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Biomedical subjects

K Tanimoto

Publications and source records attributed to K Tanimoto.

At least 73 records · Page 4Linked to original sources
PubMed1999

Effects of altered gene order or orientation of the locus control region on human beta-globin gene expression in mice.

The five human beta-type-globin genes, epsilon, Ggamma, Agamma, delta and beta, are close together and are regulated by a locus control region (LCR) located at the 5' end of the locus. Here we investigate the functional consequences of this organization with respect to temporal regulation of the individual genes, by using recombination techniques to invert the order of either the genes or the LCR in vivo. Our analysis of transgenic mice bearing either normal or mutant transgenes leads to two new observations. First, the position of the epsilon-globin gene next to the LCR is mandatory for its expression during the yolk-sac stage of erythropoiesis. Second, LCR activity is orientation dependent, and so the LCR does not act as a simple enhancer to stimulate transcription of the globin genes. Thus, in the absence of any change in transgene integration position, transgene copy number, trans-acting factors or other resident genetic information, simple inversion of the human genes or the LCR fundamentally alters the transcription of beta-type globin genes.

Animals↗
PubMed1999

Regulation of estrogen receptor alpha gene mediated by promoter B responsible for its enhanced expressionin human breast cancer.

We have previously reported that transcription from a distal promoter (promoter B) of the estrogen receptor alpha (ERalpha) gene is responsible for the increased expression of ERalpha in human breast carcinomas. This paper first characterized the promoter B region in terms of transient transfection experiments with luciferase using MCF-7 cells. Gradual deletions from the 5'-end of promoter B resulted in a decrease in promoter activity corresponding to the deleted lengths; a deletion of 39 bp in a non-coding exon 1a, drastically diminished the activity, indicating existence of an important cis -element. Furthermore, electrophoretic mobility shift assay and subsequent mutational analysis indicated that this element containing nucleotide sequence CTGGAAAG forms a specific DNA-protein complex. This element was capable of transactivating a heterogeneous SV40 promoter in MCF-7 cells, confirming that the element is a transcriptional enhancer; the trans -acting factor binding to the element was named ERBF-1 (estrogen receptor promoter B associated factor-1). The ERBF-1 was exclusively expressed in those cells expressing ERalpha mRNA transcribed from promoter B. Our findings indicate that ERBF-1 plays an important role in the expression of the ERalpha gene transcribed from promoter B, which is selectively utilized in breast cancer.

Breast Neoplasms↗
PubMed1999

A noninvasive method of measuring wave intensity, a new hemodynamic index: application to the carotid artery in patients with mitral regurgitation before and after surgery.

Wave intensity (WI) is a new hemodynamic index, which is defined as (dP/dt)(dU/dt) at any site of the circulation, where dP/dt and dU/dt are the time derivatives of blood pressure and velocity, respectively. Arterial WI in normal subjects has two positive sharp peaks. The first peak occurs during early systole when a forward-traveling compression wave is generated by the left ventricle. The magnitude of this peak increases markedly with an increase in cardiac contractility. The second peak, which occurs towards the end of systole, is caused by generation of a forward-traveling expansion wave by the ability of the left ventricle to actively stop aortic blood flow. The interval between the R wave of the ECG and the first peak of WI (R-1st peak interval) and the interval between the first and second peaks (1st-2nd interval) are approximately equal to the preejection period and left ventricular ejection time, respectively. Using a combined Doppler and echo-tracking system, we obtained carotid arterial WI noninvasively. We examined the characteristics of WI in 11 patients with mitral regurgitation (MR) before and after surgery, and 24 normal volunteers. In the MR group before surgery, the second peak was decreased and the (1st-2nd interval)/(R-R interval) ratio was reduced, compared with the normal group (140 +/- 130 vs 750 +/- 290mmHg m/s3. P < 0.0083; 20.7% +/- 3.4% vs 26.7% +/- 2.8%, P < 0.083). There were no significant differences in the first peak between the normal group and the MR group before and after surgery. The second peak in the MR group was increased significantly (P < 0.016 vs before surgery) to 1,150 +/- 830mmHg m/s3 in the early period after surgery (stage I), and to 1,090 +/- 580mmHgm/s3 in the late period after surgery (stage II). These values did not differ significantly from that of the normal group. At stage I, the (R-1st peak interval)/ (R-R interval) ratio was increased from 13.4% +/- 2.7% to 20.6% +/- 5.6% (P < 0.016 vs before surgery). At stage II, this ratio decreased to 16.2% +/- 2.8% (P < 0.016 vs stage I). but was still significantly higher than that before surgery. The (1st-2nd interval)/(R-R interval) ratio increased significantly after surgery (P < 0.016 vs before surgery) to values (27.0% +/- 4.5% at stage I and 28.9% +/- 2.6% at stage II) which did not differ significantly from that of the normal group. The recovery of the second peak after surgery suggests that the left ventricle had recovered the ability to actively stop aortic blood flow. Wave intensity is useful for analyzing changes in the working condition of the heart.

