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Biomedical subjects

N Okamoto

Publications and source records attributed to N Okamoto.

At least 235 records · Page 13Linked to original sources
PubMed1992

Molecular heterogeneity of beta-thalassemia in Thailand.

beta-Globin genes in 294 chromosomes of beta-thalassemia homozygotes and patients of beta-thalassemia/HbE in the northeast, the middle and the south of Thailand were analyzed by the PCR related techniques: dot blot hybridization, direct restriction assay, direct cloning and direct sequencing of the amplified DNA fragments. Twelve different mutations were detected at various frequencies. They are an A-G at-28, codon 19 (AAC-AGC), a G-T at IVS-1 nt1,a G-C at IVS-1 nt5, a C-T at IVS-2 nt654, a G addition in codons 8/9, a C deletion in codon 41, a 4 bp deletion in codons 41/42, an A addition in codons 71/72, an AAG-TAG in codon 17, a CAG-TAG in codon 26, a TAC-TAA in codon 35 and a 8 bp deletion in codons 123-125. We also developed allele specific-polymerase chain reaction to facilitate non-radioactive detection of the mutation. Origins and spread of mutations are speculated based on the results of determination of haplotypes and frameworks that are linked to the thalassemia alleles.

Base Sequence↗
PubMed1992

[The study on intravesical instillation of THP in the treatment of in-situ and superficial bladder cancers].

The efficacy and safety of Pirarubicin (THP), administered by intravesical instillation, have been studied in recurrent multiple superficial bladder cancer patients and patients who tested positive by urine cytology but lacked protuberant legions (CIS). The average age and range of the 19 patients (M 15, F4) studied were 63.3 (37-84). Twelve patients had protuberant, multiple cancer and 7 patients had CIS. Sixteen of the cases were recurrent disease. Twenty mg THP, delufed in 40 ml of 5% glucose solution were instilled for 2 hours once or twice a week. Each patients received 8 treatments. One week after the last treatment, the therapeutic result was evaluated on the bases of cystoscopy and urine cytology. Before and after administration, CBC and biochemical blood tests were run. Nine of the 12 patients (75%) with multiple recurrent tumor and all the 7 patients with CIS showed complete response. The total outcome for CR was 84.2% in this study. Intravesical instillation with THP did not cause any serious side effects.

Administration, Intravesical↗
PubMed1991

In vitro uptake of bromodeoxyuridine by human hepatocellular carcinoma and its relation to histopathologic findings and biologic behavior.

The in vitro uptake of bromodeoxyuridine (BrdU) by hepatocellular carcinoma (HCC) cells was studied in 30 hepatectomized patients. Labeling of the nuclei by BrdU expressed as labeling index (LI) was 5.6 +/- 3.2% (mean +/- standard deviation), with a considerable variation from case to case. The mean LI in Grade III to IV cancers (less differentiated, by Edmondson and Steiner's classification, 11.1 +/- 2.1%) was significantly larger (P less than 0.001) than that in Grade I to II cancers (more differentiated, 4.5 +/- 2.0%). Capsule formation was found in all 17 patients except one (94%) with a low DNA synthetic HCC (LI less than 6.0%) compared with seven of 13 (54%) with a high DNA synthetic HCC (LI greater than or equal to 6.0%, P less than 0.02). The 2-year survival rate after surgery was significantly higher (P less than 0.02), and intrahepatic metastasis was significantly less (P less than 0.05) in the former group than in the latter. The BrdU LI of HCC tumors showed a strong correlation with histopathologic findings and the biologic behavior of HCC.

Adult↗
PubMed1991

Complete primary structure of human collagen alpha 1 (V) chain.

Several cDNA clones, encoding prepropeptide of human collagen alpha 1(V) chain, have been isolated. The prepropeptide (1838 amino acids length) of the alpha 1(V) chain was composed of a putative signal peptide, a large NH2-terminal noncollagenous region, a main collagenous region, and a COOH-terminal noncollagenous region. The signal peptide contained many leucine residues. The NH2-terminal noncollagenous region was much larger than those of the other collagens and had a region homologous to the COOH-terminal domain of laminin A chain, but it did not contain a cysteine-rich region that was maintained in the region of the other collagens. This region also contained probable tyrosine sulfation sites, and short collagenous sequences that were interrupted by three noncollagenous segments. The main collagenous region of the alpha 1(V) chain consisted of 338 repeats of Gly-X-Y-triplet. This region had a high degree (82%) of homology with the amino acids of the collagen alpha 1(XI) chain. The COOH-terminal noncollagenous region resembled that of the alpha 1(XI) chain, too, and 8 residues of cysteine that were important for the formation of the triple helix structure of collagens were observed. These results suggest that the alpha 1(V) chain belongs to the fibrillar collagen relative to the alpha 1(XI) chain, but codon usage of the alpha 1(V) cDNA was clearly different from those of the other fibrillar collagens including the alpha 1(XI), while it was similar to type IV collagen. This result supposes a different evolution of the alpha 1(V) gene from those of the other fibrillar collagens.

