Spontaneous peritoneal malignant mesothelioma in a geriatric japanese macaque (Macaca fuscata).

A 28.5-year-old female Japanese macaque (Macaca fuscata) was euthanatized because of abdominal distension due to severe ascites. Nodular lesions of varying sizes up to 5 mm in diameter were distributed diffusely on the surface of the omentum, mesentery and parietal peritoneum. No neoplastic masses were detected in any visceral organ. The nodules were composed of proliferation of mono- or multi-layered epithelial-like cells occasionally showing papillary growth and sheets of small round or polygonal cells. Signet ring-like cells and tubular structures were occasionally present. Neoplastic cells were strongly positive to cytokeratin, and occasionally to vimentin. Based on gross and histopathological findings, this tumor was diagnosed as an epithelial type of peritoneal malignant mesothelioma, the first reported case in the non-human primates.     

Root mucilage enhances aluminum accumulation in Melastoma malabathricum,an aluminum accumulator

Root mucilage is gelatinous polysaccharide-containing material exuded from the outer layers of the root cap. Although mucilage has been suggested to play several roles in plant growth, its role in mineral uptake has not been well understood. Melastoma malabathricum L. is an aluminum (Al) accumulator growing in tropical acid soils. This species accumulates more than 10 mg Al g⁻¹ DW in leaves and roots. Root mucilage is generally known to immobilize metal cations such as Al in the rhizosphere. However, we found that roots of M. malabathricum exuded large amounts of mucilage. Using the Zea mays L. mucilage as a control, we have recently shown that mucilage of M. malabathricum has unique physical and chemical characteristics, and facilitates Al uptake in this species. Since M. malabathricum cannot grow well in Al-deficient soil (nonacid soils), this species might have developed a mechanism for Al acquisition. We have also discussed the reason for this species'' requirement of Al, a nonessential element.Key words: aluminum accumulator, cation adsorption, Melastoma malabathricum L., polysaccharide, root mucilage, uronic acidPlant roots exude various chemical compounds. Root mucilage is a gelatinous high molecular weight compound, consisting mainly of polysaccharides, and is exuded from the outer layers of the root cap. One of the suggested roles of mucilage in plant growth is detoxification (fixation) of toxic metal cations, including Al in acidic soils.¹ Polysaccharides in mucilage contain uronic acids,² the carboxyl groups of which might adsorb and inactivate Al in the rhizosphere.³ However, Li et al.,⁴ suggested that the contribution of mucilage to Al inactivation in the rhizosphere of Zea mays L. is almost negligible owing to its small amount.Melastoma malabathricum L. is an Al accumulator growing in tropical acidic soils and is one of the dominant woody species growing in acid sulfate soils in tropical Asia, Australia and Polynesia. This species accumulates more than 10 mg Al g⁻¹ DW in leaves and roots.⁵ It is known that the growth of non-essential element-accumulating plants is often enhanced by the application of the accumulated element (e.g., Na in a Na accumulator plant). The growth of M. malabathricum is enhanced by Al application under hydroponic conditions.⁶ It has been predicted that this growth enhancement is due to alleviation of iron toxicity⁷ or a disorder of organic acid metabolism in the absence of Al.⁸ Recently, we observed that the roots of M. malabathricum exuded large amounts of mucilage under “Al deficient” conditions, raising a question about the role of mucilage in this species.Our recent study indicated that M. malabathricum mucilage facilitates Al uptake in this species.⁹ Contrastingly, uptake of other cations such as K, Ca and Mg were not affected. To the best of our knowledge, this is the first study to demonstrate that mucilage selectively enhances mineral uptake in plant. To elucidate the factors that were responsible for these characteristics of M. malabathricum mucilage, we compared the physical and chemical properties of M. malabathricum mucilage with that of Z. mays mucilage, which is known to strongly bind to Al.