Visualization of a coronary collateral channel by multislice spiral computed tomography.
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Aged↗
Biomedical subjects
Yuichi Sato
Publications and source records attributed to Yuichi Sato.
Regression of an atherosclerotic coronary artery plaque demonstrated by multislice spiral computed tomography in a patient with stable angina pectoris.
Multislice spiral computed tomography (MSCT) permits direct visualization of not only coronary artery stenosis but also atherosclerotic plaques in patients with coronary artery disease. In this report, we describe a patient with stable angina in whom the regression of the plaque was documented by serial MSCT examinations. In the patient, a 46-year-old man with stable angina, MSCT revealed a stenotic lesion at the proximal portion of the left anterior descending artery. Axial, curved multiplanar reconstruction and cross-sectional images consistently depicted a protruding computed tomography low-signal mass suggesting an atherosclerotic plaque. Intracoronary ultrasound (ICUS) also documented an eccentric soft plaque with an echo-lucent mass suggesting a lipid core. Lipid-lowering therapy with pravastatin was started. Follow-up MSCT performed 7 months later documented an increase in the luminal area while the external vessel area remained unchanged. The regression of the plaque was also confirmed by a follow-up ICUS study. MSCT was thought to be feasible for serial evaluation of the plaque size and texture.
Angina Pectoris↗
Cationic comb-type copolymers as an artificial nucleic acid-chaperone: spectroscopic analyses for DNA/copolymer interaction.
We have reported previously that the cationic comb-type copolymer, PLL-g-Dex, accelerated DNA strand exchange reaction while stabilizing DNA duplexes. In this research, we showed the effects of cationic PLL-g-Dex copolymer on hybridization of self-complementary octamer oligonucleotides. NMR studies suggested that PLL-g-Dex copolymer preferentially interacted with a duplex DNA rather than a single-stranded DNA, and did not perturb local structures of DNA duplexes. CD studies also supported inert nature of the copolymer upon hybrid structure. From these results we concluded that the accelerating mechanisms of the copolymer did not involved partial perturbation of duplex structure.
Biopolymers↗
Design of artificial nucleic acid chaperones for DNA engineering.
We have shown that the comb-type copolymer consisting of a polycation backbone and hydrophilic side chains stabilizes DNA hybrids. Furthermore, the copolymers showed the activity to accelerate DNA strand exchange reactions between double helical DNA and its complementary DNA. The copolymer was considered to stimulate breakage and reassociation of base pairing and act as an artificial nucleic acid chaperone. The polymer's chaperoning activity was elaborated for rapid and precise judging of a subtle difference in DNA sequences. One base alternation out of 20mer DNA was quickly detected by the strand exchange assay employing the copolymer. From these, we conclude that the copolymer would be a useful material in DNA engineering that employs rapid and precise DNA folding.
Biopolymers↗
Polycation-accelerated strand exchange (PASE) for SNPs typing.
In the previous study (Chem. Eur. J., 7, 176 (2001), J. Am. Chem. Soc., 124, 12676 (2002)), we demonstrated that the cationic comb-type copolymer (PLL-g-Dex, CCC) composed of a cationic poly(L-lysine) backbone and water-soluble side chains of dextran accelerated the DNA strand exchange reaction between double helical DNA and its homologous single strand. In this study, Polycation-Accelerated Strand Exchange (PASE) assay was applied to discriminate single-base mismatch in DNA sequence such as single nucleotide polymorphisms (SNPs). We could discriminate the 20mer DNA with a single-base mismatch from the full matched DNA with high efficacy by PASE.
Base Pair Mismatch↗
A novel murine model of oral candidiasis with local symptoms characteristic of oral thrush.
A conventional and easy method to establish a murine oral candidiasis model, which has not only a stable yeast population in the oral cavity but also symptoms characteristic of oral thrush, was developed by using a sedative agent. Mice were immunosuppressed with prednisolone and were given tetracycline hydrochloride. They were orally infected with 10(6) viable cells of Candida albicans by means of a cotton swab and enough chlorpromazine chloride had been injected to keep them in a sedative state about for 3 hr after inoculation. From day 3 to day 7 post inoculation, 10(5)-10(6) colony forming units of Candida were recovered from the oral cavity of each mouse and whitish, curd-like patches were observed on most parts of tongue. Microscopically, germ tubes had appeared on the tongue surface. This model would be a useful experimental oral candidiasis for investigating the pathogenesis of C. albicans oral infection and the efficacy of various antifungal agents microbiologically and symptomatically.
