Low-Temperature Fabrication of Bulk-Type All-Solid-State Lithium-Ion Battery Utilizing Nanosized Garnet Solid Electrolytes

Garnet-type Li7 La3 Zr2 O12 (LLZ) materials are attracting attention as solid electrolytes (SEs) in oxide-based all-solid-state batteries (ASSBs) owing to their high ionic conductivity. Although the electrochemical stability of LLZ against Li metal is demonstrated with possible high energy density, high-temperature sintering above 1000 °C, which is required to achieve high Li-ion conductivity, results in the formation of insulating impurities at the electrode-electrolyte interfaces. Here, nanosized fine-particle samples of Ta-substituted Li6.5 La3 Zr1.5 Ta0.5 O12 (LLZT) are successfully prepared at a remarkably low temperature of 400 °C utilizing an amorphous precursor oxide. The dense LLZT SE sintered by hot pressing at 500 °C shows room-temperature Li-ion conductivity of 1.03 × 10-4 S cm-1 without any additives. In addition, the bulk-type NCM-graphite full battery cell fabricated with the LLZT fine particles through a hot-pressing sintering method at 550 °C exhibits a good charge-discharge performance at room temperature with the bulk-type areal discharge capacity of 0.831 mAh cm-2 . The nanosized garnet SE strategy demonstrated in this study paves the way for the formation of oxide-based ASSBs by low-temperature sintering.

Low-Temperature Sintering of a Garnet-Type Li6.5La3Zr1.5Ta0.5O12 Solid Electrolyte and an All-Solid-State Lithium-Ion Battery

Garnet-type Ta-substituted Li₇La₃Zr₂O₁₂ materials attract considerable attention as solid electrolytes for use in future oxide-based all-solid-state lithium-ion batteries owing to their superior ionic conductivity and chemical and electrochemical stabilities. However, high-temperature sintering above 1000 °C, which is needed to realize high lithium-ion conductivity, results in the formation of insulating interface impurities at the electrode-electrolyte interface. Herein, the low-temperature sintering of the Li_6.5La₃Zr_1.5Ta_0.5O₁₂ (LLZT) solid electrolyte at a remarkably low temperature of 400 °C was demonstrated using the submicrometer-sized garnet-type LLZT fine powder sample prepared at 600 °C through a reaction of Li₂O and La_2.4Zr_1.2Ta_0.4O₇. The lithium-ion conductivity at 25 °C was 4.54 × 10^-5 S cm^-1 without any additives through low-temperature sintering at 400 °C. In addition, the preliminary battery performance of the oxide-based all-solid-state LiNi_1/3Co_1/3Mn_1/3O₂-Li₄Ti₅O₁₂ full-battery cell fabricated at 400 °C using the present LLZT fine powder sample as the solid electrolyte was demonstrated.

Isolation and characterization of a novel Bacillus thuringiensis strain expressing a novel crystal protein with cytocidal activity against human cancer cells

AIMS

To characterize a novel, unusual, Bacillus thuringiensis strain, to clone its Cry gene and determine the spectrum of action of the encoded Cry protein.

METHODS AND RESULTS

The B. thuringiensis strain, referred to as M15, was isolated from dead two-spotted spider mites (Tetranychus urticae Koch; Arthropoda: Arachnida: Tetranychidae). It is an autoagglutination-positive strain and is therefore non-serotypeable. A sporulated culture produces a roughly spherical parasporal inclusion body, the crystal, tightly coupled to the spore. Although the crystal appears to be composed of at least two major polypeptides of 86 and 79 kDa as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Southern hybridization indicates that the corresponding crystal protein gene is likely present in only one copy. The crystal protein gene was cloned and, based on nucleotide sequence homology with an orthologous cry31Aa1 gene, assigned the name cry31Aa2. Although initially isolated from spider mites, B. thuringiensis M15 is non-toxic to spider mites and it does not produce the wide spectrum beta-exotoxin. Assays on mammalian cells, however, reveal that Cry31Aa2, when cleaved with trypsin, is cytocidal to some human cancer cells but not to normal human cells. No cytocidal activity was induced after protease treatment of Cry31Aa2 with either chymotrypsin or proteinase K. Trypsin, chymotrypsin and proteinase K cleavage sites were determined.

CONCLUSIONS

The B. thuringiensis strain M15 exhibits specific cytocidal activities against some human cancer cells.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study raises questions as to the actual role of this bacterial strain and its crystal protein in the environment. It may be possible to further develop the Cry31Aa2 protein to target specific human cancer cells.

Bacillus thuringiensis serovar shandongiensis strain 89-T-34-22 produces multiple cytotoxic proteins with similar molecular masses against human cancer cells

AIMS

To prove that Bacillus thuringiensis serovar shandongiensis strain 89-T-34-22 produces several novel cytotoxic proteins against human leukaemic T cells.

METHODS AND RESULTS

Parasporal inclusion protein was solubilized and processed by proteinase K and was separated by anion-exchange chromatography. Cytopathic effects of each fraction against MOLT-4 and Jurkat cells were monitored.

CONCLUSIONS

Existence of at least two novel cytotoxic proteins was suggested and N-terminal sequences of the newly identified proteins were determined to be QSTTDVIREY and X (Y or I) (P or I) NLANELA (X indicates uncertain amino acids). Molecular masses of the two proteins were approx. 27-28 kDa.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study, we demonstrated that the strain 89-T-34-22 produces at least two novel cytotoxic proteins with similar molecular masses against human cancer cells. This is the first strain of B. thuringiensis which produces multiple cytotoxic proteins against human cancer cells.

Charge-ordered state in single-crystalline CaFeO3 thin film studied by x-ray anomalous diffraction

X-ray anomalous diffraction, together with a band-structure calculation, was employed to obtain a quantitative understanding of the charge-ordering state in a single-crystalline CaFeO3 thin film. The experimental result shows a characteristic energy dispersion of the nearly inhibited reflection at 150 K, implying Fe atoms split into two distinct states. The energy dispersion is in good agreement with the calculated spectrum based on the LDA+U scheme. The calculation also reveals an electronic structure of the system where holes in the oxygen orbital surround one of the distinct Fe atoms, in spite of the total electron number in both Fe atoms remaining unchanged.

Ordered charge asphericity around dysprosium and structural deformation in DyB2C2

The orbitally ordered phase of DyB2C2 has been studied by nonresonant x-ray diffraction with high-brilliance synchrotron radiation. From the condition of diffraction, the symmetry property of the charge distribution around dysprosium has been concluded at the quadrupolar level. The quantitative inspection, furthermore, indicates that the observed signals cannot be interpreted as arising only from the 4f electrons of dysprosium responsible for the ordering; instead, the experiment can be described rather well by considering a distortion of the metaloid network concomitant with the ordering.

Self-regeneration of a Pd-perovskite catalyst for automotive emissions control

Catalytic converters are widely used to reduce the amounts of nitrogen oxides, carbon monoxide and unburned hydrocarbons in automotive emissions. The catalysts are finely divided precious-metal particles dispersed on a solid support. During vehicle use, the converter is exposed to heat, which causes the metal particles to agglomerate and grow, and their overall surface area to decrease. As a result, catalyst activity deteriorates. The problem has been exacerbated in recent years by the trend to install catalytic converters closer to the engine, which ensures immediate activation of the catalyst on engine start-up, but also places demanding requirements on the catalyst's heat resistance. Conventional catalyst systems thus incorporate a sufficient excess of precious metal to guarantee continuous catalytic activity for vehicle use over 50,000 miles (80,000 km). Here we use X-ray diffraction and absorption to show that LaFe(0.57)Co(0.38)Pd(0.05)O(3), one of the perovskite-based catalysts investigated for catalytic converter applications since the early 1970s, retains its high metal dispersion owing to structural responses to the fluctuations in exhaust-gas composition that occur in state-of-the-art petrol engines. We find that as the catalyst is cycled between oxidative and reductive atmospheres typically encountered in exhaust gas, palladium (Pd) reversibly moves into and out of the perovskite lattice. This movement appears to suppress the growth of metallic Pd particles, and hence explains the retention of high catalyst activity during long-term use and ageing.