Amino Acid Sequence↗
PubMed1991

Abnormal development of cardiovascular systems in rat embryos treated with bisdiamine.

Administration of N,N'-bis(dichloroacetyl)-1,8-octamethylenediamine, bisdiamine, in pregnant Donryu rats on day 10 of gestation induces a high incidence of cardiovascular anomalies in fetuses. Bisdiamine administration induced aplasia of the sixth aortic arch artery, with both the right and left primitive pulmonary arteries being directly linked to the truncus, and resulting in four types of malformation of pulmonary arteries (PAs). When two primitive PAs shared a single root, the consequence was either pulmonary trunk hypoplasia, as is seen in tetralogy of Fallot, or type I persistent truncus arteriosus (PTA) as classified by Collet and Edwards. When root portions of two PAs did not fuse, either type II or type III PTA resulted. In controls, the right dorsal aorta (DA) between the right seventh intersegmental artery (IA) and the site where both DAs fuse degenerated and the left aortic arch (AA) and the right subclavian artery (SA) were formed. Bisdiamine administration induced two additional types of vascular anomalies. In one of these, the right DA between the right 4AA and the right 7IA degenerated and a left AA accompanied by an aberrant right SA resulted. In the other type, the left DA between the left 4AA and the left 7IA degenerated and a right AA accompanied by an aberrant left SA resulted. These results indicate that administration of bisdiamine induces malformation in the great blood vessels by disturbing persistency and degeneration of aortic arch arteries and DAs.

Abnormalities, Drug-Induced↗
PubMed1991

Lymphocytes stimulate progesterone production by cultured human granulosa luteal cells.

After follicular rupture, massive invasion of blood vessels with neovascularization of the developing corpus luteum takes place, providing many chances for direct contact of luteal cells with resident and migrating immune cells. We studied the effects of peripheral blood lymphocytes on progesterone production by human granulosa luteal cells isolated from women undergoing in vitro fertilization. During 6 days of culture, progesterone production by granulosa luteal cells was significantly increased when they were cultured together with autologous or allogenic peripheral blood lymphocytes. This stimulatory effect was also observed on the addition of medium conditioned with peripheral blood lymphocytes and was synergistic with gonadotropin stimulation. The activity was present in the fraction retained by ultrafiltration with a 30,000 molecular weight cutoff filter and was preserved after heating at 56 degrees C for 30 minutes but disappeared after heating at 70 degrees C for 15 minutes. These findings suggest that lymphocytes infiltrating the corpus luteum during early luteinization can stimulate the function of human granulosa luteal cells through the action of some protein-like humoral factor(s) of higher molecular weight than that of previously identified lymphokines and indicate a possible paracrinologic regulatory role for lymphocytes in ovarian function.

Cells, Cultured↗
PubMed1991

Orientation of HLA-DNA gene and identification of a CpG island-associated gene adjacent to DNA in human major histocompatibility complex class II region.

We have constructed the detailed physical map of the HLA class II gene region by the pulsed field gel electrophoresis (PFGE) and cosmid walking technique. In this process, the DNA gene was found to be located telomeric to DPA1 with the 5'----3' orientation which is the same as the DPA1 and DPA2 genes, but opposite to the DQA1, DQA2 and DRA genes. This orientation is reverse to that of the counterpart gene in the rabbit major histocompatibility complex region. About 30 kb downstream from the DNA gene towards DOB, a CpG island characterized by clustered sites for rare cutting restriction enzymes and frequently associated with the 5' end of housekeeping genes was identified by PFGE and cosmid walking. From a complementary DNA (cDNA) library constructed from a Epstein-Barr virus-transformed B-cell line, a cDNA clone was isolated using the genetic probe from this CpG island. Its nucleotide sequences suggested that it represented a new non-HLA gene with a single copy which was of little genetic polymorphism and named NAT (DNA-associated transcript). Northern blot analysis showed that the NAT gene was expressed with a 4-kb transcript in all of tissues examined so far.

Base Sequence↗
PubMed1991

Induced microseizures in West syndrome.

