Site-specific relaxation of peptide bond planarity induced by electrically attracted proton/deuteron observed by neutron crystallography.

In structural biology, peptide bonds, fundamental linkages between hundreds of amino acids, of which a protein molecule is composed, have been commonly treated as a plane structure just as Linus Pauling et al. proposed. In this paper, a site-specific peptide bond relaxation mechanism by deuterons whose localization has been suggested by neutron crystallography is proposed. Such deuteron was observed as an arm of neutron scattering length density protruding from the carbonyl oxygen atoms in the main chain in the omit map drawn by neutron crystallography of human lysozyme. Our comprehensive study using x-ray and neutron diffraction and 15 N chemical shifts of individual amide nitrogen atoms within the same peptide bond strongly suggests the relaxation of the electronic resonance structure because of site-specific modulation by protons/deuterons localized on the electron orbital of the carbonyl oxygen. All experimental data used in this examination were obtained at room temperature, which is preferable for enzymatic activity. Such a close interaction between the electron resonance structure of a peptide bond and the exchangeable protons/deuterons well agreed with that observed in an intermediate state in an amide hydrolytic reaction simulated by the ab-initio calculation including water molecules.

Quantification method of motor function recovery of fingers by using the device for home rehabilitation.

After leaving hospital, patients can carry out rehabilitation by using rehabilitation devices. However, they cannot evaluate the recovery by themselves. For this problem, a device which can both carry out the rehabilitation and evaluation of the degree of recovery is required. This paper proposes the method that quantifies the recovery of the paralysis of fingers to evaluate a patient automatically. A finger movement is measured by a pressure sensor on the rehabilitation device we have developed. A measured data is used as a time-series signal, and the recovery of the paralysis is quantified by calculating the dissimilarity between a healthy subject's signal and the patient's signal. The results of those dissimilarities are integrated over all finger to be used as a quantitative scale of recovery. From the experiment conducted with hemiplegia patients and healthy subjects, we could trace the process of the recovery by the proposed method.

The type III Secretion System of Bradyrhizobium japonicum USDA122 mediates symbiotic incompatibility with Rj2 soybean plants.

The rhcJ and ttsI mutants of Bradyrhizobium japonicum USDA122 for the type III protein secretion system (T3SS) failed to secrete typical effector proteins and gained the ability to nodulate Rj2 soybean plants (Hardee), which are symbiotically incompatible with wild-type USDA122. This suggests that effectors secreted via the T3SS trigger incompatibility between these two partners.

Comparison of preparation methods for the evaluation of nerve axons.

We have conducted a study to compare various preparation methods, including a certain number of new methods, to find which ones are best suited to the morphological evaluation of nerve fibers in the pyramidal tract of the human medulla oblongata. Our main concern was to find fixation and staining methods that would minimize errors, especially regarding the tissue shrinkage ratio and the ease of staining. From the two fixation methods we examined, the most satisfactory was the secondary chromic acid fixation (which gave the best overall results when followed by nitrocellulose embedding), as it gives the lowest shrinkage ratio with the narrowest range (10 +/- 0%). Among the ten staining methods we tested, we found that the most suitable for morphological evaluation were the discriminative staining methods (Luxol fast blue-Periodic acid-Schiff-Hematoxylin stain, Masson-Goldner-Goto method and modified Hematoxylin-Eosin stain) and the silver impregnation methods (Luxol fast blue-Silver impregnation and Luxol fast blue-Silver impregnation-Periodic acid-Schiff-Hematoxylin).

Morphological evaluation of the human pyramidal tract: gender and age differences.

Using a preparation method composed of secondary chromic acid fixation, nitrocellulose embedding and Luxol fast blue-PAS-hematoxylin stain (a discriminative staining method) for the purpose of axonal discrimination, we examined 43 human spinal cords (31 males and 12 females) at the C5 level to find the differences due to gender and aging in axons of the lateral corticospinal tract. These results can be of great help in understanding the motor functions in relation to gender differences and the aging process.

