Search PubMed⌕ Search

Biomedical subjects

N Nagai

Publications and source records attributed to N Nagai.

At least 55 records · Page 3Linked to original sources
PubMed2000

Age and magnetic effects on ectopic bone formation induced by purified bone morphogenetic protein.

A mixture of heparin-Sepharose-purified bovine bone morphogenetic protein (BMP) and type I atellocollagen was implanted in the subcutaneous tissues of 4-week, 10-month and 18-month-old rats. The implants were removed at 7, 14 and 21 days after implantation. The effects of rat age on ectopic bone formation were evaluated on the explants using H&E staining, morphometric analysis, alkaline phosphatase (ALP) activity and calcium (Ca) content determination, as well as immunohistochemical staining of type IV collagen present in the basement membrane of blood vessels. On day 14 and 21, bone was observed in 4-week and 10-month-old rats but the amount of bone formed in the later was less than in the former. In 18-month-old rats, bone was first found focally in very limited regions of the explants on day 21 and the amount of bone was much less than in 4-week-old rats. At all periods ALP activity was higher in younger rats. On day 7, there were more blood vessels in the explants of 4-week-old rats than in those of 10- or 18-month-old rats. On day 14 and 21, more blood vessels were found in the central regions of the explants in 4-week-old rats than in the same regions in 10- or 18-month-old rats. The findings in the present study indicated that the rate and quantity of ectopic bone formation were reduced, and that the difference in blood vessel distribution might be related to the reduction in ectopic bone formation in aged rats, and suggest that the difference in blood vessel distribution is related to ectopic bone formation. Magnetism can stimulate ectopic bone formation induced by BMP.

Journal Article↗
PubMed2000

Macrophage-colony stimulating factor inhibits the growth of human ovarian cancer cells in vitro.

The effect of macrophage-colony stimulating factor (M-CSF), which regulates the growth and differentiation of haematopoietic progenitor cells on the growth of ovarian cancer cells was investigated in three ovarian cancer cell lines in vitro. The spontaneous growth of these cells was significantly inhibited by the addition of M-CSF in a concentration-dependent manner over 96 h of culturing. The maximum response was obtained with 10 ng/ml (3857 U/ml) of M-CSF by counting the viable cell number using the trypan blue exclusion assay. [(3)H]-thymidine incorporation by these cells was also suppressed following a 96-h incubation with M-CSF. The inhibitory effect of M-CSF was reversed by the addition of anti-M-CSF monoclonal antibody. Flow cytometric analysis revealed that the treated ovarian cancer cells arrested at the G0/G1 phase of the cell cycle. These cells expressed M-CSF receptors on their surface as detected by Scatchard plot analysis using (125)I-labelled M-CSF. These results indicate that M-CSF has an antitumour activity for ovarian cancer cells and suggest that it can be applied for the treatment of this disease.

Antineoplastic Agents↗
PubMed2000

Neutrophil elastase may play a key role in developing symptomatic disseminated intravascular coagulation and multiple organ failure in patients with head injury.

OBJECTIVE: To study the mechanism associated with the development of symptomatic disseminated intravascular coagulation (DIC) after head injury. METHODS: Plasma parameters were analyzed in patients with symptomatic (group A, n = 10) and asymptomatic DIC (group B, n = 15) induced by head injury, and in patients in whom DIC was caused by sepsis (group C, n = 10). RESULTS: Levels of fibrinogen, alpha2PI-plasmin complex and platelets in group A (58.1 mg/dL, 22.4 microg/mL, 16.0 x 10(4)/ mm3) and group B (98.3, 22.1, 16.6 x 10(4)) were comparable, but differed significantly from those in group C (297.4, 2.4, 6.3 x 10(4)). Significant differences were observed between groups A and B in both neutrophil-elastase (1,528 vs. 293 microg/ml) and D-dimer (42.1 vs. 17.6 microg/mL). CONCLUSION: Neutrophil elastase may be implicated in the development of symptomatic DIC after head injury, whose characteristics include "enhanced fibrinolysis with minimal platelet loss."

Adolescent↗
PubMed2000

Peritoneal and peripheral B-1-cell populations in patients with endometriosis.

