Nisin F, intraperitoneally injected, may have a stabilizing effect on the bacterial population in the gastro-intestinal tract, as determined in a preliminary study with mice as model

AIMS

To determine if nisin F has an effect on the bacterial population in the gastro-intestinal tract.

METHODS AND RESULTS

Six male C57BL/6 mice were intraperitoneally injected with 200 μl sterile saline and six with nisin F (200 μl, equivalent to 640 arbitrary units). Fecal samples were collected before injection and 8, 24 and 48 h after injection, and the bacteria amplified by PCR-DGGE using 16S rDNA primers. The composition of the bacterial population in the gastro-intestinal tract (GIT) of mice that were injected with saline changed during 48 h, whereas the bacterial population in the GIT remained relatively unchanged in animals injected with nisin F.

CONCLUSIONS

These results suggest that nisin F inhibits the growth of specific bacteria in the GIT within the first 4 h. Furthermore, the species remained repressed for at least 44 h after one intraperitoneal injection with nisin F.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report suggesting that nisin F may have a stabilizing effect on the bacterial population in the gastro-intestinal tract.

Number fluctuations of sparse quasiparticles in a superconductor

We have directly measured quasiparticle number fluctuations in a thin film superconducting Al resonator in thermal equilibrium. The spectrum of these fluctuations provides a measure of both the density and the lifetime of the quasiparticles. We observe that the quasiparticle density decreases exponentially with decreasing temperature, as theoretically predicted, but saturates below 160 mK to 25-55/μm(3). We show that this saturation is consistent with the measured saturation in the quasiparticle lifetime, which also explains similar observations in qubit decoherence times.

Influence of carbohydrates on the isolation of lactic acid bacteria

AIMS

  To determine the influence of carbohydrates on enrichment isolation of lactic acid bacteria from different niches.

METHODS AND RESULTS

  Lactic acid bacteria in three traditional fermented products in southern Africa (amasi, mahewu and tshwala) and in three fresh samples (two flowers and a fruit) were enrichment cultured in media supplemented with 13 different carbohydrates. Diversity of lactic acid bacteria was determined by PCR-denaturing-gradient gel electrophoresis. Carbohydrates used in enrichment media had a big impact on the isolation of lactic acid bacteria from fermented products. Depending on the carbohydrates tested, the number of species detected ranged from one to four in amasi, one to five in mahewu and one to three in tshwala. Fructose and mannitol selected for relatively higher numbers of lactic acid bacteria in fermented products. Specific relationships between substrates and lactic acid bacteria have been noted. On the other hand, small influences were found among carbohydrates tested in flowers and fruit.

CONCLUSION

  Carbohydrates have a big impact on the isolation of a variety of lactic acid bacteria in fermented food.

SIGNIFICANCE AND IMPACT OF THE STUDY

  This is the first study that reports the influence of carbohydrates on the enrichment of lactic acid bacteria.

Thermal Stability of Structurally Controlled Lamellae and Hexagonal Mesoporous Silicate Thin Films

Thin films of mesoporous materials have been synthesized recently as lamellar, one dimensional hexagonal and cubic structures at substrate surfaces as well as at air/liquid interfaces. The present work investigates thermally induced structural changes of lamellar and one-dimensional hexagonal(1-dH) mesostructured silicate thin films, which is less known at the moment. The 1-dH films proved to be much more thermally stable than the lamellar ones; Open-pore one dimensionalhexagonalmesoporous thin films are obtained by the calcination of the films, where as the lamellarphase has collapsed after the surfactants removal.

Analysis of the effect of structural materials in a wall-less tissue-equivalent proportional counter irradiated by 290 MeV u(-1) carbon beam

Effects of structural materials in a wall-less tissue-equivalent proportional counter were evaluated based on the calculation of energy deposits by EGS5 and the measurement of lineal energy distributions using 290 MeV u(-1) carbon beams. It is found that the correction of measured data based on simulation is necessary for understanding the energy deposition spectra in the homogeneous condition in tissues.

NMR (1D and 2D) and X-ray crystallographic studies of Ni(II) complex with N-(2-mercaptophenyl)-4-methoxysalicylideneimine and triphenylphosphine

Mononuclear nickel(II) complex, viz. [Ni(L)(PPh(3))] (where L is dianion of N-(2-mercaptophenyl)-4-methoxysalicylideneimine) has been synthesized and characterized by means of elemental analysis, electronic, IR and NMR [(1)H, (13)C{(1)H} and (31)P{(1)H}, DEPT, (1)H-(1)H COSY, ge-HSQC, ge-HMBC] spectroscopic techniques. Structural analysis of the complex by single crystal X-ray crystallography indicated the presence of square planar coordination geometry (ONSP) about nickel. One of the phenyl rings of triphenylphosphine involve in C-H...pi interactions with H6b, H13 and H32 to form a three dimensional network which stabilizes the structure of complex.