⁴ The results are summarized in Figure 1A. Critical differences in the physical properties that can affect Al uptake of roots were evaluated. M. malabathricum mucilage has higher adsorption affinities for trivalent cations, whereas Z. mays mucilage has a higher affinity for divalent cations. Moreover, ²⁷Al NMR analysis and bioassay indicated that the binding strength between mucilage and Al was very weak in M. malabathricum mucilage and its ionic activity was nearly equal to inorganic monomeric Al ions.Open in a separate windowFigure 1Characterization of root mucilage in Melastoma malabathricum. (A) Differences in physical and chemical properties of mucilage between M. malabathricum and Zea mays. (B) Hypothetical model of selective adsorption of cation in M. malabathricum and Z. mays. Mucilage of M. malabathricum has high affinity for trivalent cations because of its higher charge density. (C) Hypothetical scheme of Al acquisition in M. malabathricum.What is the primary factor behind such special characteristics of Al adsorption in the M. malabathricum mucilage? In general, a cation exchanger with a high charge density exhibits preferences for trivalent cations.¹⁰ The cation exchange capacity per unit volume in the M. malabathricum mucilage is nearly twice as high as that in Z. mays mucilage because of its higher proportion of uronic acid (glucuronic acid) (Fig. 1B). This high charge density is considered to be the primary reason for higher affinity of the trivalent cation in M. malabathricum mucilage. Conversely, the weak binding strength between mucilage and Al is possibly due to the higher degree of methylation in M. malabathricum mucilage. It has been suggested that like unmethylated polyuronic acid, partly methylated polyuronic acid can form “egg box” junctions;¹¹ however, the binding strength is weak.¹² In addition, the lower pH of M. malabathricum mucilage is also responsible for the weak binding strength.M. malabathricum has evolved in extremely acidic soils. This medium, with a certain level of Al ion, might be suitable for the growth of this species, as opposed to Al-free medium. Recently, we found that water-soluble Ca, Mg and oxalate concentrations in both shoots and roots of M. malabathricum grown hydroponically in the absence of Al were significantly lower than that in the presence of Al (Fig. 2). Irrespective of Al concentration in the medium, M. malabathricum synthesizes a high concentration of oxalate, which is a ligand for Al detoxification in plant tissue.⁸ The high concentration of oxalate would make insoluble precipitates with Ca and Mg when grown in the absence of Al, inducing severe deficiency of these elements in M. malabathricum. Therefore, mechanisms of Al acquisition are essential for M. malabathricum when growing in Al deficient soils (Fig. 1C).Open in a separate windowFigure 2Ratio of water-soluble K, Ca, Mg and oxalate to total concentration in Melastoma malabathricum grown in a nutrient solution with or without 0.5 mM AlCl₃ for 30 days. Water soluble K, Ca, Mg and oxalate concentrations were determined by ICP-OES or capillary electrophoresis after extracting with deionized water (lyophilized sample:water = 1:10). Total K, Ca and Mg concentrations were determined by ICP-OES after wet-digestion. Total oxalate concentrations were determined by capillary electrophoresis after extracting with 0.2 M HCl. The standard nutrient solution contained 0.54 mM N (NH₄NO₃), 32 µM P (NaH₂PO₄·2H₂O), 0.15 mM K (K₂SO₄:KCl = 1:1), 0.25 mM Ca (CaCl₂·2H₂O), 0.16 mM Mg (MgSO₄·7H₂O), 35.8 µM Fe (FeSO₄·7H₂O), 1.8 µM Mn (MnSO₄·4H₂O), 9.26 µM B (H₃BO₃), 0.62 µM Zn (ZnSO₄·7H₂O), 0.036 µM Cu (CuSO₄·5H₂O) and 0.01 µM Mo ((NH₄)₆Mo₇O₂₄·4H₂O); total SO₄ = 0.21 mM. There was no significant difference in total concentrations between the treatments.     

