Colonial Morphology of Treponemes Observed by Electron Microscopy

The colonial morphology of three strains of cultivable, nonpathogenic treponemes including a human oral treponeme was examined by light and electron microscopy. Treponema phagedenis strains Kazan and Reiter produced large white colonies on the surface of solid media composed of sterility test broth, 0.9 to 3.1% agar, rifampin, and 12.5% rabbit or horse serum. A human oral treponeme, strain G7201, grew as diffused white zones on 0.9 to 3.1% agar plates. Under the cultural conditions employed agar concentrations slightly affected the time of appearance of colonies of the three strains of treponemes. When the colonies of these three strains were viewed by scanning electron microscopy, differences in their colonial morphology were observed. The 11-day-old colonies of human oral strain G7201 were very small, 5 to 15 μm in diameter, and had a slight irregular border. Kazan treponemes developed circular, entire and low convex colonies. Scanning and transmission electron microscopy revealed that the colonies of Reiter treponemes contained spherical forms almost up to 5 μm in diameter, each consisting of an outer membrane and a treponemal main body. They were very similar to the spherical bodies produced by strain G7201 in sucrose-containing broth.     

Enhancing the fungicidal activity of amphotericin B via vacuole disruption by benzyl isothiocyanate,a cruciferous plant constituent

Amphotericin B (AmB), a typical polyene macrolide antifungal agent, is widely used to treat systemic mycoses. In the present study, we show that the fungicidal activity of AmB was enhanced by benzyl isothiocyanate (BITC), a cruciferous plant-derived compound, in the budding yeast, Saccharomyces cerevisiae. In addition to forming a molecular complex with ergosterol present in fungal cell membranes to form K⁺-permeable ion channels, AmB has been recognized to mediate vacuolar membrane disruption resulting in lethal effects. BITC showed no effect on AmB-induced plasma membrane permeability; however, it amplified AmB-induced vacuolar membrane disruption in S. cerevisiae. Furthermore, the BITC-enhanced fungicidal effects of AmB significantly decreased cell viability due to the disruption of vacuoles in the pathogenic fungus Candida albicans. The application of the combinatorial antifungal effect of AmB and BITC may aid in dose reduction of AmB in clinical antifungal therapy and consequently decrease side effects in patients. These results also have significant implications for the development of vacuole-targeting chemotherapy against fungal infections.     

An Internal View of the Spherical Body of Treponema macrodentium as Revealed by Scanning Electron Microscopy

The osmium-dimethyl sulfoxide-osmium method for clear visualization of intracellular structure was used to observe the detailed inner structure of the spherical bodies produced in vitro by a human oral treponeme. Scanning electron microscopy of the cracked spherical body revealed no morphological differences between the outer and inner surfaces of the spherical body membrane, and that multiple folded or somewhat linear main bodies adhere closely to the inner surface. In addition, axial flagella partially free from the main bodies spread widely within the body to make a network, and a number of blebs ranging from approximately 1 μm to 0.2 μm in diameter were located near the terminal or subterminal areas of the main bodies. The origin of the blebs and the mechanism of spherical body formation are discussed.     

Evidence of increased synthesis of δ-aminolevulinic acid dehydratase in experimental lead-poisoned rats

δ-Aminolevulinic acid dehydratase (porphobilinogen synthase; 5-aminolevulinate hydro-lyase, EC 4.2.1.24) was purified from rat and rabbit erythrocytes to a homogeneous state. Specific activities were 26.0 and 26.6 units/mg protein for the rat and rabbit enzymes, respectively, and their estimated molecular weight was 280 000, each consisting of 8 subunits of M_r 35 000. In order to quantitate rat δ-aminolevulinic acid dehydratase at several stages of lead-poisoning, a radioimmunoassay technique using goat antiserum against the rat enzyme was developed for the first time. This technique was specific, reproducible and high sensitive allowing determination of 1 ng enzyme. When drinking water containing 25 mM lead acetate was given daily to rats ad lib. the δ-aminolevulinic acid dehydratase activity in the blood, assayed without any pretreatment, decreased to 8% of the control level on the next day. On the contrary, the restored enzyme activity, assayed in the presence of Zn²⁺ and dithiothreitol, was greater than normal by the fourth day of lead administration in bone-marrow cells and by the ninth day in the peripheral blood. The increased activity level stayed the same from the ninth day onward. The enzyme content as determined directly by the radioimmunoassay technique at this stage was about 2-fold above that the control. There was no significant difference in the number of reticulocytes and the distribution profile of different types of reticulocytes between the lead-exposed and non-exposed rats. Therefore, the increase in the amount of δ-aminolevulinic acid dehydratase in erythrocytes of lead-poisoned rats was suggested to be due to an increased rate of synthesis in the bone-marrow cells.     

Cloning and nucleotide sequence of the isoamylase gene from Pseudomonas amyloderamosa SB-15

The gene (iam) coding for isoamylase (glycogen 6-glucanohydrolase) of Pseudomonas amyloderamosa SB-15 was cloned. Its nucleotide sequence contained an open reading frame of 2313 nucleotides (771 amino acids) encoding a precursor of secreted isoamylase. The precursor contained a signal peptide of 26 amino acid residues at its amino terminus and three regions homologous with those conserved in alpha-amylases (1,4-alpha-D-glucan 4-glucanohydrolase) of species ranging from prokaryotes to eukaryotes. These homologous regions were also found in another debranching enzyme, pullulanase (pullulan 6-glucanohydrolase) from Klebsiella aerogenes. Sequences of the isoamylase also showed significant homology with those between positions 300 and the carboxyl terminus of pullulanase. The regions required for the specificity of isoamylase were discussed on the basis of a comparison of its amino acid sequence with those of alpha-amylases, cyclomaltodextrin glucanotransferases, and pullulanase.     