OBJECTIVE: The purpose of this study was to investigate the frequency of B-1 cells in the peritoneal cavity and peripheral blood of patients with endometriosis. MATERIALS AND METHODS: We examined 31 patients with endometriosis and 14 normal nonpregnant women. Peripheral blood cells and peritoneal exudate cells (PECs) were stained with FITC or PE-labeled anti-CD5/CD19 monoclonal antibodies. Immunofluorescence analysis was performed using a flow cytometer. The significance of differences between the patient and control groups was determined by the non-parametric Mann-Whitney test. RESULTS: There was no significant difference in the percentages of B-1 cells in the peripheral blood of women with and without endometriosis (median, 22.7%; range, 4.7-92.3% vs median, 20.05%; range, 11.1-12.6%, respectively). Endometriosis patients with antinuclear antibodies (ANAs) demonstrated significantly elevated B-1 cells compared to both endometriosis patients without ANAs and normal controls (p < 0.005 and p < 0.05, respectively). Endometriosis patients demonstrated significantly higher B-1 cell populations (B-1 cells/total B-cell ratio) in PECs than did non-endometriosis patients (p < 0.05). CONCLUSIONS: The peripheral B-1-cell population in patients with endometriosis is related to ANA production. B-1 cells might play important roles in the development of endometriosis through autoantibody production.

Adult↗
PubMed2000

Effects of paternal lymphocyte immunization on peripheral Th1/Th2 balance and TCR V beta and V gamma repertoire usage of patients with recurrent spontaneous abortions.

PROBLEM: The mechanism of immunotherapy for patients with recurrent spontaneous abortions is not well understood. In order to investigate the suppressor mechanism of paternal lymphocyte immunization, we examined peripheral blood lymphocyte subpopulations and the repertoire of T-cell receptor (TCR) gene segments. METHOD OF STUDY: Twelve patients with recurrent miscarriage were treated with immunization with paternal lymphocyte vaccinations three times during 12-14 weeks. Before and 2 weeks after the final inoculation, lymphocyte subsets and intra-cellular interferon (IFN)-gamma and/or interleukin (IL)-4 production were examined by flow cytometry. TCR V beta and V gamma repertoires were examined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: We found no significant difference in CD4/CD8 ratios, prevalence of CD56+CD3+ or CD57+CD3+ cells (possible extrathymic T cells), gamma(delta)T cells, and CD5+ CD19+ (B-1) cells. However, by in vitro activation with phorbol 12-myristate 13-acetate (PMA) and ionomycin, peripheral CD4 cells demonstrated a significant decrease of IFN-gamma-producing T helper 1 (Th1) cells and an increase of IL-4-producing T helper 2 (Th2) cells after immunotherapy. Seven of nine patients who exhibited remarkable decreases in Th1/Th2 ratios became pregnant within 6 months after three courses of immunotherapy, and four women delivered healthy babies, while none of the three patients who exhibited an increased or unchanged Th1/Th2 ratio had full-term pregnancies (chi2 < 0.0001). Further, changes in usage of TCR V beta and V gamma gene segments were observed after immunotherapy in six patients examined. CONCLUSION: Our findings suggest a shift of Th1-dominant to Th2-dominant status by vaccination might play important roles in maintaining successful pregnancies. Induction of some T cells that utilize different TCR repertoires possibly suppresses maternal rejection reactions.

Abortion, Habitual↗
PubMed2000

Expression of telomerase reverse transcriptase mRNA and its quantitative analysis in human endometrial cancer.