Hepatozoon ursi n. sp. (Apicomplexa: Hepatozoidae) in Japanese black bear (Ursus thibetanus japonicus)

Morphological and genetic features of a new Hepatozoon species, Hepatozoon ursi n. sp., in Japanese black bear (Ursus thibetanus japonicus) were studied. Schizogonic developmental stages were observed in the lungs of Japanese black bears. The schizonts were sub-spherical in shape and 45.7+/-4.6 x 42.7+/-4.5 microm in size. Each mature schizont contained approximately 80-130 merozoites and 0-5 residual bodies. The merozoites were 7.0+/-0.7 x 1.8+/-0.3 microm in size. Intraleukocytic gametocytes were slightly curved, cigar-like in shape and had a beak-like protrusion at one end. The size of the gametocytes was 10.9+/-0.3 x 3.3+/-0.2 microm. The analyses of the18S rRNA gene sequences supported the hypothesis that H. ursi n. sp. is different from other Hepatozoon species. Mature Hepatozoon oocysts were detected in two species of ticks (Haemaphysalis japonica and Haemaphysalis flava) collected on the bears infected with H. ursi n. sp. Two measured oocysts were 263.2 x 234.0 microm and 331.8 x 231.7 microm, respectively. The oocysts contained approximately 40 and 50 sporocysts, respectively. The sporocysts were sub-spherical in shape and 31.2+/-2.5 x 27.0+/-2.9 microm in size. Each sporocyst contained at least 8-16 sporozoites, with the sporozoites being 12.2+/-1.4 x 3.5+/-0.5 microm in size. H. ursi n. sp. is the first Hepatozoon species recorded from the family Ursidae.     

Eradication of intractable malignant ascites by abdominocentesis,reinfusion of concentrated ascites,and adoptive immunotherapy with dendritic cells and activated killer cells in a patient with recurrent lung cancer: a case report

Introduction

Dynamic retinal vessel analysis represents a well-established method for the assessment of vascular reactivity during both normal conditions and after various provocations. We present a case where the subject showed abnormal retinal vessel reactivity after fasting voluntarily for 20 hours.

Case presentation

A healthy, 21-year-old man who fasted voluntarily for 20 hours exhibited abnormal retinal vascular reactivity (dilation and constriction) after flicker provocation as measured using the Dynamic Retinal Vessel Analyser (Imedos, Jena, Germany).

Conclusion

The abnormal vascular reactivity induced by fasting was significant; abnormal levels of important nutrients due to fasting and dehydration could play a role through altering the concentration of vasoactive substances such as nitric oxide. This hypothesis needs further investigation.     

Characterization of CO2 flux in three Kobresia meadows differing in dominant species

Aims Kobresia meadows, the dominant species of which differ in different habitats, cover a large area of alpine grassland on the Qinghai-Tibetan Plateau and act as potential CO₂ sinks. Kobresia meadows with different dominant species may differ in carbon sink strength. We aimed to test the hypothesis and to clarify the differences in CO₂ sink strength among three major Kobresia meadows on the plateau and the mechanisms underlying these differences.Methods We measured the net ecosystem exchange flux (NEE), ecosystem respiration flux (ER), aboveground biomass (AGB) and environmental variables in three Kobresia meadows, dominated by K. pygmaea, K. humilis, or K. tibetica, respectively, in Haibei, Qinghai. NEE and ER were measured by a closed-chamber method. Environmental variables, including photosynthetic photon flux density (PPFD), air and soil temperature and air and soil moisture, were monitored during the above flux measurements.Important findings The measured peak AGB increased with soil water content and was 365, 402 and 434 g dry weight m^{-2<-sup> for K. pygmaea, K. humilis and K. tibetica meadow, respectively. From the maximum ecosystem photosynthetic rate in relation to PPFD measured during the growing season, we estimated gross ecosystem photosynthetic potential (GEP max) as 22.2, 29.9 and 37.8 μmol CO₂ m-2<-sup> s-1 for K. pygmaea, K. humilis and K. tibetica meadow, respectively. We estimated the respective gross primary production (GPP) values as 799, 1-063 and 1?158 g C m-2<-sup> year-1 and ER as 722, 914 and 1-011 g C m-2<-sup> year-1. Average net ecosystem production (NEP) was estimated to be 76.9, 149.4 and 147.6 g C m-2<-sup> year-1 in K. pygmaea, K. humilis and K. tibetica meadows, respectively. The results indicate that (i) the three meadows were CO₂ sinks during the study period and (ii) Kobresia meadows dominated by different species can differ considerably in carbon sink strength even under the same climatic conditions, which suggests the importance of characterizing spatial heterogeneity of carbon dynamics in the future.}     

