Electrical stimulation of the suprachiasmatic nucleus of the hypothalamus causes hyperglycemia

We have presented evidence suggesting that the suprachiasmatic nucleus (SCN) is involved in central regulation of glucose homeostasis. To elucidate this role of the SCN, we examined the effects of its electrical stimulation on glucose metabolism in male Wistar rats. During and shortly after this stimulation, we observed hyperglycemia associated with enhanced hyperglucagonemia but no immediate hyperinsulinemia. In addition, we detected significant increase in liver glycogen phosphorylase alpha activity and significant decrease in the liver glycogen content. These findings suggest that the SCN is important in control of glucose homeostasis through effects on glucagon and insulin secretions and liver glycogen metabolism.     

Frequent detection of anti-recoverin cytotoxic T-lymphocyte precursors in peripheral blood of cancer patients by using an HLA-A24-recoverin tetramer

Recoverin is a photoreceptor-specific calcium binding protein that is only expressed in the retina in normal tissues. Aberrant expression of recoverin, however, has been observed in several cancer tissues and may cause a very rare autoimmune disease, cancer-associated retinopathy (CAR). It has been suggested that CAR-positive cancer patients have a more favorable prognosis than CAR-negative cancer patients. To estimate the status of recoverin-specific T cells in such cancer patients, we generated an HLA-A24-recoverin peptide tetramer. By use of the tetramer, we could directly assess the frequency of CTL precursors (CTLp) of 20 HLA-A24(+) cancer patients with ten colon, six stomach and four breast cancers, and seven healthy individuals. Four cancer patients showed a CTLp frequency higher than 0.9%. Seven cancer patients including the former four patients and two healthy individuals showed specific anti-recoverin cytotoxic responses in an HLA-A24-restricted manner after in vitro stimulation with the recoverin peptide. Moreover, five cancer patients analyzed in an independent experiment using different peripheral blood mononuclear cells (PBMC) samples showed similar CTLp and cytotoxic T lymphocyte (CTL) frequencies and cytotoxic responses, suggesting that the CTLp frequency analyzed by the tetramer and the cytotoxic response may have a good correlation. Thus, we hypothesize that anti-recoverin CTLp may exist in some cancer patients, and that anti-recoverin CTL may be readily induced.     

Flesh‐eating Streptococcus pyogenes triggers the expression of receptor activator of nuclear factor‐κB ligand

Human CD46 is a receptor for the M protein of group A streptococcus (GAS). The emm1 GAS strain GAS472 was isolated from a patient suffering from streptococcal toxic shock‐like syndrome. Human CD46‐expressing transgenic (Tg) mice developed necrotizing fasciitis associated with osteoclast‐mediated progressive and severe bone destruction in the hind paws 3 days after subcutaneous infection with 5 × 10⁵ colony‐forming units of GAS472. GAS472 infection induced expression of the receptor activator of nuclear factor‐κB ligand (RANKL) while concomitantly reducing osteoprotegerin expression in the hind limb bones of CD46 Tg mice. Micro‐computed tomography analysis of the bones suggested that GAS472 infection induced local bone erosion and systemic bone loss in CD46 Tg mice. Because treatment with monoclonal antibodies (mAbs) against mouse CD4⁺ and CD8⁺ T lymphocytes did not inhibit osteoclastogenesis, T lymphocyte‐derived RANKL was not considered a major contributor to massive bone loss during GAS472 infection. However, immunohistochemical analysis of the hind limb bones showed that GAS472 infection stimulated RANKL production in various bone marrow cells, including fibroblast‐like cells. Treatment with a mAb against mouse RANKL significantly inhibited osteoclast formation and bone resorption. These data suggest that increased expression of RANKL in heterogeneous bone marrow cells provoked bone destruction during GAS infection.     

Metabolic Quotient Measured by Free-Water Method in Six Enclosures with Different Silver Carp Densities

Quasi-continuous DO and pH measurements (total 47 days) were conducted during enclosure experiments (6 enclosures; 5 × 5 × 2.5 m), in which a biomass gradient of silver carp was created. After subtracting the air–water exchanges of O₂ and CO₂, the chemical and biochemical changes in DO (dissolved oxygen) and DIC (dissolved inorganic carbon) were estimated in order to evaluate MQ (metabolic quotient: DO change divided by DIC change) at intervals of 1 hour. By removing small absolute changes below the threshold value (0.01 mM h^?1), the averaged values of the 24 MQ means for the respective 1-hour periods ranged from 0.96 to 1.20 in the six enclosures. Because the MQs in the daytime inversely correlated well with the ratio of NH⁺ ₄–N to (NH⁺ ₄–N + NO^? ₃–N), not the ecosystems, i.e., density of fish, community structure of zooplankton and phytoplankton, but the form of nitrogen uptaken for primary production principally determined the MQs. The higher MQs observed in the daytime compared with the nighttime (from 14% to 21% except 3% for one enclosure) could not be explained by the denitrification and/or dissolution of CaCO₃ in the sediments, therefore suggesting the selectively faster decomposition of part of the organic matter provided through primary production, in other words, an accumulation of another part of the organic matter in the diurnal and/or daily time scale.     

