A Similar Expression Pattern of Adhesion Molecules between Intermediate TCR Cells in the Liver and Intraepithelial Lymphocytes in the Intestine

Two major populations of extrathymically differentiated T cells exist in the liver and intestine. Such T cells in the liver have TCR of intermediate intensity (i.e., intermediate TCR cells) and constitutively express IL-2 receptor β-chain (IL-2Rβ), whereas those in the intestine, especially intraepithelial lymphocytes, have TCR of bright intensity, consisting of a mixture of IL-2Rβ⁺ and IL-2Rβ^–. All mature thymocytes and thymus-derived T cells seen in the peripheral immune organs are TCR-bright⁺IL-2Rβ^– under resting conditions. When the expression pattern of adhesion molecules, including CD44, L-selectin, LFA-1 and ICAM-1, was compared among these T-cell populations, they displayed quite unique patterns of expression. All extrathymic T cells in the liver, intestine, and even other organs were CD44⁺L-selectin^– LFA-1⁺⁺ICAM-1⁺, whereas thymocytes and thymus-derived T cells were CD44^– L-selectin⁺LFA-1⁺ICAM-1^–. This inverted expression of adhesion molecules between extrathymic T cells and thymus-derived T cells might be associated with their unique tissue-localization.     

The number of species occurring in a sample of a biotic community and its connections with species-abundance relationship and spatial distribution

Connections among species-abundance (i-m _i ), species-frequency (i-F _i ), and species-sample size (S _n -n) relationships were examined on the basis of the mapping data of a natural forest in Thailand. The spatial distribution of individual trees without any discrimination of species was nearly random. Provided that the spatial distribution of each species was random, thei-m _i and thei-F _i relationship was reconstructed from each other in terms of the total number of species (S) and the total number of individuals (N) in the data. The number of species (S _n ) in a subsample consisting ofn individuals was then obtained from thei-F _i relationship. Logarithm ofS _n increased with logn and showed a convex curve through the origin. The values of diversity indices based onN andS(orn andS _n ) were affected by sample size. These trends were further examined on the basis of 944 data sets of biotic communities and three mathematical models of anS-N relationship. The properties of species-area relation were discussed in the light of these results.     

金花茶花药愈伤组织的体细胞减数分裂

金花茶(Camellia petelotii)的小孢子单核期花药,经培养和继代培养6个月后的愈伤组织中,发现有少量体细胞进行减数分裂。在减数第一和第二次分裂中,同源染色体的配对和分离基本正常,最后形成四分体。该愈伤组织经石蜡切片和压片观察,发现其主要由大量的液化细胞和贮藏细胞所组成,此外,还有少部分分生细胞。没有发现进一步的分化。其染色体数目,2n=30者占71.7%其余则为非整倍体。     

Involvement of Collagen Synthesis in Tissue Reconstitution by Dissociated Sponge Cells

Cells dissociated from the sponge Haliclona permollis reconstituted a new body by the following three consecutive processes: (1) Reaggregation, cells aggregate as a spheroidal mass. (2) Spreading, aggregates flatten and spread. (3) Reconstruction, aggregates coalesce into a reconstituted body. Cells in the process of reconstitution incorporated ¹⁴C-proline into proteins, converting 17% of it to hydroxyproline and synthesize collagen molecules during this process. Inhibitors of collagen biosynthesis did not affect the reaggregation, but caused incomplete morphogenesis in the processes of spreading and reconstruction: cycloheximide and 2,2'-dipyridyl inhibited spreading while 3-aminopropionitrile induced incomplete reconstruction. These findings suggested that spreading and reconstruction, but not reaggregation require both synthesis and cross-linking of collagens. Three polypeptides with molecular weights of 58 K, 160 K and 180 K were identified in sponge cells as collagens by immunoblot analysis with antibodies against sea urchin collagen and studies on susceptibilities to collagenase and pepsin. The 58 KDa polypeptide appeared in reconstituted bodies but not in dissociated cells, suggesting its importance in tissue reconstitution by dissociated cells.     

The development of emotion regulation ability between the ages of 13 and 18 months in Japanese infants during the strange situation as a function of mothers' styles of emotion expression

The purposes of this study were two-fold. First, it compared Japanese infants' (N=129) abilities to regulate emotions at 13 months and 18 months of age, using the Strange Situation procedure. Second, it examined the relationship between the development of emotion regulation and the mother's emotion expression style as assessed by the Emotion Expression Style Questionnaire (EESQ). The total number of subjects who successfully completed all 8 episodes of the Strange Situation procedure increased significantly during the aging between 13 and 18 months of age, indicating that as a group these infants increased their ability to cope with stressful situations. However, infants who had mothers with negative emotion expression styles did not show greater capacity for emotion regulation at 18 months. These findings suggest that the development of emotion regulation is mediated by the mother's emotion expression style.     