Microbial oxidases of acidic -amino acids

Two microbial oxidases of acidic -amino acids have been purified to homogeneity. One is a -aspartate oxidase of the yeast Cryptococcus humicolus UJ1 that was induced markedly with -aspartate and is far more active toward -aspartate than -glutamate. The other is a -glutamate oxidase of Candida boidinii 2201 that preferred -glutamate to -aspartate as a substrate in terms of k_cat/K_m, but was not induced very effectively by -glutamate. The most potent competitive inhibitor of the C. humicolus -aspartate oxidase was malonate, and that of the C. boidinii -glutamate oxidase was -malate. The former enzyme was a homotetramer of 160 kDa consisting of subunits of 40 kDa, each of which contained 1 mol of FAD, while the latter was a monomer of 45 kDa. The N-terminal sequences of both enzymes were similar to those of other FAD enzymes and contained a consensus sequence common to most enzymes binding ADP-containing nucleotides. Peroxisomal localization of the C. humicolus -aspartate oxidase was shown by subcellular fractionation and morphological analysis via electron microscopy of C. humicolus cells, where induction of the enzyme was accompanied by induction of catalase and development of peroxisomes. The apo-form of C. humicolus -aspartate oxidase, prepared by removal of FAD was a monomeric protein of 40 kDa, and its binding with FAD proceeded in two stages. The K_d for the apoprotein-FAD complex was very low (8.2×10⁻¹² M) consistent with the observed tight binding. The C. humicolus -aspartate oxidase was essentially similar to other flavoprotein oxidases of acidic and neutral -amino acids with respect to its spectral properties and sensitivity to specific modifying reagents for arginyl and histidyl residues.     

Characterization of root mucilage from Melastoma malabathricum, with emphasis on its roles in aluminum accumulation

Plant roots exude viscous polysaccharides, called mucilage. One of the suggested roles of mucilage is immobilization of toxic metal cations, including aluminum (Al), in the rhizosphere. Mucilage exuded from roots of Melastoma malabathricum (Al accumulator) was characterized in comparison with that of Zea mays (maize; Al nonaccumulator). Removal of mucilage significantly reduced Al accumulation in M. malabathricum. The cation adsorption affinity of M. malabathricum mucilage was higher for Al and lanthanum (La) than for barium (Ba), whereas that of maize mucilage was in the order Ba > La > Al. A (27)Al nuclear magnetic resonance (NMR) spectrum of the Al-adsorbed mucilage and bioassay with alfalfa seedlings indicated that the concentrated Al in the mucilage of M. malabathricum, unlike that of maize, bound very weakly to cation exchange sites of mucilage. The higher charge density in M. malabathricum mucilage, derived from unmethylated uronic acid, is inferred to be related to preferential adsorption of trivalent cation. Not only a higher degree of methylation in the uronic acid (glucuronic acid) but also H(+) release from roots to the mucilage appears to be responsible for the loose binding of Al in M. malabathricum mucilage. These characteristics of mucilage may help Al hyperaccumulation in M. malabathricum.     

