Biomedical subjects

S Ito

Publications and source records attributed to S Ito.

At least 145 records · Page 8Linked to original sources

PubMed2001

Endoscopic sonography in the diagnosis of gallbladder wall lesions in patients with gallstones.

PURPOSE: The purpose of this study was to evaluate the diagnostic accuracy of endoscopic sonography (EUS) in the detection of gallbladder wall lesions in patients with and without gallstones. METHODS: We retrospectively reviewed the medical records, sonograms, and sonographic reports of 62 patients who underwent cholecystectomy for gallbladder wall lesions evaluated by EUS. We assessed the accuracy of EUS in diagnosing gallbladder wall lesions in the presence or absence of gallstones and on the basis of the size and number of stones and the size of the gallbladder wall lesions. We also evaluated the effect of acoustic shadowing. The EUS results were compared with the histopathologic results. RESULTS: EUS correctly diagnosed the gallbladder wall lesions in 17 (71%) of 24 patients with gallstones and in 34 (89%) of 38 patients without gallstones. The diagnostic accuracy of EUS was 86% in patients with gallbladder wall lesions smaller than 20 mm and 79% in patients with gallbladder wall lesions 20 mm or larger. The diagnostic accuracy was 75% in patients with gallstones smaller than 5 mm and 67% in patients with stones 5 mm or larger. The accuracy was 67% in patients with 1-5 stones and 83% in patients with 6 or more stones. None of these differences was statistically significant. Acoustic shadowing did not affect the diagnostic accuracy of EUS. CONCLUSIONS: The diagnostic accuracy of EUS for gallbladder wall lesions is not affected by the presence of gallstones. However, better diagnostic criteria must be established based on larger studies, and technical refinements of the equipment are needed to increase the accuracy of EUS in the diagnosis of gallbladder wall lesions.

Cholelithiasis↗

PubMed2001

Relationship between bone marrow cellularity and apparent diffusion coefficient.

This study was performed to determine if there is a relationship between apparent diffusion coefficient (ADC) and cellularity of bone marrow of the posterior ilium. Four groups of various marrow cellularity underwent diffusion-weighted echo-planar imaging: 1) adults with normal hypocellularity (21 patients); 2) adults with normal normocellularity (13 patients); 3) young children with normal hypercellularity (5 patients); and 4) adults with lymphoma-related hypercellularity (3 patients). In all adults, marrow cellularity was confirmed by uni-or bilateral bone marrow biopsies. In children, the iliac marrow was presumed hypercellular because of their ages. A total of 66 ADC values of bone marrow calculated from diffusion-weighted images with b-values of 30 and 300 seconds/mm(2) was evaluated. Hypercellular marrow (normal and lymphoma-related) showed the highest mean ADC, and hypocellular the lowest ADC. Statistically significant differences were found between three groups of normal marrow: hypocellular, normocellular, and hypercellular. There is a positive correlation between ADC and cellularity of bone marrow. J. Magn. Reson. Imaging 2001;13:757-760.

Adult↗

PubMed2001

Is Borrmann type IV gastric carcinoma a surgical disease? An old problem revisited with reference to the result of peritoneal washing cytology.

BACKGROUND AND OBJECTIVES: Borrmann type IV gastric carcinoma (B-4) remains a disease with poor prognosis despite an aggressive surgical approach. Cytology examination of the peritoneal washes is an established prognostic factor for gastric carcinoma in general, and may be useful for identifying adequate treatment strategy for B-4. METHODS: Pathologic data from 70 patients with B-4 who underwent laparotomy and peritoneal washing cytology during the recent 6 years were retrieved from a prospective computer database and reviewed. Prognostic significance of the cytology examination along with other known clinicopathologic variables was evaluated by univariate and multivariate analyses. RESULTS: Long-term survivors were observed only among the patients who were treated with curative R0 resection. Prognosis of the patients with positive cytology and no other residual disease (R1) was extremely poor and was equivalent to that of the patients undergoing noncurative R2 resection. No difference in survival, either, was observed between the patients treated by R2 resection and those who did not undergo resection. Multivariate analysis identified cytology examination as an independent prognostic factor. CONCLUSIONS: Peritoneal washing cytology plays an important role in staging B4. Positive cytology findings as well as other evidence of disseminated disease may indicate that gastrectomy should be avoided.