Amphotericin B↗
Noninvasive coronary artery imaging by multislice spiral computed tomography.
Although the excellent spatial resolution of multislice spiral computed tomography (MSCT) enables the coronary arteries to be visualized, its limited temporal resolution results in poor image reproducibility because of cardiac motion artifact (CMA) and hence limits its widespread clinical use. A novel retrospectively ECG-gated reconstruction method has been developed to minimize CMA. In 88 consecutive patients, the scan data were reconstructed using 2 retrospectively ECG-gated reconstruction methods. Method 1: the end of the reconstruction window (250 ms) was positioned at the peak of the P wave on ECG, which corresponded to the end of the slow filling phase during diastole immediately before atrial contraction. Method 2 (conventional method): relative retrospective gating with 50% referred to the R-R interval was performed so that the beginning of the reconstruction window (250 ms) was positioned at the halfway point between the R-R intervals of the heart cycle. The quality of the coronary artery images was evaluated according to the presence or absence of CMA. The assessment was applied to the left main coronary artery (LMCA), the left anterior descending artery (LAD, segments #6, #7 and #8), the left circumflex artery (LCx, segments #11 and #13) and the right coronary artery (RCA, segments #1, #2 and #3). The first diagonal artery (#9-1), the obtuse marginal artery (#12-1), the posterior descending artery (#4-PD), the atrioventricular node branch (#4-AV) and the first right ventricular branch (RV) were also evaluated. Of the 88 patients, 85 were eligible for image evaluation. Method 1 allowed visualization of the major coronary arteries without CMA in the majority of patients. The LCA system (segments #5-7, #11 and #13) and the proximal portion of the RCA were visualized in more than 94% of patients. Artifact-free visualization of the distal portion of the LAD (segment #8) and RCA (#4PD and #4AV), and side branches (#9-1, #12-1 and RV) was also achieved in more than 80% of patients. On the other hand, CMA occurred frequently on images obtained by Method 2. The LCx and RCA systems were the most affected by CMA, revealing only 41% artifact-free visualization of the segment #13, 39% of #1, 15% of #2 and 32% of #3. Thus, Method 1, which avoids the ventricular motion occurring during the rapid filling and atrial contraction phases, gives superior image quality over the conventional ECG-gated reconstruction method.
Algorithms↗
Noninvasive assessment of coronary artery disease by multislice spiral computed tomography using a new retrospectively ECG-gated image reconstruction technique.
The present study was designed to investigate the accuracy of multislice spiral computed tomography (MSCT) in detecting coronary artery disease, compared with coronary angiography (CAG), using a new retrospectively ECG-gated reconstruction method that reduced cardiac motion artifact. The study group comprised 54 consecutive patients undergoing MSCT and CAG. MSCT was performed using a SOMATOM Volume Zoom (4-detector-row, Siemens, Germany) with slice thickness 1.0 mm, pitch 1.5 (table feed: 1.5 mm per rotation) and gantry rotation time 500 ms. Metoprolol (20-60 mg) was administered orally prior to MSCT imaging. ECG-gated image reconstruction was performed with the reconstruction window (250 ms) positioned immediately before atrial contraction in order to reduce the cardiac motion artifact caused by the abrupt diastolic ventricular movement occurring during the rapid filling and atrial contraction periods. Following inspection of the volume rendering images, multiplanar reconstruction images and axial images of the left main coronary artery (LMCA), left anterior descending artery (LAD), left circumflex artery (LCx) and right coronary artery (RCA) were obtained and evaluated for luminal narrowing. The results were compared with those obtained by CAG. Of 216 coronary arteries, 206 (95.4%) were assessable; 10 arteries were excluded from the analysis because of severe calcification (n=4), stents (n=3) or insufficient contrast enhancement (n=3). The sensitivity to detect coronary stenoses >or=50% was 93.5% and the specificity to define luminal narrowing <50% was 97.2%. The positive predictive value and the negative predictive value were 93.5% and 97.2%, respectively. The sensitivity was still satisfactory (80.6%) even when non-assessable arteries were included in the analysis. The new retrospectively ECG-gated reconstruction method for MSCT has excellent diagnostic accuracy in detecting significant coronary artery stenoses.
