Siladenoserinols A-L: new sulfonated serinol derivatives from a tunicate as inhibitors of p53-Hdm2 interaction

Siladenoserinols A-L were isolated from a tunicate as inhibitors of p53-Hdm2 interaction, a promising target for cancer chemotherapy. Their structures including the absolute configurations were elucidated to be new sulfonated serinol derivatives, each of which contains a 6,8-dioxabicyclo[3.2.1]octane unit and either glycerophosphocholine or glycerophosphoethanolamine moiety. They inhibited p53-Hdm2 interaction with IC(50) values of 2.0-55 μM. Among them, siladenoserinol A and B exhibited the strongest inhibition with an IC(50) value of 2.0 μM.

Manadosterols A and B, sulfonated sterol dimers inhibiting the Ubc13-Uev1A interaction, isolated from the marine sponge Lissodendryx fibrosa

Two new dimeric sterols, manadosterols A (1) and B (2), were isolated from the marine sponge Lissodendryx fibrosa collected in Indonesia. The two compounds are comprised of two sulfonated sterol cores connected through the respective side chains. Manadosterols A (1) and B (2) inhibited the Ubc13-Uev1A interaction with IC(50) values of 0.09 and 0.13 μM, respectively. They are the second and third natural compounds showing inhibitory activities against the Ubc13-Uev1A interaction and are more potent than leucettamol A (IC(50), 106 μM), the first such inhibitor, isolated from another marine sponge.

Evidence for Acquisition in Nature of a Chromosomal 2,4-Dichlorophenoxyacetic Acid/(alpha)-Ketoglutarate Dioxygenase Gene by Different Burkholderia spp

We characterized the gene required to initiate the degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) by the soil bacterium Burkholderia sp. strain TFD6, which hybridized to the tfdA gene of the canonical 2,4-D catabolic plasmid pJP4 under low-stringency conditions. Cleavage of the ether bond of 2,4-D by cell extracts of TFD6 proceeded by an (alpha)-ketoglutarate-dependent reaction, characteristic of TfdA (F. Fukumori and R. P. Hausinger, J. Bacteriol. 175:2083-2086, 1993). The TFD6 tfdA gene was identified in a recombinant plasmid which complemented a tfdA transposon mutant of TFD6 created by chromosomal insertion of Tn5. The plasmid also expressed TfdA activity in Escherichia coli DH5(alpha), as evidenced by enzyme assays with cell extracts. Sequence analysis of the tfdA gene and flanking regions from strain TFD6 showed 99.5% similarity to a tfdA gene cloned from the chromosome of a different Burkholderia species (strain RASC) isolated from a widely separated geographical area. This chromosomal gene has 77.2% sequence identity to tfdA from plasmid pJP4 (Y. Suwa, W. E. Holben, and L. J. Forney, abstr. Q-403, in Abstracts of the 94th General Meeting of the American Society for Microbiology 1994.). The tfdA homologs cloned from strains TFD6 and RASC are the first chromosomally encoded 2,4-D catabolic genes to be reported. The occurrence of highly similar tfdA genes in different bacterial species suggests that this chromosomal gene can be horizontally transferred.

Preparation, crystallization and preliminary X-ray diffraction analysis of the DNA-binding domain of the Ets transcription factor in complex with target DNA

The Ets2 transcription factor is a member of the Ets transcription-factor family. Ets2 plays a role in the malignancy of cancer and in Down's syndrome by regulating the transcription of various genes. The DNA-binding domain of Ets2 (Ets domain; ETSD), which contains residues that are highly conserved among Ets transcription-factor family members, was expressed as a GST-fusion protein. The aggregation of ETSD produced after thrombin cleavage could be prevented by treatment with NDSB-195 (nondetergent sulfobetaine 195). ETSD was crystallized in complex with DNA containing the Ets2 target sequence (GGAA) by the hanging-drop vapour-diffusion method. The best crystals were grown using 25% PEG 3350, 80 mM magnesium acetate, 50 mM sodium cacodylate pH 5.0/5.5 as the reservoir at 293 K. The crystals belonged to space group C2, with unit-cell parameters a = 85.89, b = 95.52, c = 71.89 A, beta = 101.7 degrees and a V(M) value of 3.56 A(3) Da(-1). Diffraction data were collected to a resolution of 3.0 A.