A proposal of framework to obtain an integrated biodiversity indicator for agricultural ponds incorporating the simultaneous effects of multiple pressures

One of the promising approaches to monitoring biodiversity is assessing the status of pressures driving the biodiversity state. To achieve this, we need to identify the principal pressures that cause simultaneous biodiversity loss across taxonomic groups and clarify how multiple pressures act synergistically or at least simultaneously to decrease biodiversity in the focal ecosystem. Here, we used a series of 64 ponds as a case study and we developed a framework for an integrated biodiversity indicator that took into consideration the estimated relative importance of multiple pressures. The indicator is defined as a function of the pressure(s) and is parameterized to explain a number of individual indicators of biodiversity, such as richness, abundance, and functional diversity of focal taxa. We selected aquatic macrophytes, Odonata, and benthic macroinvertebrates as the focal taxa. In addition, we focused on three types of pressure: eutrophication (represented by total phosphorus, total nitrogen, suspended solids, chlorophyll a, and density of cyanobacteria of pond water), habitat destruction (land-use type around the pond and pond bank protection), and invasive alien species (abundance of bluegill, largemouth bass, red swamp crayfish, and American bullfrog). We then evaluated the relationships among direct pressures and the individual biodiversity indicators and used a hierarchical Bayesian approach to calculate the integrated biodiversity indicator. Using this framework, we demonstrated that eutrophication had greater effects on the state of biodiversity of the agricultural ponds than did habitat destruction or the presence of invasive alien species. We also showed that the integrated indicator could well explain the behaviors of several individual biodiversity indicators, including total richness, endangered species richness, and functional diversity of focal taxa. These results demonstrate the advantages of the framework in providing a more practical method for assessing biodiversity, and quantifying the relative importance of the major threats to biodiversity to prioritize strategies in conservation planning and policy making.     

Changes in the intracellular concentration of acetyl-CoA and malonyl-CoA in relation to the carbon and energy metabolism of Escherichia coli K12

Intracellular concentrations of acetyl-CoA and malonyl-CoA in Escherichia coli K12 were determined by a malonyl-CoA: acetyl-CoA cycling technique. Under aerobic growth conditions with glucose the acetyl-CoA and malonyl-CoA concentrations varied over a range of 0.05-1.5 nmol (mg dry wt)-1 (20-600 microM) and 0.01-0.23 nmol (mg dry wt)-1 (4-90 microM), respectively. The intracellular concentration of acetyl-CoA was highest in exponentially growing cells and it fell rapidly to less than 5% of the maximum level when the organism entered stationary phase after exhaustion of glucose. A linear relationship was observed between the intracellular concentration of total acyl-CoA and the logarithm of the concentration of glucose in the medium. Consequently, the acetyl-CoA/malonyl-CoA ratios also varied drastically, in a range of 0.6-41.7, under different conditions. Of several carbon sources tested, glucose was the most effective for promoting the synthesis of cellular acetyl-CoA. For cells grown on glycerol or acetate the maximum concentrations of total acyl-CoA were significantly lower. In cells incubated with citrate (not used as a carbon source by E. coli), the level was consistent with that in cells starved for exogenous carbon sources.     

Somatic embryogenesis ofCyclamen persicum Mill. ‘Anneke’ from aseptic seedlings

Summary InCyclamen persicum Anneke, explants from the various vegetative organs of aseptic seedling formed embryoids. The optimal responses were recorded in Murashige and Skoog (MS) medium enriched with 5.0µM 2,4-dichlorophenoxyacetic acid (2,4-D), 0.5µM kinetin and 3–6% sucrose. Embryogenesis was enhanced at higher temperature of 25–30°C. On the other hand, light inhibited embryogenesis. Histological and morphological studies confirmed that the embryoids were indeed somatic embryos.Abbreviations MS Murashige and Skoog - 2,4-D 2,4-dichlorophenoxyacetic acid     

A novel point mutation in congenital erythropoietic porphyria in two members of Japanese family

The molecular basis of the uroporphyrinogen III synthase (UROIIIS) deficiency was investigated in two members of a Japanese family. This defect in heme biosynthesis is responsible for a rare autosomal recessive disease: congenital erythropoietic porphyria (CEP) or Günther’s disease. The first patient was homoallelic for a novel missense mutation: a T to C transition of nucleotide 634 that predicted a serine to proline substitution at residue 212 (S212P). The second patient appeared heteroallelic, carrying the same missense mutation and a nonsense mutation: a C to T change at nucleotide 745, resulting in a premature stop at codon 249, instead of a glutamine (Q249X). The corresponding mutated proteins were expressed in Escherichia coli and no residual activity was observed. A family study was also performed to determine the carrier status. Received: 18 July 1995     

Expression of gibberellin 3 beta-hydroxylase gene in a gravi-response mutant, weeping Japanese flowering cherry.

Expressions of the gibberellin biosynthesis gene were investigated in a normal upright type and a gravi-response mutant, a weeping type of Japanese flowering cherry (Prunus spachiana), that is unable to support its own weight and elongates downward. A segment of the gibberellin 3 beta-hydroxylase cDNA of Prunus spachiana (Ps3ox), which is responsible for active gibberellin synthesis, was amplified by using real-time RT-PCR. The content of Ps3ox mRNA in the weeping type was much greater than that in the upright type, while the endogenous gibberellin level was much higher in the elongating zone of the weeping type. These results suggest that the amount and distribution of synthesized gibberellin regulate secondary xylem formation, and the unbalanced distribution of gibberellin affects the gravi-response of the Prunus tree.