Search PubMed⌕ Search

Biomedical subjects

T Iijima

Publications and source records attributed to T Iijima.

At least 109 records · Page 6Linked to original sources
PubMed2001

Alterations of repeated sequences in 5' upstream and coding regions in colorectal tumors from patients with hereditary nonpolyposis colorectal cancer and Turcot syndrome.

One of the characteristics of tumors from patients with germline mutations of DNA mismatch repair genes is instability at microsatellite regions (MSI). We analysed alterations at repeated sequences of coding regions, as well as those of 5' upstream regions, in 29 MSI-High colorectal tumors from patients with hereditary nonpolyposis colorectal cancer (HNPCC) and Turcot syndrome. We found that repeated sequences in 5' upstream regions were altered in these tumors, at considerable frequencies. The (A)10 repeat in the promoter region (position -178 to approximately -169) of the GAPDH gene was altered in 17% of the tumors. The (A)10(TA)9 in the 5' upstream region (position -318 to approximately -291) of the mitochondrial isoleucyl tRNA synthetase gene (IleRS-A), coded in nuclear DNA, was altered in 59% of the tumors, whereas (A)9 in the 5' upstream region (position -859 to approximately -851) of cytoplasmic isoleucyl tRNA synthetase gene (IleRS-B) was not altered. Alteration at repeated sequences in the coding regions were 72% at TGFbetaRII(A)10, 24% at IGFIIR(G)8, 45% at BAX(G)8, 55% at E2F4(CAG)13, 66% at caspase-5 (A)10, 31% at MBD4(A)10, 55% at hMSH3(A)8 and 34% at hMSH6(C)8. The number of altered genes increased with the advancement of carcinoma according to Dukes categories: mean numbers of altered genes within these 10 genes were 2.6 for Dukes A, 4.7 for Dukes B and 7.8 for Dukes C. The mean number for adenomas was 2.0. These results suggest that the MSI phenotype also causes alteration of 5' upstream regions which may affect apoptosis and some mitochondrial functions in HNPCC and Turcot tumors, and that accumulation of altered genes with repeated sequences is associated with the progression of HNPCC and Turcot colorectal tumors.

Adenoma↗
PubMed2001

Observation of Cabibbo suppressed B --> D(*)K- decays at Belle.

We report observations of the Cabibbo suppressed decays B-->D((*))K- using a 10.4 fb(-1) data sample accumulated at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) storage ring. We find that the ratios of Cabibbo suppressed to Cabibbo favored branching fractions are B(B--->D0K-)/B(B--->D0pi(-)) = 0.079+/-0.009+/-0.006, B(B(0)-->D+K-)/B(B(0)-->D+pi(-)) = 0.068+/-0.015+/-0.007, B(B--->D(*0)K-)/B(B--->D(*0)pi(-)) = 0.078+/-0.019+/-0.009, and B(B(0)-->D(*+)K-)/B(B(0)-->D(*+)pi(-)) = 0.074+/-0.015+/-0.006. These are the first observations of the B-->D+K-, D(*0)K-, and D(*+)K- decay processes.

Journal Article↗
PubMed2001

Observation of large CP violation in the neutral B meson system.

We present a measurement of the standard model CP violation parameter sin2 phi(1) based on a 29.1 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson is fully reconstructed as a J/psi K(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psi K(L), or J/psi K(*0) decay and the flavor of the accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we determine sin2 phi(1) = 0.99+/-0.14(stat)+/-0.06(syst). We conclude that we have observed CP violation in the neutral B meson system.

Journal Article↗
PubMed2001

Presence of IFN-gamma and IL-4 in human periapical granulation tissues and regeneration tissues.

To study mediators associated with the progression of disease and the process of bone regeneration in human apical periodontitis, we examined samples of periapical granulation tissues and regeneration tissues obtained from five patients by use of immunohistochemical methods. Periapical granulation tissues were found to contain a large number of CD4-positive T cells and CD68-positive monocytes/macrophages (CD4: 35.2%, CD68: 32.7%). The CD4-positive T cells and CD68-positive monocytes/macrophages were predominantly present in regeneration tissues (CD4: 62.1%, CD68: 16.0%). In these the percentages of CD4-positive T cells were higher as compared with periapical granulation tissues (from 35.2% to 62.1%). In periapical granulation tissues, CD4-positive T cells stained positively for interferon-gamma (IFN-gamma) and negatively for interleukin-4 (IL-4). In regeneration tissues, IL-4-producing cells could be detected. However, IFN-gamma-producing cells could not be detected. These results suggest that IFN-gamma and IL-4 may modulate the pathogenesis of infectious disease and the process of bone regeneration in local inflammation sites such as human apical periodontitis.

