[Procedures and the significance of Evidence-based Medicine].
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to T Fukui.
Explore the source record for details and available documents.
Mer-NF8054X is a new type of steroid whose structure has been established as 11-oxo-18, 22-cycloergosta-6, 8(14)-diene-3beta, 5beta, 9beta, 23S-tetraol (an 18, 22-cycloergostane), which has been reported to have antifungal activity against Aspergillus fumigatus. However, other biological activities are unknown. Herein, we reported that Mer-NF8054X inhibited cell growth of HL60 human leukemia cells, when used either singly or in combination with retinoic acid (RA). In addition, Mer-NF8054X alone induced differentiation and apoptosis of HL60 cells. The induction of differentiation of HL60 cells by Mer-NF8054X was synergistic in combination with RA. On the other hand, Emesterone A, an analogue of Mer-NF8054X which is missing a hydroxy residue from the third position, showed much lower activity than Mer-NF8054X on the inhibition of cell growth and the induction of cell differentiation and apoptosis. However, Emesterone B, an analogue of Emesterone A which is missing a hydroxy residue from the fifth position, showed higher activity than Emesterone A but lower activity than Mer-NF8054X when examined for the inhibition of cell growth and the induction of cell differentiation and apoptosis. These results suggested that Mer-NF8054X and its analogs may be a new type of differentiation inducing agent. The hydroxy residue at the third position or fifth position in Mer-NF8054X may be necessary, but not essential, for inhibition of growth and induction of both differentiation and apoptosis of HL60 cells. In addition, Mer-NF8054X enhanced the differentiation of HL60 cells induced by RA. Based on these results, Mer-NF8054X may have utility in the clinic in combination with RA for leukemia patients.
Falconensones A and B are new type of yellow pigment isolated from the mycelial extract of ascomycetous fungi, Emericella falconensis or Emericella fruticulosa, whose structures are similar to retinoic acid (RA). To date, biological activities of falconensones have not been reported. Herein, we reported that falconensone A inhibited growth of HL60 human leukemia cells, when used either singly or in combination with RA. Falconensone A alone did not induce differentiation of HL60 cells. However, falconesone A enhanced the differentiation of HL60 cells induced by 10 nM RA, and its effect was synergistic. On the other hand, falconensone B, the 4'-nor-methyl derivative of falconensone A, showed much lower activity than falconensone A on the inhibition of cell growth. In addition, synthetic derivatives of falconensone A, falconensone A p-bromophenylhydrazone and falconensone A dioxime, were more potent on the inhibition of cell growth and the induction of differentiation than natural falconensones A and B. These compounds induced differentiation of HL60 cells into monocyte/macrophage-like cells, different from granulocyte-like cells induced by RA. These results suggest that falconensone A may be a new type of antiproliferative agent, and that the methyl residue at the 4' position of the cyclopentenone ring of falconensone A may be necessary for biological activity. In addition, falconensone A enhanced RA-induced differentiation of HL60 cells, while its derivatives alone showed growth inhibition and induction of differentiation of HL60 cells. Based on these results, falconensone A and its derivatives may have clinical utility in the treatment of leukemia.
Explore the source record for details and available documents.
BACKGROUND: Stereotactic radiation therapy is highly effective in the treatment of small brain metastases, regardless of the histology. This suggests that small extracranial malignancies may be curable with similar radiation therapy. The authors developed a novel treatment unit for administering such therapy. METHODS: The unit consisted of a linear accelerator (linac), an X-ray simulator (X-S), computed tomography (CT), and a table. The gantry axes of the three machines were coaxial and could be matched by rotating the table. Patients were instructed to perform shallow respiration with oxygen. The motion of the tumor was monitored with the X-S. When the motion was slight enough, the table was rotated to the CT. To include all geometric movement on the CT images, each scan was made while the patient was performing shallow respiration. After the CT positioning, the table was rotated to the linac, and non-coplanar treatment was given. Beginning in October 1994, 45 patients with 23 primary or 43 metastatic lung carcinomas were treated. Radiation doses at the 80% isodose line were 30-75 gray in 5-15 fractions over 1-3 weeks with or without conventional radiation therapy. RESULTS: The treatment was performed with no or minimal adverse acute symptoms. The daily treatment time was short. During a median follow-up of 11 months, local progression occurred in 2 of 66 lesions. Interstitial changes in the lung were limited. CONCLUSIONS: With this unit and procedure, focal radiation therapy similar to stereotactic radiation therapy is possible for extracranial sites. The preliminary experience appeared safe and promising, and further exploration of this approach is warranted.
