Differences in parasitism of Meloidogyne incognita and two genotypes of M. arenaria on Solanum torvum in Japan

Two genotypes of root‐knot nematode, Meloidogyne arenaria (A2‐O and A2‐J), are found in Japan. They were distinguished from each other based on mitochondrial DNA sequences. The primer set (C2F3/1108) amplified a 1.7‐kb fragment from A2‐J, whereas a 1.1‐kb fragment was amplified from A2‐O. M. arenaria (A2‐O) was detected in local regions of southern Japan, whereas M. arenaria (A2‐J) was widespread from the Kyushu region to the Tohoku region. The distribution of M. arenaria (A2‐J) overlaps with the cultivation area of eggplant. Solanum torvum is used worldwide as a rootstock for eggplant cultivation, and it is resistant to Meloidogyne spp. In particular, it is reported that S. torvum is resistant to M. arenaria outside Japan. In this study, we inoculated S. torvum rootstock cultivars with M. arenaria (A2‐J), M. arenaria (A2‐O) and Meloidogyne incognita populations. Although M. incognita and M. arenaria (A2‐O) produced only a few egg masses on S. torvum, thereby confirming its resistance, the four geographical populations of M. arenaria (A2‐J) produced large numbers of egg masses on S. torvum. This study confirmed that S. torvum is resistant to M. incognita and M. arenaria (A2‐O) populations, but susceptible to populations of M. arenaria (A2‐J) in the eggplant production area of Japan.     

Synthesis and evaluation of 11C-labeled coumarin analog as an imaging probe for detecting monocarboxylate transporters expression

Upregulated monocarboxylate transporters (MCTs) in tumors are considered diagnostic imaging targets. Herein, we synthesized the positron emission tomography probe candidates coumarin analogs 2 and 3, and showed 55 times higher affinity of 2 for MCTs than a representative MCT inhibitor. Whereas [¹¹C]2 showed low tumor accumulation, probably due to adduct formation with plasma proteins, [¹¹C]2 showed high initial brain uptake, suggesting that the scaffold of 2 has properties that are preferable in imaging probes for the astrocyte–neuron lactate shuttle. Although further optimization of 2 is required, our findings can be used to inform the development of MCT-targeted imaging agents.     

Goniodomin A, an antifungal polyether macrolide, exhibits antiangiogenic activities via inhibition of actin reorganization in endothelial cells.

Goniodomin A (GDA) is an antifungal polyether macrolide isolated from the dinoflagellate Goniodoma pseudogoniaulax. Previous studies revealed that GDA profoundly affected cytoskeletal reorganization. We examined the effect of GDA on the angiogenic properties of vascular endothelial cells. GDA itself did not affect proliferation of, migration of, and tube formation in type I collagen gels by, bovine aortic endothelial cells (BAECs). Proliferation of BAECs stimulated by bFGF was not affected by GDA at concentrations of up to 10 nM. However, at similar concentrations, GDA significantly inhibited bFGF-induced migration and tube formation in type I collagen gels by BAECs. Actin reorganization is required for cell migration. GDA caused the perinuclear aggregation of filamentous actin and inhibited stress fiber formation in bFGF- or VEGF-stimulated BAECs and lysophosphatidic acid-stimulated HeLa cells. However, GDA did not affect stress fiber structures already formed through Gbetagamma expression or in constitutively active RhoA mutant HeLa cells. Finally, GDA inhibited forming of vasucular system in a chorioallantoic membrane. Our results indicated that GDA suppressed angiogenic properties of ECs at least in part through the inhibition of actin reorganization and inhibited angiogenesis in vivo.     

Turnover of Acinar and Islet Cells in the Pancreas of Monosodium Glutamate‐Treated Obese Mice