Isolation of Bacillus thuringiensis from intertidal brackish sediments in mangroves

Intertidal brackish sediments in mangroves were examined for isolation of Bacillus thuringiensis strains with novel toxicity spectra. A total of 18 B. thuringiensis isolates were recovered from eight sediment samples (36.4%) out of 22 samples tested. The frequency of B. thuringiensis was 1.3% among the colonies of Bacillus cereus/B. thuringiensis group. While five isolates were allocated to the four H serogroups, the majority of the isolates were serologically untypable or untestable. Two isolates belonging to the serovar israelensis/tochigiensis (H14/19) exhibited strong toxicities against larvae of the mosquito, Culex pipiens molestus, and mammalian cells (sheep erythrocyte and two human cancer cell lines) in vitro. The other 16 isolates showed no toxicity against the mosquito and mammalian cells. None of the isolates showed larvicidal activity against the diamondback moth, Plutella xylostella. Strong lectin activities against sheep erythrocytes were associated with two serologically untestable isolates and an H3 isolate.

The influence of commonly prescribed synthetic drugs for peptic ulcer on the pharmacokinetic fate of glycyrrhizin from Shaoyao-Gancao-tang

The influence of synthetic drugs prescribed for peptic ulcer on the pharmacokinetic fate of glycyrrhizin (GL) from Shaoyao-Gancao-tang (SGT, a traditional Chinese formulation, Shakuyaku-Kanzo-to in Japanese) was investigated in rats. Co-administration of histamine H2-receptor antagonist (cimetidine) and anticholinergic drug (scopolamine butyl bromide) with SGT didn't influence the area under the plasma concentration-time curves (AUC) of glycyrrhetic acid (GA), an active metabolite derived from GL in SGT. The AUC of GA from SGT were significantly reduced by co-administration of synthetic drugs commonly used for peptic ulcer in a triple therapy (OAM), a combination of a proton pump inhibitor (omeprazole) and two antibiotics (amoxicillin and metronidazole). We found that the reduction of AUC in OAM treatment was due to the antibacterial effect of amoxicillin and metronidazole on intestinal bacteria in rat which lead to the decrease of GL-hydrolysis activity. The present study suggests that it may not be a proper way to use triple therapy containing antibiotics simultaneously with SGT for healing of chronic ulcers.

Quantitative analysis of gene expressions of vascular endothelial growth factor-related factors and their receptors in renal cell carcinoma

Vascular endothelial growth factor (VEGF)-related factors are believed to regulate angiogenesis, an essential event in the growth of solid tumors. In this study, we investigated the expression of VEGF-related factor genes (VEGF, VEGF-B, and VEGF-C) and their receptor genes (VEGFR-1 and VEGFR-2) in renal cell carcinoma (RCC). There were significant differences in the expression level of VEGF, VEGFR-1 and VEGFR-2 between RCC and the corresponding normal renal tissue. The expression level of VEGF in the tumor tissue significantly correlated with those of VEGFR-1 and VEGFR-2. Expression levels VEGF-B and VEGF-C genes were not significantly different between RCC and normal renal tissue. A moderate to high protein expression for VEGF, VEGFR-1, and VEGFR-2 was observed in both the tumor cells and the endothelial cells, whereas the protein expression was low for VEGF-B and VEGF-C. The present results suggested that VEGF and its receptors VEGFR-1 and VEGFR-2 cooperates to play a crucial role in the angiogenesis of RCC, while VEGF-B and VEGFR-C may not. Furthermore, since VEGFR-1 and VEGFR-2 proteins were expressed in the tumor cells as well as in the endothelial cells, these receptors may also be responsible for the progression of RCC.

Effect of pH on metabolism of glycyrrhizin, glycyrrhetic acid and glycyrrhetic acid monoglucuronide by collected human intestinal flora

Collected human intestinal flora (whole bacteria) was incubated with glycyrrhizin (GL), glycyrrhetic acid (GA), glycyrrhetic acid monoglucuronide (GAMG) and a combination of the three for 10 min at 37 degrees C under pH 5.6 and 7.0. The effect of these components on GL beta-D-glucuronidase activity, GAMG beta-D-glucuronidase activity and metabolite production in whole bacteria was examined. GL and GA were not metabolized at pH 5.6 and 7.0 by whole bacteria, while the level of GAMG changed at both pH 5.6 and 7.0. However, preincubated whole bacteria converted GA and a combination containing GA to other metabolites removed 3alpha-hydroxyglycyrrhetic acid and 3-oxoglycyrrhetic acid. The level of GL beta-D-glucuronidase activity remaining in whole bacteria after exposure to both GA and GAMG was above its initial level at pH 5.6 and 7.0, and the level of GAMG beta-D-glucuronidase activity remaining after exposure to GL, GA and GAMG was suppressed against control at pH 5.6 and 7.0. It is found that intestinal bacteria had similar action against GL, GA and GAMG at between pH 5.6 and 7.0.

Specificity of lectin activity of Bacillus thuringiensis parasporal inclusion proteins

Sheep erythrocyte-agglutinating parasporal inclusion proteins from four Bacillus thuringiensis strains (FITC-20, FITC-73, FITC-76 and IBC-1456) were examined for lectin activity against erythrocytes from four mammalian (rabbit, horse, cow and guinea pig) and an avian (chicken) species. Of the five erythrocyte species, only rabbit cells were agglutinated with the protein of the human cancer cell-killing strain IBC-1456. No haemagglutination (HA) activities were shown in other protein-erythrocyte combinations. The lectin activity of the strain IBC-1456 against rabbit cells was strongly inhibited by preincubation with D-galactose. Overall results revealed that the B. thuringiensis lectins have a preference for sheep erythrocytes.

Chrono and clinical pharmacokinetic study of tacrolimus in continuous intravenous administration

BACKGROUND

The circadian variation of clinical pharmacokinetics of tacrolimus in kidney transplant recipients receiving continuous intravenous administration has not been clarified. The aim of this study was to evaluate the circadian variation of this drug in continuous intravenous administration, with regard to the dosing scheme for conversion from intravenous to oral therapy.

METHODS

The blood concentration-time curve was studied in 10 living-related kidney transplant recipients, aged 18-51 years (mean, 36.5 years), 1 day before operation for preoperative oral administration, the third postoperative day for continuous intravenous administration and the sixth postoperative day at the conversion from intravenous to oral therapy.

RESULTS

Although the total body clearance of daytime was slightly higher than that of night-time, the intravenous tacrolimus infusion maintained an adequate therapeutic blood concentration for 24 h. There were significant differences between the preoperative and the postoperative state in the area under the curve, total body clearance and bioavailability for the oral administration. The mean absolute bioavailability was 17.7% in preoperative and 11.1% in postoperative state, respectively and a large interindividual variation was confirmed in this parameter, which was 7.0-27.2% for preoperative and 6.4-22.0% for postoperative area under the curve, respectively.

