Biomedical subjects

K Abe

Publications and source records attributed to K Abe.

At least 685 records · Page 38Linked to original sources

PubMed1998

Crocin antagonizes ethanol inhibition of NMDA receptor-mediated responses in rat hippocampal neurons.

We have previously found that crocin (crocetin di-gentiobiose ester) antagonizes the inhibitory effect of ethanol on long-term potentiation in the rat hippocampus in vivo and in vitro. To explore mechanisms underlying the antagonism of crocin against ethanol, we investigated the effects of ethanol and crocin on synaptic potentials mediated by N-methyl-d-aspartate (NMDA) receptors in the dentate gyrus of rat hippocampal slices. Synaptic potential mediated by non-NMDA receptors was recorded in normal medium (1.3 mM Mg2+), while NMDA receptor-mediated synaptic potential was isolated in low (0.13 mM) Mg2+ medium containing the non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (10 microM). Crocin (10 microM) alone did not affect synaptic potentials mediated by non-NMDA nor NMDA receptors. Non-NMDA response was slightly inhibited by 100 mM ethanol, while NMDA response was selectively inhibited by lower concentrations (10-50 mM) of ethanol. Crocin (10 microM) did not affect the inhibition of non-NMDA response by 100 mM ethanol, but significantly blocked the inhibition of NMDA response by 10-50 mM ethanol. In addition, we performed whole-cell patch recording with primary cultured rat hippocampal neurons, and confirmed that crocin blocked ethanol inhibition of inward currents evoked by application of NMDA. These results suggest that crocin specifically antagonizes the inhibitory effect of ethanol on NMDA receptor-mediated responses in hippocampal neurons.

Animals↗

PubMed1998

Association study of a functional catechol-O-methyltransferase gene polymorphism in Japanese schizophrenics.

Catechol-O-methyltransferase (COMT) is an enzyme which inactivates catecholamine neurotransmitters by methylation, and is considered a candidate for involvement in schizophrenia. A functional COMT gene polymorphism influencing the enzyme activities, the high activity (val-108) and the low activity allele (met-108), was recently confirmed. We investigated a genetic association between schizophrenia and the COMT gene polymorphism in 150 Japanese schizophrenics and controls. We detected the low activity met-108 allele more frequently in schizophrenics than in the controls, and found that subjects sharing the met-108 allele (val/met and met/met) are significantly more common in the patients than in the controls. The results suggest that the low activity met-108 allele may be involved in susceptibility for schizophrenia.

Alleles↗

PubMed1998

Origin and mechanism of formation of 45,X/47,XX,+21 mosaicism in a fetus.

Chromosome analysis of amniotic fluid cells from a 17-week-old fetus with a nuchal cystic hygroma showed a 45,X/47,XX,+21 karyotype. Analyses of cord blood lymphocytes, skin fibroblasts, amniotic membrane, and chorionic villi demonstrated both cell lines in various proportions. We studied the origin and mechanism of formation of the double mosaic aneuploid using Q-banded chromosomal heteromorphisms, and one RFLP, two VNTRs, one tetranucleotide repeat, 28 CA repeat markers, mapped to every member of chromosomes. The heteromorphic markers examined showed no discordant patterns in parent-to-child transmission or between the two cell lines except for those in chromosomes 21 and X. Fetal DNA was extracted from its established monoclonal fibroblast cell lines with 45,X or 47,XX,+21 karyotypes. Genotyping with the DNA markers showed that each cell line was identical at every locus, except for chromosome 21 or X loci, indicating that the fetus was not a chimera but a mosaic. The 21-trisomic cells had one paternal allele and two maternal heterozygous alleles at the D21S270 locus, and the 45,X (21-disomic) cells had two biparental alleles. Alleles at two X chromosomal loci, DXS991 and DXS8057, were biparental in the 47,XX,+21 cells, whereas only the paternal allele was retained in the 45,X cells. Based on these findings, we concluded that the fetus started as a 47,XX,+21 zygote that had resulted from nondisjunction at the maternal first meiotic division and that one each of the maternally derived chromosomes 21 and X was lost during an early mitotic division, leading to the mosaicism.