Angina Pectoris↗
Detection of coronary artery aneurysms, stenoses and occlusions by multislice spiral computed tomography in adolescents with kawasaki disease.
In patients with Kawasaki disease (KD), serial evaluation of coronary artery aneurysms (CAAs) and luminal narrowing is essential for risk stratification and therapeutic management. Therefore, non-invasive assessment of the status of the coronary artery is of utmost importance in patient management. Multislice spiral computed tomography (MSCT) permits non-invasive visualization of the entire coronary artery system and was used in the evaluation of 4 patients with KD. CAAs and high-grade coronary artery stenoses were detected by MSCT and corroborated the findings of coronary angiograms performed within the previous 2 years. MSCT has the potential to be the standard diagnostic tool in adolescents with KD.
Adolescent↗
Relationship between left atrial appendage function and left atrial thrombus in patients with nonvalvular chronic atrial fibrillation and atrial flutter.
The relationship between the left atrial appendage (LAA) function, as assessed by transesophageal echocardiography, and the incidence of left atrial thrombus was evaluated in 62 patients with nonvalvular chronic atrial fibrillation (AF; n=50) and atrial flutter (AFL; n=12). It was hypothesized that in both AF and AFL not only the LAA flow velocity (LAAFV), but also the frequency of the LAA movement (the LAA flow time, LAAFT) is a major contributing factor to thrombus formation. LAAFT was defined as the average duration of LAA flow with emptying and filling waves. The patients with AF were divided into 2 groups: lone AF (n=14) and non-lone AF (n=36). LAA thrombus was found in 6 patients with none-lone AF. LAAFV was lower and LAAFT was shorter in patients with thrombus as compared with patients without thrombus (12.0+/-2.2 cm/s vs 24.1+/-10.6 cm/s, 68.7+/-1.5 ms vs 72.9+/-3.3 ms, p<0.01, respectively). Patients with AFL had higher LAAFV and longer LAAFT than those with chronic AF. The present data suggest that, in addition to LAAFV, LAAFT characterized LAA function and might serve as a predictor of thrombus formation in chronic AF. With respect to LAA function, patients with lone AF or AFL are at low risk for thrombus formation.
Aged↗
The expression of pancreatic endocrine markers in centroacinar cells of the normal and regenerating rat pancreas: their possible transformation to endocrine cells.
To determine the progenitor nature of centroacinar cells (CACs), we attempted to compare the expression pattern of endocrine cell markers and PDX-1 (pancreatic duodenal homeobox gene 1) in CACs of both the quiescent and the regenerating rat pancreas. In the normal pancreas, most CACs were relatively small cells with sparse cytoplasm and oval or elongated nuclei. In addition, we noticed a distinct population of a small number of large cells with round nuclei in the centroacinar region. By immunohistochemistry, 0.21% and 0.3% of CACs in normal rat pancreas were respectively found positive for glucagon and insulin, being large CACs and designated as GL-CAC and IL-CAC. They also exhibited the mRNA of each hormone by in situ hybridization (ISH). The ISH signal for glucagon but not insulin was also detected in a subset of small CACs (designated GS-CAC). The expression of PDX-1 was also observed in subsets of small and large CACs (PS-CAC and PL-CAC, respectively). After a 90% pancreatectomy, the relative frequency for GS-CACs, but not those for other CACs, was significantly reduced in two days after surgery. On day 7 after surgery, the number of GS-CACs recovered to preoperative levels, whereas GL-CACs, IL-CACs, PS-CAC, and PL-CAC gradually increased to about double in number. From these results, a portion of CACs was suggested to differentiated into endocrine cells. A possible cell lineage is discussed for endocrine neogenesis during pancreatic regeneration.
Animals↗
[Anti-Candida albicans activity of essential oils including Lemongrass (Cymbopogon citratus) oil and its component, citral].
