Separation and quantification of serum alkaline phosphatase isozymes in the rat by affinity electrophoresis

The purpose of this study was to examine the possibility of separation and quantification of serum alkaline phosphatase (ALP) isozymes in rats by wheatgerm lectin affinity electrophoresis. Cellulose acetate electrophoresis of the liver and bone ALPs without lectin results in overlapping bands, but in the presence of lectin, the mobility of the band of bone enzyme was retarded and well separated from the liver enzyme band. With this affinity electrophoretic method, we determined the serum ALP isozymes in fed and fasting rats grouped by age. As a result, the absolute activity of bone isozyme showed a downward trend with age in the fed and fasting rats. The serum ALP activity was steadily higher in fed rats than in fasting rats, and the increase was due to intestinal ALP isozyme. There was low activity bordering complete absence in liver isozyme under both nutritional conditions. The affinity electrophoretic method provided a rapid, reproducible, and relatively simple technique for further clinical characterization of ALP isozyme in the rat serum.     

Unique T Cells with Unconventional Cytokine Profiles Induced in the Livers of Mice during Schistosoma mansoni Infection

During infection with Schistosoma, serious hepatic disorders are induced in the host. The liver possesses unique immune systems composed of specialized cells that differ from those of other immune competent organs or tissues. Host immune responses change dramatically during Schistosoma mansoni infection; in the early phase, Th1-related responses are induced, whereas during the late phase Th2 reactions dominate. Here, we describe unique T cell populations induced in the liver of mice during the period between Th1- and Th2-phases, which we term the transition phase. During this phase, varieties of immune cells including T lymphocytes increase in the liver. Subsets of CD4⁺ T cells exhibit unique cytokine production profiles, simultaneously producing both IFN-γ and IL-13 or both IFN-γ and IL-4. Furthermore, cells triply positive for IFN-γ, IL-13 and IL-4 also expand in the S. mansoni-infected liver. The induction of these unique cell populations does not occur in the spleen, indicating it is a phenomenon specific to the liver. In single hepatic CD4⁺ T cells showing the unique cytokine profiles, both T-bet and GATA-3 are expressed. Thus, our studies show that S. mansoni infection triggers the induction of hepatic T cell subsets with unique cytokine profiles.     

Regulation of active and quiescent somatic stem cells by Notch signaling

Somatic stem/progenitor cells actively proliferate and give rise to different types of mature cells (active state) in embryonic tissues while they are mostly dormant (quiescent state) in many adult tissues. Notch signaling is known to regulate both active and quiescent states of somatic stem cells, but how it regulates these different states is unknown. Recent studies revealed that the Notch effector Hes1 is expressed differently during the active and quiescent states during neurogenesis and myogenesis: high in the quiescent state and oscillatory in the active state. When the Hes1 expression level is high, both Ascl1 and MyoD expression are continuously suppressed. By contrast, when Hes1 expression oscillates, it periodically represses expression of the neurogenic factor Ascl1 and the myogenic factor MyoD, thereby driving Ascl1 and MyoD oscillations. High levels of Hes1 and the resultant Ascl1 suppression promote the quiescent state of neural stem cells, while Hes1 oscillation-dependent Ascl1 oscillations regulate their active state. Similarly, in satellite cells of muscles, known adult muscle stem cells, high levels of Hes1 and the resultant MyoD suppression seem to promote their quiescent state, while Hes1 oscillation-dependent MyoD oscillations activate their proliferation and differentiation. Therefore, the expression dynamics of Hes1 is a key regulatory mechanism of generating and maintaining active/quiescent stem cell states.     