Demography↗

PubMed2001

CpG island of rat sphingosine kinase-1 gene: tissue-dependent DNA methylation status and multiple alternative first exons.

It is generally recognized that CpG islands are not methylated in normal tissues. SPHK1 is a key enzyme catalyzing the production of sphingosine 1-phosphate, a novel signaling molecule for the proliferation and differentiation of various cells, including neural cells. Sequencing of genomic DNA and cDNA reveals that rat Sphk1a consists of six exons encoding 383 amino acids. Furthermore, we identified six alternative first exons for mRNA subtypes (Sphk1a, -b, -c, -d, -e, and -f) within a 3.7-kb CpG island. The CpG island contains a tissue-dependent, differentially methylated region (T-DMR; approximately 200 bp), which is located - 800 bp upstream of the first exon of Sphk1a. T-DMR is hypomethylated in the adult brain where Sphk1a is expressed, whereas it is hypermethylated in the adult heart where the gene is not expressed. In fetal tissues, hypomethylation of T-DMR is not associated with expression of Sphk1a, which suggests that differential availability of transcription factors is also likely to be involved in the mechanism of its expression. Here, we identify rat Sphk1, using multiple alternative first exons for the subtypes, and demonstrate that there is a CpG island bearing T-DMR.

Alternative Splicing↗

PubMed2001

A novel alkaline endoglucanase from an alkaliphilic Bacillus isolate: enzymatic properties, and nucleotide and deduced amino acid sequences.

A highly alkaline endo-1,4-beta-glucanase (Egl) was purified to homogeneity from a culture broth of alkaliphilic Bacillus sp. strain KSM-N252. The optimal pH for activity was as high as 10, and the optimal temperature was 55 degrees C. The molecular mass and isoelectric point were around 50 kDa and pH 4.2, respectively. The enzyme hydrolyzed carboxymethyl cellulose in a random fashion. Unlike previously reported Egls, the enzyme was highly active on p-nitrophenyl cello-oligosaccharides and acid-swollen cellulose, and its activity was stimulated by cellobiose at high concentrations. The entire gene for the enzyme contained a 1,476-bp single open reading frame encoding 492 amino acids, including a 29-amino-acid signal peptide. The mature enzyme (463 amino acids: 51,174 Da) exhibited moderate homology to other family 5 alkaline Egls. In the C-terminal region, a carbohydrate-binding module that belongs to family XII was repeated. Furthermore, four and six repeats of Pro-Pro-Ser/Thr-Glu/Asp-Pro-(Glu) were found immediately before the first and second carbohydrate-binding modules, respectively.

Amino Acid Sequence↗

PubMed2001

Tissue factor increases in the aqueous humor of proliferative diabetic retinopathy.

BACKGROUND: Tissue factor (TF) is a cellular initiator of the coagulation cascade and is upregulated by the major factors of diabetic angiopathy, TF might thus be one of the key molecules in diabetic retinopathy (DR). PURPOSE: To measure TF in diabetic eyes and evaluate its possible role in DR. METHODS: TF concentration in the aqueous humor of the eyes in 44 patients with diabetes and 35 age-matched control patients was evaluated by ELISA. The concentration of TF in aqueous humor (AH) was compared with the grade of DR. The concentration of TF in AH was also compared with duration of diabetes, renal function, and blood glucose control. The serum TF concentration in each group was also compared. The correlation between the serum TF and aqueous TF in each patient was analyzed. The effect of vascular endothelial growth factor (VEGF) on the TF activity of cultured bovine retinal endothelial cells was evaluated. RESULTS: The mean TF concentration in AH was higher in patients with active proliferative DR (244.5 pg/ml) than in either those with non-proliferative DR (132.4 pg/ml, P<0.05) or the control patients (114.9 pg/ml, P<0.01). The serum TF concentration in active proliferative DR patients (348.3 pg/ml) was significantly higher than in either non-proliferative DR patients, (235.9 pg/ml, P<0.01) or in the controls (223.5 pg/ml, P<0.01). However, the TF concentration of AH was not significantly correlated to that of the serum in each patient. The TF concentration in AH closely correlated with the grade of DR and protein concentration. VEGF increased the biological activity of TF in vitro. CONCLUSION: The origin of TF in AH, however, is still not clearly understood. Nonetheless, TF in AH directly reflects the severity of ocular diabetic change, and the present results indicate that TF indeed plays some role in the progression of DR.