Alleles↗

PubMed1998

Systemic administration of interleukin-12 can restore the anti-tumor potential of B16 melanoma-draining lymph node cells impaired at a late tumor-bearing state.

We investigated the effect of the systemic administration of interleukin (IL)-12 on the anti-tumor potential of tumor-draining lymph nodes (LNs). Tumor-draining LN cells on day 10 after s.c. inoculation of B16 melanoma showed a significant anti-tumor effect against established pulmonary metastases after in vitro expansion, whereas those on either day 20 or 30 exhibited an impaired anti-tumor potential. However, i.p. injections of IL-12 (0.5 microg) on days 18, 20 and 22 significantly increased the total number of tumor-draining LN cells on day 24 and, furthermore, restored their anti-tumor potential after in vitro expansion. In addition, i.p. injection of IL-12 (0.1 microg) on days 20, 22, 24, 26 and 28 significantly suppressed the growth of s.c.-inoculated B16 melanoma and finally cured the tumors in 6 of 12 mice (50%), whereas dissection of the tumor-draining LNs on day 18, prior to the IL-12 treatment, decreased both the IL-12-induced anti-tumor effect and the percentage of cured mice (8.3%). Cured mice acquired a specific protective immunity. Collectively, our results indicate that the systemic administration of IL-12 can restore the immunotherapeutic potential of tumor-draining LNs, which was impaired at the late tumor-bearing state, and that the IL-12-induced systemic anti-tumor activity is preceded by the restoration of an anti-tumor response in tumor-draining LNs.

Animals↗

PubMed1998

Effects of Microwave Heating on the Loss of Vitamin B(12) in Foods.

To clarify the effects of microwave heating on the loss of vitamin B(12) in foods, raw beef, pork, and milk were treated by microwave heating and then their vitamin B(12) contents were determined according to a chemiluminescent vitamin B(12) assay with hog intrinsic factor. Appreciable loss ( approximately 30-40%) of vitamin B(12) occurred in the foods during microwave heating due to the degradation of vitamin B(12) molecule by microwave heating. When hydroxo vitamin B(12), which predominates in foods, was treated by microwave heating and then analyzed by silica gel 60 thin layer chromatography, two vitamin B(12) degradation products were found. One of the compounds with a R(f)() of 0.16 was purified and partially characterized. The vitamin B(12) degradation product did not show any biological activity in the growth of a vitamin B(12) requiring microorganism, Euglena gracilis Z, and was not bound to hog intrinsic factor, a mammalian vitamin B(12) binding protein. Intravenous administration of the compound (1 µg/day) for 7 days to rats showed that the compound neither has toxicity nor acts as a vitamin B(12) antagonist in mammals. These results indicate that the conversion of vitamin B(12) to the inactive vitamin B(12) degradation products occurs in foods during microwave heating.

Journal Article↗

PubMed1998

Effects of polyelectrolyte complex (PEC) on human periodontal ligament fibroblast (HPLF) function. I. Three-dimensional structure of HPLF cultured on PEC.

Human periodontal ligament fibroblast (HPLF) cultured on tissue culture dishes (TCD), irrespective of the presence of serum, showed only a spreading form. In contrast, using polyelectrolyte complex (PEC) as a matrix, HPLF showed spreading, round, and aggregate forms. Cells of the inner part of the aggregate contacted with each other to form a three-dimensional structure, and this condition corresponded to typical tissues in vivo. These seemed to be related to the interrelation between growth and morphology; that is, the HPLF of the spreading form was considered to belong to a proliferation phase, and the HPLF of the round and aggregate forms, with a little growth, seemed to belong to a functional phase of the cell cycle, indicating that PEC is able to control such cell functions as proliferation, morphology, and differentiation. The cell aggregate was observed only on PEC with carboxymethyl residues and was stained by alizarin red (AR), which suggested mineralization. The spreading cells on PEC containing sulfate residues were not stained by AR. Therefore, it was found that there was a certain relationship between cell growth and morphology, and that PEC affected the cell cycle and promoted proliferation and differentiation of HPLF.

