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Biomedical subjects

T Ito

Publications and source records attributed to T Ito.

At least 415 records · Page 23Linked to original sources
PubMed2000

Comparative analyses of megakaryocytes derived from cord blood and bone marrow.

Thrombocytopenia is typically observed in patients undergoing cord blood transplantation. We hypothesized that delayed recovery of the platelet count might be caused by defects in the megakaryocytic differentiation pathway of cord blood progenitors. To test this hypothesis, we compared the features of in vitro megakaryocytopoiesis between cord blood progenitors and those in bone marrow cells after isolation of CD34+ cells as progenitors. The proliferative responses of the progenitors in cord blood are higher than those in bone marrow cells in the presence of interleukin (IL)-3, stem cell factor (SCF) and thrombopoietin (TPO). However, the ability to generate mature megakaryocytes was higher in bone marrow progenitors than in cord blood in the same in vitro culture system, when examined by the expression of CD41, polyploidy and proplatelet formation. Furthermore, an earlier induction of c-mpl protein, a receptor for TPO, was observed in the progenitors from bone marrow than in those from cord blood in the presence of SCF and IL-3. Therefore, the ability to generate mature megakaryocytes in bone marrow progenitors is superior to that in cord blood, and the delayed engraftment of platelets after cord blood transplantation might be attributed to the features of cord blood megakaryocyte progenitors.

Antigens, CD34↗
PubMed2000

Genetic linkage of Kozak sequence polymorphism of the platelet glycoprotein Ib alpha with human platelet antigen-2 and variable number of tandem repeats polymorphism, and its relationship with coronary artery disease.

The -5 C/T polymorphism of platelet glycoprotein (GP) Ib alpha is a major determinant of the level of GP Ib/V/IX complex surface expression. We investigated the frequency of this polymorphism among Asian populations. The gene frequencies of cytosine (C) in this polymorphism were 0.283 and 0.219 in Japanese and Korean populations respectively. The C allele is linked with human platelet antigen (HPA)-2a and smaller types of variable number of tandem repeats (VNTR). A novel allele, C-HPA-2a-D of VNTR, was found. No association was observed between these alleles and coronary artery disease in this case-control study. The clinical relevance of this polymorphism in the thrombotic status remains undetermined.

Adult↗
PubMed2000

Disruption of an Arabidopsis cytoplasmic ribosomal protein S13-homologous gene by transposon-mediated mutagenesis causes aberrant growth and development.

We identified a Dissociation (Ds) transposon-inserted Arabidopsis mutant of a gene (AtRPS13A) homologous to cytoplasmic ribosomal protein (RP) S13. We named our mutant pointed first leaf (pfl) 2 because of its similar phenotype to the pfl1 mutant of the RPS18 gene. This mutant caused multiple phenotypic changes, including aberrant leaf and trichome morphology, retarded root growth, and late flowering. Microscopic analysis showed that the first leaf blade of pfl2 contained a significantly reduced number of palisade cells, which suggests that the mutant phenotype was caused by reduced cell division. However, no phenotypic changes were observed during reproductive growth. In Arabidopsis, the RPS13 protein was encoded by a small expressed gene family including AtRPS13A. A pfl1 pfl2 double mutant showed no additive effect. These results suggest that RPS13 functions in quantitative and pleiotropic ways during growth and development, and that mutations at different kinds of RP gene loci are accumulatable without serious growth defects because they belong to small gene families.

Amino Acid Sequence↗
PubMed2000

Effects of bright light on cognitive and sleep-wake (circadian) rhythm disturbances in Alzheimer-type dementia.

Twenty-seven patients with Alzheimer-type dementia (ATD) were treated with bright light therapy in the morning for four consecutive weeks. The cognitive state of each patient was evaluated with the Mini-Mental-State Examination (MMSE) and circadian rhythm with actigram before and after therapy for all of the patients and those of two groups divided by the severity criteria of the Clinical Dementia Rating. The therapy improved the circadian rhythm disturbances. Although the therapy caused no remarkable effects on dementia severity, it improved the MMSE scores, especially in the early stages of ATD. These results suggest that bright light therapy improved the circadian rhythm disturbances and then bettered the cognitive state in early-stage ATD.