Adolescent↗
PubMed2001

Structure-Activity study of retinoid agonists bearing substituted dicarba-closo-dodecaborane. Relation between retinoidal activity and conformation of two aromatic nuclei.

We have investigated the structure activity relationships of the potent retinoid agonist, 4-[4-(2-propyl-1,2-dicarba-closo-dodecaboran-l-yl)phenylamino]benzoic acid (BR403), which we have previously reported. Substitution of a methyl group on the aromatic nucleus or a methyl group on the nitrogen atom, or replacement of the amino group with ether, methylene, carboxyl or 1,1-ethylene greatly decreased the activity. The relatively planar conformation at the phenyl-N-phenyl moiety seems to play a critical role in the appearance of the biological activity.

Animals↗
PubMed2001

Expression of mouse igf2 mRNA-binding protein 3 and its implications for the developing central nervous system.

Functional analyses of neural RNA-binding proteins have focused mainly on their roles as modulators of posttranscriptional gene regulation, e.g., alternative splicing, dendritic mRNA localization, and local translation. Here we identified a mouse homologue of human IMP3, which is known to bind to and repress the translation of igf2 leader 3 mRNA. The mouse igf2 mRNA-binding protein 3 (mIMP3) is a member of the zipcode binding protein-1 (ZBP-1) family previously reported in chick fibroblast cells. mIMP3 was expressed in undifferentiated neuroepithelial cells and some postmitotic neurons at early embryonic stages (E10.5--E12.5), and its expression level decreased after the midembryonic stage (E12.5) until birth. The expression profile of mIMP3 is very similar to that of mouse igf2 leader 3 mRNA. In vitro UV cross-linking experiments showed that mIMP3 preferentially bound to igf2 leader 3 mRNA rather than igf2 leader 4 mRNA and did not bind the zipcode region of beta-actin or c-myc mRNA. Furthermore, persistent expression of mIMP3 protein in an undifferentiated P19 cell line revealed that mIMP3 inhibited neuronal differentiation morphologically and immunohistochemically. Taken together, these observations raise the possibility that mIMP3 represses neuronal differentiation through the regulation of igf2 mRNA expression.

5' Untranslated Regions↗
PubMed2001

Measurement of B(0)(d)-B_(0)(d) mixing rate from the time evolution of dilepton events at the upsilon(4S).

We report a determination of the B(0)(d)-&B_(0)(d) mixing parameter Deltam(d) based on the time evolution of dilepton yields in Upsilon(4S) decays. The measurement is based on a 5.9 fb(-1) data sample collected by the Belle detector at KEKB. The proper-time difference distributions for same-sign and opposite-sign dilepton events are simultaneously fitted to an expression containing Deltam(d) as a free parameter. Using both muons and electrons, we obtain Deltam(d) = 0.463+/-0.008 (stat)+/-0.016 (syst) ps(-1). This is the first determination of Deltam(d) from time evolution measurements at the Upsilon(4S). We also place limits on possible CPT violations.

Journal Article↗
PubMed2001

Measurement of the CP violation parameter sin2 phi(1) in B(0)(d) meson decays.

We present a measurement of the standard model CP violation parameter sin2 phi(1) (also known as sin2beta) based on a 10.5 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e(+)e(-) collider. One neutral B meson is reconstructed in the J/psiK(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psiK(L), or J/psipi(0) CP-eigenstate decay channel and the flavor of the accompanying B meson is identified from its charged particle decay products. From the asymmetry in the distribution of the time interval between the two B-meson decay points, we determine sin2 phi(1) = 0.58(+0.32)(-0.34)(stat)+0.09-0.10(syst).

Journal Article↗
PubMed2001

Asian multicenter trials on urinary type IV collagen in patients with diabetic nephropathy.

To investigate the changes of renal type IV collagen turnover in diabetic nephropathy, urinary type IV collagen was measured by a highly sensitive one-step sandwich enzyme immunoassay (EIA). Urinary samples were obtained from 698 diabetic patients and 191 healthy adults. Among the patients, 264 had urinary albumin levels of less than 29 mg/g.creatine (Cr) (Stage I: normoalbuminuric stage), 169 had microalbuminuria from 30 to 299 mg/g.Cr (Stage II: microalbuminuric stage), 84 patients had macroalbuminuria of more than 300 mg/g.Cr and serum Cr of less than 1.1 mg/dl (Stage IIIA: macroalbuminuric stage without renal dysfunction), 97 had macroalbuminuria of more than 300 mg/g.Cr and serum Cr of more than 1.2 mg/dl (Stage IIIB: macroalbuminuric stage with renal dysfunction), and 84 had renal failure (Stage IV). The levels of urinary type IV collagen in Stages II, IIIA, IIIB, and IV were significantly higher than those in Stage I (P < 0.0001). The level of urinary type IV collagen in Stage I (5.00 +/- 0.23 microg/g.Cr; mean +/- SE) was also higher than that in normal adults (3.44 +/- 0.11 microg/g.Cr; mean +/- SE). These levels increased gradually due to progression of the clinical stage of diabetic nephropathy. It appears that the levels of urinary type IV collagen can be a useful marker for detecting renal injuries in diabetes according to our Asian multicenter trials.