Adult↗
PubMed1999

Immunohistochemical localization of antigen presenting cells in liver from patients with primary biliary cirrhosis; highly restricted distribution of CD83-positive activated dendritic cells.

In order to have insights into the abnormal immune regulation in primary biliary cirrhosis (PBC), different types of antigen presenting cells (APC) were localized immunohistochemically in liver specimens from 26 patients with PBC and compared with the distributions of APC from 11 and 10 patients with chronic hepatitis C (CH-C) and large bile duct obstruction, respectively. In all diagnostic conditions, 30-90% of the infiltrating cells were positive for HLA DR. In PBC, the numbers of interdigitating cells (IDC) were significantly higher than the numbers of CD83-positive dendritic cells (DC) (34.0 +/- 38.8 vs. 5.5 +/- 7.1/specimen, mean +/- SD, p < 0.05). On the other hand, the numbers of IDC (14.2 +/- 20.0/specimen) and CD83-positive DC (7.9 +/- 8.7/specimen) were almost similar in CH-C (p > 0.05). Positive stainings for IDC and CD83-positive DC were rarely seen in large bile duct obstruction. This is the first report on the existence of activated CD83-positive DC in PBC. The significantly increased numbers of IDC and the highly restricted distributions of CD83-positive DC in PBC indicate that activated DC may play a role in the abnormal immune pathogenesis of PBC.

Adult↗
PubMed1999

Clinical and histopathological analyses of desmoplastic ameloblastoma.

Desmoplastic ameloblastoma (DA) is an unusual subtype of ameloblastoma characterized by pronounced desmoplastic stroma. There is, however, still argument whether DA is a distinct clinicopathologic entity. To enhance knowledge of DA, 7 cases of DA (7.9%) were retrieved from 89 ameloblastomas field in the Department of Oral Pathology, Hiroshima University School of Dentistry and analyzed clinicopathologically and histopathologically. The mean age of the patients with DA and non-DA at the time of the diagnosis was 40.6 +/- 5.9 years and 33.1 +/- 2.0 years, respectively. The male-to-female ratio was 2.5:1 in DA and 1.8:1 in non-DA. Four (57%) DAs were located in the maxilla where only 6% of the non-DA occurred. Interestingly, all DAs arose in the anterior/premolar area of the jaws and 6 cases were located mainly within the alveolus. None of the DA showed typical radiographic features of ameloblastoma. In 5 DAs, scattered radiopacities were observed in the radiolucent lesion and gave preoperative diagnoses of non-ameloblastomatous lesions or even osteosarcoma. All DAs showed pronounced desmoplastic stroma where there were compressed tumor islands usually lacking a peripheral layer of ameloblastic cells and a central zone of stellate reticulum. There was cystic change within the epithelial nests in 3 DAs and true glandular structures with mucus cells in a case of DA. Tumor islands often infiltrated into marrow spaces of surrounding bone. There was no capsule formation. Recurrence rate was 14% in DA and 20% in non-DA. The present study based on data of DA in the Japanese population supports that DA must be considered as a distinct clinicopathologic entity.