Among 222 primary colorectal cancers we examined, 58 showed no detectable APC mutations by the protein truncation test. We screened those 58 tumors for somatic mutations in the beta-catenin gene. Although amino acid substitutions in serine or threonine residues in exon 3 had been reported, we found no such mutations; however, in seven tumors, we detected somatic interstitial deletions of 234-760 bp, each of which included all or part of exon 3. Short nucleotide sequences at both ends of each deletion were either identical or complementary, indicating that repeated or inversely repeated sequences were involved in the somatic rearrangements. Reverse transcription-PCR experiments using RNAs isolated from three of these seven tumors detected transcripts that lacked exon 3, in addition to the normal transcript. In one of these cases, we confirmed accumulation of aberrant beta-catenin protein in cytoplasm and nuclei of cancer cells by Western and immunohistochemical analyses. This result suggested that, in the absence of a peptide encoded by exon 3, beta-catenin is stabilized and has a dominant oncogenic effect on colorectal tumorigenesis.
Explore the source record for details and available documents.
The ability of Alcaligenes eutrophus to grow and produce polyhydroxyalkanoates (PHA) on plant oils was evaluated. When olive oil, corn oil, or palm oil was fed as a sole carbon source, the wild-type strain of A. eutrophus grew well and accumulated poly(3-hydroxybutyrate) homopolymer up to approximately 80% (w/w) of the cell dry weight during its stationary growth phase. In addition, a recombinant strain of A. eutrophus PHB-4 (a PHA-negative mutant), harboring a PHA synthase gene from Aeromonas caviae, was revealed to produce a random copolyester of 3-hydroxybutyrate and 3-hydroxyhexanoate from these plant oils with a high cellular content (approximately 80% w/w). The mole fraction of 3-hydroxyhexanoate units was 4-5 mol% whatever the structure of the triglycerides fed. The polyesters produced by the A. eutrophus strains from olive oil were 200-400 kDa (the number-average molecular mass). The results demonstrate that renewable and inexpensive plant oils are excellent carbon sources for efficient production of PHA using A. eutrophus strains.
To attain long-term bioreaction in organic solvents with living microorganisms, we tried to protect the microorganisms from the toxicity of the solvent by immobilization. In this study, baker's yeast, which is not tolerant to organic solvents such as isooctane, was selected as a model microorganism and the immobilized living yeast cells were examined for activity in the steroselective reduction of ethyl 3-oxobutanoate to ethyl (S)-3-hydroxybutanoate in isooctane; an activity that correlated well with the viability of the yeast cells. It was found that double entrapment, that is, further entrapment of calcium-alginate-gel-entrapped cells with a urethane prepolymer, made it possible for the yeast to remain viable in isooctane, although other conventional immobilization methods, such as single entrapment using polysaccharide or synthetic resin prepolymers, were insufficient for its protection. Furthermore, doubly entrapped living yeast cells could carry out the stereoselective reduction in isooctane repeatedly for a long period (more than 1200 h) with occasional cultivation. Thus, double entrapment enabled a microorganism sensitive to organic solvents to survive over long-term bioreaction in an organic solvent.
We report herein the case of an 80-year-old woman who underwent successful redo coronary artery bypass grafting (CABG) for a saphenous vein graft aneurysm found 10 years after her initial operation. On presentation, coronary angiography (CAG) revealed aneurysmal dilatation of the saphenous vein graft and severe stenosis of the left main trunk (LMT). A percutaneous transluminal coronary angioplasty (PTCA) of the LMT lesion was performed; however, a CAG after the PTCA revealed restenosis and the patient developed anginal chest pain at rest. Thus, repeat CABG was urgently carried out, which was followed by a good outcome. Histological examination of the aneurysmal dilatation showed a true aneurysm. Only 15 other cases of redo CABG for this indication have been reported, the features of which are also discussed.
