Functional kupffer cells migrate to the liver from the intraperitoneal cavity

We established a method of KC transplantation by intraperitoneal (i.p.) injection using EGFP-expressing cells (EGFP-KCs) and normal KCs. The novel method is easier and less invasive than conventional methods so that it is not only technically advantageous but also ethically preferable for experiments using animals. We demonstrated that KCs migrated to the liver following i.p. Injection. Engraftment in the liver was not observed for peritoneal macrophages (pMPs). This suggests that KCs migrate to the liver via a sorting mechanism. KC injection decreased the KC number at 24 h and then recovered the KCs at 10 days to a normal level. Additionally, recovery to the normal level by KC injection was observed in mice with KC depletion induced by GdCl₃. These results suggest that a regulatory mechanism exists for controlling the number of KCs.     

MIC-A allele profiles and HLA class I associations in Behçet's disease

Recently a new family of non-classical MHC molecules, the MHC class I chain-related protein (MIC), encoded by genes located in the major histocompatability complex have been identified. On the basis of the location of MIC genes and the structure and expression of MIC molecules it has been postulated that MIC may be a susceptibility factor in Behçet's disease (BD). We investigated the association of the 16 described external domain alleles and the transmembrane triplet repeats of MIC-A with BD in a Middle Eastern population. DNA from ninety-five patients and 102 age- and sex-matched controls were analyzed by polymerase chain reaction using allele specific primers. Our results show an increase of MIC-A*009 in the BD patient group 44/95 (46%) compared with controls 24/102 (24%) (χ²=11.3, OR=2.8, P=0.00078). MIC-A*009 was also found to be strongly associated with HLA-B51 in the patients 39/44 (88%) when compared with controls 10/24 (42%) (χ²=4, P=0.04). MIC-A*009 was also found in linkage disequilibrium with HLA-B52, but only in controls. The A6 form of a MIC-A transmembrane triplet repeat was found to be significantly raised in the patients (80/95; 84%;) compared with controls (58/102, 57%) (χ²=17.5, OR=4, P=0.000028). Although the MIC-A associations described are highly significant, the association with HLA-B51 independently remains the most significant factor (χ²=56.8, P<10^–6). The data suggests that as both MIC-A*009 and A6 are in strong linkage disequilibrium with HLA-B51, they are unlikely to be the susceptibility gene for BD but may be markers for additional risk factors.     

N-terminal [Glu]3 moiety of γ-glutamyl peptides contributes largely to the activation of human calcium-sensing receptor,a kokumi receptor

ABSTRACT

γ-glutamyl peptides have been suggested to impart kokumi properties to foods by activating human calcium-sensing receptor (hCaSR). In this study, the relationship between γ-glutamyl peptide structure and hCaSR activity was systematically analyzed using γ-[Glu]_(n=0-4)-α-[Glu]_(n=0-3)-Tyr. Our results suggest that N-terminal [Glu]₃ moiety is very important for hCaSR activities of γ-glutamyl peptides.     

Nuclear magnetic resonance evidence for the dimer formation of beta amyloid peptide 1–42 in 1,1,1,3,3,3-hexafluoro-2-propanol

Alzheimer's disease involves accumulation of senile plaques in which filamentous aggregates of amyloid beta (Aβ) peptides are deposited. Recent studies demonstrate that oligomerization pathways of Aβ peptides may be complicated. To understand the mechanisms of Aβ(1–42) oligomer formation in more detail, we have established a method to produce ¹⁵N-labeled Aβ(1–42) suited for nuclear magnetic resonance (NMR) studies. For physicochemical studies, the starting protein material should be solely monomeric and all Aβ aggregates must be removed. Here, we succeeded in fractionating a “precipitation-resistant” fraction of Aβ(1–42) from an “aggregation-prone” fraction by high-performance liquid chromatography (HPLC), even from bacterially overexpressed Aβ(1–42). However, both Aβ(1–42) fractions after 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) treatment formed amyloid fibrils. This indicates that the “aggregation seed” was not completely monomerized during HFIP treatment. In addition, Aβ(1–42) dissolved in HFIP was found to display a monomer–dimer equilibrium, as shown by two-dimensional ¹H–¹⁵N NMR. We demonstrated that the initial concentration of Aβ during the HFIP pretreatment altered the kinetic profiles of Aβ fibril formation in a thioflavin T fluorescence assay. The findings described here should ensure reproducible results when studying the Aβ(1–42) peptide.     