Isolation and partial characterization of the major glycoproteins of horse and swine erythrocyte membranes

The major glycoproteins of horse and swine erythrocyte membranes were isolated and examined chemically and immunologically. The major glycoprotein of horse erythrocyte membranes had a molecular weight of 33 000 and consisted of 46.2% protein and 53.8% carbohydrate, of which 9.4% was hexose, 10.1% hexosamine and 33.7% sialic acid. This glycoprotein was associated with activity for the infectious mononucleosis heterophile antigen.There were two different major glycoproteins in swine erythrocyte membranes. One major glycoprotein had a molecular weight of 46 200 and consisted of 34.2% protein and 65.8% carbohydrate, of which 18% was hexose, 19% hexosamine and 27.2% sialic acid. This glycoprotein had phytohemagglutinin (Phaseolus vulgaris) binding activity. The other glycoprotein had a molecular weight of 29 000 and consisted of 50.4% protein and 49.6% carbohydrate, of which 6.4% was hexose, 7.0% hexosamine and 36.3% sialic acid. This glycoprotein had weak or absent phytohemagglutinin binding activity.     

Association between light exposure at night and manic symptoms in bipolar disorder: cross-sectional analysis of the APPLE cohort

ABSTRACT

Previous studies have found that keeping the room dark at night was associated with a decrease in manic symptoms for patients with bipolar disorder (BD). However, the association between light at night of real-life conditions and manic symptoms is unclear. We investigated the association between bedroom light exposure at night and manic symptoms in BD patients. One-hundred and eighty-four outpatients with BD participated in this cross-sectional study. The average light intensity at night during sleep was evaluated using a portable photometer for seven consecutive nights. Manic symptoms were assessed using the Young Mania Rating Scale (YMRS), and scores ≥5 were treated as a “hypomanic state.” The median (interquartile range) YMRS score was 2.0 (0–5.0), and 52 (28.2%) participants were in a hypomanic state. The prevalence of a hypomanic state was significantly higher in the participants with an average light intensity at night exposure of ≥3 lux than in those with <3 lux (36.7% versus 21.9%; P = .02). In multivariable logistic regression analysis adjusted for BD type, depressive symptoms, sleep duration, and daytime physical activity, the odds ratio (OR) for a hypomanic state was significantly higher for the participants with an average light intensity at night exposure of ≥3 lux than for those with <3 lux (OR: 2.15, 95% confidence interval: 1.09–4.22, P = .02). This association remained significant at the cutoff value of YMRS score ≥6 (OR: 2.51, 95% confidence interval: 1.15–5.46; P = .02). The findings of this study indicate bedroom light exposure at night is significantly associated with manic symptoms in BD patients. Although the results of this cross-sectional investigation do not necessarily imply causality, they may serve to inform beneficial nonpharmacological intervention and personalized treatment of BD patients.     

Effects of Protamine Sulfate on Dengue Type 1 Viral Activities

Protamine treatment of type 1 dengue-infected mouse brain suspension resulted in precipitation of several viral specific activities. Complement-fixation activity was almost completely precipitated by protamine. The complement-fixation components recovered in the precipitate were comparable to a non-precipitated reference dengue 1 antigen in their homologous and heterologous reactions. Dengue hemagglutinin was also precipitated by the same treatment. The precipitated hemagglutinin was resolved into three components by buoyant density centrifugation, whose densities were 1.236, 1.215, and 1.178 g/ml, respectively. Three similar HA components were detected in non-protamine treated virus preparations. In both instances the highest-titered HA fraction possessed a buoyant density of 1.21–1.22 g/ml. These HA components were tested in the hemagglutination-inhibition reaction and were proved to be virus-specific. Cesium chloride density gradient centrifugation was shown to be useful for removing possible inhibitor(s) of viral specific hemagglutinin.     

Transport and Fixation of Inorganic Carbon during Photosynthesis in Cells of Anabaena Grown under Ordinary Air: III. Some Characteristics of the HCO3--Transport System in Cells Grown under Ordinary Air

In cells of cyanobacterium Anabaena variabilis grown under ordinaryair (low-CO₂ cells), the transport of both CO₂ and HCO₃^–was significantly enhanced by Na⁺. This effect was pronouncedas the external pH increased. When low-CO₂ cells were treatedwith an inhibitor of carbonic anhydrase (CA), only CO₂ transportbut not HCO₃^– transport, was inhibited. The initial rateof photosynthetic carbon fixation as a function of the concentrationof internal inorganic carbon (IC) was practically the same irrespectiveof whether CO₂ or HCO₃^– was externally supplied. Theseresults suggest that IC is actively transported through theplasma membrane in a form of HCO₃^– probably by some transporterand that the transmembrane Na⁺ gradient is involved in thisIC transport system. Free CO₂ may be hydrated by CA to HCO₃^–and then transported to the cells by this transporter. On the other hand, CO₂ is actively taken up by cells grown withair containing 5% CO₂ (high-CO₂ cells) though the enhancingeffect of Na⁺ was much smaller in high- CO₂ cells than in low-CO₂cells. The initial rate of fixation as a function of internal IC concentrationindicated that the rate of the carboxylation reaction of accumulatedIC is higher in I0W-CO₂ cells than in high-CO₂ cells. The studieswith ethoxyzolamide indicated that even in low-CO₂ cells, CAdoes not function inside Anabaena cells. These results suggestthat inside the low-CO₂ cells of Anabaena, some mediator(s)facilitates the transport of IC to RuBPCase. (Received January 23, 1987; Accepted April 24, 1987)