Biocompatible Materials↗

PubMed1998

Effects of polyelectrolyte complex (PEC) on human periodontal ligament fibroblast (HPLF) function. II. Enhancement of HPLF differentiation and aggregation on PEC by L-ascorbic acid and dexamethasone.

In addition to many types of extra cellular matrix (ECM) in vivo, cells are stimulated by many types of vitamins, hormones, growth factors, etc. In this paper the effects of L-ascorbic acid 2-phosphate (Asc-2P) and dexamethasone (Dex) on proliferation and differentiation of human periodontal ligament fibroblast (HPLF) using polyelectrolyte complex (PEC) as a matrix in vitro will be discussed. The PEC was composed of chitosan as a polycation, with carboxymethyl (CPEC) or sulfated chitin (SPEC). Asc-2P (0.2 mM) inhibited the growth of HPLF on CPEC, but promoted the growth on SPEC. Moreover, the aggregation of HPLF on CPEC was inhibited by Asc-2P, but that on SPEC was induced in the presence of Asc-2P and Dex. Although Asc-2P reduced an increase in alkaline phosphatase (ALPase) activity of HPLF on CPEC as well, it induced a twofold increase in ALPase activities on SPEC and TCD. Furthermore, in the medium containing Asc-2P and 100 mM of Dex, cell growth was inhibited, but ALPase activity was promoted on both SPEC and TCD to form many aggregates on SPEC. ALPase activity increased by twofold over that of HPLF cultured in the medium containing only Asc-2P. Therefore, it is suggested that the cell functions of HPLF are controlled by the combination of PEC and additives.

Alkaline Phosphatase↗

PubMed1998

Apoptosis of lymphocytes induced by glucocorticoids and relationship to therapeutic efficacy in patients with systemic lupus erythematosus.

OBJECTIVE: Glucocorticoids (GCs) are the drugs of first choice for treatment of systemic lupus erythematosus (SLE). However, the disease in some patients is resistant to these agents. This study evaluated the possibility of a relationship between response to GC treatment and the rate of apoptosis in vitro, and also analyzed Bcl-2 and Fas expression on peripheral blood mononuclear cells (PBMC) from patients with SLE in relation to GC-induced apoptosis. METHODS: Twenty-seven SLE patients and 13 normal controls were studied. Disease activity scores were determined before and after treatment and used to divide patients into 2 groups: GC-resistant and GC-responsive. Isolated PBMC were stimulated with anti-CD3 monoclonal antibodies, cultured with various concentrations of GC, and analyzed by alamar blue assay to determine the LC50, defined as the concentration of GC lethal to 50% of the cells. We measured the expression of CD4, CD8, Fas, and Bcl-2 by FACStar plus flow cytometry. RESULTS: Lymphocytes in the GC-resistant group of SLE patients showed a significantly lower percentage of GC-induced apoptotic cells than did lymphocytes from the responsive group or from normal controls. The LC50 in the resistant group was significantly higher than that in normal controls or the responsive group. The lymphocytes remaining in the resistant group after GC treatment were mainly CD8+, with a high expression of Bcl-2. There was no significant difference in Fas expression between the GC-responsive and GC-resistant groups. CONCLUSION: Determination of the LC50 may be useful in predicting the efficacy of GC treatment in SLE patients, and may be of use in considering other treatment options. CD8 and Bcl-2 double-positive lymphocytes that are insensitive to the apoptotic effect of GCs may play a role in the resistance to these agents in SLE patients.

Adolescent↗

PubMed1998

Accumulation of human T lymphotropic virus type I-infected T cells in the salivary glands of patients with human T lymphotropic virus type I-associated Sjögren's syndrome.

OBJECTIVE: To clarify the involvement of human T lymphotropic virus type I (HTLV-I) in the pathogenesis of Sjogren's syndrome (SS). METHODS: In HTLV-I-seropositive patients with SS, HTLV-I proviral DNA in the labial salivary glands (SG) was detected by polymerase chain reaction (PCR) amplification of the extracted cellular DNA, and the localization in the SG was examined by in situ PCR hybridization. RESULTS: The cellular DNA extracted from the SG contained full HTLV-I proviral DNA, which was present in the nucleus of the infiltrating T cells, but not in either the SG epithelial cells or the acinar cells. Furthermore, the viral loads in the SG were approximately 8 times to 9 x 10(3) times higher than those in the peripheral blood mononuclear cells. CONCLUSION: Accumulation of HTLV-I-infected T cells in the SG suggests that HTLV-I likely causes the self-reactive T cells to proliferate, which, as a result, induces SS.