Aged↗
PubMed2000

Myoepithelioma of the lacrimal gland: report of a case with potentially malignant transformation.

Myoepithelioma of the lacrimal gland is extremely rare and only four cases, one of which was malignant, have been reported in detail. The present report describes a case of lacrimal gland myoepithelioma in a Japanese male with histological features suggestive of potentially malignant transformation. The excised tumor consisted of two components, a central nodular component and a peripheral component surrounding the former. These components were separated by a fibrous tissue. Microscopically, both components were comprised almost entirely of spindle-shaped cells, but with some epithelioid cells containing glycogen granules. Extracellular spaces in the peripheral component were filled with eosinophilic materials with the occasional crystalloid structures, which were immunoreactive for collagen type I. Neoplastic cells were immunoreactive focally for vimentin and S-100, but negative for cytokeratins, epithelial membrane antigen, muscle actin, smooth muscle actin, desmin, myosin, and glial fibrillary acidic protein. The neoplastic cells in the central component showed nuclear pleomorphism and atypia with a higher frequency of mitotic figures, and higher labelings of proliferation markers than those in the peripheral component. Neither invasion, necrosis, nor hemorrhage was observed in the tumor. From these findings we proposed a diagnosis of potentially malignant myoepithelioma.

Adult↗
PubMed2000

Malignant phyllodes tumor of the prostate.

We report a case of malignant phyllodes tumor of the prostate which is the eleventh reported case in the world. Phyllodes tumor of the prostate is extremely rare and histologically resembles mammary phyllodes tumor. Phyllodes tumor of the prostate is classified into benign, borderline and malignant, but health professionals should carefully follow up the borderline cases in case they take a malignant clinical course. This case was the first to be treated by pre- and postoperative radiation therapy. Although the patient had a slight response to radiation therapy, he eventually developed metastasis. Because malignant phyllodes tumor of the prostate is a very aggressive tumor, people with the condition should undergo systemic chemotherapy as adjuvant therapy.

Adult↗
PubMed2000

Interstitial cystitis in Japan.

OBJECTIVE: To determine the prevalence of interstitial cystitis in Japan, and to analyse the diagnostic criteria and treatments most commonly used by Japanese urologists. Materials and methods Questionnaires were sent to 300 urologists at major hospitals, including medical university hospitals, throughout Japan, asking about the number of patients with interstitial cystitis, its epidemiology, diagnosis and therapy. RESULTS: The prevalence of interstitial cystitis was 1.2 per 100 000 patients and 4.5 per 100 000 female patients; the male/female ratio was 1 : 5.8. Most Japanese urologists used two or more diagnostic criteria; bladder biopsy was the most common diagnostic method. Dimethyl sulphoxide instillations and corticosteroids were the most frequently used therapies. CONCLUSION: The prevalence of interstitial cystitis in Japan is markedly lower than that reported in Europe and North America. The reasons for this difference were not only racial but also the lack of awareness among Japanese urologists and patients about interstitial cystitis.

Adult↗
PubMed2000

Incidence of Type 1 diabetes mellitus in children aged 0-14 in Japan, 1986-1990, including an analysis for seasonality of onset and month of birth: JDS study. The Data Committee for Childhood Diabetes of the Japan Diabetes Society (JDS).

AIMS: To detect the incidence of childhood Type 1 diabetes mellitus (DM) (0-14 years) in Japan and to find out whether there is a seasonal pattern in the onset of disease and month of birth of children with diabetes. METHODS: Ascertained data for the period 1986-1990 could be collected in 35 out of 47 local government areas representing 69.4% of the childhood population (aged 0-14 years) of Japan. RESULTS: A total of 1,260 children with Type 1 DM were identified (738 girls, 522 boys). With age there was a progressive increase in incidence from 0.7 to 2.1/10(5) in boys and from 0.6 to 3.5/10(5) in girls. With the exception of 1987, when a coxsackie B3 virus epidemic was registered, no seasonal variation in the month of onset was observed, nor was a seasonal pattern of the month of birth registered in this cohort. CONCLUSIONS: Compared to European countries, the USA and Israel, the Japanese cohort of children with diabetes presents the following differences: the incidence is much lower, there is a preponderance of girls and there is (with one exception) no seasonal pattern.

