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Biomedical subjects

T Suga

Publications and source records attributed to T Suga.

At least 19 recordsLinked to original sources

Actinobacillus actinomycetemcomitans Y4 capsular polysaccharide induces IL-1beta mRNA expression through the JNK pathway in differentiated THP-1 cells.

Capsular polysaccharide from Actinobacillus actinomycetemcomitans Y4 (Y4 CP) induces bone resorption in a mouse organ culture system and osteoclast formation in mouse bone marrow cultures, as reported in previous studies. We also found that Y4 CP inhibits the release of interleukin (IL)-6 and IL-8 from human gingival fibroblast (HGF). Thus Y4 CP induces various responses in localized tissue and leads to the secretion of several cytokines. However, the effects of Y4 CP on human monocytes/macrophages are still unclear. In this study, THP-1 cells, which are a human monocytic cell line, were stimulated with Y4 CP, and we measured gene expression in inflammatory cytokine and signal transduction pathways. IL-1beta and tumour necrosis factor (TNF)-alpha mRNA were induced from Y4 CP-treated THP-1 cells. IL-1beta mRNA expression was increased according to the dose of Y4 CP, and in a time-dependent manner. IL-1beta mRNA expression induced by Y4 CP (100 microg/ml) was approximately 7- to 10-fold greater than that in the control by real-time PCR analysis. Furthermore, neither PD98059, a specific inhibitor of extracellular signal-regulated kinase nor SB203580, a specific inhibitor of p38 kinase prevented the IL-1beta expression induced by Y4 CP. However, JNK Inhibitor II, a specific inhibitor of c-Jun N-terminal kinase (JNK) prevented the IL-1beta mRNA expression induced by Y4 CP in a concentration-dependent manner. These results indicate that Y4 CP-mediated JNK pathways play an important role in the regulation of IL-1beta mRNA. Therefore, Y4 CP-transduced signals for IL-1beta induction in the antibacterial action of macrophages may provide a therapeutic strategy for periodontitis.

Aggregatibacter actinomycetemcomitans↗

Tumour matrilysin expression predicts metastatic potential of stage I (pT1) colon and rectal cancers.

BACKGROUND AND AIMS: Nodal metastases are indisputable determinants of prognosis for colon and rectal cancer. Using classical histological criteria, many attempts to predict nodal metastasis have failed, preventing the adequate management of stage I (pT1) cancer. We investigated the role of tumour matrilysin in predicting metastatic potential, and discuss its potential use in individualising treatment of pT1 colon and rectal cancer. METHODS: The gene signature associated with nodal metastasis was investigated by cDNA array in 24 colon and rectal cancers. We studied 494 colon and rectal cancer patients to identify risk factors for nodal metastasis and evaluated the potential to predict nodal metastasis by either the logistic regression model or the Bayesian neural network model with built-in matrilysin. We then inferred possible causality of nodal metastasis from structural equation modelling. RESULTS: cDNA array revealed that matrilysin was maximally upregulated in the metastasis signature identified. Tumour matrilysin expression emerged as a stage independent risk factor for nodal metastasis, resulting in a similar predictive performance in receiver operating characteristic curve analysis in the two models. A Bayesian approach called automatic relevance determination identified matrilysin as one of the most relevant predictors examined. Structural equation modelling suggested possible direct causality between matrilysin and nodal metastasis. CONCLUSIONS: We have provided evidence that tumour matrilysin expression is a promising biomarker predicting nodal metastasis of colon and rectal cancer. Analysis of tumour matrilysin expression would help clinicians achieve the goal of individualised cancer treatment based on the metastatic potential of pT1 colon and rectal cancer.

Adenocarcinoma↗

Functional expression of high-affinity receptor for immunoglobulin E on mast cells precedes that of tryptase during differentiation from human bone marrow-derived CD34 progenitors cultured in the presence of stem cell factor and interleukin-6.