The effects of 12 essential oils, popularly used as antifungal treatments in aromatherapy, on growth of Candida albicans were investigated. Mycelial growth of C. albicans, which is known to give the fungus the capacity to invade mucosal tissues, was inhibited in the medium containing 100 micro g/ml of the oils: lemongrass (Cymbopogon citratus), thyme (Thymus vulgaris), patchouli (Pogostemon cablin) and cedarwood (Cedrus atlantica). Not only lemongrass oil but also citral, a major component of lemongrass oil (80%), in the range of 25 and 200 micro g/ml inhibited the mycelial growth but allowed yeast-form growth. More than 200 micro g/ml of citral clearly inhibited both mycelial and yeast-form growth of C. albicans. These results provide experimental evidence suggesting the potential value of lemongrass oil for the treatment of oral or vaginal candidiasis.
Candida albicans↗
Relationship between the expression of E-, N-cadherins and beta-catenin and tumor grade in astrocytomas.
Cadherins are cell-surface glycoproteins that mediate Ca2+-dependent, homophilic cell-cell adhesion. The classical cadherins, E- and N-cadherins, connect to beta-catenin, the lining protein. There appears to be a relationship between their dysfunction and tumor invasion and metastasis. The aim of our study was to examine the possibility of a relationship between alterations in the E- and N-cadherin and catenin expression and malignancy in astrocytomas. Forty-five astrocytomas (18 glioblastomas, 16 anaplastic astrocytomas, and 11 diffuse astrocytomas) were collected and stained immunohistochemically for cadherins and beta-catenin. None of the astrocytomas were immunoreactive for E-cadherin. N-cadherin and beta-catenin were present at cell-cell borders in 61% of glioblastomas and 31% of anaplastic astrocytomas. The incidence of immunoreactivity for N-cadherin and beta-catenin increased significantly with the histological grade of astrocytomas (p = 0.001, by Kruskal-Wallis test). Moreover, in anaplastic astrocytomas and glioblastomas, the Ki-67 labeling indices in both N-cadherin-positive and beta-catenin-positive cases were higher than that in negative cases (p = 0.05 and 0.03, respectively, by Fisher's exact test). These results suggest that the expression of N-cadherin or beta-catenin may be related to the biological behavior of astrocytomas.
Astrocytoma↗
Gastric carcinoid tumors without autoimmune gastritis in Japan: a relationship with Helicobacter pylori infection.
In Japan, most cases of gastric carcinoid tumor (GCT) are unassociated with either autoimmune gastritis (AIG) showing type-A chronic atrophic gastritis (CAG-A) or Zollinger-Ellison syndrome (ZES). However, the pathogenesis of this tumor remains unknown. Recent studies have determined that Helicobacter pylori infection induces gastric carcinoid in Mongolian gerbils and that H. pylori lipopolysaccharide exerts a mitogenic effect on ECL cells. We examined five patients with histologically diagnosed GCT, 40 patients with H. pylori-positive gastric ulcer (Hp+GU), 24 patients with H. pylori-positive duodenal ulcer (Hp+DU), and 12 patients with AIG showing CAG-A topographically. We compared the prevalence of H. pylori infection, and the levels of gastrin and pepsinogen (PG) in the serum of patients with GCT with those of patients with Hp+GU, or Hp+DU, and AIG. We also investigated the histological characteristics of the tumor and the gastric corpus mucosa in the GCT patients. The levels of serum gastrin and PG I and II were measured using an RIA kit. In all five (100%) patients with GCT, H. pylori infection was present, without any evidence of AIG or ZES. The serum levels of gastrin in the GCT patients were higher than those in either Hp+GU or Hp+DU patients and lower than those in the AIG patients. In contrast, serum PG I levels and the PG I/II ratio were lower in the GCT group than in the Hp+GU or Hp+DU groups. Histologically, all GCTs were ECL cell tumors and peritumoral corporal mucosal atrophy was observed in four of the five patients with GCT. In conclusions, H. pylori infection and hypergastrinemia were found in the patients with GCT without AIG. This finding suggests that H. pylori infection may induce corporal mucosal atrophy and hypergastrinemia that can produce a GCT with time.
Adult↗
Detection of epstein-barr virus in nasal T-cell lymphoma.