We have previously shown that prostaglandin E2 (PGE2) and IL-4 inhibit the priming of IFN-gamma-production during the differentiation of naive CD4+ T cells from human cord blood by different signal-transducing mechanisms. To compare and analyse the molecular mechanisms by which PGE2 and IL-4 inhibit the priming of IFN-gamma production, we investigated the effects of PGE2 and IL-4 on the methylation of the IFN-gamma gene during the in vitro differentiation of naive CD4+ T cells. In human naive CD4+ T cells, which produce primarily IL-2 and a little amount of IFN-gamma, the IFN-gamma gene was methylated. After stimulation via TCR, CD4+ T cells produced IFN-gamma and the CpG dinucleotide contained within the TATA proximal regulatory element of the IFN-gamma gene was partially hypomethylated. Both IL-4 and PGE2 inhibited the hypomethylation of this site and the acquisition of IFN-gamma-producing ability. In contrast to the SnaBI site in the TATA proximal regulatory element, the HpalI site in the first intron of the IFN-gamma gene of the CD4+ T cells from cord blood was completely methylated even after stimulation via TCR. 5-azacytidine restored the IFN-gamma-producing ability of these cells treated with IL-4 and PGE2. These findings suggest that, although the signal transduction that inhibits the priming of IFN-gamma-production is different for each reagent, the protection from hypomethylation of the regulatory region of the IFN-gamma gene is involved in the molecular mechanisms by which these reagents inhibit the priming of IFN-gamma-production during the differentiation of human naive CD4+ T cells.
The objective of this paper was to investigate what kind of postgraduate education in medical ethics medical residents in Japan receive and what they want for ethical education and guidelines. Sixteen teaching hospitals that provide a general internal medicine residency programme in Japan were used (145 medical residents working at the departments of general internal medicine). A total of 114 residents participated in our survey, yielding a response rate of 79%. Of these, 28% received education in medical ethics more than once a month; 24% were offered it only when ethical problems were involved in actual patient care; and 18% answered that opportunities were very rare and sporadic. A full 30% had received no education in medical ethics at all. Many residents (71%) learned medical ethics from individual supervising doctors. A majority of the residents had been taught about informed consent (79%) and doctor-patient relationships (54%); 46% had learned about the appropriateness of truth telling and of ethical decisions regarding withholding and withdrawing a life-sustaining treatment, respectively. A total of 85 residents (75%) wanted to have more comprehensive education in medical ethics, 13% could not decide, and 12% did not want it. Many (66%) thought that both doctors and ethical philosophers should jointly teach medical ethics in postgraduate residency programmes. The results suggest that many residents desire more comprehensive and interdisciplinary education in medical ethics and educators in Japan should aim to develop education programmes to meet these desires.
Since minor vitamins such as biotin are not yet registered as food additives in Japan, these cannot be used to supplement infant formulas or foods, despite their nutritional value. Therefore, the biotin contents of infant formulas made in Japan were determined and compared with those from the United States (US). The Japanese products were obtained from five companies, while the US products were limited to those from one company. The average content of total biotin in 11 Japanese products for nursing of normal infants (standard formulas) was 1.04 micrograms/100 kcal (0.69 microgram/100 ml), which was significantly lower than that in two US products (2.56 micrograms/100 kcal, 1.71 micrograms/100 ml). The total biotin content in 26 Japanese infant formulas specially prepared for medical treatment and prevention of disease (special formulas) was 0.45 microgram/100 kcal (0.30 microgram/100 ml) on average. This was less than a fifth of the level in the three US products (1.82 micrograms/100 kcal, 1.22 micrograms/100 ml). There was no difference in the proportion of free biotin (the percent of active biotin to total biotin) between the Japanese and US standard formulas (67.7% and 77.2%, respectively). However, in special formulas the mean proportion of the free biotin in the Japanese products (29.4%) was lower than that in the US products (71.2%). The nutrient intake of infants is limited to the maternal milk and/or infant formulas. These findings suggest that Japanese infant formulas should be appropriately improved to maintain growth and good health. Biotin should be registered as a food additive in Japan so that it can be used to fortify infant formulas.