BACKGROUND: CD34(+) progenitor cells develop into tryptase(+), CD117(+) mast cells when cultured in the presence of recombinant human stem cell factor (rhSCF). However, spontaneous IgE receptor (FcepsilonRI) expression during human mast cell development is not well examined. OBJECTIVE: Here, the expression and function of FcepsilonRI in and on human bone marrow-derived mast cells (HBMMCs) during development were investigated. METHODS AND RESULTS: At 4 weeks of culture, predominant cells expressed high-affinity IgE receptor alpha chain (FcepsilonRIalpha) on the cell surface determined by flow cytometry, but CD117 was less expressed. Immunocytochemistry with antitryptase mAb and anti-FcepsilonRIalpha mAb revealed intracellular and surface expression of FcepsilonRIalpha at 2 weeks of culture, but tryptase was less expressed. FcepsilonRIalpha mRNA transcript preceded that of tryptase mRNA at 2 weeks of culture determined by real-time RT-PCR, and FcepsilonRIalpha, FcepsilonRIbeta, FcepsilonRIgamma, and tryptase mRNA increased along with differentiation. FcepsilonRIalpha cross-link on HBMMC and 4-week-old mast cells/mast cell precursors induced the release of IL-5 and granulocyte macrophage-colony stimulating factor, which was enhanced by rhSCF. CONCLUSION: These data indicated that HBMMC constitutively and spontaneously expressed functional FcepsilonRI subunits at the early stage of differentiation, probably because of the differences in the ability and functional property of progenitors.

Antigens, CD34↗

Detection of tryptase-, chymase+ cells in human CD34 bone marrow progenitors.

BACKGROUND: Mast cells (MCs) arise from haematopoietic stem cells. We have recently reported that CD34(+) progenitors derived from human bone marrow (BM) develop into tryptase+, chymase+ MCs when cultured in the presence of recombinant human stem cell factor (rhSCF) and recombinant human IL-6 (rhIL-6). In an experiment for the expression of chymase during differentiation, chymase+ cells were detected in human BM, but tryptase+ cells were not found. OBJECTIVE: The purpose of this study was to show the appearance of chymase+ cells in CD34(+) cells with an origin different from MC differentiation. METHODS: CD34(+) cells from human BM were sorted with anti-CD117 monoclonal antibody (mAb), and cytospins of CD34(+), CD34(+)CD117(+), or CD34(+)CD117(-) were prepared. These cells were cultured with rhSCF+rhIL-6 for 12 weeks. Some of the cells were subjected to either histological stain with Wright-Giemsa or immunocytochemistry with anti-chymase mAb. Real-time RT-PCR was also performed to compare the transcriptional level of chymase from each cell preparation. RESULTS: Chymase was expressed in CD34(+) cells as well as human MCs by immunocytochemistry. Substantial CD34(+)CD117(-) cells, but not CD34(+)CD117(+) cells, were stained immunocytochemically with anti-chymase mAb. For 1 week culture with rhSCF+rhIL-6, no cells expressed chymase in any preparation. Real-time RT-PCR revealed positivity for chymase mRNA in CD34(+) cells, but it reduced at 1 week of culture, and increased as cells developed into MCs. Chymase mRNA in CD34(+)CD117(+) cells was negligible compared with that in CD34(+)CD117(-). Tryptase mRNA was below the detectable level in CD34(+) cells, and increased along with MC differentiation. After 12 weeks of culture, CD34(+)CD117(+) developed predominantly into MCs, whereas CD34(+)CD117(-) developed into monocytes/macrophages. CONCLUSION: Our findings suggested that chymase is present not only in MCs but also in CD34(+)CD117(-) BM progenitors, but that its origin is different from the MC lineage.

Antigens, CD34↗

Review of combination of peritoneal dialysis and hemodialysis as a modality of treatment for end-stage renal disease.