The close relationship between Epstein-Barr virus (EBV) and nasal T-cell lymphoma (NTL) has frequently been reported. However, the status of the infection, either lytic or latent, is obscure. This study involved 16 patients with NTL. Phenotypes of lymphoma cells were examined by immunohistochemical staining using CD3, CD4, CD8, CD20 and CD45RO monoclonal antibodies. EBV-encoded small nuclear RNA (EBER)-1 and EBV NotI tandem repeat region were detected by reverse transcription, using a rapid (< or = 60 min) in situ hybridization technique. Tumor cells expressed at least one T-cell marker, such as CD3, CD4, CD8 and CD45RO. CD20 was not detected in any of the cases. EBER-1 was identified in all cases; no Notl tandem DNA repeat was demonstrated. All cases demonstrated a T-cell phenotype. These data suggest that NTL is associated with EBV infection in the latent phase.
Antigens, CD↗
Expression of Epstein-Barr virus-encoded small nuclear RNA 1 in Japanese nasopharyngeal carcinomas.
An examination was made of the incidence of the Epstein-Barr virus (EBV) genome and its exact localization in 39 cases of nasopharyngeal carcinoma (NPC) in Japanese patients by means of in situ hybridization (ISH) with a digoxigenin-labeled Epstein-Barr virus-encoded small nuclear RNA 1 (EBER1) oligonucleotide probe. Hybridization signals were observed in the nucleus of tumor cells in all 39 NPCs, including keratinizing carcinomas. The signals varied greatly in intensity from case to case and even from cell to cell in the same tumor, but were recognized in most tumor cells in each case. Signals could occasionally be seen in limiting number of infiltrating small lymphocytes but were absent in all tumors of the tongue, midpharynx and hypopharynx. Combined immunohistochemistry-ISH studies indicated that EBER1 signals were restricted to tumor cells positive for cytokeratin. As a result of this study, it is now possible to perform large-scale retrospective analyses using routine formalin-fixed, paraffin-embedded tissue sections and to combine ISH for the EBV genome with immunohistochemistry for cytokeratin to determine the epithelial features of EBV genome-possessing cells. All NPCs were clearly shown to be EBV-infected, thus indicating that EBV is essential for the oncogenesis of NPCs.
Carcinoma↗
Investigation of DNA strand exchange mechanisms mediated by cationic polymers.
It was observed that conjugation of dextran for PLL provided PLL-g-Dex with new properties of enhancing and accelerating inter-nucleotide recognition (1, 2, 3). In this paper, we report the effects of cationic PLL-g-Dex copolymers on base-pair formation of self-complementary octamer oligonucleotide by using NMR and CD analysis. NMR studies revealed that PLL-g-Dex copolymer did not affect hydrogen-bondings between bases in DNA duplex. CD studies also supported inert nature of the copolymer upon hybrid structure.
Base Sequence↗
Expression of Pit-1 and growth hormone-releasing hormone receptor mRNA in human pituitary adenomas: difference among functioning, silent, and other nonfunctioning adenomas.
We analyzed the expression of Pit-1 and growth hormone-releasing hormone receptor (GHRH-R) mRNA in various types of functioning and nonfunctioning adenomas using a quantitative reverse transcriptase polymerase chain reaction (RT-PCR) method. Among clinically nonfunctioning adenomas, tumors considered as silent adenomas were reclassified on a pathologic basis. Competitive RT-PCR showed that the levels of Pit-1 and GHRH-R mRNA expression in silent somatotroph adenomas and silent prolactinomas were similar to those in the corresponding functioning adenomas. In silent thyrotroph adenomas, both mRNAs showed high levels of expression that were similar to those in functioning and silent somatotroph adenomas. The results suggest that the cause of the silence in these tumors seems to be in the downstream to transcription of Pit-1 gene in the signaling pathway leading to hormone secretion. Competitive RT-PCR assay could distinguish silent adenomas of the Pit-1 group from the other nonfunctioning adenomas in the expression levels of Pit-1 and GHRH-R mRNAs. In the future, precise diagnosis of various adenomas may become possible by assaying transcription factors such as steroidogenic factor-1 and thyrotroph embryonic factor, which are thought to be related to adenohypophyseal cytodifferentiation.
Adenoma↗