Dissociation and reassociation of bacterial membrane components

The dissociation of the phospholipid, lipopolysaccharide, and protein components of the bacterial cell envelope results in loss of enzyme activities which are normally located in the cell envelope structure and which are involved in lipopolysaccharide biosynthesis. The activity of one of these enzymes, UDP-galactose:lipopolysaccharide α,3 galactosyl transferase, can be restored by the reassociation of purified phospholipid, lipopolysaccharide, and enzyme protein. Reconstitution of activity occurs in stepwise fashion: lipopolysaccharide + phospholipid → lipopolysaccharide·phospholipid See PDF for Equation enzyme·lipopolysaccharide·phospholipid. The intermediates in the reaction were isolated by gradient centrifugation. The final ternary complex behaves in a similar manner to the intact cell envelope in the enzyme reaction and appears to represent the reconstitution of a portion of the membranous portion of the cell envelope.

Current status of the medical expenses for the treatment of arteriosclerosis obliterans in Japan

AIM

We aimed to determine the current status of the medical expenses for the treatment of arteriosclerosis obliterans (ASO) and evaluate the cost effectiveness of the medical practices employed in ASO treatment in Japan.

METHODS

We performed a prospective observational study using 140 ASO patients. The cost of the medical practices comprised the costs of outpatient treatment, pharmacological agents, and hospitalization. To compare the average monthly costs, the patients were divided into preintervention, postintervention, or conservative-therapy groups. To compare the total costs and effectiveness of each treatment, the patients who had first visited our division during the study period were classified into surgery, endovascular-revascularization (EVR), or conservative-therapy groups. The adverse reactions of the 4 most popular agents for ASO were investigated, and bleeding events were assessed specifically.

RESULTS

The average monthly costs for outpatient treatment and pharmacological agents were yen 168,002 in conservative cases, yen 149,871 in preoperation cases, and yen 128,527 in postoperation cases. The mean total costs were yen 5,407,950 in conservative cases, yen 7,375,290 in surgical cases, and yen 2,631,650 in EVR cases. The average change of the gauge in clinical status was 0.57 in conservative cases, 2.13 in surgical cases, and 2.25 in EVR cases. Warfarin induced more bleeding complications than the other agents.

CONCLUSION

The costs of pharmacological agents represented much of the medical costs in any treatment groups.

Impact of the new nuclear decay data of ICRP publication 107 on inhalation dose coefficients for workers

The impact a revision of nuclear decay data had on dose coefficients was studied using data newly published in ICRP Publication 107 (ICRP 107) and existing data from ICRP Publication 38 (ICRP 38). Committed effective dose coefficients for occupational inhalation of radionuclides were calculated using two sets of decay data with the dose and risk calculation software DCAL for 90 elements, 774 nuclides and 1572 cases. The dose coefficients based on ICRP 107 increased by over 10 % compared with those based on ICRP 38 in 98 cases, and decreased by over 10 % in 54 cases. It was found that the differences in dose coefficients mainly originated from changes in the radiation energy emitted per nuclear transformation. In addition, revisions of the half-lives, radiation types and decay modes also resulted in changes in the dose coefficients.

Monitoring the bacterial community during fermentation of sunki, an unsalted, fermented vegetable traditional to the Kiso area of Japan

AIMS

To investigate the microbial community in sunki, an indigenous, unsalted, fermented vegetable, made from the leaves of red beet.

METHODS AND RESULTS

Fermenting samples were collected at 1- to 2-day intervals from four houses and investigated by culture-dependent and culture-independent techniques. PCR-Denaturing-Gradient-Gel-Electrophoresis profiles indicated that the bacterial community was stable and Lactobacillus delbrueckii, Lact. fermentum and Lact. plantarum were dominant during the fermentation. This result agreed well with that obtained by the culturing technique. Moulds, yeasts or bacteria other than lactic acid bacteria (LAB) were not detected.

CONCLUSIONS

The bacterial community was stable throughout the fermentation, and Lact. delbrueckii, Lact. fermentum and Lact. plantarum were dominant. The acidic pH and lactic acid produced by LAB probably preserve the sunki from spoilage.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report on the use of both culture-dependent and culture-independent techniques to study the bacterial community in sunki. A combination of culture-dependent and culture-independent techniques is necessary for the analysis of complex microbial communities.