Because the contribution of residual renal function (RRF) to total solute clearance is often significant in continuous ambulatory peritoneal dialysis (CAPD), loss of RRF over time can lead to inadequate dialysis if appropriate prescription management strategies are not pursued. Additionally, declines in ultrafiltration caused by increases in peritoneal permeability may limit continuation of CAPD therapy. Peritoneal dialysis and hemodialysis (PD + HD) combination therapy (complementary dialysis therapy) is an alternative method. This therapy allows the patient to maintain daily activities, as with CAPD, while undergoing once-a-week HD supplements for the insufficient removal of solutes and water. This therapy allows for the continuation of PD without shifting to total HD in PD patients who continue to have uremic symptoms even after individualization of the PD prescription. This treatment option is psychologically more acceptable to patients and may be expected to provide such accompanying beneficial effects as peritoneal resting, improvement of QOL and reduction in medical cost.

Combined Modality Therapy↗

Hepatic induction of mitochondrial and cytosolic acyl-coenzyme a hydrolases/thioesterases in rats under conditions of diabetes and fasting.

Acyl-coenzyme A (CoA) hydrolases/thioesterases are a group of enzymes that catalyze the hydrolysis of acyl-CoA thioesters to free fatty acids and CoA-SH. The potency of these enzymes may serve to modulate intracellular concentrations of acyl-CoAs, free fatty acids, and CoA to affect various cellular functions, including lipid metabolism. In this study, we investigated the effect of diabetes and fasting on the protein levels of mitochondrial (MTE-I) and cytosolic acyl-CoA thioesterases (CTE-I), multigene family members of this class of enzymes, in adult rat liver. Rats were treated with alloxan to induce diabetes or fasted for 72 hours. Western blot analysis with the liver homogenates revealed 2.8-fold and 3.8-fold increases in MTE-I and 8.5-fold and 9.2-fold increases in CTE-I under the diabetic and fasting conditions, respectively, compared with the control in which the level of MTE-I was 4.3-fold higher than CTE-I. Serum level of free fatty acids was elevated 5-fold and 2.5-fold in diabetic and fasted rats, respectively. These results confirm the adaptive induction of MTE-I and CTE-I in response to fatty acid overload in the liver, being consistent with their auxiliary role in fatty acid degradation.

Animals↗

Actual behaviour of N-butyl-2-cyanoacrylate (histoacryl) in a blood vessel: a model of the varix.

BACKGROUND AND STUDY AIMS: Though many gastric varices are treated endoscopically with n-butyl-2-cyanoacrylate, its behavior in varices is not known precisely. MATERIALS AND METHODS: We created a varix model. A volume of 0.7 ml or 1.4 ml of 71.4 % n-butyl-2-cyanoacrylate, a tissue adhesive, was injected into vinyl tubes of 0.4, 0.6, 0.9, and 1.2 cm in diameter, which were filled with still blood or flowing blood. The tissue adhesive was also injected into the inferior vena cava or femoral vein of dogs. RESULTS: N-butyl-2-cyanoacrylate was similarly polymerized in the vinyl tubes and the animal veins. A volume of 0.7 ml of the tissue adhesive could block all tubes up to 0.6 cm in diameter. A double quantity of the tissue adhesive could block tubes 0.9 and 1.2 cm in diameter, with flow velocities up to 10 cm/s and up to 5 cm/s, respectively. Some polymer masses were fragmented. CONCLUSIONS: One rapid shot of the tissue adhesive can block a vessel 0.6 cm or less in diameter with fast flow velocity, and a vessel up to 1.2 cm in diameter with slow flow velocity. Fast blood flows in a larger diameter vessel and slow injection of the tissue adhesive may result in fragmentation. This model of the varix was useful for assessing the effect of tissue adhesive used to treat gastric varices.

Animals↗

Localization of [14C]clarithromycin in rat gastric tissue when administered with lansoprazole and amoxicillin.