Adult↗

PubMed2001

Clinicopathological significance of fibrotic capsule formation around liver metastasis from colorectal cancer.

PURPOSE: The fibrous capsule around hepatocellular carcinoma is well known to be an indicator of a good prognosis. However, the fibrotic stromal response in the liver to a metastatic tumor remains unclear. PATIENTS AND METHODS: In order to clarify the prevalence of fibrotic capsular formation around liver metastases as well as the prognostic and biological significance of the fibrotic capsule, 69 colorectal cancer patients, who underwent radical hepatectomy due to liver metastases, were investigated using immunohistochemical methods. RESULTS: Encapsulated metastases as defined by a thick fibrotic band surrounding the entire surface of a metastasis were detected in 20% of the cases. The rate of initial recurrence in the remnant liver, which is a strong indicator for poor prognosis of colorectal liver metastasis, was significantly lower in the encapsulated metastasis group as compared with the non-encapsulated metastasis group. Proliferating fibroblastic cells in the capsule were myofibroblasts positively stained for alpha-smooth muscle actin (alpha-SMA) and they deposited dense extracellular matrices rich in collagen Type 1 in the layer of the inner half and secreted MMP-1, MMP-2, and TIMP-1 in the layer of the outer half of the capsule. Activation of alpha-SMA positive hepatic stellate cells (HSC) was also observed in the liver parenchyma adjacent to metastases. CONCLUSIONS: The results indicate that fibrotic capsular formation is associated with a lower rate of initial local recurrence in the remnant liver, and that the capsule may serve as a mechanical and chemical barrier to local invasion by metastatic tumor cells. Proliferating stromal cells in the capsule are myofibroblasts, probably derived from HSC activated by colorectal liver metastasis in the liver parenchyma.

Actins↗

PubMed2001

Th1/Th2 cytokine profiles and their relationship to clinical features in patients with chronic hepatitis C virus infection.

PURPOSE: An imbalance in helper T-cell type 1 (Th1) and type 2 (Th2) cytokines is suggested to play an important role in the pathogenesis of chronic viral infections, but this issue is not resolved in patients with hepatitis C virus (HCV) infection. The aim of this study was to clarify the relationship between the balance of Th1 and Th2 cytokines and liver damage. METHODS: We investigated cytokine levels in the peripheral blood and liver tissue of patients with chronic HCV infection (n = 59) by three different methods; we used flow cytometry to detect intracellular cytokines, and we measured cytokine titers in sera and in the supernatants of lymphocyte cultures with enzyme-linked immunosorbent assays (ELISAs). RESULTS: In both CD4+ and CD8+ cells, interferon (IFN) gamma-producing cell populations increased, while there was no difference in interleukin (IL)-10 production, indicating a shift to a Th1 cytokine profile with the progression of liver disease. With respect to the ratio of IFN-gamma to IL-10, a correlation was found in CD4+ cells between peripheral blood and liver tissue (r = 0.98; P = 0.0011). Th1 cytokine was predominant in intrahepatic CD4+ cells, while it was predominant in peripheral blood CD8+ cells. CONCLUSIONS: These findings indicate a correlation between dominant Th1 response and disease activity and progression. In addition, we suggest that intrahepatic CD4+ T cells play a pathogenetic role in the hepatic injury of HCV infection.

Aged↗

PubMed2001

Enzymatic properties of the highly thermophilic and alkaline pectate lyase Pel-4B from alkaliphilic Bacillus sp. strain P-4-N and the entire nucleotide and amino acid sequences.