Three major components of telomerase, i.e., human telomerase RNA (hTERC), telomerase-associated protein (TEP1), and the human telomerase reverse transcriptase (hTERT), have been identified. Among them, TERT expression is very closely related to telomerase activity. The purpose of this study was to evaluate the implications of TERT expression and telomerase activity in endometrial cancer. Fresh surgical specimens of 36 endometrial carcinomas (CA group) and 9 samples of postmenopausal endometrial tissue without malignancy (NP group) were obtained at operation in our hospital. These specimens were analyzed for telomerase activity and TERT expression by TRAP assay and RT-PCR, respectively, and the detection and quantitative analysis were made. The results for endometrial cancer were compared with those for normal endometrium and with the clinical data. In the CA group, TERT expression was detected in 35/36 subjects (97.2%), whereas in 1/9 subject (11.1%) from the NP group. Relative TERT mRNA expression was 0.50 in the CA group, and this was significantly higher compared with the level of 0.10 in the NP group (p<0.05). Telomerase activity was detected in 34/36 subjects (94.4%) from the CA group and in 3/9 subjects (33.3%) from the NP group (p<0.05), while the RTA was 30.9 and 0.2, respectively (p<0.05). There was a significant correlation between the relative TERT expression and RTA (n=45, R=0.413, p<0.05). RTA was significantly higher at an advanced surgical stage (FIGO II, III or IV) than at an early stage (FIGO 0 or I) (52.4 vs. 20.4, p<0.05), but other clinical factors showed no relationship with TERT and RTA values. The detection and quantitative analysis of telomerase activity and TERT expression is helpful for distinguishing malignant from normal endometrium when the patient is postmenopausal, even if the tumor is very small or of low malignancy.

Adenocarcinoma↗
PubMed2000

Expression of matrix metalloproteinases (MMP-2, MMP-9, MT1-MMP) and their inhibitors (TIMP-1, TIMP-2) in common epithelial tumors of the ovary.

Matrix metalloproteinases (MMPs) are known to play an important role in cancer cell invasion by mediating the degradation of extracellular matrix proteins. The activity of such MMPs are regulated by tissue inhibitors of metalloproteinases (TIMPs). In this study, we investigated the immunohistochemical expression of MMP-2, MT1-MMP, TIMP-2, MMP-9, and TIMP-1 in 114 epithelial ovarian tumors (14 adenomas, 22 borderline tumors, and 78 adenocarcinomas). mRNA expression of MMP-2, MT1-MMP, and TIMP-2 was determined by RT-PCR in selected samples. The diffuse positive rates of MMP-2, MT1-MMP, TIMP-2, and MMP-9 in ovarian carcinomas were significantly higher than those in the borderline and in benign tumors. Conversely, the diffuse positive rate of TIMP-1 was higher in the benign and borderline ovarian tumors than that in ovarian carcinomas. The percentages of the cases with triple diffuse positive expression for MMP-2, MT1-MMP, and TIMP-2 within the same tumor was significantly higher in malignant tumors than those in borderline and in benign tumors. With respect to clinical stage, the triple diffuse positive rate in advanced-stage (stage II/III/IV) carcinomas was significantly higher than that in early-stage (stage I) carcinomas. A significantly higher triple diffuse positive rate was also observed in high-grade (grade 2/3) disease than in low-grade (grade 1) disease. Considerable levels of mRNA expression of MMP-2, MT1-MMP and TIMP-2 were detected in all selected samples that showed triple diffuse positive immunostaining, confirming the co-expression of MMP-2, MT1-MMP, and TIMP-2 at the transcriptional level within the same tumor. All cases with diffuse positive expression for MMP-9 showed regional or negative TIMP-1 expression. The diffuse positive rate of MMP-9 was significantly higher in ovarian carcinomas with lymph node metastasis than in those without lymph node metastasis. Our results suggest that the overexpression of MMP-2, MT1-MMP, TIMP-2, and MMP-9 and down-regulation of TIMP-1 may contribute to the development or enhanced growth capacity of ovarian tumors. Co-expression of MMP-2, MT1-MMP, and TIMP-2 within the same tumor seems to play an important role in the progression of ovarian cancer. Elevated MMP-9 expression together with low expression of TIMP-1 may also contribute to the lymph node metastasis of ovarian carcinoma cells.

Female↗
PubMed2000

Clinicocytopathological and immunohistochemical study of adenoma malignum of the uterine cervix.