After oral and intravenous administration of [14C]clarithromycin to rats, c. 60-70% of the radioactivity in the gastric tissue was found to be distributed in the mucosal layer. Co-administration of lansoprazole and amoxicillin had no apparent effect on this distribution pattern of [14C]clarithromycin. The amount of unchanged [14C]clarithromycin in gastric contents increased with co-administration of lansoprazole and amoxicillin. Microautoradiograms of the gastric mucosa showed that [14C]clarithromycin was highly distributed in the mucous layer and in surface epithelial cells following oral administration. Homogeneous distribution of radioactivity was evident in the fundic gland. With iv administration, [14C]clarithromycin seemed to be secreted by both secreting cells in the gland base and surface epithelial cells.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Change in concentrations of luteinizing hormone subunit messenger ribonucleic acids in the estrous cycle of beef cattle.

Changes in the concentrations of LH subunit messenger ribonucleic acids (mRNAs) and in the LH content of the anterior pituitary of beef cattle were studied during the estrous cycle. Japanese beef cows were classified according to the expected day of the estrous cycle: stage I (early-luteal phase, days 1-4; day 1=day of ovulation), stage II (early-mid-luteal phase, days 5-10), stage III (late-mid-luteal phase, days 11-17) and stage IV (follicular phase, days 18-20), according to the morphology of the ovaries. The anterior pituitaries of the cows were collected and the levels of alpha and LHbeta subunit mRNAs were determined by slot-blot analyses. The LH content of the anterior pituitary was measured by radioimmunoassay. The level of alpha subunit mRNA in the pituitary of cows was highest in stage I and decreased significantly by stage II (P<0.05); thereafter it tended to increase. The level of LHbeta subunit mRNA did not change significantly during the estrous cycle. The LH content of the pituitary of cows was low in stage I and tended to increase by stage II, then to decrease from stage II to III, and to increase significantly from stage III to IV (P<0.05). These results suggest that the highest levels of gene expressions of alpha subunit in the anterior pituitary occur in the early-luteal phase of beef cows, while the LH content is increased most in the follicular phase. The enhanced gene expressions of common alpha subunit in the early-luteal phase could be important in replenishing the bovine anterior pituitary with LH, which is depleted of hormone by the LH surge or the enhanced pulsatile release.

Animals↗

Monitoring of phthalic acid monoesters in river water by solid-phase extraction and GC-MS determination.

An analytical method for monitoring 10 phthalic acid monoesters in river water was investigated by solid-phase extraction, methylation with diazomethane, and GC-MS. Two cartridge-type solid phases packed with octadesyl-coated silica (C18) and styrenedivinyl polymer (PS-2) and one disk-type solid phase made from octadesyl-coated styrenedivinylbenzene polymer (SDB-XD) were investigated in solid-phase extraction. PS-2 gave the highest recoveries of the three solid phases, and recoveries of more than 80% of the monoesters in filtered water samples were obtained at pH 2 to 3 with PS-2 at the spiked level of 0.1 microg L(-1), except for monomethyl-phthalate (MMP), in which more than 72% of the monoesters were recovered. For the monoesters in the suspended solids (SS), an acidic methanol extract of SS was added to purified water acidified to pH 2, and the monoesters were extracted with PS-2. The recoveries of the monoesters in SS were more than 80%, but the recoveries of MMP were more than 57%. The method detection limit (MDL) of each phthalic acid monoester in 500 mL of water sample and in 2 mg of dry weight of SS ranged from 0.010 to 0.030 microg L(-1) and from 1 to 11 microg g(-1), respectively. Monitoring of phthalic acid monoesters in the Tama River in Tokyo was conducted every month from March 1999 to February 2000 using the present method. MMP, mono-n-butyl-phthalate (MBP), and mono-(2-ethylhexyl)-phthalate (MEHP) were detected at concentrations of 0.030-0.0340, 0.010-0.480, and 0.010-1.30 microg L(-1), respectively, in the filtered water samples but were not detected in SS. Dimethyl-phthalate (DMP), di-n-butyl-phthalate (DBP), and di-(2-ethylhexyl)-phthalate (DEHP) were detected in the river water at concentrations of 0.010-0.092, 0.008-0.540, and 0.013-3.60 microg L(-1), respectively. Diethyl-, di-iso-butyl-, and benzylbutyl-phthalates were also detected at concentrations of nanograms per liter, whereas the corresponding monoesters did not appear. The concentrations of MBP and MEHP in the river water were slightly lower than those of the corresponding diesters at the majority of sampling sites and sampling times.