Adult↗

PubMed1998

Longitudinal study of cerebrospinal fluid levels of tau, A beta1-40, and A beta1-42(43) in Alzheimer's disease: a study in Japan.

To clarify the alterations of tau, amyloid beta protein (A beta) 1-40 and A beta1-42(43) in the cerebrospinal fluid (CSF) that accompany normal aging and the progression of Alzheimer's disease (AD), CSF samples of 93 AD patients, 32 longitudinal subjects among these 93 AD patients, 33 patients with non-AD dementia, 56 with other neurological diseases, and 54 normal control subjects from three independent institutes were analyzed by sensitive enzyme-linked immunosorbent assays. Although the tau levels increased with aging, a significant elevation of tau and a correlation between the tau levels and the clinical progression were observed in the AD patients. A significant decrease of the A beta1-42(43) levels and a significant increase of the ratio of A beta1-40 to A beta1-42(43) were observed in the AD patients. The longitudinal AD study showed continuous low A beta1-42(43) levels and an increase of the ratio of A beta1-40 to A beta1-42(43) before the onset of AD. These findings suggest that CSF tau may increase with the clinical progression of dementia and that the alteration of the CSF level of A beta1-42(43) and the ratio of A beta1-40 to A beta1-42(43) may start at early stages in AD. The assays of CSF tau, A beta1-40, and A beta1-42(43) provided efficient diagnostic sensitivity (71%) and specificity (83%) by using the production of tau levels and the ratio of A beta1-40 to A beta1-42(43), and an improvement in sensitivity (to 91%) was obtained in the longitudinal evaluation.

Aged↗

PubMed1998

In situ detection of hepatitis B, C, and G virus nucleic acids in human hepatocellular carcinoma tissues from different geographic regions.

We performed a retrospective study to determine the prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis G virus (HGV) genomes in formalin-fixed, paraffin-embedded liver tissues from hepatocellular carcinoma (HCC) patients in various geographic areas. The prevalence of each hepatitis virus in the liver tissues that have both carcinoma and noncarcinoma regions was different among the countries. HCV was the most prevalent in Japan (75 of 122 [61.5%]), Spain (9 of 15 [60%]), and the United States (27 of 65 [41.5%]); HBV was the most prevalent in Korea (45 of 55 [82%]) and among Japanese Americans in Hawaii (4 of 8 [50%]). Genotype II/1b was the most common genotype of HCV encountered in HCCs in these countries. In contrast, HGV RNA was undetectable in all tested HCCs. "Cryptogenic HCC," defined as HCC of unknown etiology, was seen 4 (3%) and 4 (6.2%) of Japanese and American patients, respectively, but this was not found in other countries. Interestingly, patients with HCC related to primary biliary cirrhosis (4.6%), who were excluded from analysis as hepatitis virus infections, were present only in the United States, but not in other countries. This study suggests that HCV, particularly genotype II/1b, and HBV may play an important role in hepatocarcinogenesis in these countries. There was no evidence of any relation between HGV infection and development of HCC.

Adult↗

PubMed1998

Gravimorphism in rice and barley: promotion of leaf elongation by vertical inversion in agravitropically growing plants.

We have compared shoot responses of agravitropic rice and barley plants to vertical inversion with those of normal ones. When rice plants were vertically inverted, the main stems of a japonica type of rice, cv. Kamenoo, showed negative gravitropism at nodes 2-15 of both elongated and non-elongated internodes. However, shoots of lazy line of rice, lazy-Kamenoo, bent gravitropically at nodes 11-15 only elongated internodes but not at nodes 2-10 of non-elongated ones. Thus, shoots of Kamenoo responded gravitropically at all stages of growth, whereas shoots of lazy-Kamenoo did not show gravitropic response before heading. In Kamenoo plants, lengths of both leaf-sheath and leaf-blade were shortened by vertical inversion, but those of the vertically inverted plants of lazy-Kamenoo were significantly longer than the plants in an upright position. When agravitropic and normal plants of barley were vertically inverted, the same results as in rice were obtained; elongation of both leaf-sheath and leaf-blade was inhibited in normal barley plants, Chikurin-Ibaragi No. 1, but significantly stimulated in agravitropic plants of serpentina barley. These results suggest that vertical inversion of rice and barley plants enhances the elongation growth of leaves in the absence of tropistic response.

