enucleate sieve-tube members. In this study, in-situ hybridization experiments confirmed that expression of RPP13-1 is restricted to companion cells within the mature phloem. To test the hypothesis that RPP13-1 enters the sieve tube, via plasmodesmata, recombinant RPP13-1 was expressed in Escherichia coli, extracted, purified and fluorescently labeled with fluorescein isothiocyanate (FITC) for use in microinjection experiments into tobacco (Nicotiana tabacum L.) mesophyll cells. The FITC-RPP13-1 moved from the injected cell into surrounding cells, whereas the E. coli thioredoxin, an evolutionary homolog of RPP13-1, when similarly labeled and injected, failed to move in this same experimental system. In addition, co-injection of RPP13-1 and FITC-dextrans established that RPP13-1 can induce an increase in plasmodesmal size exclusion limit to a value greater than 9.4 but less than 20 kDa. Nine mutant forms of RPP13-1 were constructed and tested for their capacity to move from cell to cell; two such mutants were found to be incapable of movement. Crystal-structure prediction studies were performed on wild-type and mutant RPP13-1 to identify the location of structural motifs required for protein trafficking through plasmodesmata. These studies are discussed with respect to plasmodesmal-mediated transport of macromolecules within the companion cell-sieve tube complex. Received: 6 June 1997 / Accepted 25 June 1997     

Action of phenolic antioxidants on various active oxygen species

The action of phenolic antioxidants, such as probucol, on various active oxygen species was investigated using luminol chemiluminescence and spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). The various active oxygen species, including hydroxyl radicals (Fenton reaction), superoxide anions, singlet oxygen and hypochlorite ions were examined with phenolic antioxidants under aqueous and nonaqueous conditions. Probucol showed a quenching effect on both superoxide anions and hypochlorite ions in nonaqueous solution. However, it had no effect on hydroxyl radicals. α-Tocopherol, a natural phenolic antioxidant, showed a stronger quenching effect on superoxide anions and hypochlorite ions than probucol, and quenched hydroxyl radicals in nonaqueous solution. Furthermore, Trolox showed a quenching effect on all active oxygen species in both aqueous and nonaqueous solution. The antioxidants were studied under comparable conditions in a series of test systems and the reactivity profiles depicted as ‘radar charts’ which are helpful for characterizing antioxidant action.     

Ecological wood anatomy of NepaleseRhododendron (Ericaceae). 2. Intraspecific variation

The intraspecific relationship of selected wood anatomical characters with stem diameter, plant height, and altitude was investigated in four NepaleseRhododendron species:R. anthopogon, R. lepidotum, R. campanulatum, andR. arboreum, i.e., two shrubs, one subtree, and one tree. We studied 23 to 27 specimens for each species.R. anthopogon grew from 3,380 to 4,950 m,R. lepidotum from 2,060 to 4,720 m,R. campanulatum from 2,790 to 4,140 m, andR. arboreum from 1,430 to 3,460 m. Multiple regression analysis and actual distribution of character values show that the wood anatomical characters having a significant correlation with non-anatomical factors differ between species. The number of significant characters are two inR. anthopogon andR. campanulatum, five inR. lepidotum, and nine inR. arboreum and tends to be small in species having smaller altitudinal ranges. Average pore area, most strongly correlated with non-anatomical factors in interspecific variation, is significantly correlated only inR. lepidotum andR. arboreum. The general trends in intraspecific variation among four NepaleseRhododendron species differ from the trends found in interspecific variation within the genus and are characteristic of each species.