Structure of magnesiumphthalocyanine complexes

Magnesiumphthalocyanine (MgPc; blue pigment) has attracted attention as a material useful for laser printers because of its near IR absorption. Two kinds of six-coordinate MgPc complexes have been grown from solution and their structures have been analyzed: MgPc/(H2O)2 (N-methyl-2-pyrrolidone)2 (crystal 1) and MgPc/(2-methoxyethanol)2 (crystal 2). The crystal data of crystal 1 are: MgPc/(H2O)2(NMP)2, Mr = 773.15, monoclinic, P21/n, a = 6.876(2) Å, b = 21.427(4) Å, c = 12.994(6) Å, β = 102.20(2)°, V = 1871(1) Å3, Z = 2, Dx = 1.375, Dm = 1.38 Mgm-3, graphite-monochromated MoK α, λ = 0.7107 Å, F(000) = 812.00, μ = 1.07 mm-1, T = 296 K, R = 0.074 for 1606 reflections. The crystal data of crystal 2 are: MgPc/(CH3OCH2CH2OH)2, Mr = 689.03, monoclinic, P21/n, a = 12.37(1) Å, b = 8.078(6) Å, c = 17.974(9) Å, β = 109.70(7)°, V = 1690(2) Å3, Z = 2, Dx =1.354, Dm = 1.37 Mgm -3, graphite-monochromated MoKα, λ = 0.7107 Å, F(000) = 720.00, μ = 1.08 mm-1, T = 296 K, R = 0.080 for 1407 reflections. In both complexes, the MgPc skeleton is found to be deformed as characterized by the molecular symmetry of Ci in contrast to D4h assumed for MgPc in the free space.

ICRP Publication 107. Nuclear decay data for dosimetric calculations

In this report, the Commission provides an electronic database of the physical data needed in calculations of radionuclide-specific protection and operational quantities. This database supersedes the data of Publication 38 (ICRP, 1983), and will be used in future ICRP publications of dose coefficients for the intake of or exposure to radionuclides in the workplace and the environment.The database contains information on the half-lives, decay chains, and yields and energies of radiations emitted in nuclear transformations of 1252 radionuclides of 97 elements. The CD accompanying the publication provides electronic access to complete tables of the emitted radiations, as well as the beta and neutron spectra. The database has been constructed such that user-developed software can extract the data needed for further calculations of a radionuclide of interest. A Windows-based application is provided to display summary information on a user-specified radionuclide, as well as the general characterisation of the nuclides contained in the database. In addition, the application provides a means by which the user can export the emissions of a specified radionuclide for use in subsequent calculations.

Characterization of Lactococcus garvieae isolated from radish and broccoli sprouts that exhibited a KG+ phenotype, lack of virulence and absence of a capsule

AIMS

To identify Lactococcus garvieae isolates from radish and broccoli sprouts and compare them with virulent and less virulent mutant strains obtained from yellowtails with regard to KG phenotype, presence of a capsule and virulence towards yellowtails and mice.

METHODS AND RESULTS

Comparative 16S rRNA gene sequence analysis of six isolates obtained from radish and broccoli sprouts indicated that they were L. garvieae (similarity >99%). They were compared with KG9502, Lg2 and ATCC49156 strains obtained from yellowtails. A less virulent mutant strain Lg2-S was obtained by Lg2 subculture. Biochemical characterization of the six strains resembled that of KG9502, Lg2, ATCC49156 and Lg2-S, except for saccharose and tagatose acidification and the presence of hippuricase. These six strains were nonpathogenic towards yellowtails and mice, nonsusceptible to bacteriophages and demonstrated heterogeneity on pulsed-field gel electrophoresis analysis. Using transmission electron microscopy, a capsule was observed in KG9502 and Lg2 but not in ATCC49156 and Lg2-S.

CONCLUSIONS

We isolated L. garvieae strains that lacked pathogenicity towards yellowtails and mice from radish and broccoli sprouts; these were noncapsulated and exhibited KG(+) phenotype.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first documentation of L. garvieae isolated from terrestrial plants. These isolates exhibited genetic diversity; however, they were noncapsulated and nonpathogenic towards yellowtails and mice.

Numerical system utilising a Monte Carlo calculation method for accurate dose assessment in radiation accidents

A system utilising radiation transport codes has been developed to derive accurate dose distributions in a human body for radiological accidents. A suitable model is quite essential for a numerical analysis. Therefore, two tools were developed to setup a 'problem-dependent' input file, defining a radiation source and an exposed person to simulate the radiation transport in an accident with the Monte Carlo calculation codes-MCNP and MCNPX. Necessary resources are defined by a dialogue method with a generally used personal computer for both the tools. The tools prepare human body and source models described in the input file format of the employed Monte Carlo codes. The tools were validated for dose assessment in comparison with a past criticality accident and a hypothesized exposure.