Adolescent↗
PubMed1999

Polymorphisms of the CYP1A1 and GSTM1 gene involved in oral squamous cell carcinoma in association with a cigarette dose.

The genetic polymorphisms of CYP1A1 and GSTM1 genes among 100 Japanese patients with oral squamous cell carcinomas (SCC) were investigated to evaluate the role of genetic susceptibility in carcinogenesis of the oral cavity. The presence of the rare homozygote of CYP1A1, m2/m2, was significantly more frequent in the patient group (15.0%) than the control group (8.0%) (Odds ratio (ORs) = 3.6 95% Confidential Interval (CI): 1.4-9.5). The heterozygotic variant, m1/m2, was also frequently seen in oral SCC patients. This meant that the m2 allele was observed in more than half of the patients. The null genotype of GSTM1 was found in 43.0% of the patient group. This was not significantly different from the controls (40.0%). When the life time cigarette consumption dose of the patients was considered with respect to genotypes of CYP1A1, the mean smoking index (SI) of oral SCC patients with m2/m2 was found to be less than half of the mean SI among the patients with m1/m1 genotype (P < 0.02). The ORs of the m2/m2 genotype was found to be significantly high in a comparison of various subsites of the oral cavity, except for the floor of the mouth. Our results indicate that the rare homozygote of CYP1A1, m2/m2, is associated with increased risk of oral SCC, in particular, at low cigarette dose levels. The results also suggested that the involvement of such susceptibility in oral carcinogenesis might be different between the subsites of the oral cavity.

Adult↗
PubMed1999

Relationship between bone mineral density and tooth loss in elderly Japanese women.

OBJECTIVE: To evaluate the relationship between vertebral bone mass and tooth loss and jaw bone mass in elderly Japanese women. METHODS: Mandibular cortical bone mass, alveolar bone height and number of teeth present (total, anterior, and posterior) were compared with the 3rd lumbar vertebral bone mineral density (L3BMD), measured by dual energy computed tomography (DEQCT), in 90 Japanese women by means of multiple regression analysis, controlling for body mass index, menopausal status, years since menopause and self-reported periodontal condition. RESULTS: Mandibular cortical bone mass and number of posterior teeth were associated with both alveolar bone height and L3BMD, but there was no association between alveolar bone height, number of anterior teeth present and L3BMD. CONCLUSION: Our results suggest that the loss of posterior teeth may be associated with a decrease not only in alveolar bone height, but also alveolar bone mineral density (BMD). The latter may be related to a decrease of lumbar vertebral BMD.

Adult↗
PubMed1999

Bone formation in a carcinoma of the maxillary antrum.

Malignant tumors of the paranasal sinuses are rare: about 80% are found in the maxillary sinus123. The presence of dense radiopaque masses in combination with destruction of the bone margins suggests osteosarcoma or aspergillosis4 rather than carcinoma. We present a unique mucoepidermoid carcinoma of the maxillary antrum containing new bone formation and discuss the differential diagnosis.

Aged↗
PubMed1999

Potent synergistic effect of sho-saiko-to, a herbal medicine, during vaccine therapy in a murine model of hepatitis B virus carrier.

BACKGROUND: Traditional herbal medicine, sho-saiko-to (TJ-9), improves subjective symptoms, and a recently developed vaccine therapy reduces the viral replication in some chronic hepatitis B virus (HBV)-carriers. The study presented here considers the impact of a combination of vaccine therapy and TJ-9 and the mechanism underlying the therapeutic effect of TJ-9. MATERIALS AND METHODS: HBV-transgenic mice (HBV-Tg) expressing similar levels of HBV-related antigens and HBV DNA were used as an animal model of HBV-carrier state, and were assigned to receive either a TJ-9-enriched diet or a monthly injection of vaccine containing hepatitis B surface antigen (HBsAg), or both, for 12 consecutive months. RESULTS: Twelve months after starting the therapy, 9% (1 of 11), 61% (11 of 18), and 100% (10 of 10) of HBV-Tg receiving only the TJ-9-treatment, only the monthly vaccine, and both the TJ-9 and vaccine, respectively, responded to therapy and became completely negative for HBsAg. Spleen lymphocytes and antigen presenting cells (APC) from TJ-9-treated HBV-Tg produced significantly higher levels of IgM, IgG and antibodies to keyhole limpet hemocyanin (KLH) and showed significantly higher stimulatory capacity in allogenic mixed leukocyte reaction (MLR) compared with the spleen cells and APC from HBV-Tg receiving normal diet without TJ-9 (P < 0.05). CONCLUSION: These data confirm the therapeutic role of TJ-9 during HBV infection and inspire optimism of a widespread use of TJ-9 during immune therapies.