Adolescent↗
PubMed2000

Glomerular and extraglomerular immune complex deposits in a bone marrow transplant recipient.

A 44-year-old man developed nephrotic syndrome 9 months after HLA-identical sibling bone marrow transplantation. Membranous changes consisted mainly of alterations of glomeruli, which were interpreted as chronic graft-versus-host disease (GVHD) caused by lodging of the circulating immune complex. In the tubules, a lumpy deposition of IgG and complement breakdown products was distributed along the tubular basement membrane, which coincided with the peculiar deposits ascertained by electron microscopy. These findings suggest that an extraglomerular reaction should be considered in evaluating renal involvement of GVHD.

Adult↗
PubMed2000

Survivin promotes cell proliferation in human hepatocellular carcinoma.

Survivin is a recently described inhibitor of apoptosis. Because suppression of apoptosis is important for carcinogenesis and tumor growth, we investigated the expression and function of survivin in human hepatocellular carcinomas (HCCs). We have shown that 4 HCC cell lines and 7 out of 8 human HCC tissues expressed survivin messenger RNA (mRNA), whereas expression of survivin mRNA was not detected in normal liver and nontumor areas of these tissues using the reverse transcription polymerase chain reaction. Survivin was detected primarily in the nucleus by immunofluorescence staining of HCC cells. In addition, 14 of 20 (70%) HCC tissues showed positive nuclear staining for survivin, whereas nontumor tissues showed little detectable staining by immunohistochemistry. Survivin expression strongly correlated with the proliferation index but not significantly with the apoptosis index in HCC tissues. Therefore, we performed cell cycle analysis after survivin transfection and showed that overexpression of survivin resulted in a decrease in the G(0)/G(1) phase and an increase in the S phase in all 4 HCC cell lines. Furthermore, we have found that survivin interacted with cyclin-dependent kinase 4 (Cdk4) and overexpression of survivin released p21(WAF1/Cip1) (p21) from Cdk4. From these results, we conclude that survivin promotes cell proliferation by interacting with Cdk4 and releasing p21 from Cdk4. This may play an important role in carcinogenesis and progression of human HCCs.

Apoptosis↗
PubMed2000

Chemotherapeutic agents augment TRAIL-induced apoptosis in human hepatocellular carcinoma cell lines.

TNF-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in various transformed cell lines but not in almost-normal tissues. It is regulated by 2 death receptors, TRAIL receptor 1 (TRAIL-R1) and TRAIL-R2, and 2 decoy receptors, TRAIL-R3 and TRAIL-R4. We investigated the expression of TRAIL-R- and TRAIL-induced apoptosis in human hepatocellular carcinomas (HCCs). TRAIL-R1, -R2, and -R4 were expressed in 6 HCC cell lines examined, but TRAIL-R3 was expressed in only 2 of the 6 cell lines. In addition, immunohistochemical results revealed a high and prevalent expression of TRAIL-R1 and -R2 in human HCC tissues. Despite the expression of TRAIL-R1 and -R2, all 6 HCC cell lines showed resistance to TRAIL-induced apoptosis with no relation to nuclear factor kappa B (NF-kappaB) levels induced by TRAIL. TRAIL-induced death signal was inhibited with both decreased caspase-8 and caspase-3 activity. However, TRAIL induced significant apoptosis in the presence of a subtoxic level of actinomycin D, indicating that the TRAIL-induced apoptotic pathway is in place in these cell lines. In addition, we found that treatment with conventional chemotherapeutic agents, doxorubicin and camptothecin, dramatically augmented TRAIL-induced cytotoxicity in most of the HCC cell lines. Actinomycin D and camptothecin almost completely suppressed NF-kappaB induction by TRAIL, whereas doxorubicin had little effect. These results indicate that TRAIL, in combination with chemotherapeutic agents, may have therapeutic potential in the treatment of human HCC.