Chemistry Techniques, Analytical↗

Toxicity and effects of 2,6-di-tert-butyl-4-methylphenyl N-methylcarbamate (terbutol) on hepatic cytochrome P450 in F344 rats.

The subacute toxicity and effects of 2,6-di-tert-butyl-4-methylphenyl N-methylcarbamate (terbutol) on hepatic microsomal cytochrome P450 (P450) were investigated in male and female F344 rats. Rats were given 0.25, 0.5, and 1.0% terbutol for 28 days. Liver weights of male and female rats increased at all dose levels. The compound did not affect activity or amount of serum biochemical markers related to hepatic damage. The concentrations of terbutol in rat serum were less than 0.1 microM, and its major metabolites in serum were 2,6-di-tert-butyl-4-carboxyphenyl N-methyl-carbamate and 2,6-di-tert-butyl-4-carboxyphenol. In male rats, P450 and cytochrome b5 (b5) contents, and NADPH cytochrome c reductase (fp2) activity in liver microsomes were increased about 2-fold by 1% terbutol administration for 7 to 28 days. Among the P450-dependent monooxygenase activities in liver microsomes, 7-benzyloxyresorufin-O-debenzylase (BROD) activity was greatly increased by 100-fold, and 7-ethoxyresorufin-O-deethylase (EROD), 7-ethoxycoumarin-O-deethylase (ECOD), and aminopyrine-N-demethylase (APND) activities were elevated 2- to 3-fold. 7-Methoxyresorufin-O-deethylase (MROD), erythromycin-N-demethylase (EMND), estradiol 2-hydroxylase (ED2H), chlorzoxazone 6-hydroxylase (CZ6H), and lauric acid omega-hydroxylase (LAOH) activities were unchanged. For the activities of testosterone hydroxylation, testosterone 16beta-hydroxylase (T16BH) activity was markedly increased by 30-fold, and testosterone 6beta-hydroxylase (T6BH) and testosterone 7alpha-hydroxylase (T7AH) activities were slightly elevated. Testosterone 2alpha-hydroxylase (T2AH) activity was not affected. Terbutol 4-methylhydroxylase (T4MH) activity was increased 9-fold by 1% terbutol. In an immunoinhibition study, T4MH activity in liver microsomes from 1% terbutol-treated rats was decreased about 50% by polyclonal anti-rat CYP2B1, whereas polyclonal anti-rat CYP2A1 and CYP2C11 did not affected the activity. These results indicate that terbutol increased CYP2B subfamily in rat liver microsomes, and that the compound did not cause serious hepatic damage.

Administration, Oral↗

Development of a time-resolved fluorometric method for observing hybridization in living cells using fluorescence resonance energy transfer.