Genes, Plant↗

PubMed1998

Potential for qualitative diagnosis of tumors and tumorous lesions in the liver with Tc-99m-GSA SPECT--correlation with pathological evaluation and MRI findings.

To evaluate the effect of technetium-99m-labeled DTPA-galactosyl human serum albumin (Tc-99m-GSA) SPECT imaging for qualitative diagnosis of hepatic lesions. The subjects were 29 patients with pathologically confirmed hepatic lesions (21 malignant and 8 benign lesions). SPECT data were obtained at about 30 minutes after injecting 185 MBq (5 mCi) of Tc-99m-GSA. The GSA SPECT findings were compared with those of pathological evaluation and T2-weighted MR images (T2WI). Of 29 lesions, 17 showed decreased accumulation, and three exhibited increased accumulation. The other nine lesions were undetectable. The malignant lesions which showed increased accumulation were all well differentiated hepatocellular carcinomas (HCCs). One of the eight benign lesions exhibited increased accumulation. The three lesions which showed increased accumulation of GSA exhibited hypointensity on T2WI, whereas the malignant lesions which showed decreased accumulation of GSA exhibited hyperintensity on T2WI. The GSA SPECT findings correlate well with those of T2WI. GSA SPECT may be useful for qualitative diagnosis of focal liver lesions. If a lesion is suspected of being HCC, increased accumulation may indicate well differentiated HCC.

Adenocarcinoma↗

PubMed1998

[Three cases of right-sided active endocarditis with multiple pulmonary infarction].

We have experienced three patients with right-sided active endocarditis combined with multiple pulmonary infarction. Ventricular septal defect (VSD), aortic regurgitation (AR), tricuspid regurgitation (TR) and congestive heart failure were present in case 1. TR was present in case 2. VSD, TR and patent ductus arteriosus were present in case 3. alpha-Streptococcus caused endocarditis in case 1 and 3; Candida albicans caused endocarditis in case 2. Antibotic therapy had no effect in case 2 and 3. Case 1 and 3 developed pulmonary hemorrhage, which resolved before the operation in case 1, but not in case 3. Our three patients underwent surgery and recovered successfully. They were discharged on the 43th, 58th and 32th postoperative day and are presently free of clinical symptoms. These experiences suggest surgery should be undertaken in the following situations: 1. antibiotic therapy has no effect on the infection, 2. hemodynamics are worsening, and 3, pulmonary infarction and pulmonary hemorrhage occur repeatedly.

Aged↗

PubMed1998

[Case report of surgical repair of left ventricular free wall rupture using GRF glue and pericardial patch].

A 73-year-old woman with acute myocardial infarction (Seg. 6: 100%) was admitted to our hospital. She underwent percutaneous transluminal angioplasty (PTCA) and stent insertion to Seg. 6 on that day and anticoagulant therapy with urokinase and heparin was started in CCU. On the 4th day, chest pain developed suddenly and echocardiography revealed cardiac tamponade, so we suspected left ventricular free wall rupture. When blood pressure increased to 100 mmHg in the operating room, the left ventricular free wall rupture became "blow out" type. After establishing extracorporeal circulation, we glued Xenomedica and autologous pericardium using gelatin-resorcin-formaldehyde glue (GRF glue) to the linear tear without damaging the myocardium and coronary arteries and reducing left ventricular volume. Bleeding was completely controlled. This experience suggests that this procedure might be effective for left ventricular free wall rupture.

Aged↗

PubMed1998

Immunological competence and nutritional status in patients with lung cancer.