Adjuvants, Immunologic↗
PubMed1999

So-called 'hybrid' lesion of desmoplastic and conventional ameloblastoma: report of a case and review of the literature.

So-called 'hybrid' lesion of ameloblastoma, which is composed of desmoplastic ameloblastoma and conventional follicular/plexiform ameloblastoma, is an unusual variant of ameloblastoma and only eight cases of 'hybrid' lesion have been published in the English literature. To enhance knowledge of this interesting tumor, we add a case of 'hybrid' lesion that occurred in the right mandible of a 48-year-old Japanese male. Radiographic examination disclosed a honeycomb appearance at the anterior alveolar region, combined with a unicystic radiolucency in the molar region of the mandibular body. Histologically, the former showed microscopic features of desmoplastic ameloblastoma and the latter those of follicular ameloblastoma with focal granular cell transformation. The lesion was enucleated with curettage of surrounding bone and the lesional cavity was marsupialized. Although tumor tissues reappeared at 3, 5, 7 and 14 months after the surgery, the patient has remained disease free for 11 years after the last vaporization by CO2 laser of the recurred tumor. Many more cases of 'hybrid' lesion are needed to clarify the clinicopathological, histopathological and biological characteristics of this interesting variant of ameloblastoma.

Ameloblastoma↗
PubMed1999

Reconsideration of the TMJ condylar position during internal derangement: comparison between condylar position on tomogram and degree of disk displacement on MRI.

The objective of this study was to investigate condylar position during different degrees of disk displacement. The degree of disk displacement was evaluated on 1.5 Tesla high-field sagittal MR images of 76 joints (48 patients; mean age 19.4 years) and was classified into three grades (1 to 3). To establish condylar position, the anterior, superior and posterior joint spaces were measured on corrected tomograms. The possible relationship between condylar position, indicated by the width of joint space and successive degree of disk displacement, was compared by a one-way factorial ANOVA (p < 0.05). The anterior joint space was significantly larger in grades 1, 2, and 3 disk displacements than in grade 0 pointing to a dorsal condylar position. The posterior joint space was significantly smaller in grades 1 and 2 compared with grade 0. When the degree of the disk displacement becomes severe (i.e., grade 3 disk displacement), the posterior joint space tends to increase to a similar distance as in a normal healthy joint pointing to a more normal condylar position.

Adolescent↗
PubMed1999

Hypersensitive site 2 specifies a unique function within the human beta-globin locus control region to stimulate globin gene transcription.

The human beta-globin locus control region (LCR) harbors both strong chromatin opening and enhancer activity when assayed in transgenic mice. To understand the contribution of individual DNase I hypersensitive sites (HS) to the function of the human beta-globin LCR, we have mutated the core elements within the context of a yeast artificial chromosome (YAC) carrying the entire locus and then analyzed the effect of these mutations on the formation of LCR HS elements and expression of the genes in transgenic mice. In the present study, we examined the consequences of two different HS2 mutations. We first generated seven YAC transgenic lines bearing a deletion of the 375-bp core enhancer of HS2. Single-copy HS2 deletion mutants exhibited severely depressed HS site formation and expression of all of the human beta-globin genes at every developmental stage, confirming that HS2 is a vital, integral component of the LCR. We also analyzed four transgenic lines in which the core element of HS2 was replaced by that of HS3 and found that while HS3 is able to restore the chromatin-opening activity of the LCR, it is not able to functionally replace HS2 in mediating high-level globin gene transcription. These results continue to support the hypothesis that HS2, HS3, and HS4 act as a single, integral unit to regulate human globin gene transcription as a holocomplex, but they can also be interpreted to say that formation of a DNase I hypersensitive holocomplex alone is not sufficient for mediating high-level globin gene transcription. We therefore propose that the core elements must productively interact with one another to generate a unique subdomain within the nucleoprotein holocomplex that interacts in a stage-specific manner with individual globin gene promoters.