We cloned two genes for alkaline pectate lyase, pel-4A and pel-4B, from alkaline pectinase-producing alkaliphilic Bacillus sp. strain P-4-N. The pel-4B gene product Pel-4B was purified to homogeneity and characterized. The purified enzyme had an isoelectric point of pH 9.6 and a molecular mass of 35 kDa, values close to those of the pel-4A gene product Pel-4A. The pH and temperature optima for activity were as high as 11.5 and 70 degrees C, respectively, which are the highest among the pectate lyases reported to date. The mature Pel-4B (304 amino acids; 33,868 Da) was structurally related to the enzymes in the polysaccharide lyase family 1 and showed 35.6% identity with Pel-4A on the amino acid level. It showed significant homology to other pectate lyases in the same family, such as the enzymes from alkaliphilic Bacillus sp. strains KSM-P7 and KSM-P103 and the fungi Aspergillus nidulans and Colletotrichum gloeosporioides f. sp. malvae.

Amino Acid Sequence↗

PubMed2001

Mutation and association analysis of the interferon regulatory factor 2 gene (IRF2) with atopic dermatitis.

Interferon regulatory factor 2 (IRF-2) is a member of a family of transcriptional factors involved in the modulation of cellular responses to interferons (IFNs) and viral infection as well as in the regulation of cell growth and transformation. Irf2 knockout mice show T helper 1 (Th1) cell development defect and spontaneous development of an inflammatory skin disease. To determine if there are any mutations in IRF2 associated with development of atopic dermatitis (AD), we screened for mutations in the 5' flanking and coding regions of IRF2 in AD patients and control subjects by single-strand conformational polymorphism (SSCP) analysis. We found three mutations in the promoter region ([-829C>T, -830C>T], -684C>T, and -467G>A), one silent mutation in exon 9 (921G>A), and a 10-bp deletion in the 3' untranslated region (1739[ATCCC]8>6). Among them, the -467G allele and the haplotype of the -467G, 921A, and 1739(ATCCC)8 alleles were transmitted preferentially to AD-affected children (P = 0.02 and P = 0.007, respectively). Our data suggest that IRF-2 plays some role in the development of AD in the Japanese population.

Alleles↗

PubMed2001

A dominant interference collagen X mutation disrupts hypertrophic chondrocyte pericellular matrix and glycosaminoglycan and proteoglycan distribution in transgenic mice.

Collagen X transgenic (Tg) mice displayed skeleto-hematopoietic defects in tissues derived by endochondral skeletogenesis.(1) Here we demonstrate that co-expression of the transgene product containing truncated chicken collagen X with full-length mouse collagen X in a cell-free translation system yielded chicken-mouse hybrid trimers and truncated chicken homotrimers; this indicated that the mutant could assemble with endogenous collagen X and thus had potential for dominant interference. Moreover, species-specific collagen X antibodies co-localized the transgene product with endogenous collagen X to hypertrophic cartilage in growth plates and ossification centers; proliferative chondrocytes also stained diffusely. Electron microscopy revealed a disrupted hexagonal lattice network in the hypertrophic chondrocyte pericellular matrix in Tg growth plates, as well as altered mineral deposition. Ruthenium hexamine trichloride-positive aggregates, likely glycosaminoglycans (GAGs)/proteoglycans (PGs), were also dispersed throughout the chondro-osseous junction. These defects likely resulted from transgene co-localization and dominant interference with endogenous collagen X. Moreover, altered GAG/PG distribution in growth plates of both collagen X Tg and null mice was confirmed by a paucity of staining for hyaluronan and heparan sulfate PG. A provocative hypothesis links the disruption of the collagen X pericellular network and GAG/PG decompartmentalization to the potential locus for hematopoietic failure in the collagen X mice.

Animals↗

PubMed2001

Cholesteryl ester transfer protein and atherosclerosis in Japanese subjects: a study based on coronary angiography.