The content of protein, fibre and minerals of leaves of selected Acacia species indigenous to north-western Tanzania

Browse tree leaves of six species of Acacia (A. angustissima L., A. drepanolobium L., A. nilotica L., A. polyacantha L., A. senegal L., A. tortilis L.) were screened for chemical composition, including minerals and trace elements. Crude protein (CP) varied among the species from 145 (A. senegal) to 229 g/kg DM (A. angustissima). The species had moderate to high levels of minerals. The concentrations of Ca, P, Mg and S varied among the species from 14.6-31.5, 3.5-4.9, 1.4-3.0 and 1.7-2.8 g/kg DM, respectively. The forages showed relatively low concentrations of trace elements. Content of trace elements varied among the species from 4.5-23.8, 99.4-173.6, 146.2-432, 41.0-90.1, 10.9-22.2 and 0.05-0.65 mg/kg DM for Cu, Mo, Fe, Mn, Zn and Co, respectively. All leaves of browse species would meet the normal requirements for Ca, P, Mg and S in ruminants, although some species had higher levels of Ca than tabulated mineral requirements in livestock. Assayed Cu, Mn, Zn and Co would satisfy the lower range of recommended requirements of trace elements depending on their bioavailability. Therefore, browse leaves from Acacias could form good sources of CP and mineral supplements to ruminants.     

Unprecedented olefin-dependent histidine-kinase inhibitory of zerumbone ring-opening material

Zerumbone ring-opening derivative, 4 (10E/10Z=3/2), inhibited autophosphorylation of the essential histidine-kinase YycG existing in Bacillus subtilis constituting a two-component system (TCS). Generation of 4E-form could be regulated chemically using the difference from the ring-opening reactivity of the precursor forming of 4 and pure 4E was isolated. The stereoisomer, 4E, showed main inhibition activity of autophosphorylation of YycG (IC(50)=63.5 microM).     

Thiazolidinediones increase arachidonic acid release and subsequent prostanoid production in a peroxisome proliferator-activated receptor gamma-independent manner

Thiazolidinedione, peroxisome proliferator-activated receptor gamma (PPARgamma) agonist, has been used as an anti-diabetic drug and as an useful tool to elucidate multiple PPARgamma functions by in vitro and in vivo studies. We investigated the effects of thiazolidinediones on prostanoid production in lipopolysaccharide-stimulated cells. The high concentrations (>10 microM) of rosiglitazone and pioglitazone significantly increased lipopolysaccharide-stimulated prostanoid production such as thromboxane A2 and prostaglandin E2. However, PPARgamma antagonist could not inhibit them. In PPARgamma-deficient cells, thiazolidinediones increased prostaglandin E2 production. Thiazolidinediones increased arachidonic acid (AA) release from the cell membrane by not stimulating AA releasing process involving several phospholipase A2s but inhibiting AA reuptaking process. The expression of cyclooxygenase-1 and cyclooxygenase-2 were not affected by thiazolidinediones. In this study, we demonstrated that high concentrations of TZDs increased AA release by the inhibition of AA reuptaking process, leading to subsequent increase in the prostanoid production in a PPARgamma-independent manner. This mechanism provides useful information for the elucidation of multiple PPARgamma functions and diabetic drug therapy.     

Necdin is required for terminal differentiation and survival of primary dorsal root ganglion neurons

Necdin is expressed predominantly in postmitotic neurons and serves as a growth suppressor that is functionally similar to the retinoblastoma tumor suppressor protein. Using primary cultures of dorsal root ganglion (DRG) of mouse embryos, we investigated the involvement of necdin in the terminal differentiation of neurons. DRG cells were prepared from mouse embryos at 12.5 days of gestation and cultured in the presence of nerve growth factor (NGF). Immunocytochemistry revealed that necdin accumulated in the nucleus of differentiated neurons that showed neurite extension and expressed the neuronal markers microtubule-associated protein 2 and synaptophysin. Suppression of necdin expression in DRG cultures treated with antisense oligonucleotides led to a marked reduction in the number of terminally differentiated neurons. The antisense oligonucleotide-treated cells did not attempt to reenter the cell cycle, but underwent death with characteristics of apoptosis such as caspase-3 activation, nuclear condensation, and chromosomal DNA fragmentation. Furthermore, a caspase-3 inhibitor rescued antisense oligonucleotide-treated cells from apoptosis and significantly increased the population of terminally differentiated neurons. These results suggest that necdin mediates the terminal differentiation and survival of NGF-dependent DRG neurons and that necdin-deficient nascent neurons are destined to caspase-3-dependent apoptosis.