Animals↗
PubMed1999

YM116, 2-(1H-imidazol-4-ylmethyl)-9H-carbazole, decreases adrenal androgen synthesis by inhibiting C17-20 lyase activity in NCI-H295 human adrenocortical carcinoma cells.

The concentrations of androstenedione and dehydroepiandrosterone, products of C17-20 lyase, in the medium after a 6-hr incubation of NCI-H295 cells were decreased by YM116 (2-(1H-imidazol-4-ylmethyl)-9H-carbazole) (IC50: 3.6 and 2.1 nM) and ketoconazole (IC50: 54.9 and 54.2 nM). 17Alpha-hydroxyprogesterone, a product of 17alpha-hydroxylase, was increased by YM116 (1-30 nM) and by ketoconazole (10-300 nM) and then was decreased at higher concentrations of both agents (IC50: 180 nM for YM116, 906 nM for ketoconazole), indicating that YM116 and ketoconazole were 50- and 16.5-fold more specific inhibitors of C17-20 lyase, respectively, than 17alpha-hydroxylase. Compatible with these findings, progesterone, a substrate of 17alpha-hydroxylase, was increased by these agents. Cortisol production was inhibited by YM116 and ketoconazole (IC50: 50.4 and 80.9 nM, respectively). YM116 was a 14-fold more potent inhibitor of androstenedione production than cortisol production, whereas ketoconazole was a nonselective inhibitor of the production of both steroids. YM116 and ketoconazole inhibited the C17-20 lyase activity in human testicular microsomes (IC50: 4.2 and 17 nM, respectively). These results demonstrate that YM116 reduces the synthesis of adrenal androgens by preferentially inhibiting C17-20 lyase activity.

Adrenal Cortex Hormones↗
PubMed1999

[Detection of Ki-67 in liver biopsy specimens using monoclonal antibody to Mib-1].

Ki-67 antigen was visualized in formalin-fixed, paraffin-embedded liver biopsy specimens using monoclonal antibody to Mib-1 to identify the proliferating hepatocytes. Thirty liver specimens obtained from 10 patients with chronic hepatitis (CH) or liver cirrhosis (LC) and 10 patients with hepatocellular carcinoma were studied. Liver specimens were treated with a pepsin solution or heated with autoclave or treated with microwave as a part of antigen retrieval system; then stained with an immunoperoxidase method using a monoclonal antibody to Ki-67 (Mib-1). Stable stainings were obtained in the sections treated with autoclave. Ki-67 was detected in the nuclei of hepatocytes, bile duct epithelium, fibroblast and infiltrating mononuclear cells. In patients with CH and LC, the numbers of hepatocytes positive for Ki-67 has a good co-relation with serum GPT level (p < 0.01), while has no relationship with the degree of fibrosis. The number of hepatocytes positive for Ki-67 has a good co-relation with the degree of the differentiation of hepatocellular carcinoma. Detection of proliferating hepatocytes using Mib-1 is useful to understand the degree of proliferation.

Adolescent↗
PubMed1999

Abnormal FHIT transcripts found in both lung cancer and normal lung tissue.