We undertook a cross-sectional analysis on CETP and atherosclerosis among Japanese subjects, by means of CETP mass assay, its gene polymorphism and coronary angiogram. The 110 consecutive patients who underwent coronary angiography were enrolled into the study except for those over 70 years and taking lipid-lowering drugs. Association was analyzed among plasma lipid and lipoproteins, CETP mass, its gene polymorphisms and the finding in coronary angiography. Four CETP-deficiency heterozygotes were identified and excluded from the analysis. CETP mass level showed neither significant correlation with the coronary score (CS) (r=0.06, P=0.52) nor the difference between the groups eventually diagnosed as coronary heart disease (CHD) positive and CHD negative (2.36+/-0.57 vs. 2.24+/-0.21, P=0.24). CETP mass correlated with the total and LDL cholesterol (r=0.43, P<0.001; r=0.36, P<0.001, respectively) but not with HDL cholesterol (r=0.08, P=0.40). While I405V polymorphism had no impact on CETP mass, HDL cholesterol or CS, CETP mass was low with TaqIB polymorphism (B1B1>B2B2, P<0.05) only in the low CS group (<4). Among the lipid and lipoprotein, HDL cholesterol had a greater impact than LDL cholesterol on coronary atherosclerosis. We concluded that CETP mass in plasma does not correlate with coronary atherosclerosis as whole in the non-CETP-deficient. However, the B2B2 genotype in CETP TaqIB polymorphism, only when it decreases the CETP level, may act as a protective factor against atherosclerosis. It should also be noted that CETP mass in general correlates to total and LDL cholesterol, so that it would be an indirect atherogenic parameter.

Carrier Proteins↗

PubMed2001

Physiology of diapause and cold hardiness in the overwintering pupae of the fall webworm Hyphantria cunea (Lepidoptera: Arctiidae) in Japan.

The fall webworm Hyphantria cunea Drury, which was accidentally introduced to Japan in 1945, overwinters on the ground in pupal diapause. Diapause termination, as indicated by the respiration rate and the period required for adult emergence, began in March and ended in April. Cold hardiness (the ability to survive exposure to -15 degrees C) decreased linearly with diapause development from November to the following April under field conditions. Cold hardiness of diapause pupae (DP) decreased as the acclimation temperature decreased from 15 to -10 degrees C, whereas cold hardiness of non-diapause pupae (NDP) remained high as the acclimation temperature decreased from 5 to -5 degrees C. However, H. cunea in Japan can survive exposure to -5 degrees C for two weeks, whether it is in a diapause or non-diapause state. Trehalose was the main sugar detected in the body, but its level was less than 0.8%. Trehalose levels increased in field-collected pupae from January to March. DP accumulated less trehalose than NDP, as the acclimation temperature was decreased from 5 to -5 degrees C. The alanine content in field-collected pupae increased from November to February. Both diapause and low temperature caused an accumulation of alanine. These results suggest that under field conditions, overwintering pupae of H. cunea in Japan do not accumulate high levels of sugars and polyols and do not develop a high level of cold hardiness. Furthermore, DP do not accumulate high levels of sugars and polyols and their ability to survive exposure to -15 degrees C is not greater than that of NDP. The physiological and biochemical bases of diapause in H. cunea from Japan are discussed.

Journal Article↗

PubMed2001

Flow cytometric analysis of aberrant antigen expression of blasts using CD45 blast gating for minimal residual disease in acute leukemia and high-risk myelodysplastic syndrome.

To evaluate the availability of quantification of blasts with aberrant antigen expression (AAE) using CD45 gating for minimal residual disease (MRD), 15 patients with acute leukemia (AL) and myelodysplastic syndrome (MDS) were studied. In patients with complete remission (CR), the frequency of blasts with AAE (%AAE) by CD45/side scatter (SSC) gating was significantly higher than that by the traditional forward scatter (FSC)/SSC combination (median, 4.1 vs. 0.3%, P<0.0001). We also demonstrated two representative cases, in which leukemia relapse could be predicted before 3 weeks and the early treatment for MRD could be performed for MRD after allogeneic bone marrow transplantation (BMT). These results indicate that this procedure is very useful for the evaluation of the quality of CR.

Acute Disease↗

PubMed2001

Neuronal activity in the monkey fronto-opercular and adjacent insular/prefrontal cortices during a taste discrimination GO/NOGO task: response to cues.

The neural coding of taste information in the fronto-opercular cortex (Fop) and the orbitofrontal area (OFA) was investigated by recording neural activities in monkeys performing a NaCl-water discrimination GO/NOGO task. Responses to GO (NaCl) and NOGO cues (water) were recorded from 160 neurons, of which 118 differentially responded to two cues (differential, Dif neurons), and 42 showed the same response (non-differential, ND neurons). Differential neurons included equal numbers of GO- and NOGO-dominant subtypes. Dif and ND neurons may code for different cues, e.g., taste and touch, as shown by our previous study [Jpn. J. Physiol. 44 (1994) 141]. The response latency of neurons in the exposed Fop was distributed with two modes, one at the shortest bin (100 ms) and one at the bin of 400-800 ms, but neurons in the buried Fop and OFA all had long latency. Such a difference between the two cortical groups of neurons suggests different roles in taste discrimination tasks. Most neurons did not show changes in the discharges or latency with varying concentrations of NaCl. The results indicate that neurons in the areas surveyed code for taste information differently in the task-performing state compared with the non-behaving state examined in previous studies.