Aged↗
PubMed2001

Different distribution of the activated areas in the dorsal premotor cortex during visual and auditory reaction-time tasks.

Sensorimotor association is an essential aspect of behavior. The dorsal part of the premotor cortex (PMd) is known to have an important role in sensorimotor association. Although it is suggested that the partially segregated groups of neurons are involved in sensorimotor association in different sensory modalities, it is not yet clear whether these groups occupy the PMd to the same or different extent. Therefore, we performed a functional magnetic resonance imaging study to compare activated regions in the PMd during simple reaction-time tasks with visual and auditory cues. Eight normal volunteers performed two simple reaction time tasks with a conventional on-off design; one is with a visual cue and the other is with an auditory cue. In both tasks, two regions in the left primary motor area (M1) (4a and 4p) and the bilateral PMd were activated. The two activated regions in the left M1 occupied the same areas in both the visual and the auditory tasks. However, in the PMd, the activated regions were situate medially during the visual task and laterally during the auditory task, along the precentral sulci. There was no overlap of significantly activated regions between two tasks, and areas specifically activated during the visual task were observed in the middle of the precentral sulci, bilaterally. The results suggest that the distribution of PMd subregions involved in sensorimotor association differ when the sensory cues are in different modalities.

Adult↗
PubMed2001

Demonstration of the postcommissural fibres of the fornix in short-inversion time inversion-recovery imaging on a high-field system.

Short-inversion time inversion-recovery (STIR) imaging using a 3 tesla system was assessed to reveal the postcommissural fibres (PF) of the fornix, which have rarely been highlighted neuroradiologically in the clinical setting. We studied 27 normal subjects. Sequence parameters were TR/TE/TI 8000/52/ 150 ms. STIR was expected to take advantage of the high signal-to-noise ratio of a high-field system, due to the long repetition time. PF were identifiable in axial and coronal slices in all cases. They were bordered anteriorly and superiorly by the anterior commissure and posteriorly and inferiorly by the mamillary body. Behind the anterior commissure, they ran in an arch-shaped posterior and inferior course in the hypothalamic nuclei and joined the mamillary body anterolaterally. They usually extended through three 3-mm slices (with 1 mm interslice gap) in anteroposterior and vertical dimensions. Little variation was observed in their course or size. Demonstration of the PF would provide a more detailed correlation of human neuroanatomy to hypothalamic function and individualised understanding of hypothalamic pathology and influence therapy.

Adolescent↗
PubMed2001

Serum acid phosphatase as a tumour marker in giant cell tumour of bone.

The serum acid phosphatase value was examined in nine patients with giant cell tumour of bone. Five showed a high level of acid phosphatase, which fell to within normal limits after surgery. Although the remaining four patients showed a normal acid phosphatase level before surgery, the postoperative acid phosphatase level was lower than the preoperative level in each case. Therefore, it is strongly suggested that serum acid phosphatase is a useful tumour marker in diagnosing giant cell tumour of bone as well as in evaluating the efficacy of treatment.

Acid Phosphatase↗
PubMed2001

Soft-tissue haemangioma and periosteal new bone formation on the neighbouring bone.

Deeply situated soft-tissue haemangioma sometimes causes periosteal new bone formation on the neighbouring bone. The purpose of this study was to elucidate the aetiological factors for this phenomenon. We studied 25 patients with soft-tissue haemangioma on whom plain radiographs and computed tomography (CT) and/or magnetic resonance imaging (MRI) examinations were performed. We examined the presence or absence of periosteal new bone formation, haemangioma-bone distance, size of haemangioma and pain. Periosteal new bone formation was seen in 12 of 25 patients. In these 12 patients, the haemangioma was adjacent to the bone in 11 patients, while the haemangioma-bone distance was 4 mm in the other patient. In the remaining 13 patients who had no periosteal new bone formation, the haemangioma-bone distance was 5-27 mm. Pain in the former group was stronger than that in the latter group, the difference being statistically significant. There was no statistically significant difference in size of haemangioma between the two groups. Therefore, the main factor that induces periosteal new bone formation on the neighbouring bone was not the size of haemangioma, but the distance between the haemangioma and the bone.

Adolescent↗
PubMed2001

Kat1-antigen--a reliable immunological marker for identifying osteoclast precursors of rats: detection of subpopulations among precursors and initiation of osteoclastogenesis.