The rate of infection in patients with malignant disease is significantly higher than in patients with benign disease. To investigate whether immunological competence is impaired in patients with lung cancer, we assessed neutrophil function (chemotaxis, phagocytosis, bacterial killing activity, and superoxide production), monocyte function (phagocytosis and killing activity), lymphocyte subsets using flow cytometry, and proliferation of lymphocytes stimulated by phytohemagglutinin, concanavalin A, and pokeweed mitogen. Studies were performed on 22 untreated patients with lung cancer and 21 age-matched healthy volunteers. Nutritional status was assessed by Niederman's nutritional index. In patients with lung cancer neutrophil chemotaxis, monocyte phagocytosis and killing, proliferation of lymphocytes stimulated by phytohemagglutinin and concanavalin A, but not pokeweed mitogen, and the number of natural killer cells were significantly lower than in healthy volunteers, whereas gammadelta T cells were increased (p < 0.05). The mean score on Niederman's nutritional index was worse in patients than in healthy volunteers (p < 0.001). Our results suggest that the impaired immunological competence and undernutrition may be among the mechanisms causing increased susceptibility to infection in patients with lung cancer.

Adenocarcinoma↗

PubMed1998

An active metabolite of carbamazepine, carbamazepine-10,11-epoxide, inhibits ion channel-mediated catecholamine secretion in cultured bovine adrenal medullary cells.

We have recently reported inhibitory effects of carbamazepine (CBZ) on ion channel-mediated secretion of catecholamines in bovine adrenal medullary cells. Here, we report the effects of carbamazepine-10,11-epoxide (CBZ-E), an active metabolite of CBZ, and carbamazepine-10,11-diol (CBZ-D), a non-active metabolite, on 22Na+ influx, 45Ca2+ influx and catecholamine secretion in cultured adrenal medullary cells. CBZ-E, but not CBZ-D inhibited 22Na+ influx, 45Ca2+ influx and catecholamine secretion induced by carbachol or veratridine with a half-maximal inhibitory concentration (IC50) of 0.26 or 0.68 microg/ml, respectively. CBZ-E also inhibited high K+-evoked 45Ca2+ influx and catecholamine secretion (IC50 = 0.3 microg/ml), but CBZ-D did not. These findings suggest that CBZ-E, but not CBZ-D, attenuates catecholamine secretion by inhibiting nicotinic acetylcholine receptor-associated ion channels, voltage-dependent Na+ channels and voltage-dependent Ca2+ channels in the cells. This inhibition of CBZ-E as well as CBZ may be related to the clinical effects in neuropsychiatric disorders.

Adrenal Medulla↗

PubMed1998

Sigmoidal curve shift in idiopathic hypoparathyroidism and pseudohypoparathyroidism.

The sigmoidal curves plotting serum parathyroid hormone (PTH) against serum Ca in primary hyperparathyroidism and secondary hyperparathyroidism due to renal failure deviate to the right. We previously found the leftward curve shift in PTH-deficient hypoparathyroidism. In the present study, we investigated the curve shift in pseudohypoparathyroidism (PHP) with secondary hyperparathyroidism due to target organ resistance to PTH. In renal failure the sigmoidal curves move to the left after vitamin D3 treatment. We also examined the effect of vitamin D3 on the curve shift in pseudohypoparathyroidism (PHP) and idiopathic hypoparathyroidism (IHP). Before vitamin D3 treatment, the sigmoidal curve deviated to the left in both types of hypoparathyroidism. After vitamin D3 treatment it moved to the right. These results indicate that vitamin D3 and/or extracellular Ca modify the relationship between PTH and Ca dynamics even in hypoparathyroid disorders with decreased or increased maximum serum PTH. Following vitamin D3 treatment, the point plotting baseline serum PTH against baseline serum Ca moved to the right at first in accordance with the rightward shift of the sigmoidal curve and then the point moved downward in PHP or downward in IHP. These changes suggest that vitamin D3 resets PTH secretion at a higher extracellular Ca level at first and then suppresses it in a time-dependent manner. 1, 25(OH)2D3 and/or extracellular Ca may be the determinant factors of the sigmoidal curve shift in hypoparathyroid disorders. Mechanisms other than the Ca sensing system error may contribute to the curve shift.

Adult↗