Antibiotics, Antineoplastic↗
PubMed2000

Pancreatoblastoma treated by delayed operation after effective chemotherapy.

A case of pancreatoblastoma in a 4-year-old girl is presented. She was admitted with an abdominal mass and vomiting in August 1994. Computed tomography scan showed a 10- x 8- x 7-cm mass occupying both the head and body of the pancreas. Serum alpha-fetoprotein (AFP) level was 9,600 ng/mL (normal, <8.3 ng/mL). Results of open biopsy of the tumor showed pancreatoblastoma. Chemotherapy was administered using the new A-1 regimen consisting of cyclophosphamide, etoposide, pirarubicin, and cisplatin. After 3 cycles of chemotherapy, the size of the tumor was reduced to 5 x 4 x 3 cm, the portal vein became patent, and the AFP value decreased to 98.1 ng/mL. Total removal of the tumor was performed leaving the head and tail of the pancreas. Postoperative chemotherapy continued for 2 years. The patient has been disease free for 5 years, and her serum AFP remained within normal levels.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Interaction on metabolic clearance between A-type and B-type natriuretic peptides in patients with heart failure.

A-type and B-type natriuretic peptides (ANP and BNP) are secreted into the systemic circulation via the coronary sinus. Plasma levels of ANP and BNP at the coronary sinus should directly determine the systemic circulating levels. However, the metabolic clearance of these hormones are dependent on similar systems, natriuretic peptide clearance receptor (NPR-C) and neutral endopeptidase 24.11 (NEP), suggesting a possible interaction between ANP and BNP on metabolic clearance. In this study, we examined the interaction on metabolic clearance in patients with heart failure. We obtained blood samples from the coronary sinus and aortic root in 100 patients with heart failure and 28 control subjects. The difference in ANP and BNP levels between the coronary sinus and the aortic root is reflected partly by the metabolic clearance in the pulmonary circulation. In this study, we examined the possible interaction on metabolic clearance between ANP and BNP using a statistical procedure. The ratio of the level of BNP to ANP (BNP/ANP) was significantly higher in the aortic root than in the coronary sinus at any stage of heart failure. We performed multiple regression analysis using ANP and BNP levels at the coronary sinus as independent variables (X1 and X2, respectively) and the ANP level at the aortic root as a dependent variable (Y). The analysis showed that both X1 and X2 were significant variables in the equation. On the other hand, we performed the same analysis using the BNP level at the aortic root as a dependent variable (Y). The analysis showed that only X2 was a significant variable in the equation. This study suggests that (1) the metabolic clearance in the pulmonary circulation is higher for ANP versus BNP and (2) the amount of ANP cleared in the pulmonary circulation depends on the amount of both ANP and BNP secreted from the heart, whereas the amount of BNP cleared in the pulmonary circulation is dependent solely on the amount of BNP secreted from the heart.

Aorta↗
PubMed2000

Immunoaffinity purification and characterization of native placental leucine aminopeptidase/oxytocinase from human placenta.

cDNA cloning of placental leucine aminopeptidase (P-LAP)/cystinyl aminopeptidase (CAP)/oxytocinase demonstrated that this enzyme is a type II integral membrane protein, which means that native P-LAP, found in placenta, is membrane-bound and that the soluble form of this enzyme, found in maternal sera, is most likely derived from the native form. The presence of the different forms of the protein makes it difficult to purify homogeneously. In the current study we prepared antibody specific to native P-LAP and used it to purify native P-LAP from microsomal fractions of human placenta to homogeneity, 5039-fold within 4 h, by immunoaffinity chromatography. Zn(2+)and Cu(2+)strongly inhibited the enzyme but Ca(2+)did not. Amastatin was a more potent inhibitor than bestatin and leupeptin. Using antibodies against native P-LAP, protein having 83 per cent of l -methionine insensitive Leu-p-nitroanilide cleaving activity, was immunoprecipitated from the microsomal fraction of human placenta. The availability of a specific antibody against native P-LAP permits the rapid purification and the preliminary immunoassay of the enzyme. Establishment of simple purification and assay methods for the native, membrane bound form of P-LAP pave the way to elucidating the roles and processing systems of this enzyme.