CONCLUSION

This study proposes that intravenous administration is a safe and appropriate method to achieve the required blood concentration in patients with various tacrolimus metabolism in the early post-transplant period. As the oral tacrolimus absorption was found to be variable between preoperative and postoperative states in identical patients, the conversion dosage cannot be calculated from preoperative oral or postoperative intravenous pharmacokinetics. Frequent blood concentration monitoring is needed to ensure safe treatment.

BCL10 is not a major target for frequent loss of 1p in testicular germ cell tumors

The deletion of chromosome 1p is one of the frequent genetic alterations found in testicular germ cell tumors (GCTs), suggesting the presence of a tumor suppressor gene. BCL10, which was identified as a gene altered in mucosa-associated lymphoid tissue lymphoma, has been mapped at 1p22. The gene has been reported to be mutated in a variety of human cancers. In this study, we investigated the allelic deletions on 1p and the mutation of BCL10 in 51 GCTs comprising 30 seminomas and 21 non-seminomatous germ cell tumors. Loss of heterozygosity (LOH) on 1p was tested using three microsatellite markers. The search for BCL10 mutations in each of the three exons was screened by a single-stranded conformation polymorphism (SSCP) analysis and samples with abnormal bandshifts were directly sequenced. LOH at at least one locus tested was found in 42% (21/49) of the tumors (43% of seminomas and 38% of NSGCTs). SSCP and direct sequence analyses revealed that there were single nucleotide polymorphisms at codon 5, 8, 162, and intron 1. However, there were no somatic mutations of BCL10 in the 51 tumors. In support of the previous studies, our results demonstrated that LOH on 1p is frequent in both seminomas and NSGCTs, indicating that there is an important tumor suppressor on 1p in GCT. However, the results indicate that BCL10 is not a candidate target gene of the 1p deletion.

Bacillus thuringiensis: a common member of microflora in activated sludges of a sewage treatment plant

Bacillus thuringiensis was recovered at a high frequency from activated-sludge system environments in an urban sewage-digestive plant. All of the test materials, sampled at several digesting steps, contained the organism. Of 515 colonies belonging to the B. cereus/B. thuringiensis group, 45 (8.7%) were assigned to B. thuringiensis. The highest density of this bacterium was 1.6 x 103 cfu/ml in a scum sample of the first aeration basin. Among the 45 isolates, 7 were assigned to the known H serovars. Two isolates of the serovar kenyae isolates exhibited Lepidoptera-specific toxicity. Diptera-specific toxicity was shown by an isolate of serovar israelensis and a serologically undefined isolate. Lectin activity was associated with 12 isolates.

A 28 kDa protein of the Bacillus thuringiensis serovar shandongiensis isolate 89-T-34-22 induces a human leukemic cell-specific cytotoxicity

A 28 kDa protein that exhibits cytocidal activity specific for human leukemic T (MOLT-4) cells was purified from proteinase K-digested parasporal inclusion of a Bacillus thuringiensis serovar shandongiensis isolate. The N-terminal sequence of the protein was identical with that of the 32 kDa protein, regarded as a protoxin, of the inclusion proteins. The median effective concentration of this protein was 0.23 microg/ml against MOLT-4 cells and its specific activity was 7.9 times greater than that of the whole inclusion proteins. The 28 kDa protein induced necrosis-like cytotoxicity against MOLT-4 cells and the cytopathic effect with the passage of time was characterized by cell swelling, nuclear membrane isolation and chromatin condensation.

Screening of the Bacillus thuringiensis Cry1Ac delta-endotoxin on the artificial phospholipid monolayer incorporated with brush border membrane vesicles of Plutella xylostella by optical biosensor technology

The binding of Cry1Ac, an insecticidal protein of Bacillus thuringiensis, to a brush border membrane (BBM) isolated from midguts of the diamondback moth Plutella xylostella was examined by surface plasmon resonance (SPR)-based biosensor. BBM was mixed with 1,3-ditetradecylglycero-2-phosphocholine (PC14), a neutral charged artificial lipid, and was reconstructed to a monolayer on a hydrophobic chip for the biosensor. The binding of Cry1Ac to the reconstructed monolayer was analyzed by a two-state binding model, and it was shown that Cry1Ac bound to the monolayer in the first step with an affinity constant (K(1)) of 508 nM, followed by the second uni-molecular step with an equilibrium constant (K(2)) of 0.472. The overall affinity constant K(d) was determined to be 240 nM. The binding was markedly inhibited by N-acetyl-D-galactosamine (K(i)=8 mM). The monolayer was shown to retain a high affinity to Cry1Ac, providing an insect-free system for rapid and large-scale screening of B. thuringiensis insecticidal proteins by the SPR-based biosensor technology.

Distinct microsatellite alterations in upper urinary tract tumors and subsequent bladder tumors

PURPOSE

Although synchronous and/or metachronous tumor development is common in urothelial cancer, genetic and biological differences in upper urinary tract and bladder tumors are unclear. We compared the genetic alteration pattern in multifocal disease in patients with upper urinary tract and subsequent bladder tumors, and those with recurrent bladder tumor.

MATERIALS AND METHODS

Using 21 microsatellite markers on the 8 chromosomal arms 2q, 4p, 4q, 8p, 9p, 9q, 11p and 17p we analyzed 34 tumors from 15 patients with upper urinary tract and subsequent bladder disease, and 70 tumors from 22 with recurrent bladder disease.

RESULTS

Judging from the patterns of genetic alterations multifocal tumors were considered to have derived from an identical progenitor cell in 7 of 13 evaluable patients (54%) with upper urinary tract and subsequent bladder tumors, and 16 of 19 (84%) who were evaluable with recurrent bladder tumor. These data confirm the view that seeding or intraepithelial spread is a major mechanism for the multifocal development of urothelial cancer in general. However, a discordant microsatellite alteration pattern in multifocal tumors was observed in 6 of 7 patients (86%) with upper urinary tract and subsequent bladder lesions but in 2 of 16 (13%) with recurrent bladder cancer (p <0.005).

CONCLUSIONS

Our results imply that upper urinary tract neoplasms may be genetically more unstable than bladder neoplasms. The implantation of tumor cells from upper urinary tract to bladder may involve additional and diverse genetic alterations. Furthermore, a considerable number of multifocal upper urinary tract and subsequent bladder lesions may arise independently via field cancerization mechanism. Our study indicates that the factors contributing to multifocal development are different in the 2 groups.

Hypermethylation at 9q32-33 tumour suppressor region is age-related in normal urothelium and an early and frequent alteration in bladder cancer

Transcriptional silencing by CpG island hypermethylation of gene regulatory regions is one mechanism for inactivation of tumour suppressor genes. Chromosome 9q deletion is frequently found in transitional cell carcinoma (TCC) of the bladder and upper urinary tract and one of the putative tumour suppressor loci has been mapped to 9q32-33. A gene designated as DBCCR1 was identified in the candidate region and its mRNA expression is thought to be suppressed by hypermethylation. To understand the role of hypermethylation in TCC, we evaluated the methylation status of 20 CpG sites of the DBCCR1 5'-CpG island region in a total of 69 tumours from 45 patients, 21 normal urothelial specimens, and six bladder cancer cell lines. Aberrant hypermethylation levels were found in 36 (52%) of 69 tumours without any association with tumour grade or stage. Methylation was weakly detected in the normal urothelium in association with ageing. Although recurrent tumours tended to have higher methylation levels than the initial tumours, the methylation pattern was mostly maintained between multifocal TCCs in individual patients. The results suggest that hypermethylation of the DBCCR1 region is one of the earliest alterations in the development of TCCs and there may be an age-related hypermethylation-based field defect in normal urothelium. Methylator or methylation-resistant phenotype seems to be maintained during multifocal development or recurrence of most TCCs.