Light-induced phase-shifting of the peripheral circadian oscillator in the hearts of food-deprived mice.

In the present study, we investigated the effect of fasting on photoentrainment of the peripheral circadian oscillator in the mammalian heart. Northern blotting showed that a single light pulse applied at an appropriate time in constant darkness, caused obvious phase-shifting in the circadian expression rhythm of the mammalian clock gene Period2 (mPer2) even in the hearts of food-deprived mice. Fasting did not significantly affect either the phase or the light-induced phase-shifts of the mPer2 rhythm. Although several studies of temporal feeding restriction have indicated that feeding is the dominant timing cue for mammalian peripheral oscillators, our findings suggest that feeding is not essential for mammals to induce phase resetting of the circadian oscillator in the heart.     

The effects of calystegines isolated from edible fruits and vegetables on mammalian liver glycosidases

The polyhydroxylated nortropane alkaloids called calyste-ginesoccur in many plants of the Convolvulaceae, Solanaceae, andMoraceae families. Certain of these alkaloids exhibit potentinhibitory activities against glycosidases and the recentlydemonstrated occurrence of calystegines in the leaves, skins,and sprouts of potatoes (Solatium tuberosum), and in the leavesof the eggplant (S.melongena), has raised concerns regardingthe safety of these vegetables in the human diet. We have surveyedthe occurrence of calystegines in edible fruits and vegetablesof the families Convolvulaceae, Solanaceae, and Moraceae byGC-MS. Calystegines A3, B1, B2, and C1 were detected in allthe edible fruits and vegetables tested; sweet and chili peppers,potatoes, eggplants, tomatoes, Physalis fruits, sweet potatoes,and mulberries. Calystegines B1 and C1 were potent competitiveinhibitors of the bovine, human, and rat β-glucosidaseactivities, with K₁ values of 150, 10, and 1.9 µM, respectivelyfor B1 and 15,1.5, and 1 µM, respectively, for C1. CalystegineB2 was a strong competitive inhibitor of the -galactosidaseactivity in all the livers. Human β-xylosidase was inhibitedby all four nortropanes, with calystegine C1 having a K₁ of0.13 µM. Calystegines A3 and B2 selectively inhibitedthe rat liver β-glucosidase activity. The potent inhibitionof mammalian β-glucosidase and -galactosidase activitiesin vitro raises the possibility of toxicity in humans consuminglarge amounts of plants that contain these compounds. edible plants calystegines glycosidase inhibitors bovine, human, and rat liver     

Studies on the factors influencing larval settlement in Balanus amphitrite and Mytilus galloprovincialis

Understanding of factors influencing settlement(attachment and metamorphosis) of marine invertebratelarvae is of great importance in aquaculture andcontrol of biofouling. The influence of two factors onsettlement of larvae was assessed from two separateinvestigations: 1, the influence of age (endogenousfactor) on cyprids of the barnacle Balanusamphitrite; and 2, the influence of a microbial film(exogenous factor) on pediveligers of the mussel Mytilus galloprovincialis.The settlement response of cypris larvae of B.amphitrite was found to be age-dependent. Oldercyprids responded more readily to settlement factorsthan newly molted ones. In M.galloprovincialis, competent pediveligers settled inresponse to a microbial filmed surface but not toan unfilmed surface. Moreover, a factor with MW of lessthan 5000 dalton, derived from culture medium of abacterial strain C1.1 (Pseudomonas-Alteromonasgroup), induced the settlement of M. galloprovincialis larvae.Thus, marine invertebrate larvae may require a periodof competence acquisition, during which they arepoorly responsive to settlement inducers. Uponacquisition of competence, larvae readily respondto external cues (e.g. microbial film, bacterialextracellular products).     

Rapid Identification by Polymerase Chain Reaction of Staphylococcal Exfoliative Toxin Serotype A and B Genes

A new system was designed to detect staphylococcal exfoliative toxin A (ETA) and B (ETB) genes by the polymerase chain reaction (PCR). The primer pairs for the ETA gene (eta) were 20 and 20-mer, and its PCR product was a 741-bp eta fragment, while the primer pairs for the ETB gene (etb) were also 20 and 20-mer, and its PCR product was a 629-bp etb fragment. When these primers were simultaneously used in the PCR, the two types of ET were clearly detected as two bands in an ETA and ETB double-producer using only one colony within 3 hr. We examined 66 strains of Staphylococcus aureus isolated from patients with staphylococcal scalded skin syndrome (SSSS) and compared the results obtained by ELISA and PCR. The same results were obtained for 56 of the strains, i.e., 30 strains were ETA producers, 20 strains were ETB producers, and 6 strains were double-producers. However, positive results were obtained for 5 of the 10 non-ET-producing strains. Two of these strains were judged by PCR as ETA producers and three as ETB producers. Thus, PCR is very sensitive and rapid in detecting ETA and ETB gene fragments in colonies isolated from patients with SSSS.