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Age-associated alterations in the mucosal immune system are generally termed mucosal immunosenescence. The major change seen in the aged mucosa is a failure to elicit an antigenspecific secretory IgA (SIgA) antibody response, which is a central player for host defense from various pathogens at mucosal surfaces. In this regard, it would be a first priority to compensate for mucosal dysregulation in the elderly in order to maintain their health in aging. We have successfully established antigen-specific SIgA antibody responses in aged (2 years old) mice, which provide protective immunity from Streptococcus pneumoniae and influenza virus infections, by using a new adjuvant system consisting of a plasmid encoding Flt3 ligand (pFL) and CpG ODN. In order to explore possible use of current mucosal vaccine strategies for the elderly, we have adoptively transferred adipose tissue-derived mesenchymal stem cells (AMSCs) to aged mice prior to mucosal vaccination. This immune therapy successfully resulted in protective antigen-specific antibody responses in the intestinal mucosa of aged mice that were comparable to those seen in young adult mice. In this regard, we postulate that adoptively transferred AMSCs could augment dendritic cell functions in aged mice. The potential cellular and molecular mechanisms whereby AMSCs restore mucosal immunity in immunosenescence are discussed in this short review. A stem cell transfer system could be an attractive and effective immunologic intervention strategy to reverse mucosal immunosenescence. [ABSTRACT FROM AUTHOR]

The elongation of pollen tubes in Lilium longiflorum cv. Hinomoto after self-incompatible pollination stopped halfway, but that after cross-compatible pollination (cross with cv. Georgia) did not. The elongation of pollen tubes after self-pollination was enhanced by exogenous cAMP and by pertussis toxin or cholera toxin, which activates adenylate cyclase. The level of endogenous cAMP in pistils after self-pollination was approximately one half of that after cross-pollination. Furthermore, the activity of adenylate cyclase in pistils after self-pollination was also approximately one half of that after cross-pollination. By contrast, cAMP phosphodiesterase in pistils after self-pollination was approximately 2 times as high as that after cross-pollination. A possible correlation between self-incompatibility and the low level of endogenous cAMP in lily pistils is discussed on the basis of these results. [ABSTRACT FROM PUBLISHER]

The effects of exogenous cAMP on the activities of the stress enzymes were studied using the extracts from stigmas and styles of Lilium longiflorum cv. Hinomoto without pollination in relation to self-incompatibility. The activity of NADH- and NADPH-dependent oxidases (O2--forming enzymes) was inhibited by cAMP. This inhibition was noncompetitive with NAD(P)H. [ABSTRACT FROM AUTHOR]

An attempt was made to examine the possible connection between self-incompatibility in Lilium longiflorum and the stress response using pistils after self-incompatible pollination. The growth of pollen tubes in the pistil after self-incompatible pollination was promoted by treatment with germanium compounds [(GeCH2CH2COOH)2O3 and GeO2], which are scavengers of active oxygen species, such as O2− and H2O2. The promotion by germanium compounds of the growth of pollen tubes after self-incompatible pollination was reflected by the detection of elevated levels of activity of superoxide-forming NADPH-dependent oxidase, xanthine oxidase, superoxide dismutase, catalase and ascorbate peroxidase, all of which are associated with stress responses, in pistils upon self-incompatible pollination as compared to the activities of these enzymes after cross-compatible pollination. A possible connection between self-incompatibility and stress in pistils upon self-incompatible pollination is discussed on the basis of these results. [ABSTRACT FROM AUTHOR]

Objective: The aim was to investigate the effects of a calcium antagonist (diltiazem) and a catecholamine (noradrenaline) on extracellular potassium accumulation during global ischaemia. Methods: Extracellular potassium concentration ([K+]e) was measured during 30 min global ischaemia in the isolated rat heart using a valinomycin potassium sensitive electrode. Contracture development during ischaemia was measured throughout with an intraventricular balloon inserted into the left ventricle and myocardial adenine nucleotides were measured in separate series of hearts. Results: In control hearts, [K+]e showed a characteristic triphasic change during 30 min global ischaemia. This consisted of an early rising phase followed by a transient falling phase after the initial peak of [K+]e, and then a late rising phase. Diltiazem suppressed the rate of rise of [K+]e during early ischaemia, but extended the time course of the early [K+]e rise with the higher dose, abolishing the transient falling phase of [K+]e. During late ischaemia, the rise in [K+]e was attenuated by diltiazem. Noradrenaline also suppressed the early extracellular potassium accumulation, but in contrast to diltiazem, hastened the time course of the late [K+]e rise. Conclusions: Although diltiazem suppresses the early potassium loss during ischaemia as previously described, the drug also decreases the [K+]e fall by some as yet unknown mechanism, so that the [K+]e level becomes higher than control during the falling phase.Cardiovascular Research 1992;26:1040-1045 [ABSTRACT FROM PUBLISHER]

The lymphoid tissues of monkeys infected with wild measles virus were examined by light microscopy and the fluorescent antibody technique. There was a good correlation between distribution of viral antigen and giant cells, most of which were of the reticular type. A large amount of viral antigen was always detected in giant cells, which suggested that these cells might be formed as a result of growth of measles virus in situ. Major growth sites of measles virus were found to be as the spleen, lymph nodes, and tonsils. It also appeared that the thymus and cecum might be involved to a lesser extent than the other lymphoid organs. Evidence of growth of virus in the bone marrow was not obtained. The possibility that the reticular cells are a main target of growth of measles virus was considered. [ABSTRACT FROM PUBLISHER]

Developments of Yaba monkey poxvirus and structures associated with it were electron-microscopically investigated. In the cytoplasm of the infected cells, numerous micelles appear near granular inclusions. The micelles are about 400A in diameter with a unit-membrane, which are located predominantly adjacent to the semicircular immature virus particles. Those micelles seem to develop in the following manner, that is, they assemble in several numbers to make a membranous structure like shell membrane (primary membrane of the virus) and they grow gradually to be encircled with each other as forming the inner membrane. The inner membrane and surface subunits compose an immature virus particle, of which the latter might regulate the arcs of membrane in a constant diameter (3,000 ∼ 4,000A). Then a dense material like nucleoid is formed in the circular structure. Subsequently, two high density parts of the membranous structures emerge in the circular structure to make the core membrane. Finally, the core becomes a dumbbell-shaped structure with lateral bodies and is encircled with myelin figure structure. [ABSTRACT FROM PUBLISHER]