Occurrence of abnormal transcripts of the FHIT (fragile histidine triad) gene has been reported in various types of cancer. On the other hand, aberrant transcripts are sometimes found in non-neoplastic tissues, so the relationship between the presence of abnormal transcripts of the FHIT gene and cancer pathogenesis is controversial. We investigated alterations in the FHIT locus, detected by nested reverse transcription-polymerase chain reaction and/or allelic status, in 88 primary lung cancers and normal lung tissues, and 22 normal lung tissues with metastatic lung cancer as a control. The frequencies of abnormal transcripts were 59% in lung cancer, 35% in paired normal lung, and 64% in normal control lung; the difference in frequencies between lung cancer and paired normal lung was significant, while that between lung cancer and normal control lung was not. Sequence analysis revealed that there were no cancer-specific abnormal transcripts entirely missing two or more exons, nor were the abnormal transcripts of lung cancer identical with those of paired normal lung in the same individual. Furthermore, we found no correlation between loss of heterozygosity in the FHIT locus and occurrence of abnormal FHIT transcripts. These results suggest that the presence of abnormal FHIT transcripts, in terms of their frequency and variety, is not cancer-specific in lung carcinogenesis, and the abnormality may be mainly due to abnormal splicing and processing of the transcripts. To estimate the precise function of the FHIT gene, further study of the FHIT protein in lung carcinogenesis is needed.

Acid Anhydride Hydrolases↗
PubMed1998

Rescue of angiotensinogen-knockout mice.

Angiotensinogen, the precursor of angiotensins I and II, is a critical component of the renin-angiotensin system that plays an important role in regulating blood pressure and electrolyte homeostasis. Genetically altered mice lacking angiotensinogen (Agt-KO) showed an expected phenotype, such as marked hypotension, but unexpected ones including abnormal kidney morphology, reduced survival rates of newborns, and impaired blood-brain barrier function after cold injury. To examine whether disruption of the angiotensinogen gene is responsible for the observed phenotypes, we generated a line of mice heterozygous for the mouse angiotensinogen gene under the control of a mouse metallothionein-I promoter (MT-Agt) and crossmated transgenic mice with Agt-KO mice. The resulting mice (MT-Agt(+/-)/Agt(-/-):MT-Agt/KO) produced the plasma level of angiotensin I comparable to that of wild-type mice, and the mutant phenotypes were rescued. These results indicated that the resultant phenotypes due to the genetic deficiency of mouse angiotensinogen can be corrected by restoring angiotensinogen and angiotensin I in the circulation.

Angiotensin I↗
PubMed1998

Novel nonsteroidal inhibitor of cytochrome P450(17alpha) (17alpha-hydroxylase/C17-20 lyase), YM116, decreased prostatic weights by reducing serum concentrations of testosterone and adrenal androgens in rats.

BACKGROUND: The purpose of this study was to determine the effects of a nonsteroidal C17-20 lyase inhibitor, 2-(1H-imidazol-4-ylmethyl)-9H-carbazole (YM116), on serum concentrations of androgens and ventral prostatic weight in rats. METHODS: Serum concentrations of testosterone and of dehydroepiandrosterone sulfate and prostatic weights were measured in rats treated with YM116. RESULTS: YM116 inhibited testicular C17-20 lyase competitively (Ki, 0.38 nM), and decreased the serum testosterone concentration in gonadotropin-releasing hormone-treated rats (ED50, 0.7 mg/kg), indicating that YM116 was about 21-24 times more potent than other C17-20 lyase inhibitors such as ketoconazole and liarozole, and was twice as potent as CB7630. YM116 also reduced dehydroepiandrosterone sulfate levels in ACTH-treated castrated rats (ED50, 11 mg/kg). YM116 (40 mg/kg, p.o., for 2 weeks) was almost comparable to bilateral orchiectomy with respect to the time course and magnitude of the reduction in prostatic weight. Each of these two treatments decreased the prostatic weight 3 days following the treatment. Contrarily, leuprolide transiently increased the prostatic weight and then decreased it. YM116 (100 mg/kg) had no effect on the serum cortisol level in guinea pigs, and slightly decreased the serum aldosterone level in rats. CONCLUSIONS: YM116 is a selective C17-20 lyase inhibitor which decreases rat prostatic weight by reducing androgen production in the testes and adrenal glands.

Abiraterone Acetate↗