Effects of different molting procedures on incidence of Salmonella infection in flocks of naturally contaminated laying hens in a commercial egg-producing farm by detection of yolk antibodies to Salmonella in eggs.

Indirect enzyme-linked immunosorbent assays (ELISAs) have been applied to detect immunoglobulin Y antibodies to different serotypes of Salmonella in the yolks of chicken eggs with heat-extracted antigens of Salmonella enterica serotypes Agona (SA), Cerro (SC), Enteritidis (SE), Montevideo (SM), and Putten (SP). The egg yolk samples examined were classified as positive if their ELISA absorbance values exceeded the value for eggs from specific-pathogen-free flocks by more than two standard deviations. Of 30 egg yolk samples from three flocks vaccinated with a killed SE vaccine, 29 were antibody positive by the ELISA assay for the SE antigen. Four to 29 of the 29 yolk samples showed positive results for the other serovars, although the absorbance values for SE were higher than those obtained for the other serotypes in each of the yolk samples. All 30 yolks from three flocks that were not administered any SE vaccines were found to be antibody negative for SE, and two samples were determined to be positive for SC. Thirty-nine or 40 eggs were obtained from each of four layer flocks in a commercial egg production farm where the laying houses were naturally contaminated with SA, SC, SM, SP, Salmonella serovar Infantis (SI), and untypeable strains. The ELISA absorbance values for SM in the egg yolks obtained from the two flocks molted through feed withdrawal when the birds restarted laying were significantly (P < 0.05) higher than those observed in the yolks obtained before the molt. In egg yolks from the two other flocks that were molted through a wheat bran diet, there was no significant difference between the absorbance values before and after the molt. The observations in the present study provide further evidence to suggest that a molt initiated through the administration of a wheat bran diet can reduce the risk for Salmonella problems in a commercial egg-producing setting.

Symbiotic Bradyrhizobium japonicum reduces N2O surrounding the soybean root system via nitrous oxide reductase.

N(2)O reductase activity in soybean nodules formed with Bradyrhizobium japonicum was evaluated from N(2)O uptake and conversion of (15)N-N(2)O into (15)N-N(2). Free-living cells of USDA110 showed N(2)O reductase activity, whereas a nosZ mutant did not. Complementation of the nosZ mutant with two cosmids containing the nosRZDFYLX genes of B. japonicum USDA110 restored the N(2)O reductase activity. When detached soybean nodules formed with USDA110 were fed with (15)N-N(2)O, they rapidly emitted (15)N-N(2) outside the nodules at a ratio of 98.5% of (15)N-N(2)O uptake, but nodules inoculated with the nosZ mutant did not. Surprisingly, N(2)O uptake by soybean roots nodulated with USDA110 was observed even in ambient air containing a low concentration of N(2)O (0.34 ppm). These results indicate that the conversion of N(2)O to N(2) depends exclusively on the respiratory N(2)O reductase and that soybean roots nodulated with B. japonicum carrying the nos genes are able to remove very low concentrations of N(2)O.

New method of denitrification analysis of bradyrhizobium field isolates by gas chromatographic determination of (15)N-labeled N(2).

To evaluate the denitrification abilities of many Bradyrhizobium field isolates, we developed a new (15)N-labeled N(2) detection methodology, which is free from interference from atmospheric N(2) contamination. (30)N(2) ((15)N(15)N) and (29)N(2) ((15)N(14)N) were detected as an apparent peak by a gas chromatograph equipped with a thermal conductivity detector with N(2) gas having natural abundance of (15)N (0.366 atom%) as a carrier gas. The detection limit was 0.04% (30)N(2), and the linearity extended at least to 40% (30)N(2). When Bradyrhizobium japonicum USDA110 was grown in cultures anaerobically with (15)NO(3)(-), denitrification product ((30)N(2)) was detected stoichiometrically. A total of 65 isolates of soybean bradyrhizobia from two field sites in Japan were assayed by this method. The denitrification abilities were partly correlated with filed sites, Bradyrhizobium species, and the hup genotype.