Adenoma malignum is a rare type of very highly differentiated adenocarcinoma of the uterine cervix, and is quite difficult to diagnose because there are few findings definitely suggesting malignancy on cytologic or histologic examination. We recently encountered four patients with adenoma malignum and reviewed their clinicocytopathological and immunohistochemical findings. The most characteristic symptom was a watery discharge and an enlarged cervix was palpable, while multiple cystic lesions (MCL) were observed by transvaginal and abdominal ultrasonography, CT or MRI. On cytodiagnosis, the cervical gland cells formed large sheets or showed a palisading arrangement. Slightly enlarged nuclei and yellowish-orange staining of the cytoplasmic mucus were the characteristic findings. On histological examination, many cervical glands of different sizes were present and extended deep into the muscle layer, while branching or papillary growth into the lumen was also observed. On immunohistochemical study, HIK1083, a monoclonal antibody for gastric gland mucous cell mucin, was found to be positive in 3 of 4 cases, and this was fairly useful in the diagnosis of adenoma malignum.

Adenocarcinoma↗
PubMed2000

Effect of intestinal helminthiasis on nutritional status of schoolchildren.

This study was conducted in a rural agricultural area in Siniloan, Republic of the Philippines. The subjects were the school children. The nutritional status of 58 children infected with helminthiasis (Ascaris lumbricoides and Trichuris trichiura) was compared with that of 19 uninfected controls. Prevalence of Ascaris and Trichuris was 40.3% and 71.4% respectively, and 36.4% of infected children had both Ascaris and Trichuris infections. Statistically significant evidence of an adverse effect of helminthiasis on serum albumin levels was found, but no child had inadequate levels of other nutrients. Although helminthic infections increase the level of immunoglobulin E (IgE) in children endemically exposed to these parasites, there was no significant difference in the serum IgE among Ascaris or Trichuris infected groups in this study.

Adolescent↗
PubMed1999

Role of plasminogen system components in focal cerebral ischemic infarction: a gene targeting and gene transfer study in mice.

BACKGROUND: The role of plasminogen system components in focal cerebral ischemic infarction (FCI) was studied in mice deficient in plasminogen (Plg-/-), in tissue or urokinase plasminogen activator (tPA-/- or uPA-/-), or in plasminogen activator inhibitor-1 or alpha2-antiplasmin (PAI-1(-/-) or alpha2-AP-/-). METHODS AND RESULTS: FCI was produced by ligation of the left middle cerebral artery and measured after 24 hours by planimetry of stained brain slices. In control (wild-type) mice, infarct size was 7.6+/-1.1 mm3 (mean+/-SEM), uPA-/- mice had similar infarcts (7.8+/-1.0 mm3, P=NS), tPA-/- mice smaller (2.6+/-0.80 mm3, P<0.0001), PAI-1(-/-) mice larger (16+/-0.52 mm3, P<0.0001), and Plg-/- mice larger (12+/-1.2 mm3, P=0.037) infarcts. alpha2-AP-/- mice had smaller infarcts (2. 2+/-1.1 mm3, P<0.0001 versus wild-type), which increased to 13+/-2.5 mm3 (P<0.005 versus alpha2-AP-/-) after intravenous injection of human alpha2-AP. Injection into alpha2-AP-/- mice of Fab fragments of affinospecific rabbit IgG against human alpha2-AP, after injection of 200 microg human alpha2-AP, reduced FCI from 11+/-1.5 to 5.1+/-1.1 mm3 (P=0.004). CONCLUSIONS: Plg system components affect FCI at 2 different levels: (1) reduction of tPA activity (tPA gene inactivation) reduces whereas its augmentation (PAI-1 gene inactivation) increases infarct size, and (2) reduction of Plg activity (Plg gene inactivation or alpha2-AP injection) increases whereas its augmentation (alpha2-AP gene inactivation or alpha2-AP neutralization) reduces infarct size. Inhibition of alpha2-AP may constitute a potential avenue to treatment of FCI.

Adenoviridae↗
PubMed1999

The human genome has only one functional hsp47 gene (CBP2) and a pseudogene (pshsp47).