Objective: Subcutaneous administrations of monosodium glutamate (MSG) to neonatal animals result in obesity and induce the toxicity on the central nervous system, and furthermore, have an effect on entero‐pancreatic hormone. The effect of MSG on the cell turnover of organs, especially the pancreas, has received little attention until now. This study was designed to examine the effect of MSG on pancreatic cell turnover by immunohistochemistry and [³H]thymidine autoradiography. Research Methods and Procedures: Male JcI‐ICR strain mice were SC injected with MSG (2 mg/g body weight daily) for 5 days after birth, received 112 repeated injections of [³H]thymidine at 6‐hour intervals for 28 days after birth, and then were killed immediately thereafter, or 30, 60, or 120 days after the last injection. Autoradiography was performed on sections immunostained for glucagon, insulin, and somatostatin. Results: After continuous labeling, most pancreatic cells were labeled, and thereafter, labeling of cells decreased in control and MSG‐treated mice. The mean grain counts of acinar cells in MSG‐treated mice decreased more slowly than those in control mice. On the other hand, those of islet cells, including glucagon, insulin, and somatostatin cells, decreased more rapidly in MSG‐treated mice than those in control mice. Discussion: Cell turnover of acinar cells was decelerated and that of islet cells including glucagon, insulin, and somatostatin cells was accelerated in MSG‐treated mice pancreas. MSG‐induced hypothalamic lesions exert the contrary influences on the cell turnover of acinar and islet cells.     

Differential expression of granulysin and perforin by NK cells in cancer patients and correlation of impaired granulysin expression with progression of cancer

Granulysin has been identified as an effector molecule co-localized with perforin in the cytotoxic granules of cytotoxic T lymphocytes and natural killer (NK) cells, and has been reported to kill intracellular pathogens in infected cells in the presence of perforin and to induce a cytotoxic effect against tumor cells. The aim of the present study was to elucidate whether intracellular expression of granulysin and perforin by NK cells might be associated with progression of cancer. Flow cytometric analysis demonstrated high levels of perforin and granulysin expression by CD3(-) CD16(+) cells in healthy controls. In contrast, cancer patients exhibited significantly decreased levels of granulysin expression ( P<0.005), despite having equally high levels of perforin expression in comparison with healthy controls. The tumor-free patients expressed granulysin at levels similar to healthy controls, while the progressive tumor-bearing patients expressed remarkably lower levels of granulysin compared to healthy controls ( P<0.0001). Similarly, patients with an advanced performance status had significantly fewer granulysin-positive NK cells than healthy controls. Meanwhile, a considerable number of the tumor-bearing patients showed a decrease in the number of circulating NK cells, and a correlation between impaired granulysin expression and reduced circulating NK cells was observed. These findings suggest that the tumor-bearing patients with impaired granulysin expression were in an immunosuppressive state. In conclusion, impaired expression of granulysin by NK cells correlates with progression of cancer, and determination of granulysin expression might prove informative for assessing the immunological condition of cancer patients.     

Hydrogen peroxide is an endothelium-derived hyperpolarizing factor in human mesenteric arteries.

The endothelium plays an important role in maintaining vascular homeostasis by synthesizing and releasing several vasodilating factors, including prostacyclin, nitric oxide, and endothelium-derived hyperpolarizing factor (EDHF). We have recently identified that endothelium-derived hydrogen peroxide (H(2)O(2)) is an EDHF in mice. The present study was designed to examine whether this is also the case in humans. Bradykinin elicited endothelium-dependent relaxations and hyperpolarizations in the presence of indomethacin and N(omega)-nitro-l-arginine, which thus were attributed to EDHF, in human mesenteric arteries. The EDHF-mediated relaxations were significantly inhibited by catalase, an enzyme that specifically decomposes H(2)O(2), whereas catalase did not affect endothelium-independent hyperpolarizations to levcromakalim. Exogenous H(2)O(2) elicited relaxations and hyperpolarizations in endothelium-stripped arteries. Gap junction inhibitor 18alpha-glycyrrhetinic acid partially inhibited, whereas inhibitors of cytochrome P450 did not affect the EDHF-mediated relaxations. These results indicate that H(2)O(2) is also a primary EDHF in human mesenteric arteries with some contribution of gap junctions.     

Identification of seven loci for static glucokinesis and dynamic glucokinesis in mice