Subchronic (13-week) oral toxicity study, preceded by an in utero exposure phase, with arachidonate-enriched triglyceride oil (SUNTGA40S) in rats

Polyunsaturated fatty acids (PUFAs), such as arachidonic acid (ARA) and docosahexaenoic acid (DHA) are natural constituents found in human milk, fish oil or egg yolk. Until recently, infant formulas, though providing the essential fatty acid precursors for these PUFAs, did not contain preformed ARA or DHA. In this study the safety of SUNTGA40S as source of ARA, not only for use in infant formulas but also for nutritional products or food supplements, was evaluated in a subchronic study in Wistar rats, preceded by a 4-week pretreatment period of parental (F(0)) rats and exposure of the F(0) dams throughout mating, gestation and lactation. SUNTGA40S was administered at dietary levels of 0.5%, 1.5% and 5% (wt/wt) adjusted with corn oil to 5.76% added fat. An additional group received 3.65% (wt/wt) SUNTGA40S in conjunction with 2.11% (wt/wt) high DHA Tuna oil, providing an ARA:DHA ratio of 2.7:1. High-fat and low-fat controls received basal diet with or without 5.76% corn-oil supplement. The content, stability and homogeneous distribution of the test substances in the diet were confirmed under study conditions. The administration of SUNTGA40S, with or without DHA oil, did not affect health, growth, fertility or reproductive performance of the parental rats, nor pup characteristics (condition, weight gain, viability, number per litter or sex ratio). In the subchronic study with the offspring (F(1)) rats, no significant differences were found in condition, neurobehavioural observations, ophthalmoscopy, growth, urinalysis or macroscopic and microscopic findings between the test groups and the low-fat or the high-fat controls. In males of the 5% SUNTGA40S and the SUNTGA40S/DHA group, red blood cell counts, haemoglobin concentration and packed cell volume were lower and reticulocytes were slightly higher than in the high-fat and low-fat control groups. Cholesterol, triglycerides and phospholipids in plasma were lower than in the high-fat controls in both sexes in the 5% SUNTGA40S and the SUNTGA40S/DHA group and (for triglycerides only) in the 1.5% SUNTGA group. Due to the administration of extra dietary fat, food intake and prothrombin time (males only) were lower and alkaline phosphatase activity was higher in all the high-fat groups, including the corn-oil controls, as compared to the low-fat controls. The weight of the spleen was higher in males of the 5% SUNTGA40S and the SUNTGA40S/DHA group compared to both the low-fat and the high-fat controls. The effects noted in this study at high dose levels of SUNTGA40S are consistent with previously reported physiological responses to dietary intake of high PUFA containing oils. The present results provide evidence that SUNTGA40S is a safe source of arachidonic acid. Except during lactation when the intake in dams doubled, 5% Suntga40S in the diet was equivalent to an overall intake of approximately 3g/kg body weight/day in F(0) and F(1) animals.

Developing and sustaining 3-chlorophenol-degrading populations in up-flow anaerobic column reactors under circum-denitrifying conditions

Microbial consortia capable of degrading 3-chlorophenol (3-CP) were enriched in continuous up-flow column reactors under circum-denitrifying conditions. 3-CP degradation capability was developed and sustained when 3-CP was supplied at 16-21 microM, although suppression of the 3-CP degradation capability was observed when 3-CP was supplied at 42 microM. When 3-CP was stably degraded, the ratio of nitrate consumption to 3-CP degradation approached the theoretical stoichiometric value, which was calculated by assuming a 3-CP degradation-dependent nitrate reduction. Batch-incubation experiments demonstrated that the microbial consortium that was enriched in the column reactors required either nitrate or oxygen for degrading 3-CP, while 3-CP was not degraded under sulfate-degrading conditions. Although many attempts were made to sustain the microbial 3-CP degradation capability under denitrifying conditions, mostly in batch cultures, none of them have been successful so far. Therefore, the results obtained in this study may be the first to demonstrate sustainable 3-CP degradation capability under circum-denitrifying conditions.