Differences in the metabolism of glycyrrhizin, glycyrrhetic acid and glycyrrhetic acid monoglucuronide by human intestinal flora

Glycyrrhizin (1.0 mm GL), glycyrrhetic acid (1.0 mm GA) and glycyrrhetic acid monoglucuronide (1.0 mM GAMG), as well as a combination of all components added to medium at the start of growth and at the maximal stage of intestinal flora were cultured for 24 and 12 h, respectively. GL alone enhanced GL beta-D-glucuronidase activity about 2.7- to 6.8-fold and was metabolized to between 55 and almost 100% GA. GAMG alone was metabolized to almost 100% GA by GAMG beta-D-glucuronidase activity. Intestinal flora grown to a maximal stage converted GL to about 15% GA and GAMG to about 13% GA at almost 0 h. GL in combined GL and GA was consumed about 20% at 12 h and about 100% at 24 h under different culture conditions. Metabolite GA and unchanged GA were metabolized to a negligible amount of 3-oxoglycyrrhetic acid, 3alpha-hydroxyglycyrrhetic acid (3alpha-hydroxyGA) or both by 3beta-hydroxysteroid dehydrogenase and 3alpha-hydroxyGA dehydrogenase activities. Combined GL and GAMG consumed about 90% and 100% GAMG at 24 h and 12 h, respectively, regardless of culture conditions, and the consumption of GL was non-existent or negligible. Consumption of combined GL, GA and GAMG was similar to that of both combined GL and GA and combined GL and GAMG. It was found that intestinal flora can metabolize GL alone, but does not readily metabolize GL when present among its metabolites containing GL.

Baicalin, the predominant flavone glucuronide of scutellariae radix, is absorbed from the rat gastrointestinal tract as the aglycone and restored to its original form

When baicalin was orally administered to conventional rats, it was detected in their plasma for 24 h after administration, but baicalein, the aglycone of baicalin, was not detected. However, when baicalin was given to germ-free rats, only a small amount of baicalin was detected in their plasma within 2 h after the administration, its AUC0-lim (the area under the concentration-time curve from 0 to last determination time) being 12.0% of that in conventional rats. Subsequently, a considerable amount (55.1 +/- 6.2%) of baicalin was recovered from the gastrointestinal tract even 4 h after administration. When baicalein was orally administered to conventional rats, however, baicalin appeared rapidly in their plasma at an AUC0-lim value similar to that obtained after oral administration of baicalin, despite the absence of baicalein in plasma. When intestinal absorption was evaluated by the rat jejunal loop method, baicalein was absorbed readily, but only traces of baicalin were absorbed. Moreover, in conventional rats a small amount (13.4 +/- 3.1%) of baicalin and an appreciable amount (21.9 +/- 3.4%) of baicalein were recovered from the gastrointestinal tract even 4 h after oral administration of baicalin, but only a small amount (3.93 +/- 1.43%) of baicalein was detected in the intestinal tract 1 h after administration of baicalein. Baicalin was transformed to baicalein readily by the rat gastric and caecal contents. When baicalin was administered orally to conventional rats, an appreciable amount of baicalein was recovered in their gastrointestinal tracts. Moreover, baicalein was efficiently conjugated to baicalin in rat intestinal and hepatic microsomes. These results indicate that baicalin itself is poorly absorbed from the rat gut, but is hydrolysed to baicalein by intestinal bacteria and then restored to its original form from the absorbed baicalein in the body.

Characterization of the anti-cancer-cell parasporal proteins of a Bacillus thuringiensis isolate

An unusual activity, associated with non-insecticidal and non-haemolytic parasporal inclusion proteins of a Bacillus thuringiensis soil isolate, designated 89-T-26-17, was characterized. The parasporal inclusion of this isolate was bipyramidal, rounded at both ends, containing proteins of 180, 150, 120, 100, and 88 kDa. No homologies with the Cry and Cyt proteins of B. thuringiensis were detected based on N-terminal sequences. Proteolytic processing of the inclusion proteins by proteinase K, trypsin, and chymotrypsin produced a major protein of 64 kDa exhibiting cytocidal activity against human leukaemic T cells and uterus cervix cancer (HeLa) cells. The protease-activated proteins showed no cytotoxicity to normal T cells.

The clinical utility of measuring total PSA, PSA density, gamma-seminoprotein and gamma-seminoprotein/total PSA in prostate cancer prediction

BACKGROUND

To evaluate whether serum total prostate-specific antigen (PSA), PSA density (serum total PSA level divided by prostate volume), gamma-seminoprotein and gamma-seminoprotein/total PSA ratio could predict prostate cancer (PCa) prior to biopsy.

METHODS

A total of 316 consecutive patients who had undergone transrectal prostate biopsy and/or transurethral resection were examined. The prostate volume was determined by transrectal ultrasonography (TRUS) and the ability of the above-mentioned four variables to distinguish PCa from benign prostatic hyperplasia (BPH) was evaluated.

RESULTS

PCa was detected in 61 cases. Receiver-operating characteristic (ROC) analysis revealed that both the PSA density and serum total PSA were the most useful predictors of PCa among the four variables. For the patients with a serum total PSA level of 4.1-10.0 ng/ml, PSA density was significantly more accurate than total PSA (p < 0.005). An optimum PSA density value of 0.18 was chosen as a cutoff because it showed the highest sum of sensitivity and specificity, 92 and 54%, respectively. Using this PSA density cutoff, the number of biopsies could have been reduced to 57 from 63% when compared with a PSA density of 0.15.

CONCLUSIONS

PSA density was significantly more accurate than other variables in predicting PCa. To avoid unnecessary biopsies, the PSA density cutoff value of 0.18 would be recommendable for determining a prostate biopsy for Japanese males with a serum total PSA level of 4.1-10.0 ng/ml.

Parasporin, a human leukemic cell-recognizing parasporal protein of Bacillus thuringiensis

An unusual property, human leukemic cell-recognizing activity, associated with parasporal inclusions of a noninsecticidal Bacillus thuringiensis soil isolate was investigated, and a protein (named parasporin in this study) responsible for the activity was cloned. The parasporin, encoded by a gene 2,169 bp long, was a polypeptide of 723 amino acid residues with a predicted molecular weight of 81, 045. The sequence of parasporin contained the five conserved blocks commonly found in B. thuringiensis Cry proteins; however, only very low homologies (<25%) between parasporin and the existing classes of Cry and Cyt proteins were detected. Parasporin exhibited cytocidal activity only when degraded by proteases into smaller molecules of 40 to 60 kDa. Trypsin and proteinase K activated parasporin, while chymotrypsin did not. The activated parasporin showed strong cytocidal activity against human leukemic T cells (MOLT-4) and human uterus cervix cancer cells (HeLa) but not against normal T cells.