Previously we found a unique cell surface antigen [Kat1-antigen (Kat1-Ag)] expressed on rat osteoclasts. In the present study, we focused on the expression of this antigen in preosteoclasts, mononuclear precursors of osteoclasts. Immunohistochemical and immunoelectron microscopic observations of the Kat1-Ag expressed in vivo showed the antigen to be present on mononuclear cells having the morphological features of preosteoclasts. The relationship between Kat1-Ag expression and calcitonin receptor (CTR) expression was examined in detail by a double-detection technique for CTR and Kat1-Ag by use of autoradiography and immunocytochemistry, respectively. In a culture system for forming mononuclear preosteoclast-like cells, almost 100% of the mononuclear cells expressing Kat1-Ag also expressed CTR, demonstrating that Kat1-Ag is a reliable immunological marker for identifying preosteoclasts. Interestingly, a significant number of the CTR-positive mononuclear cells did not express the Kat1-Ag. Detection of these cells expressing CTR but not Kat1-Ag strongly suggests the presence of subpopulations in preosteoclasts. We also obtained evidence suggesting that expression of the Kat1-Ag is initiated during the postmitotic stage of the osteoclast progenitors.

Animals↗
PubMed2001

Seroepidemiological study of hepatitis E virus infection in Japan using a newly developed antibody assay.

PURPOSE: A seroepidemiological study of hepatitis E virus (HEV) infection was conducted in Japan, where HEV infection is not considered endemic. METHODS: IgG and IgM class antibodies to HEV were measured with a newly developed enzyme-linked immunosorbent assay in which recombinant virus-like particles were used as an antigen. A total of 1253 individuals (401 males and 852 females; age range, 6-89 years) were enrolled from two different areas: area 1 (n = 478), in which hepatitis C was endemic; and area 2 (n = 775), in which it was not endemic. RESULTS: The HEV antibody (IgG class) positive rate was 6.7% in area 1 and 4.6% in area 2. Similarly, the HAV antibody (IgG class) positive rates were 65.3% and 72.3%. The age- and sex-specific prevalence of both HAV and HEV antibodies was quite similar in the two areas, and the HAV antibody positive rate clearly increased with age in both males and females. On the other hand, the HEV antibody positive rate showed a slight tendency to increase with age in males, but not in females. None of the 32 individuals with the HEV antibody who were interviewed had a history of visiting countries in which hepatitis E was endemic. In both areas, the mean age, percentage of males, and HAV antibody positive rate were significantly higher in the group of individuals with the HEV antibody than in the group of those without it, according to conventional statistical analyses. Of the three factors age, male sex, presence of HAV antibody, and the area factor, only male sex was statistically significant (P < 0.001) on multivariate logistic regression analysis. Two (0.2%) of the total of 1253 individuals were positive for the IgM class antibody to HEV. CONCLUSIONS: Our results suggest the possibility that HEV infection is circulating in Japan at a low level. HEV infection was associated with male sex, but not with HAV infection.

Adolescent↗
PubMed2001

Osteofibrous dysplasia of the ulna.

We experienced two patients with osteofibrous dysplasia of the ulna. Both of them showed typical radiographic findings of osteofibrous dysplasia, except for location. One patient underwent surgery at the age of 15 years to confirm the diagnosis histologically. Although the tumor recurred 5 months after the surgery, expansion of the lesion seemed to cease at the age of 25 years. In the other patient, the natural course was observed. The tumor showed a tendency toward spontaneous regression at the age of 11 years. Therefore, the nature of osteofibrous dysplasia in the ulna seems to be the same as that in the tibia and fibula. Surgery must be delayed for as long as possible in osteofibrous dysplasia of the ulna, as well as that of the tibia and fibula.

Adolescent↗
PubMed2001

Involuted intraosseous lipoma of the sacrum showing high signal intensity on T1-weighted magnetic resonance imaging (MRI).

Involuted intraosseous lipoma with extensive fat necrosis resulting in cyst formation (Milgram stage III) is distinguishable from lesions without necrosis (stage I) or lesions with focal fat necrosis (stage II), based on differences in signal intensity on magnetic resonance imaging (MRI). Fat tissue has a high signal intensity on both T1- and T2-weighted MR images, whereas the extensive fat necrosis that results in cyst formation shows high signal intensity on T2-weighted images and low intensity on T1-weighted images. We report a patient in whom an intraosseous lipoma with high signal intensity on both T1- and T2-weighted MRI was found to be extensively involuted on histopathologic examination. Intraosseous lipoma appears to undergo spontaneous involution. In some patients, therefore, surgical excision may not be necessary. A correct preoperative diagnosis should reduce the necessity for a biopsy or surgery. Although lesions classified as stage I or II are easily identified by MRI, those of stage III are difficult to diagnose preoperatively by this method.

Bone Neoplasms↗