OBJECTIVE: Biotin plays important roles in carbohydrate and lipid metabolism as well as in the decarboxylation of amino acids. In this study, to determine the biotin status in elderly people, we determined the levels of biotin and other biochemical variables in their serum. METHODS: Blood was collected from 685 elderly people aged 65 years and over (284 men and 401 women) and from 2,004 reference people. Biotin levels in the serum were microbiologically quantified by the agar plate method and other biochemical variables were recorded using the autoanalyzer. RESULTS: The serum biotin level in elderly people was 10.2 +/- 7.20 pmol/ml (2.5 +/- 1.76 ng/ml), the distribution of which was skewed to the right compared to the reference group (9.4 +/- 1.43 pmol/ml) (2.3 +/- 0.35 ng/ml). However, serum biotin levels did not change with age in the elderly people and no sex-related differences were detected. On the basis of the correlation coefficients among the biochemical variables in the serum, biotin levels were correlated positively with the total cholesterol level. A negative correlation was found between the biotin level and the serum albumin, triiodothyronine, phosphate, and calcium levels. On the other hand, 5.8% of the elderly people had biotinyl IgG in their serum, which did not differ from the percentage in the reference group (4.1%). However, in the elderly people the level of biotinyl IgG positivity was significantly lower in women than in men (4.1% vs. 8.1%). In the biotinyl IgG positive elderly, the levels of parathyroid hormone and total cholesterol were lower, whereas the uric acid level was higher compared to the biotinyl IgG negative elderly. CONCLUSIONS: Although serum biotin levels are not affected by aging, the serum biotin levels of elderly people vary greatly.
Two types of active chimeric enzymes have been constructed by genetic engineering of chicken cytosolic adenylate kinase (AK) and porcine brain UMP/CMP kinase (UCK): one, designated as UAU, carries an AMP-binding domain of AK in the remaining body of UCK; and the other, designated as AUA, carries a UMP/CMP-binding domain of UCK in the remaining body of AK. Steady-state kinetic analysis of these chimeric enzymes revealed that UAU is 4-fold more active for AMP, 40-fold less active for UMP, and 4-fold less active for CMP than the parental UCK, although AUA has considerably lowered reactivity for both AMP and UMP. Circular dichroism spectra of the two chimeric enzymes suggest that UAU and AUA have similar folding structures to UCK and AK, respectively. Furthermore, proton NMR measurements of the UCK and UAU proteins indicate that significant differences in proton signals are limited to the aromatic region, where an imidazole C2H signal assigned to His31 shows a downfield shift upon conversion of UCK to UAU, and the signals assigned to Tyr49 and Tyr56 in the UMP/CMP-binding domain disappear in UAU. In contrast, AUA has a Tm value about 11 degreesC lower than AK, whereas UAU and UCK have similar Tm values. These results together show that the substrate specificity of nucleoside monophosphate (NMP) kinases can be engineered by the domain exchange, even though the base moiety of NMP appears to be recognized cooperatively by both the NMP-binding domain and the MgATP-binding core domain.
We performed a decision analysis to evaluate the usefulness of pretreatment prediction of clinically significant or insignificant tumor in patients with prostate-specific antigen (PSA)-detected stage T1c prostate cancer nonpalpable on rectal examination. Analysis was done for otherwise healthy subjects with 20 years of life expectancy. The prevalence of insignificant tumor among those with T1c prostate cancer was initially assumed to be 0.2. Quality-adjusted life expectancy was calculated and compared between 2 strategies; one with prediction-based selection of either radical prostatectomy or watchful waiting and the other with unselective assignment of one of the treatments. The selection strategy was superior when the sensitivity and specificity for detecting clinically significant tumor were 0.92 and 0.73, respectively, as reported by Epstein et al. (1994) using criteria of PSA density and Gleason score in a needle biopsy specimen. Sensitivity analysis revealed that the prediction-based selection strategy is preferred, with sensitivity and specificity constant, when the prevalence of insignificant tumor exceeds 0.16. On the other hand, when the prevalence of insignificant tumor is kept constant at 0.2, sensitivity should be 0.85 or higher for the prediction strategy to be preferred. As the prevalence of insignificant tumor among those with T1c prostate cancer increased, the prediction-based selection strategy is preferred with lower values of sensitivity and specificity for detecting significant tumor. These results suggest that a selective treatment strategy of either radical or conservative treatment based on pretreatment prediction for significant tumor is a beneficial alternative to radical prostatectomy unselectively assigned to all patients at the T1c stage, if a reasonable accuracy in prediction is attained.