In vitro cytotoxicity of non-cyt inclusion proteins of a Bacillus thuringiensis isolate against human cells, including cancer cells

A soil isolate designated 90-F-45-14, belonging to Bacillus thuringiensis serovar dakota (H15), was examined for characterization of in vitro cytotoxicity, associated with parasporal inclusion proteins, against human cells. When activated with proteolytic processing, inclusion proteins of the isolate 90-F-45-14 exhibited a moderate cytotoxicity against the human uterus cervix cancer cells (HeLa) with an EC(50) value of 60.8 microg ml(-1), while showing extremely high activities on the human leukaemic T cells (MOLT-4) and the normal T cells with EC(50) values of 0.27 and 0.20 microg ml(-1), respectively. Anti-leukaemic cell activity of the 90-F-45-14 proteins was eight to nine times greater than that of the B. thuringiensis serovar israelensis proteins containing the Cyt1 protein, a broad-spectrum cytolysin. The cytopathy by the 90-F-45-14 proteins was characterized by marked cell-ballooning, while the israelensis proteins induced early breakdown of the cells due to cytolysis. Inclusions of the isolate consisted of five major polypeptides of 170, 103, 73, 40 and 32 kDa. A 100% homology was observed in the sequence of 15 N-terminal amino acids between the proteins of 170 and 103 kDa. There was no N-terminal sequence homology between 90-F-45-14 proteins and the existing Cry/Cyt proteins of B. thuringiensis. Proteolytic processing by proteinase K yielded several proteins with molecular masses ranging from 40 to 28 kDa.

Unique appendages associated with spores of Bacillus cereus isolates

Electron microscopic observations revealed the presence of a new type of large appendage on the spores of two Bacillus cereus strains isolated from phylloplanes. The appendages were thin and sword-like in shape, having the sizes of 1.5 to 2.8 microns in length and 0.03 to 0.6 micron in width. There were no core or sheath structures in these appendages. The number of appendages on a spore ranged from three to more than twenty, radiating from the swelling on one end of the exosporium. These appendages gave a unique octopus- or jellyfish-like feature to the spores.

Noninsecticidal parasporal proteins of a Bacillus thuringiensis serovar shandongiensis isolate exhibit a preferential cytotoxicity against human leukemic T cells

A Bacillus thuringiensis isolate, 89-T-34-22, belonging to the serovar shandongiensis (H22) produced noninsecticidal and nonhemolytic proteins crystallizing into irregular-shaped parasporal inclusions. The proteins showed in vitro cytotoxicity to human cells, including cancer cells, only when activated by protease treatment. The human leukemic T (MOLT-4) cells were > 100 times more susceptible than HeLa and normal T cells to the proteins of 89-T-34-22. The cytotoxicity was dose dependent and the median effective concentration for the MOLT-4 was 3.5 microg/ml. The cytopathy induced by the 89-T-34-22 proteins was characterized by remarkable condensation of the nucleus and cell-ballooning. Five major parasporal proteins of 89-T-34-22, with molecular masses in the range of 16-160 kDa, shared no similarity with the previously reported proteins in terms of the N-terminal sequence.

Occurrence of Bacillus thuringiensis in fresh waters of Japan

Bacillus thuringiensis was recovered at a relatively high frequency from both running and still fresh waters in natural environments of Kyushu, Japan. Of 107 water samples examined, 53 (49.5%) contained this organism. The frequency of B. thuringiensis colonies was 4.4% among 4414 colonies of the Bacillus cereus/B. thuringiensis group. The density of this bacterium in fresh waters averaged 0.45 cfu/ml. Serologically, B. thuringiensis isolates were assigned to 26 H serotypes. Of these, H14/36 (H serovar israelensis/malaysiensis) was the predominant, followed by the serotypes H3abc (kurstaki), H27 (mexicanensis), H3ad (sumiyoshiensis), and H35 (seoulensis). Of 195 isolates, 52 (26.7%) exhibited larvicidal activity against aquatic Diptera; 21 killed Culex pipiens molestus (Culicidae) only, and 31 were active on both the culicine mosquito and the moth-fly, Clogmia albipunctata (Psychodidae). The Diptera-toxic isolates produced spherical or irregularly pointed parasporal inclusions.

Competition in the metabolism of glycyrrhizin with glycyrrhetic acid mono-glucuronide by mixed Eubacterium sp. GLH and Ruminococcus sp. PO1-3

Eubacterium sp. GLH possessing glycyrrhizin (GL) and glycyrrhetic acid mono-glucuronide (GAMG) beta-D-glucuronidases, Ruminococcus sp. PO1-3 possessing GL and GAMG beta-D-glucuronidases and 3beta-hydroxysteroid dehydrogenase and these mixed bacteria were cultured in GAM medium with and without GL, GAMG or both. GL added to Eubacterium sp. GLH accelerated the peaks of enhanced GL beta-D-glucuronidase activity and suppressed GAMG beta-D-glucuronidase activity, and GAMG delayed the peaks of the enhanced growth with GL and GAMG beta-D-glucuronidase activities. GL added to Ruminococcus sp. PO1-3 enhanced gradually the growth with GL and GAMG beta-D-glucuronidase activities, and GAMG enhanced slowly GL beta-D-glucuronidase activity and rapidly the growth with GAMG beta-D-glucuronidase activity. The metabolite glycyrrhetic acid (GA) was produced by Eubacterium sp. GLH and Ruminococcus sp. PO1-3 in larger amounts and faster from GAMG than from GL. GL (1.0 mM) and 1.0 mM GAMG added to these mixed bacteria enhanced the growth with GL and GAMG beta-D-glucuronidase activities and were metabolized almost completely to GA in culture of 2 d and 1 d, respectively. It was found that the metabolism of GAMG was faster than that of GL. GL with GAMG added to mixed Eubacterium sp. GLH and Ruminococcus sp. PO1-3 cultured for 0 and 1 d led to a lower level of these enzyme activities and the consumption of GAMG more quickly, not GL. Low GAMG beta-D-glucuronidase had the ability to hydrolyze GAMG well.

Association of vitamin D receptor gene polymorphism with prostate cancer and benign prostatic hyperplasia in a Japanese population

Recent studies have suggested that vitamin D is an important determinant of prostate cancer risk and inherited polymorphisms in the 3'-untranslated region (3'UTR) of the vitamin D receptor (VDR) gene are associated with the risk and progression of prostate cancer. This study was conducted to explore the association of VDR gene polymorphisms with prostate cancer risk in Japanese men who are considered to be much less influenced by environmental risk factors for prostate cancer. We studied 222 prostate cancer patients, 209 benign prostatic hyperplasia (BPH) patients, 128 male controls who were over 60 years old and without any evidence of prostate cancer or BPH, and 198 female controls. A PCR-RFLP method was used to determine three VDR gene polymorphisms in the 3'UTR characterized by restriction enzymes BsmI, ApaI and TaqI. In the BsmI polymorphism, heterozygosity or homozygosity for the absence of the BsmI restriction site was associated with one-third the risk of prostate cancer (P < 0.0001; odds ratio, 3.31; 95% confidence interval, 2.05-5.32) and with one-half the risk of BPH (P < 0.005; odds ratio, 2.07; 95% confidence interval, 1.33-3.22) compared with the male controls. The TaqI and ApaI polymorphisms did not show any significant association with either prostate cancer or BPH. The results indicate that the BsmI polymorphism in the VDR gene plays a significant role in protection against prostate cancer and BPH. Because of the racial difference in the strength of the linkage disequilibrium between the three polymorphisms, additional studies are required to apply the present results to other racial-ethnic groups.