Lectin activity of Bacillus thuringiensis parasporal inclusion proteins

Parasporal inclusion proteins from a total of 151 Bacillus thuringiensis strains, consisting of 139 Japanese isolates and the type strains of 12 H serovars, were screened for haemagglutination (HA) activity against sheep erythrocytes. Of 58 B. thuringiensis strains with HA activity, nine strains exhibited high activity and the remaining 49 strains were moderately active. The strains with high HA activity were derived from phylloplanes and soils of five geographically different localities, and belonged to H serovars kurstaki and other undefined serotype(s). The HA activities in the four selected strains were generated only when alkali-solubilised parasporal inclusion proteins were proteolytically processed. Furthermore, the lectin activity of the four strains was strongly inhibited by preincubation with N-acetylgalactosamine. The lectin-producing B. thuringiensis strains were heterogeneous in other biological activities of parasporal inclusions: insecticidal activity and cytocidal action on human leukaemia T cells.     

Structure and diversity of remnant natural evergreen broad-leaved forests at three sites affected by urbanization in Chongqing metropolis,Southwest China

Evergreen broad-leaved forests (EBLFs, lucidophyllous forests) are vegetation types characteristic of East Asia. The extent of EBLFs has decreased significantly due to long-term anthropogenic disturbance, and remnant EBLFs in urban area are rare and important landscape types contributing to biodiversity and sustainable development. This study focuses on remnant EBLFs on Mt. Gele (GL), Mt. Tieshanping (TSP), and Mt. Jinyun (JY), located from the inner city to outskirts of Chongqing metropolis, Southwest China. Species of Theaceae, Lauraceae, Symplocaceae, and other families, which are essential floristic components of primary EBLFs, were still the main components at the three sites. GL and JY showed higher biodiversity, with richer heliophytes and shade-tolerant species, respectively. Castanopsis carlesii var. spinulosa was the sole dominant species at all three sites in woody layer, with codomination by Pinus massoniana and Cinnamomum camphora at GL and by Machilus pingii and Castanopsis fargesii at JY; these evergreen broad-leaved trees all showed inverse-J or sporadic-shaped size distribution with large numbers of small stems, but the conifer tree Pinus massoniana showed unimodal distribution with small stems at GL. The height growth of tree species, especially Castanopsis carlesii var. spinulosa, was increasingly restricted from JY to TSP to GL. Sprouting is an important life history strategy at community and population level, and differences were exhibited from GL to TSP to JY. A rural–urban gradient from JY to TSP to GL was indicated in this study. Species composition, biodiversity, and stand structure of these remnant EBLFs showed obvious differences along this gradient, and conservation responses to address the effects of urbanization need to be carefully considered.     

Endogenous cytokines during a lethal infection with Listeria monocytogenes in mice

It has been demonstrated that endogenous cytokines including gamma interferon (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6) play protective roles but that IL-4 and IL-10 play detrimental roles in nonlethal Listeria monocytogenes infection in mice. In this paper, we studied the roles of endogenous cytokines in a lethal infection with L. monocytogenes in mice. TNF-alpha and IL-6 titres in the bloodstreams, spleens and livers paralleled bacterial numbers in the organs, and both these cytokines and the bacterial numbers peaked just before the mice died. The high titres of TNF-alpha notably detected in the circulation in lethal infection were different from those in nonlethal infection. The maximum production of IFN-gamma was observed before the peaks of TNF-alpha and IL-6, and IFN-gamma almost disappeared from the bloodstreams and organs just before the mice died. No notable difference of IFN-gamma titres between lethal infection and nonlethal infection in the specimens obtained from mice was observed. IL-10 was also detected in the bloodstreams earlier than the peaks of TNF-alpha and IL-6 during lethal infection, while IL-4 was never detected in the sera. The administration of monoclonal antibodies (mAbs) against TNF-alpha, IFN-gamma, IL-6, IL-4 or IL-10 failed to rescue mice from lethal L. monocytogenes infection, whereas anti-TNF-alpha mAb and anti-IFN-gamma mAb prevented mice from lethality by high-dose endotoxin shock. These results suggest that lethality in L. monocytogenes infection might not be determined solely by these cytokines.     

A case of chronic necrotizing pulmonary aspergillosis due toAspergillus nidulans

A 55-year old man without immunosuppression clinically showed a coin lesion in the right lower lung on the chest radiographs.Aspergillus nidulans was isolated and identified in both trans-bronchial lung biopsy specimen and resected tissue. The specimens revealed characteristics of chronic necrotizing pulmonary aspergillosis pathologically. Very few reports on cases of pulmonary aspergillosis due toA. nidulans exist, and we were not able to find any reports of similar cases. This case may be the first reported case of chronic necrotizing pulmonary aspergillosis due toA. nidulans.