Simultaneous removal of phenol and ammonia by an activated sludge process with cross-flow filtration

Attempts were made for removing ammonia from synthetic wastewater under the presence of phenol, which is inhibitory to nitrification, by using a single-stage activated sludge process with cross-flow filtration. Activated sludge biomass which had been acclimated with phenol for over 15 years was used for the inoculum, and synthetic wastewater was continuously supplied to the process retaining biomass at 8000 mg VSS l(-1). Phenol was completely removed, and ammonia was simultaneously nitrified to nitrate; nitrification rate reached 200 mg N l(-1) d(-1) when phenol was removed at a rate up to 300 mg l(-1) d(-1). It was observed that 0-13% of the ammonia was removed via denitrification. Intermittent aeration enhanced the denitrification rate to 160 mg N l(-1) d(-1) by utilizing phenol. and approximately 24% of the denitrified nitrogen was recovered as nitrous oxide. Methanol, which is the most commonly used electron donor in conventional nitrogen removal processes, did not enhance the denitrification rate of the phenol-acclimated activated sludge used in this study, however phenol did. The results suggest that this process potentially works as a space- and energy-saving nitrogen removal process by utilizing substances inhibitory to nitrifiers as electron donors for denitrification.

Anaerobic transformation of chlorophenols in methanogenic sludge unexposed to chlorophenols

Transformation of all 19 chlorophenol (CP) isomers was investigated in a laboratory anaerobic methanogenic sludge that had not been exposed to synthetic chemicals. Concentration of CP was analyzed over time to calculate disappearance rate constants using first-order reaction kinetics and all possible CP degradation pathways were estimated. The rate constants ranged between 0.46 x 10(-3) and 0.161 day(-1). CPs were transformed via dechlorination. The chlorine atom at the ortho-position was the most easily dechlorinated, whereas dechlorination rate at the para-position was lowest. The overall pathways of CP transformation were much less diverse than that we previously found for contaminated sediment. The Dolfing hypothesis of microbial selection of the most thermodynamically favorable pathways was not applicable for CP transformation in this study as well as previous study performed by our group.

Cyclin E overexpression in transitional cell carcinoma of the bladder

We attempted to clarify the relationship between cyclin E to p27(Kip1), Ki-67 and clinicopathologic features in transitional cell bladder carcinoma. Immunohistochemical staining of archival tissue specimens of transitional cell bladder carcinoma obtained from 94 patients was performed by the labeled streptavidin-biotin-peroxidase method. Overexpression of cyclin E protein was observed in 38 of the 94 (40.4%) specimens, and was positively correlated with histological grade, Ki-67 LI and p27(Kip1) labeling index (LI). These data suggest that cyclin E may be associated with aggressive tumor growth, and may have a relationship with p27(Kip1) for the regulation of cell cycle progression in transitional cell bladder carcinoma.