Among all the species investigated to date, only in humans is hsp47 reported to exist as two separate genes. Here we examined whether hsp47 forms a gene family, and if so, how many genes constitute the family. Cloning and sequencing of human hsp47 cDNA revealed that only one gene, identical to CBP2, was transcribed. No transcript corresponding to colligin, which was reported to be a human homologue of hsp47, was found. Genomic southern hybridization using the exon III fragment of mouse hsp47 as a probe, however, showed two bands for several restriction enzyme digests. We cloned and sequenced the gene corresponding to the extra band and found that a pseudogene (pshsp47) existed in the human genome. We have mapped this pseudogene to chromosome 9p12-p13 by fluorescent in situ hybridization (FISH) using a 3.5kb genomic fragment containing the entire pshsp47 sequence as a probe. These results suggested that functional hsp47 exists as CBP2, not as colligin, and a highly conserved pseudogene is present in the human genome.

Base Sequence↗
PubMed1999

Proteolysis of neuronal cell adhesion molecule by the tissue plasminogen activator-plasmin system after kainate injection in the mouse hippocampus.

Tissue plasminogen activator (tPA) is a serine protease that converts inactive plasminogen to the active protease plasmin and mediates extracellular metabolism. tPA is transcriptionally induced in the mouse hippocampus by pharmacological or electrical stimulation of neuronal activity and mediates excitotoxin-induced neuronal degeneration. Therefore, we hypothesized that tPA would be induced in the hippocampus after kainic acid (KA) injection into the lateral cerebral ventricle (LCV) and that the activated tPA-plasmin system would degrade the neuronal cell adhesion molecule (NCAM), which is a component of the extracellular matrix. In order to investigate this possibility, we first examined whether NCAM is a substrate for the tPA plasmin system by incubating mouse brain homogenates with tPA and plasminogen at 37 degrees C. Next, we examined the degradation of NCAM and the changes of tPA activity in the mouse hippocampus with immunohistochemical procedures and histological zymography after KA injection into both LCVs. As a result, we observed neuronal atrophy and a decrease of NCAM immunoreactivity along with an increase of tPA activity in the CA3 area of the hippocampus. These results suggest that activation of the tPA plasmin system after KA injection into the LCVs results in the degradation of NCAM in the CA3 area.

Animals↗
PubMed1999

Neuronal degeneration and a decrease in laminin-like immunoreactivity is associated with elevated tissue-type plasminogen activator in the rat hippocampus after kainic acid injection.

Tissue-type plasminogen activator (tPA) is a serine protease that converts the inactive precursor plasminogen to the active protease plasmin. In the central nervous system, tPA has been suggested to participate in plasticity, memory and the neuronal degeneration caused by excitotoxins, but its precise functions during these processes are still unclear. We show in this report that tPA antigen level and extracellular tPA activity increased in the hippocampus during the early stages of neuronal degeneration in the CA3 region following the injection of kainic acid (KA) into the lateral cerebral ventricles. The increase in tPA antigen level was transient and its peak was at 4 h after the injection. tPA activity was also increased 4 h after the injection, but it remained at a high level for more than 8 h. Histological zymography showed that the increase in tPA activity was mainly localized in the CA3 region. In the same region, the disappearance of interneuronal laminin-like immunoreactivity and atrophic changes in pyramidal neurons were observed 4 h after the injection of KA. These results suggested that such focal and transient increases in tPA synthesis and release, which result in the proteolysis of laminin through plasminogen activation, could be involved in the neuronal degeneration in the CA3 region after the injection of KA.

Animals↗
PubMed1999

Inhibition of telomerase activity and cell proliferation by a reverse transcriptase inhibitor in gynaecological cancer cell lines.

Telomerase is a ribonucleoprotein which has a RNA template to bind and extend telomere ends, so prolonging the life of tumour cells. The aim of this study was to determine whether transcriptase function of telomerase could be inhibited by the reverse transcriptase inhibitors (RTI); azydothymidine (AZT), dideoxyinosine (ddI) and AZT-5' triphosphate (AZT-TP). We examined their effects on the proliferation of cancer cells and the antitumour effects of cisplatin in vitro. The three agents did not cause major changes in telomerase activity or telomere length in MCAS cells. However, in HEC-1 cells changes in telomerase activity and telomere length were observed that were dependent on the RTI concentration and duration of exposure. ddI and AZT-TP reduced telomerase activity and shortened the length of the telomere. In the presence of RTI, the antitumour effects of cisplatin were enhanced. This was particularly evident in HEC-1 cells where there was a marked reduction in cell proliferation, appearance of morphological changes and senescent-like cells in the presence of ddI or AZT-TP. In MCAS cells, TP53 expression was increased by ddI and AZT-TP, while p21 expression was unchanged. In HEC-1 cells the expression of both TP53 and P21 was increased by ddI. Continuous administration of RTI enhanced the cell growth inhibition of cisplatin. RTI also inhibited the proliferation of some cells.