The polyhydroxyalkanoate (PHA) synthase gene of Comamonas acidovorans DS-17 (phaCCa) was cloned by using the synthase gene of Alcaligenes eutrophus as a heterologous hybridization probe. Complete sequencing of a 4.0-kbp SmaI-HindIII (SH40) subfragment revealed the presence of a 1,893-bp PHA synthase coding region which was followed by a 1,182-bp beta-ketothiolase gene (phaACa). Both the translated products of these genes showed significant identity, 51.1 and 74.2%, respectively, to the primary structures of the products of the corresponding genes in A. eutrophus. The arrangement of PHA biosynthesis genes in C. acidovorans was also similar to that in A. eutrophus except that the third gene, phaB, coding for acetoacetyl-coenzyme A reductase, was not found in the region downstream of phaACa. The cloned fragment complemented a PHA-negative mutant of A. eutrophus, PHB-4, resulting in poly-3-hydroxybutyrate accumulation of up to 73% of the dry cell weight when fructose was the carbon source. The heterologous expression enabled the incorporation of 4-hydroxybutyrate (4HB) and 3-hydroxyvalerate monomers. The PHA synthase of C. acidovorans does not appear to show any preference for 4-hydroxybutyryl-coenzyme A as a substrate. This leads to the suggestion that in C. acidovorans, it is the metabolic pathway, and not the specificity of the organism's PHA synthase, that drives the incorporation of 4HB monomers, resulting in the efficient accumulation of PHA with a high 4HB content.
Two types of polyhydroxyalkanoate (PHA) biosynthesis gene loci (phb and pha) of Pseudomonas sp. strain 61-3, which produces a blend of poly(3-hydroxybutyrate) [P(3HB)] homopolymer and a random copolymer (poly(3-hydroxybutyrate-co-3-hydroxyalkanoate) [P(3HB-co-3HA]) consisting of 3HA units of 4 to 12 carbon atoms, were cloned and analyzed at the molecular level. In the phb locus, three open reading frames encoding polyhydroxybutyrate (PHB) synthase (PhbCPs), beta-ketothiolase (PhbAPs), and NADPH-dependent acetoacetyl coenzyme A reductase (PhbBPs) were found. The genetic organization showed a putative promoter region, followed by phbBPs-phbAPs-phbCPs. Upstream from phbBPs was found the phbRPs gene, which exhibits significant similarity to members of the AraC/XylS family of transcriptional activators. The phbRPs gene was found to be transcribed in the opposite direction from the three structural genes. Cloning of phbRPs in a relatively high-copy vector in Pseudomonas sp. strain 61-3 elevated the levels of beta-galactosidase activity from a transcriptional phb promoter-lacZ fusion and also enhanced the 3HB fraction in the polyesters synthesized by this strain, suggesting that PhbRPs is a positive regulatory protein controlling the transcription of phbBACPs in this bacterium. In the pha locus, two genes encoding PHA synthases (PhaC1Ps and PhaC2Ps) were flanked by a PHA depolymerase gene (phaZPs), and two adjacent open reading frames (ORF1 and phaDPs), and the gene order was ORF1, phaC1Ps, phaZPs, phaC2Ps, and phaDPs. Heterologous expression of the cloned fragments in PHA-negative mutants of Pseudomonas putida and Ralstonia eutropha revealed that PHB synthase and two PHA synthases of Pseudomonas sp. strain 61-3 were specific for short chain length and both short and medium chain length 3HA units, respectively.