We previously showed that a specific kind of mRNA (c-fos) was detected in a living cell under a microscope by introducing two fluorescently labeled oligodeoxynucleotides, each labeled with donor or acceptor, into the cytoplasm, making them hybridize to adjacent locations on c-fos mRNA, and taking images of fluorescence resonance energy transfer (FRET) (A. Tsuji, H. Koshimoto, Y. Sato, M. Hirano. Y. Sei-Iida, S. Kondo, and K. Ishibashi, 2000, Biophys. J. 78:3260-3274). On the formed hybrid, the distance between donor and acceptor becomes close and FRET occurs. To observe small numbers of mRNA in living cells using this method, it is required that FRET fluorescence of hybrid must be distinguished from fluorescence of excess amounts of non-hybridizing probes and from cell autofluorescence. To meet these requirements, we developed a time-resolved method using acceptor fluorescence decays. When a combination of a donor having longer fluorescence lifetime and an acceptor having shorter lifetime is used, the measured fluorescence decays of acceptors under FRET becomes slower than the acceptor fluorescence decay with direct excitation. A combination of Bodipy493/503 and Cy5 was selected as donor and acceptor. When the formed hybrid had a configuration where the target RNA has no single-strand part between the two fluorophores, the acceptor fluorescence of hybrid had a sufficiently longer delay to detect fluorescence of hybrid in the presence of excess amounts of non-hybridizing probes. Spatial separation of 10-12 bases between two fluorophores on the hybrid is also required. The decay is also much slower than cell autofluorescence, and smaller numbers of hybrid were detected with less interference of cell autofluorescence in the cytoplasm of living cells under a time-resolved fluorescence microscope with a time-gated function equipped camera. The present method will be useful when observing induced expressions of mRNA in living cells.

3T3 Cells↗

Indomethacin induced bulky lymphadenopathy and eosinophilic pneumonia.

Indomethacin is one of the most popular non-steroidal anti-inflammatory drugs (NSAID). Although NSAID occasionally provoke bronchospasm and hypersensitivity pneumonia, they seldom cause lymphadenopathy. This is the first report in which NSAID induced both eosinophilic pneumonia and bulky intrathoracic lymphadenopathy simultaneously. A 76-year-old Japanese man experienced high fever and dyspnoea after using an indomethacin suppository. Computed tomography scan of his chest revealed massive mediastinal and hilar lymphadenopathy along with diffuse infiltration in both lungs. He was diagnosed to have eosinophilic pneumonia because of eosinophilia in his peripheral blood and bronchoalveolar lavage fluid (BALF). Without using glucocorticoids, the pulmonary infiltration and lymphadenopathy subsided spontaneously. As the blastoid transformation test using the lymphocytes in his BALF was positive to indomethacin, we judged that both his eosinophilic pneumonia and mediastinal lymphadenopathy were due to a hypersensitivity reaction to indomethacin. An allergic reaction to NSAID should be considered as a rare cause of mediastinal lymphadenopathy.

Aged↗

Pulmonary intravascular lymphoma complicated with Pneumocystis carinii pneumonia: a case report.

We report a case of intravascular lymphoma (IVL) complicated with Pneumocystis carinii pneumonia (PCP). A 65-year-old male complaining of dyspnea and dementia was diagnosed to have pulmonary IVL by transbronchial lung biopsy. Concomitantly, deoxyribonucleic acid sequence specific to Pneumocystis carinii was detected in bronchoalveolar lavage fluid by polymerase chain reaction. Differential responses to the sequential treatments for PCP and IVL implied that increased serum lactate dehydrogenase (LDH) was due to PCP, whereas hypoxemia and dementia were due to IVL. Although pulmonary IVL and PCP share many clinical presentations, exact diagnosis is essential for their successful treatment.

Aged↗

Effects of renal sorbitol accumulation on urinary excretion of enzymes in hyperglycaemic rats.