Blotting, Southern↗
PubMed1999

Microsatellite instability and hMSH2 gene mutation in a triple cancer (colon cancer, endometrial cancer, ovarian cancer) patient in hereditary non-polyposis colorectal cancer (HNPCC) kindred.

A patient who had triple cancer (colon cancer, endometrial cancer, and ovarian cancer) in HNPCC kindred is reported. Her family history revealed the occurrence of colon cancer in her paternal aunt and in two cousins, fulfilling the minimum HNPCC criteria. Microsatellite instability analysis revealed replication error (RER)+ in all cancer lesions at 2 microsatellite loci (D1S191, BAT 40). SSCP analysis suggested germline mutation in exon 2 of the hMSH2 gene. This case showed the importance of complete family-history investigations to identify HNPCC patients. In the near future, definitive diagnosis of HNPCC will be possible on the basis of DNA studies.

Adenocarcinoma↗
PubMed1999

Interleukin-12 augments cytolytic activity of peripheral and decidual lymphocytes against choriocarcinoma cell lines and primary culture human placental trophoblasts.

PROBLEM: Human trophoblasts are tolerant to the maternal immune system, but susceptible to interleukin (IL)-2-activated lymphocytes. IL-12 is also a key cytokine in the induction of cytotoxic responses. We administered IL-12 to peripheral blood lymphocytes (PBLs) and to decidual lymphocytes (DLs) and studied resulting cytotoxicity against trophoblasts. METHOD OF STUDY: PBLs and DLs were stimulated with rIL-2 and/or rIL-12 for 48 hr in vitro. Cytotoxicity against the choriocarcinoma cell line JEG-3, JAR, and primary culture trophoblasts were examined by LDH release assay. The proliferative response was estimated by MTT assay. Expression of cytotoxic factors was studied by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: Whereas IL-12 alone produced a modest enhancement in cytotoxicity of PBLs and DLs, the combination of IL-2 and IL-12 was most effective in trophoblast cell lysis. IL-12 enhanced the mRNA expression of T-cell specific serine protease (TSP, granzyme B) and FasL in DLs, but the expression of perforin was unchanged. Expression of these cytotoxic factors in PBLs was up-regulated by IL-12. CONCLUSION: Our findings indicate critical roles of IL-12 in the activation of maternal lymphocytes, which could possibly result in pregnancy failure syndromes.

Adult↗
PubMed1999

Age effects on ectopic bone formation induced by purified bone morphogenetic protein.

A mixture of heparin-Sepharose-purified bovine bone morphogenetic protein and type I atellocollagen was implanted in the subcutaneous tissues of 4-week, 10-month and 18-month-old rats. The implants were removed at 7, 14 and 21 days after implantation. The effects of rat age on ectopic bone formation were evaluated on the explants using haematoxylin-eosin staining, morphometric analysis, alkaline phosphatase activity and calcium content determination, as well as immunohistochemical staining of type IV collagen present in the basement membrane of blood vessels. On day 14 and 21, bone was observed in 4-week and 10-month-old rats, but the amount of bone formed in the latter was less than in the 4-week-old rats. In 18-month-old rats, bone was first found focally in very limited regions of the explants on day 21 and the amount of bone was much less than in 4-week-old rats. At all periods, alkaline phosphatase activity was higher in younger rats. On day 7, there were more blood vessels in the explants of 4-week-old rats than in those of 10-month or 18-month-old rats. On day 14 and 21, more blood vessels were found in the central regions of the explants in 4-week-old rats than in the same regions in 10-month or 18-month-old rats. The findings in the present study indicate that the rate and quantity of ectopic bone formation are reduced in aged rats, and suggest that the difference in blood vessel distribution is related to this reduction in ectopic bone formation.

Aging↗