Non-insulin-dependent diabetes mellitus (NIDDM) is characterized by a breakdown of glucose homeostasis and is responsible for serious complications in various organs and vessels. Most of the genetic factors of NIDDM are yet unknown. Here, we identified two types of genetic factors that regulate homeostasis of blood glucose by measuring various pharmacokinetic parameters, some of which are used in the non-compartment analysis of drug metabolism in 340 F₂ progeny from the NIDDM model KK-A^y/Ta Jcl mouse strain, and in non-diabetic PWK strain. We define ``static glucokinesis' as the regulation of homeostasis that occurs during glucose deprivation, and ``dynamic glucokinesis' as that during glucose stress; for instance, glucose tolerance test. Quantitative trait locus analysis revealed eight loci involved in the regulation of glucose homeostasis on chromosomes 7 (Nidd1k), 2 (Nidd2k), 1 (Nidd3k, Nidd4k, and Nidd5k), 11 (Nidd6k), 5 (Nidd7k) (named Nidd1k through Nidd7k), and 4 (Bwt1k). Nidd1k, Nidd4k, and Nidd7k were novel loci associated with NIDDM in mice. Nidd1k, Nidd2k, Nidd3k, and Nidd4k had linkage to factors characteristic of both static and dynamic glucokinesis. Nidd5k and Nidd6k showed linkage specific to markers of dynamic glucokinesis, and Nidd7k had linkage specific to static glucokinesis. Bwt1k was linked to obesity. Thus, the genetic factors for static glucokinesis and those for dynamic glucokinesis partially overlapped.     

Isolation of cDNAs encoding for two distinct isoforms of the TATA-Box binding proteins from common bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.)

The TATA-box binding protein (TBP) is one of the 4 DNA-binding proteins that has been shown to associate with the proximal promoter region (−295) of the gene for bean seed storage protein phaseolin. The −295 promoter is essential for spatial and temporal control of the phaseolin gene expression. We designed a pair of degenerated primers based on the highly conserved sequence of the carboxyl-terminal domain of yeast TBP and used PCR to amplify the corresponding sequence from the bean cDNA. By using the amplified fragment as a probe, we screened a cDNA library derived from poly A(+) RNA from developing bean seeds and isolated 2 nearly full-length cDNA clones (813 and 826 bp long). The cDNAs encode 2 distinct isoforms of bean TBP, PV1 and PV2, each with an open reading frame of 200 amino acid residues. The 2 cDNA sequences share an 85.8% overall nucleotide sequence identity, with the coding region showing a higher degree of identity (94.4%) than the 5′- and 3′-untranslated regions (69%). The deduced amino acid sequence of the bean TBP isoforms differ in only 3 amino acid residues at positions 5, 9, and 16, all located in the amino-terminal region. The carboxyl-terminal domain of 180 amino acid residues shows a high degree (>82%) of evolutionary sequence conservation with the TBP sequences from other eukaryotic species. This domain possesses the 3 highly conserved structural motifs, namely the 2 direct repeat sequences, a central basic region rich in basic amino acid residues, and a region similar to the sigma factor of prokaryote. On the basis of this and other findings, we suggest that higher plants in general may have at least 2 copies of TBP gene, presumably resulting from the global duplication of the genome. Accession numbers AF015784 and AF015785 at the GenBank.     

Anticoagulant properties of a sulfated galactan preparation from a marine green alga, Codium cylindricum

An anticoagulant was isolated from a marine green alga, Codium cylindricum. The anticoagulant was composed mainly of galactose with a small amount of glucose, and was highly sulfated (13.1% as SO Na). The anticoagulant properties of the purified anticoagulant were compared with that of heparin by assays of activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) using normal human plasma. The anticoagulant showed similar activities with heparin, however, weaker than heparin. On the other hand, the anticoagulant did not affect PT even at the concentration at which APTT and TT were strongly prolonged. The anticoagulant did not potentiate antithrombin III (AT III) and heparin cofactor II (HC II), thus the anticoagulant mechanism would be different from that of other anticoagulants isolated so far from the genus Codium.     

SAR studies of brasilicardin A for immunosuppressive and cytotoxic activities

Eleven derivatives (5-13, 15, and 16) of an immunosuppressive and cytotoxic tricyclic terpenoid, brasilicardin A (1), were prepared and assayed for inhibitory effects to the mouse mixed lymphocyte reaction (MLR) and seven human tumor cell lines. The 17N-methyl form (8) of 1 showed the most potent immunosuppressive activity in mouse MLR, while induction of more bulky group for N-17 resulted in significant decrease of the activity. Compound 8 also showed potent cytotoxic activity against DLD-1, Lu-65, A549, K562, and MOLT-4 cells, while the benzyl ester (13) of 1 exhibited potent cytotoxicity against K562, MOLT-4, and jarkat leukemia cell lines. The 17N-acetyl derivative (11) of 1 selectively inhibited the cell growth of DLD-1 cells. The methyl ester (5) of 1 showed potent cytotoxic activity against K562, MOLT-4, and Ball-1 cell lines, the last of which was resistant to 1, 8, and 13.