We studied the effects of epalrestat, a specific inhibitor of aldose reductase, on renal sorbitol accumulation and the resulting urinary enzyme excretion in hyperglycaemic rats. The activities of proximal tubule-derived enzymes such as N-acetyl-beta-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), gamma-glutamyltranspeptidase (GGT) and dipeptidyl aminopeptidase IV (DAPIV) in urine were determined in five groups of male Wistar rats (each n = 7): (a) 0.9% saline-loaded, (b) 10% glucose-loaded, (c) 10% glucose-loaded with epalrestat pretreatment, (d) 10% mannitol-loaded and (e) 10% mannitol-loaded with epalrestat pretreatment. Epalrestat was given mixed in chow at a dose of 50 mg/kg body weight. Urinary NAG, AAP, GGT and DAPIV activities were significantly increased (P<0.005, P<0.05, P<0.01, P<0.01, respectively) by the induction of hyperglycaemia. In contrast, enzyme excretion was not increased in the mannitol- or saline-loaded groups. Pre-treatment with epalrestat completely prevented the increased urinary excretion of NAG, AAP and GGT. At the end of the infusion study, renal cortical glucose concentrations of the glucose-loaded groups with and without epalrestat pretreatment were approximately fivefold higher than those of the mannitol- or saline-loaded groups (P<0.005 each). Renal cortical sorbitol concentrations of the glucose-loaded group was also approximately twofold higher than those of the mannitol- or saline-loaded groups (P<0.01 each). However, in the group that received both glucose and epalrestat, renal cortical sorbitol concentration was not increased. These results suggest that accumulation of intracellular sorbitol leads to proximal tubular cell dysfunction and abnormal enzymuria.

Acetylglucosaminidase↗

Large vessel arteritis in relapsing polychondritis.

A healthy 58-year-old woman presented with recurrent swelling and pain of the nose and both auricules. Bruits were heard over both carotid arteries. Magnetic resonance angiography revealed stenosis of both internal carotid arteries. Relapsing polychondritis was diagnosed. These symptoms improved after treatment with prednisolone and azathioprine. Although relapsing polychondritis is sometimes associated with systemic vasculitis, large vessel arteritis is rare and can negatively affect prognosis. We conclude that the detection of systemic vascular lesions, including those involving the central nervous system, can play an important role in the diagnosis of relapsing polychondritis and that early treatment is essential for a good outcome.

Arteritis↗

Invasive pulmonary aspergillosis in a puerperant with drug-induced agranulocytosis.

Invasive pulmonary aspergillosis (IPA) is an acute infection of Aspergillus species to the lungs. It generally occurs in immunocompromised hosts, especially with neutropenia. We report a 30-year-old puerperant, who developed IPA from agranulocytosis. She had been treated for threatened labor with ritodrine and cefepime, one of which induced agranulocytosis. After vaginal delivery of twins, pneumonia emerged in the right lower lobe. She was diagnosed to have IPA according to the halo sign on computed tomography (CT) and positive circulating antibody against Aspergillus, and was treated successfully with oral itraconazole followed by surgical resection. It is important to note that IPA might arise in otherwise immunocompetent hosts when neutropenia is long-standing.

Adult↗

Double-labeled donor probe can enhance the signal of fluorescence resonance energy transfer (FRET) in detection of nucleic acid hybridization.

A set of fluorescently-labeled DNA probes that hybridize with the target RNA and produce fluorescence resonance energy transfer (FRET) signals can be utilized for the detection of specific RNA. We have developed probe sets to detect and discriminate single-strand RNA molecules of plant viral genome, and sought a method to improve the FRET signals to handle in vivo applications. Consequently, we found that a double-labeled donor probe labeled with Bodipy dye yielded a remarkable increase in fluorescence intensity compared to a single-labeled donor probe used in an ordinary FRET. This double-labeled donor system can be easily applied to improve various FRET probes since the dependence upon sequence and label position in enhancement is not as strict. Furthermore this method could be applied to other nucleic acid substances, such as oligo RNA and phosphorothioate oligonucleotides (S-oligos) to enhance FRET signal. Although the double-labeled donor probes labeled with a variety of fluorophores had unexpected properties (strange UV-visible absorption spectra, decrease of intensity and decay of donor fluorescence) compared with single-labeled ones, they had no relation to FRET enhancement. This signal amplification mechanism cannot be explained simply based on our current results and knowledge of FRET. Yet it is possible to utilize this double-labeled donor system in various applications of FRET as a simple signal-enhancement method.

DNA Probes↗