Hasty effect on the metabolism of glycyrrhizin by Eubacterium sp. GLH with Ruminococcus sp. PO1-3 and Clostridium innocuum ES24-06 of human intestinal bacteria

Eubacterium sp. GLH with Ruminococcus sp. PO1-3 and Clostridium innocuum ES24-06 possessing enzymes involved in the metabolism of glycyrrhizin (GL) was cultured in GAM medium with and without 1.0 mM GL or 1.0 mM glycyrrhetic acid (GA). GL (1.0 mM) enhanced 3alpha-hydroxyglycyrrhetinate (3alpha-hydroxyGA) dehydrogenase activity, GA (1.0 mm) suppressed 3alpha-hydroxyGA dehydrogenase activity, GL beta-D-glucuronidase activity and the mixed bacterial growth, and GL and GA showed almost no change in a lower level of 3beta-hydroxysteroid dehydrogenase (3beta-HSD) activity during 5 d of culture. GL (1.0 mM) and GA (1.0 mM) were metabolized to a small amount of GA and a negligible amount of 3-oxo-glycyrrhetic acid (3-oxo-GA) and 3alpha-hydroxyGA, and to a negligible amount of 3-oxo-GA, respectively, by these mixed bacteria. These amounts coincided with those of metabolites produced from 1.0 mM GL and 1.0 mM GA added to these mixed bacteria after 24 h culture. Whole bacteria and sonicated bacteria derived from the collection of these mixed bacteria reached a maximal stage and metabolized GL to a relatively large amount of GA and 3-oxo-GA, and a negligible amount of 3alpha-hydroxyGA and GA to a small amount of 3-oxo-GA and 3alpha-hydroxyGA within 180 min. GL beta-D-glucuronidase with 3beta-HSD and 3alpha-hydroxyGA dehydrogenase partially purified from each bacterium was converted GL to 3alpha-hydroxyGA, producing metabolites of about 60% after 10 min of incubation. These mixed bacteria possessed high enzyme activities could produce the metabolites of GL in under one hour under conditions.

Effects of glycyrrhizin and glycyrrhetic acid on the growth, glycyrrhizin beta-D-glucuronidase and 3 beta-hydroxysteroid dehydrogenase of human intestinal bacteria

The peak of glycyrrhizin (GL) beta-D-glucuronidase activity for Ruminococcus sp. PO1-3 and Eubacterium sp. GLH changed to 24 h from 12 h of culture and to 12 h from 48 h, respectively, at almost the same level by the addition of 1.0 mM GL. This enzyme activity was about 20-fold higher in Eubacterium sp. GLH than in Ruminococcus sp. PO1-3. GL beta-D-glucuronidase activity of Ruminococcus sp. PO1-3 with Eubacterium sp. GLH and the intestinal flora showed a maximal peak at 12 h of culture in the presence and absence of 1.0 mM GL. This enzyme activity was about 2.5-fold higher in mixed bacteria than in intestinal flora. 3Beta-hydrosteroid dehydrogenase activity of Ruminococcus sp. PO1-3 and Ruminococcus sp. PO1-3 with Eubacterium sp. GLH was suppressed greater in the presence of GL than without GL. Also, Ruminococcus sp. PO1-3, Eubacterium sp. GLH, and a mixture of both and intestinal flora, metabolized 1.0 mM GL to glycyrrhetic acid (GA) in yields of about 10, 70, 40 and 100%, respectively, with 24 h culture. From the level of GL beta-D-glucuronidase activity, it is considered that the metabolism of GL by intestinal flora is due to both enzymatic and non-enzymatic reactions. Moreover, GA at a concentration of 1.0 mM suppressed growth of Ruminococcus sp. PO1-3, Eubacterium sp. GLH, and the mixture of both and intestinal flora, which metabolized 1.0 mM GA to a negligible amount of 3-oxo-glycyrrhetic acid, indicating the accumulation of unchanged GA. GL beta-D-glucuronidase activity of intestinal flora was enhanced by GA, which stimulated bacteria possessing particular this characteristic.

Lectin activity of Bacillus thuringiensis parasporal inclusion proteins

Parasporal inclusion proteins from a total of 151 Bacillus thuringiensis strains, consisting of 139 Japanese isolates and the type strains of 12 H serovars, were screened for haemagglutination (HA) activity against sheep erythrocytes. Of 58 B. thuringiensis strains with HA activity, nine strains exhibited high activity and the remaining 49 strains were moderately active. The strains with high HA activity were derived from phylloplanes and soils of five geographically different localities, and belonged to H serovars kurstaki and other undefined serotype(s). The HA activities in the four selected strains were generated only when alkali-solubilised parasporal inclusion proteins were proteolytically processed. Furthermore, the lectin activity of the four strains was strongly inhibited by preincubation with N-acetylgalactosamine. The lectin-producing B. thuringiensis strains were heterogeneous in other biological activities of parasporal inclusions: insecticidal activity and cytocidal action on human leukaemia T cells.

Influence of various bile acids on the metabolism of glycyrrhizin and glycyrrhetic acid by Ruminococcus sp. PO1-3 of human intestinal bacteria

Ruminococcus sp. PO1-3, an intestinal bacterium isolated from human feces, metabolized glycyrrhizin (GL) to glycyrrhetic acid (GA) and GA to 3-oxo-glycyrrhetic acid (3-oxo-GA) and possessed GL beta-D-glucuronidase and 3beta-hydroxysteroid dehydrogenase (3beta-HSD) involved in the metabolism of GL. This bacterial growth was enhanced by GL at a concentration of 0.4 mm and was suppressed by GA at concentration of 1.0 mM. Chenodeoxycholic acid, deoxycholic acid and lithocholic acid among the bile acids added to this bacterium suppressed the growth and GL beta-D-glucuronidase activity and 3beta-HSD activity incident to it at a concentration of 1.0 mM, while cholic acid, hyodeoxycholic acid and glycine and taurin conjugates of cholic acid, chenodeoxycholic acid, deoxycholic acid and lithocholic acid had almost no effect on this bacterium at a concentration of 0.2 to 1.0 mm. However, these enzyme activities of this sonicated bacteria were inhibited by all of these bile acids. Although each bile acid and GL added to bacteria at the same time suppressed the growth and the amount of metabolite GA by all bile acids used except cholic acid, taurocholic acid and taurodeoxycholic acid with GL, a combination of each bile acid and GA eased the growth inhibition caused by GA at a concentration of 0.2 mM and enhanced the amount of metabolite 3-oxo-GA by the glycine conjugate of bile acids with GA. GL or GA added after 6 h culture with each of these bile acids and bacteria was metabolized to a relatively large amount of GA by chenodeoxycholic acid and lithocholic acid and their glycine and taurine conjugates, glycocholic acid and taurodeoxycholic acid, or had almost no effect on the amount of metabolite 3-oxo-GA, respectively. These results showed that although GL added after the exposure to bile acid and GA and bile acid added at the same time as bacteria had different bile acid action, these conditions enhanced the amount of metabolite GA from GL and metabolite 3-oxo-GA from GA.

Unique activity associated with non-insecticidal Bacillus thuringiensis parasporal inclusions: in vitro cell-killing action on human cancer cells

Parasporal inclusion proteins from a total of 1744 Bacillus thuringiensis strains, consisting of 1700 Japanese isolates and 44 reference type strains of existing H serovars, were screened for cytocidal activity against human leukaemia T cells and haemolytic activity against sheep erythrocytes. Of 1684 B. thuringiensis strains having no haemolytic activity, 42 exhibited in vitro cytotoxicity against leukaemia T cells. These non-haemolytic but leukaemia cell-toxic strains belonged to several H-serovars including dakota, neoleonensis, shandongiensis, coreanensis and other unidentified serogroups. Purified parasporal inclusions of the three selected strains, designated 84-HS-1-11, 89-T-26-17 and 90-F-45-14, exhibited no haemolytic activity and no insecticidal activity against dipteran and lepidopteran insects, but were highly cytocidal against leukaemia T cells and other human cancer cells, showing different toxicity spectra and varied activity levels. Furthermore, the proteins from 84-HS-1-11 and 89-T-26-17 were able to discriminate between leukaemia and normal T cells, specifically killing the former cells. These findings may lead to the use of B. thuringiensis inclusion proteins for medical purposes.