Amino Acid Sequence↗
PubMed2000

Integrated backscatter assessment of left atrial spontaneous echo contrast in chronic nonvalvular atrial fibrillation: relation with clinical and echocardiographic parameters.

Integrated backscatter (IB) provides the quantitative assessment of left atrial spontaneous echo contrast (SEC). The IB intensity of the left atrial cavity relative to the left ventricular cavity is related to atrial thrombus in patients with atrial fibrillation (AF) or sinus rhythm. However, little is known about the relation between the quantitative SEC value of the left atrial cavity and variables implying thromboembolism in nonvalvular AF. To examine this relation, we performed transesophageal echo-cardiography with IB analysis in 65 patients with chronic nonvalvular AF. The quantitative SEC value of the left atrial cavity was defined as the difference between atrial IB intensity and ventricular IB intensity (corrected IB intensity). The corrected IB intensity was correlated with the left atrial dimension (r = 0.25, P =.049), the left atrial appendage velocity (r = -0.41, P <.001), and the duration of AF (r = 0.23, P =. 023). The corrected IB intensity was higher in patients who had a history of hypertension (3.2 +/- 2.2 dB versus 2.0 +/- 1.6 dB, P =. 018), SEC (3.9 +/- 1.9 dB versus 1.4 +/- 1.1 dB, P =.002), and left atrial thrombus (4.5 +/- 2.7 dB versus 2.2 +/- 1.7 dB, P <.001) when compared with those who did not have these abnormalities. The corrected IB intensity was significantly lower in patients with significant mitral regurgitation than in those without it (1.1 +/- 1. 2 dB versus 2.7 +/- 2.0 dB, P =.036). When the cutoff value of the corrected IB intensity was set at >/=2.0 dB, the sensitivity for left atrial thrombus was 78% and the specificity was 55%. In patients with chronic nonvalvular AF, the quantitative SEC value of the left atrial cavity depends on the duration of AF as well as the left atrial dimension and appendage velocity. Although IB may be capable of identifying patients with higher risk of cardiogenic embolism, a large-scale prospective study is needed to actually establish this.

Adult↗
PubMed2000

Anti-rat CD45RA monoclonal antibodies cross-react with glucagon.

Anti-rat CD45RA monoclonal antibody (MAb) has been used as a marker for rat B-lymphocytes (B-cells). When we applied the MAb to identify B-lymphocytes among immune cells infiltrating pancreatic islets of the BB rat, which is an animal model for human type 1 diabetes mellitus, a subpopulation of islet cells was immunostained as well. Our immunohistochemical investigations demonstrated that the stained islet cells are pancreatic alpha-cells and the MAb cross-reacts with glucagon.

Animals↗
PubMed2000

Sudden-onset tinnitus associated with arterial dissection of the vertebrobasilar system.

Magnetic resonance (MR) images of 62 patients with tinnitus were reviewed. These included T1-weighted and T2-weighted axial images and three-dimensional spoiled gradient-recalled acquisition in steady-state (3D-SPGR) imaging with gadopentetate dimeglumine. In 49 cases with tinnitus occurring gradually, the MR images of 2 cases (4.1%) suggested arterial dissection of the vertebrobasilar system. One of these patients underwent vertebral angiography (VAG) and no dissection was confirmed. In 13 cases of sudden-onset tinnitus, MR images of 3 cases (23.1%) suggested arterial dissection. Of these three cases, VAG was performed in two, resulting in arterial dissections being confirmed in two cases. It was concluded that the arterial dissection of the vertebrobasilar system was one of the causes of sudden-onset tinnitus. Abnormalities in neurotological examinations in cases with tinnitus caused by the arterial dissection of vertebrobasilar system implied that the tinnitus was caused by inner ear dysfunction.

Acute Disease↗