Inherited defects of sodium-dependent glutamate transport mediated by glutamate/aspartate transporter in canine red cells due to a decreased level of transporter protein expression

Canine red cells have a high affinity Na(+)/K(+)-dependent glutamate transporter. We herein demonstrate that this transport is mediated by the canine homologue of glutamate/aspartate transporter (GLAST), one of the glutamate transporter subtypes abundant in the central nervous system. We also demonstrate that GLAST is the most ubiquitous glutamate transporter among the transporter subtypes that have been cloned to date. The GLAST protein content was extremely reduced in variant red cells, low glutamate transport (LGlut) red cells characterized by an inherited remarkable decrease in glutamate transport activity. All LGluT dogs carried a missense mutation of Gly(492) to Ser (G492S) in either the heterozygous or homozygous state. The GLAST protein with G492S mutation was fully functional in glutamate transport in Xenopus oocytes. However, G492S GLAST exhibited a marked decrease in activity after the addition of cycloheximide, while the wild type showed no significant change, indicating that G492S GLAST was unstable compared with the wild-type transporter. Moreover, LGluT dogs, but not normal dogs, heterozygous for the G492S mutation showed a selective decrease in the accumulation of GLAST mRNA from the normal allele. Based on these findings, we conclude that a complicated heterologous combination of G492S mutation and some transcriptional defect contributes to the pathogenesis of the LGluT red cell phenotype.

[Renal cell carcinoma in a horseshoe kidney with abdominal aortic aneurysm: a case report]

We herein report a case of renal cell carcinoma in a horseshoe kidney with an abdominal aortic aneurysm in a 69-year-old man. Radiological examinations showed a left renal tumor, horseshoe kidney and abdominal aortic aneurysm. We performed a left radical nephrectomy with the division of the isthmus and artificial graft through an abdominal transperitoneal approach. Histological findings revealed clear cell type renal cell carcinoma without invasion of the capsule or renal pelvis. Only 31 cases of renal cell carcinoma in a horseshoe kidney have been reported in Japan, and our case is the 32nd. No case with abdominal aortic aneurysm has been reported previously. We assume that abdominal aortic aneurysm was associated with renal cell carcinoma by chance in the horseshoe kidney in this case. The arterial and venous supplies vary from case to case. We emphasize that arteriography and venography are very important preoperative procedures.

Antagonistic effect of N-methyltyramine on alpha2-adrenoceptor in mice

We examined the effect of N-methyltyramine (NMT) on alpha2-adrenoceptor. NMT (10(-8)-10(-3) M) inhibited the binding of [3H]p-aminoclonidine to alpha2-adrenoceptor dose-dependently. However, the IC50 value for NMT (5.53 x 10(-6) M) was higher than that for RX821002, an alpha2-adrenoceptor antagonist (1.07 x 10(-8) M). RX821002 (5 mg/kg, i.p.) inhibited hypermotility induced by scopolamine (8 mg/kg, s.c.) in male ddY mice. NMT (20 or 100 mg/kg, i.p.) was found to have a dose-dependent inhibitory effect similar to that of RX821002. These findings indicate that NMT has the properties of an alpha2-adrenoceptor antagonist. However, the affinity of NMT for alpha2-adrenoceptor is weaker than that of RX821002.

Isolation from beer and structural determination of a potent stimulant of gastrin release

Beer was subjected to five successive chromatographic procedures to isolate the gastrin release-inducing activity, guided by bioassay of the fractions in anaesthetized Donryu rats. The procedures were: (1) hydrophobic interaction chromatography (aqueous effluent with an HP20 column); (2) weak cation-exchange chromatography (1 M acetic acid eluate with a CM Sephadex C-25 column); (3) gel filtration (methanol eluate with a Sephadex LH-20 column); (4) same as (2); (5) high-performance liquid chromatography (YMC-Pack ODS-AM with 7% acetonitrile-0.01 M HCl). The active component finally isolated had a specific activity approximately 10000 times higher than that of beer. It was identified by means of mass, 1H- and 13C-nuclear magnetic resonance spectral analyses as N-methyltyramine (NMT). The dose of NMT giving maximal gastrin-releasing activity was 25 microg/kg, and the 50% effective dose was approximately 10 microg/kg on oral administration to rats. NMT was isolated and identified as a gastrin release inducer in beer. Its concentration in beer is sufficient to account for most of the activity of beer.