Purification and characterization of glycyrrhetic acid mono-glucuronide beta-D-glucuronidase in Eubacterium sp. GLH

Glycyrrhetic acid mono-glucuronide (GAMG), 1-(18beta-glycyrrhet-3-yl)-beta-D-glucopyranuroic acid, was hydrolyzed to glycyrrhetic acid (GA) by GAMG beta-D-glucuronidase in Eubacterium sp. GLH from human intestinal bacteria. The enzyme had an optimum pH of 5.0 and was purified from a crude extract by Butyl Toyopearl 650 S, Toyopearl HW-55 S, Hydroxyapatite and DEAE-Toyopearl 650 M column chromatography. The purified enzyme showed a specific activity of 495 nmol/min/mg protein and a single band on Coomassie brilliant blue staining and a molecular weight of about 43 kDa on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The apparent molecular weight was 49.5 kDa, as estimated by Toyopearl HW-55 S column chromatography. Also, the enzyme seemed to have a sulfhydryl group(s) in its active site with a Km value of 77 x 10(-3) M.

Unique synthetic peptides stimulating streptolysin S production in streptococci

A peptide has been isolated from pronase digest of bovine serum albumin as the stimulatory factor of streptolysin S (SLS) production by Streptococcus pyogenes, and its primary structure has been deduced [Akao et al. (1992) Infect. Immun. 60, 4777-4780]. To determine the essential structure for the stimulation, a peptide (P-1) having the deduced structure, in which three peptide fragments are linked by two disulfide bonds, and shorter analogs (P-2 to P-4) of peptide P-1 were chemically synthesized. Another peptide (P-5), in which Ala is inserted between the two Cys residues in the middle peptide chain of P-1, was also synthesized. These synthetic peptides were identified by mass spectrometry and analysis of amino acid compositions. The synthetic P-1 stimulated SLS production in a dose-dependent manner. Other peptide analogs also showed remarkable stimulation of SLS production. Treatment of P-1 with performic acid resulted in loss of its stimulatory activity, indicating that disulfide bridges of the peptides are necessary for their activity on SLS production. These results suggest that the unique primary structure of three peptide chains linked by two disulfide bridges is requisite for the stimulatory effect on SLS production.

Clonal and chronological genetic analysis of multifocal cancers of the bladder and upper urinary tract

Recent molecular genetic studies have suggested that multifocal urothelial cancers are derived from an identical progenitor cell. However, the clonal origin of multifocal urothelial cancers of a low-grade superficial type has not been fully defined. Using microsatellite markers, we examined genetic alterations at 20 loci on eight chromosomal arms (2q, 4p, 4q, 8p, 9p, 9q, 11p, and 17p) in 87 metachronous and/or synchronous multifocal urothelial cancers, which included 84 low-grade superficial papillary tumors from 29 patients. Judging from the patterns of loss of heterozygosity, microsatellite shifts, and the subchromosomal partial deletion, multifocal tumors in at least 20 (80%) of the 25 evaluable patients were considered to be derived from a single progenitor cell, although the possibility remained that multifocal tumors in a small subset of patients might develop from distinct progenitor cells due to field cancerization. In 13 of the 20 patients, a chronological genetic analysis was available: genetic heterogeneity was detected in 3 (23%) patients, and an apparent accumulated pattern of genetic alterations was detected in only 1 (8%) patient. In the 20 patients with multifocal tumors of an identical clonal origin, discordant microsatellite alterations were observed, with significantly lower frequencies on chromosome 9 compared to those on the other chromosomes tested. The results indicate that most multifocal low-grade superficial urothelial cancers are genetically stable despite their incidence of frequent recurrence, and genetic divergence occurs in a subset of patients. This heterotopic spread and genetic divergence may occur long before the clinical manifestation of multiplicity from a single transformed cell. These data support the previous view that heterotopic spread of transformed progenitor cells and genetic divergence occur after chromosome 9 alterations in most of low-grade superficial urothelial cancers.

Distribution of enzymes involved in the metabolism of glycyrrhizin in various organs of rat

Glycyrrhizin (GL) was hydrolyzed to glycyrrhetic acid (GA), glycyrrhetic acid mono-beta-D-glucuronide (GAMG) or both by glucuronidases in various organs of rat. GL beta-D-glucuronidase I, hydrolyzing GL to GA; GAMG beta-D-glucuronidase, hydrolyzing GAMG to GA; and 3alpha-hydroxyglycyrrhetinate (3alpha-hydroxyGA) dehydrogenase, oxidizing 3alpha-hydroxyGA to 3-oxo-GA were found in the organs of this animal. GL beta-D-glucuronidase II was distributed in the lysosomal fraction of all organs except brain; 3alpha-hydroxyGA dehydrogenase was distributed in the microsomal fraction of the liver; but other enzymes were distributed in the nuclear, lysosomal, microsomal and soluble fractions of a variety of organs. GL beta-D-glucuronidase I, GL beta-D-glucuronidase II and GAMG beta-D-glucuronidase activities in a mixture of lysosomes and microsomes of rat liver exhibited different patterns on hydroxyapatite column chromatography. These results showed the metabolic pathways of GL to be of two types: a beta-D-glucuronidase hydrolyzing GL to GA, and the other consisting of two different beta-D-glucuronidases hydrolyzing GL to GAMG and GAMG to GA.

Intestinal bacterial hydrolysis is required for the appearance of compound K in rat plasma after oral administration of ginsenoside Rb1 from Panax ginseng

Ginsenoside Rb1 from Panax ginseng root is transformed into compound K via ginsenosides Rd and F2 by intestinal bacterial flora. Among 31 defined intestinal strains from man, only Eubacterium sp. A-44 transformed ginsenoside Rb1 into compound K via ginsenoside Rd. The ginsenoside Rb1-hydrolysing enzyme isolated from Eubacterium sp. A-44 was identical to a previously purified geniposide-hydrolysing beta-D-glucosidase. When ginsenoside Rb1 (200 mg kg-1) was administered orally to germ-free rats, neither compound K nor any other metabolite was detected in the plasma, intestinal tract or cumulative faeces 7 or 15 h after administration. Most of the ginsenoside Rb1 administered was recovered from the intestinal tract, especially the caeca, and cumulative faeces indicating poor absorption of ginsenoside Rb1. When ginsenoside Rb1 was administered orally to gnotobiote rats mono-associated with Eubacterium sp. A-44, a significant amount of compound K was detected in the plasma and considerable amounts were found in the caecal contents and cumulative faeces 7 and 15 h after administration. A small amount of ginsenoside Rb1 was detected in the caecal contents only 7 h after administration. These results indicate that orally administered ginsenoside Rb1 is poorly absorbed from the gut but that its metabolite compound K, produced by ginsenoside Rb1-hydrolysing bacteria such as Eubacterium sp. A-44 in the lower part of intestine, is absorbed.