Neuritogenic effects of T cell-derived IL-3 on mouse splenic sympathetic neurons in vivo

To determine the role played by lymphocytes and cytokines in the growth of sympathetic neurons in vivo, the innervation and cytokine levels were examined in the spleens of SCID mice that lack T and B cells. Splenic noradrenaline, nerve growth factor (NGF), and IL-1beta levels were elevated in SCID mice. Immunohistochemical examination revealed that the density of tyrosine hydroxylase-positive (TH(+)) fibers of splenic central arteries in SCID mice was increased compared with wild-type C.B-17 mice, while SCID mice had significantly fewer TH(+) fibers in their periarteriolar lymphatic sheaths (PALS). Two weeks after SCID mice were injected with C.B-17 splenic T cells, their TH(+) fiber staining increased in the PALS. IL-3 levels increased significantly in SCID mice following T cell reconstitution, and the administration of anti-IL-3 Ab blocked the above T cell-induced increase in innervation in the PALS. Anti-IL-3 treatment also inhibited the regeneration of splenic sympathetic neurons in C.B-17 mice after they were chemically sympathetomized with 6-hydroxydopamine. Depletion of NK cells by anti-asialo GM1 promoted the splenic innervation in SCID mice, while there were no significant changes in the innervation between CD8(+) T cell-deficient beta(2)-microglobulin knockout mice and their wild type. Our results suggest that T cells (probably CD4(+) Th cells but not CD8(+) CTLs) play a role in regulating the sympathetic innervation of the spleen; this effect appeared to be mediated, at least in part, by IL-3. On the contrary, NK cells may exert an inhibitory effect on the sympathetic innervation.     

Lysophospholipids and ATP mutually suppress maturation and release of IL-1 beta in mouse microglial cells using a Rho-dependent pathway

The P2X7 receptor (P2X7R), an ATP-gated ion channel, plays essential roles in the release and maturation of IL-1beta in microglial cells in the brain. Previously, we found that lysophosphatidylcholine (LPC) potentiated P2X7R-mediated intracellular signals in microglial cells. In this study, we determined whether the lysophospholipids, i.e., LPC and sphingosylphosphorylcholine (SPC), modulate the ATP-induced release and processing of IL-1beta mediated by P2X7R in mouse MG6 microglial cells. LPC or SPC alone induced the release of precursor (pro-IL-1beta) and mature IL-1beta (mIL-1beta) from LPS-primed MG6 cells, possibly due to lytic functions. However, these lysophospholipids inhibited ATP-induced caspase-1 activation that is usually followed by the release of mIL-1beta. Conversely, ATP inhibited the release of pro-IL-1beta and mIL-1beta induced by LPC/SPC. This suggests that lysophospholipids and ATP mutually suppressed each function to release IL-1beta. P2X7R activation resulted in microtubule reorganization in the MG6 cells that was blocked in the presence of LPC and SPC. LPC/SPC reduced the amount of activated RhoA after stimulation with ATP, implying that these lysophospholipids block ATP-induced microtubule reorganization by interfering with RhoA activation. In addition, the microtubule inhibitor colchicine inhibited ATP-induced release of mIL-1beta similar to that of LPC and SPC. This suggests that the impairment of the microtubule reassembly may be associated with the inhibitory effects of LPC/SPC on ATP-induced mIL-1beta release. Mutual suppression by ATP and LPC/SPC on the maturation of IL-1beta was observed in LPS-primed primary microglia. Collectively, these data suggest opposing functions by lysophospholipids, either proinflammatory or anti-inflammatory, in regard to the maturation and release of IL-1beta from microglial cells.     

Restriction on conjugational transfer of pLS20 in Bacillus subtilis 168

Conjugational transfer of pLS20 in Bacillus subtilis Marburg 168 is restricted by the BsuM restriction-modification system. Restriction efficiency was measured using pLS20 derivatives possessing various numbers of XhoI sites, which are known to be recognized by BsuM. An increase in XhoI sites clearly reduced the conjugational efficiency of pLS20 as compared with that of pUB110 plasmid lacking XhoI.