Animals↗

PubMed2001

Central and peripheral roles of prostaglandins in pain and their interactions with novel neuropeptides nociceptin and nocistatin.

While acute pain has a fundamental role to operate a protective system, chronic pain associated with inflammation and nerve injury often outlasts its biological usefulness. Therefore, there has recently been great interest in the neurochemical mechanisms of hyperalgesia to noxious stimuli and tactile pain (allodynia) to innocuous stimuli with a hope to relieve persistent, intractable pain. Over several decades non-steroidal anti-inflammatory drugs and opioids have been employed for clinical management of pain. The introduction of molecular biology to pain research has enabled us to describe the mechanism of pain at the molecular level and to develop analgesics with selectivity for targets and with less adverse effects. This review focuses on current knowledge concerning mechanisms and pathways for pain induced by prostaglandins and their interactions with novel neuropeptides nociceptin/orphanin FQ and nocistatin derived from the same opioid precursor protein.

Analgesics↗

PubMed2001

Immunoreactive orexin-A in human plasma.

Orexin-A and orexin-B are newly discovered neuropeptides which are implicated in feeding behavior and arousal state. We studied immunoreactive(IR)-orexin-A concentrations in human plasma by radioimmunoassay. IR-orexin-A concentrations in plasma obtained from 17 healthy subjects in the morning were 1.94 +/- 0.24 pmol/liter (mean +/- SEM). IR-orexin-A levels in the plasma obtained at night were not significantly different from those obtained in the morning in 9 female subjects. The HPLC analysis of the plasma extract showed two immunoreactive peaks; one peak eluting in an identical position to synthetic orexin-A, and one eluting earlier. This study has shown for the first time the presence of orexin-A in human plasma.

Adult↗

PubMed2001

Adrenomedullin and its receptor complexes in remnant kidneys of rats with renal mass ablation: decreased expression of calcitonin receptor-like receptor and receptor-activity modifying protein-3.

Adrenomedullin (AM) has vasodilator and diuretic actions, similarly to natriuretic peptides. AM receptor complexes are composed of calcitonin receptor-like receptor (CRLR) and receptor-activity modifying protein-2 (RAMP2), or CRLR and RAMP3. We aimed to know whether gene expression of AM and AM receptor complexes are regulated in kidneys under pathophysiological conditions. Expression of AM, RAMP2, RAMP3 and CRLR mRNA was studied in the remnant kidney of rats with renal mass ablation using competitive quantitative RT-PCR techniques. Partial cloning was performed to determine the rat RAMP3 nucleotide sequence. In normal rat kidneys, expression levels of RAMP2, RAMP3, CRLR and AM mRNAs were 26.5 +/- 1.9 mmol/mole of GAPDH, 7.7 +/- 0.9 mmol/mole of GAPDH, 3.6 +/- 0.2 mmol/mole of GAPDH and 0.57 +/- 0.03 mmol/mole of GAPDH (mean +/- SE, n = 6), respectively. RAMP3 mRNA levels decreased significantly to about 50% and about 70% of control (sham-operated rats) 4 days and 14 days after 5/6 nephrectomy, respectively. CRLR mRNA levels also decreased significantly to about 30% and about 43% of control. Sodium intake restriction had no significant effects on the RAMP3 and CRLR gene expression. On the other hand, RAMP2 mRNA expression in the kidney was suppressed by sodium intake restriction regardless of nephrectomy, while RAMP2 levels in the remnant kidney were not significantly changed by 5/6 nephrectomy. Neither 5/6 nephrectomy or sodium intake restriction had any significant effects on the AM gene expression in the kidney. The present study showed that expression of mRNAs encoding AM, RAMP2, RAMP3 and CRLR were differentially regulated in remnant kidneys of rats with renal mass ablation.

Adrenomedullin↗