Metabolism and pharmacokinetics of orally administered saikosaponin b1 in conventional, germ-free and Eubacterium sp. A-44-infected gnotobiote rats

The metabolic fate of saikosaponin b1 (1) was investigated using conventional, germ-free and Eubacterium sp. A-44-infected gnotobiote rats. After the oral administration of 1 to germ-free rats at a dose of 50 mg/kg, no metabolite was detected in the plasma, the cecal contents or the cumulative feces through the experiment. On the other hand, when 1 was orally given to the Eubacterium sp. A-44-infected gnotobiote rats, considerable amounts of its metabolites, prosaikogenin A (2) and saikogenin A (3), were detected in the rat plasma with the respective AUC0-10 h values of 17,424 and 22,260 pmol.min/ml, similar to the case of its oral administration to conventional rats (AUC0-10 h values of 9,936 and 12,414 pmol.min/ml for 2 and 3, respectively). Furthermore, significant amounts of both metabolites were detected in the cecal contents and the cumulative feces of the gnotobiote and conventional rats, but not in those of the germ-free rats, within 10 h after the administration. Fecal and cecal activities of hydrolyzing 1 and 2 were found in the gnotobiote and conventional rats, though there were no detectable activities in the germ-free rats. Accordingly, both hydrolyzing activities in the intestinal bacteria, such as Eubacterium sp. A-44, are essential for the appearance of 2 and 3 in the rat plasma and cumulative feces, since orally administered 1 was poorly absorbed from the gastrointestinal tract.

Appearance of compound K, a major metabolite of ginsenoside Rb1 by intestinal bacteria, in rat plasma after oral administration--measurement of compound K by enzyme immunoassay

Enzyme immunoassay (EIA) for the determination of compound K (C-K), a major metabolite of ginsenoside Rb1 (G-Rb1) from Panax ginseng root by intestinal bacterial flora, was explored. Bovine serum albumin (BSA) was coupled to the C-26 position on the unsaturated side chain of C-K. Beta-D-galactosidase was introduced at the C-26 position of the saturated side chain. Antiserum, obtained by immunization of rabbits with C-K-BSA conjugate, possessed high affinity and specificity toward C-K. The EIA for C-K by the double antibody method was established in the range of 0.1--100 ng/tube. Plasma C-K after the oral administration of C-K and G-Rb1 to rats was determined by the established EIA. C-K was rapidly absorbed from the gastrointestinal tract after the administration, then slowly decreased. On the other hand, C-K appeared late and was retained for a long period of time in the plasma after the administration of G-Rb1, which itself is hardly absorbed.

Hydrolysis of glycyrrhetyl mono-glucuronide to glycyrrhetic acid by glycyrrhetyl mono-glucuronide beta-D-glucuronidase of Eubacterium sp. GLH

Glycyrrhetyl mono-glucuronide (GAMG) is an intermediate in the hydrolysis of glycyrrhizin (GL) to glycyrrhetic acid (GA). An enzyme responsible for its hydrolysis, characterized as a GAMG beta-D-glucuronidase of Eubacterium sp. (species) GLH, has been isolated from human intestinal bacteria. The pattern of GAMG beta-D-glucuronidase activity was different from that of GL beta-D-glucuronidase activity by Butyl-Toyopearl 650 S column chromatography. Thus, these enzymes showed differences in the purification ratio and substrate specificity. After this step, GAMG beta-D-glucuronidase was completely separated from GL beta-D-glucuronidase by gel filtration through Toyopearl HW-55 S, indicating that the GAMG beta-D-glucuronidase is a novel type of beta-D-glucuronidase which hydrolyzes one glucuronic acid linkage of GA.

Enzymes responsible for the metabolism of saikosaponins from Eubacterium sp. A-44, a human intestinal anaerobe

From a human intestinal bacterium, Eubacterium sp. A-44, which is capable of hydrolyzing saikosaponins to saikogenins, two glycosidases, beta-D-glucosidase and a novel type of beta-D-fucosidase, were isolated and characterized as saikosaponin-hydrolyzing beta-D-glucosidase and prosaikogenin-hydrolyzing beta-D-fucosidase. Relative to the hydrolyzing activities toward saikosaponins a, b1 and b2, the beta-D-glucosidase showed lower ability to hydrolyze saikosaponin d, but no ability to hydrolyze saikosaponin c or prosaikogenins. By Sephacryl S-300 column chromatography, the molecular weight of prosaikogenin-hydrolyzing beta-D-fucosidase was estimated to be about 130 kDa. The beta-D-fucosidase could hydrolyze prosaikogenins A and F, but not prosaikogenins D and G or saikosaponins. Relative to p-nitrophenyl beta-D-fucoside-hydrolyzing activity, this enzyme had 32.0% and 22.2% of its hydrolyzing ability toward p-nitrophenyl beta-D-glucoside and p-nitrophenyl beta-D-galactoside, respectively. p-Nitrophenyl beta-D-fucoside-hydrolyzing activity was inhibited by D-fucose, and was weakly inhibited by D-glucose, D-glucono delta-lactone, D-galactose and D-galactono delta-lactone. By combining these two glycosidases, saikosaponins a and b1 were converted to their saikogenins via the corresponding prosaikogenins.

Development of the computerized dental cast form analyzing system--three dimensional diagnosis of dental arch form and the investigation of measuring condition

To analyze the functional and morphological harmonies of the tooth and dental arch, a computerized system to measure a dental cast and to detect the apex of dental cusps and angle points of incisors was developed. Detailed morphology in the measured dental cast could be displayed distinctively by computer graphics (CG) with a surface model. Accuracy in determining the position of the apex of the dental cusp was examined by increasing the measuring pitch from 50 microns to 400 microns, the error increased gradually with increased measuring pitch. Taking the measuring error, the time for measurement and the memory size for analysis into account, a measuring pitch of 200 microns was determined to be reasonable. Three-dimensional data measurements from the apex of the dental cusp in molar, and the mesial and distal angles in canine and incisor were fitted to a polynomial formula. In the present measured model, the 4th order polynomial formula was used for the dental arch, and the 2nd order polynomial formula was used for the anteroposterior and lateral occlusal curves. These formulae could be simultaneously superimposed on the surface model of the dental cast, and displayed using CG.

A high prevalence of functional inactivation by methylation modification of p16INK4A/CDKN2/MTS1 gene in primary urothelial cancers

We analyzed the genetic and epigenetic alterations of p16INK4A/CDKN2/MTS1 gene (MTS1 gene) in 38 primary urothelial cancers. Genetic alterations of the MTS1 gene consisted of one base substitution mutation in exon 2 (2.6%) and 6 homozygous deletions (16.2%). Hypermethylation of the 5' CpG island in exon 1 of the MTS1 gene was observed in 12 tumors (37.5%). Consequently, 19 of 38 tumors (50%) showed genetic alterations or epigenetic hypermethylation of the MTS1 gene. Retention of hypermethylated MTS1 gene(s) in 36% of the tumors showing loss of heterozygosity at the critical region indicates that the methylation modification could be an initial event followed by genomic rearrangements associated with total loss of MTS1 gene function. Immunohistochemical analysis of MTS1 expression revealed that all the tumors with genetic alterations of the MTS1 gene and 9 of 12 highly methylated tumors displayed an absence of MTS1 nuclear antigen. Genetic and epigenetic changes of the MTS1 gene were not correlated with the grade and stage of tumors, indicating that these alterations are early events in urothelial carcinogenesis, in which functional inactivation by hypermethylation is a predominant mechanism.