Induced microseizures (IMS) were observed in a 5-month-old girl with symptomatic West syndrome. The seizures occurred following the suppression of infantile spasms with adrenocorticotropic hormone therapy and disappeared following the cessation of clonazepam administration. The ictal manifestations consisted of periods of irregular respiration, and respiratory arrest lasting for several seconds which often involved opening of the eyes and mild extension of the neck corresponding with the diffuse fast wave bursts in EEG activity observed during sleep. These seizures were thought to be equivalent to the IMS in Lennox-Gastaut syndrome, which have never been reported before in patients with West syndrome.

Adrenocorticotropic Hormone↗
PubMed1991

Lysis of fresh human tumor cells by autologous peripheral blood lymphocytes and tumor-infiltrating lymphocytes activated by PSK.

The protein-bound polysaccharide PSK was tested for the ability to induce in vitro autologous tumor killing (ATK) activity in human cancer patients. Peripheral blood lymphocytes (PBL) and tumor-infiltrating lymphocytes (TIL) demonstrated various levels of cytotoxicity against autologous, freshly isolated tumor cells. When PBL and TIL were cultured overnight with PSK, ATK activity was induced in previously non-reactive cases and augmented in previously reactive samples. The PSK effect was observed with PSK concentrations of 10-100 micrograms/ml that could be obtained in the blood of cancer patients who received standard oral administration of PSK. The manifestation of PSK-induced ATK required active cell metabolism and RNA and protein syntheses, but not DNA synthesis of lymphocytes. PSK-induced enhancement of ATK was not abrogated by monoclonal antibodies (mAb) directed against interferon (IFN) alpha or IFN gamma. In addition, mAb that neutralized interleukin-2 (IL-2) or mAb reactive with alpha-chain or beta-chain of IL-2 receptors (IL-2R) had no effect on PSK-induced ATK activity. Supernatants from PSK-stimulated lymphocyte cultures did not induce ATK. Cell fractionation experiments revealed that CD3-CD16+ large granular lymphocytes (LGL) and/or CD3+CD16- T lymphocytes were responsible for both spontaneous and PSK-induced ATK. PSK-activated LGL, but not T lymphocytes expressed lysis of fresh allogeneic tumor cells. These results indicate that PSK activates PBL and TIL to exhibit ATK independently of IL-2/IL-2R systems.

Adult↗
PubMed1991

Suppression by human placental protein 14 of natural killer cell activity.

Human decidua of early pregnancy contains considerable numbers of CD3-CD56+ natural killer (NK) cells. In this study, two major protein products of the decidua, placental protein 14 (PP14) and placental protein 12 (PP12), were tested for the ability to regulate human NK cell activity. In vitro overnight exposure to PP14 of blood lymphocytes or purified large granular lymphocytes (LGL) resulted in suppression of cytotoxicity against K562 target cells in a 4-h 51Cr release assay. The NK inhibition was dependent on concentrations of PP14, being detectable at 5 micrograms/ml and reaching maximum at 50 micrograms/ml. Manifestation of PP14-induced NK suppression required 18-h contact with NK cells. The suppression of NK activity by PP14 was not abolished by indomethacin. In a target binding assay the number of PP14-treated LGL binding to K562 was comparable to that of untreated ones. By contrast with PP14, PP12 produced no effects on NK cells. These results indicate that PP14 suppresses the function of NK cells, which might be involved in prevention of maternal immune rejection of fetus at the fetomaternal interface.

Cells, Cultured↗
PubMed1991

[Risk of hepatitis C virus infection by needlestick among medical employees].

We have experienced 99 medical employees who had stuck themselves by the needles used by patients in the past 5 years. Sixteen of the 99 cases (16.2%) were of the patients who had hepatitis C Virus (HCV) antibodies. We followed up these 16 medical employees during 24.8 +/- 12.0 months. We could not find any case among them who had seroconverted HCV antibody positive in their serums. We concluded that the risk of HCV infection by the needlestick accident is not so high.

Adult↗
PubMed1991

Highly effective extraction of carcinoembryonic antigen with phosphatidylinositol-specific phospholipase C.

Carcinoembryonic antigen (CEA) was highly effectively extracted with phosphatidylinositol-specific phospholipase C (PI-PLC) from various source materials. The yield of CEA was, in some cases, 20-30 times more than that obtained by the usual method with perchloric acid. Addition of 0.1-0.2 units of PI-PLC to 1 g tumor tissue and incubation at 37 degrees C for 1 h with continuous shaking seem to be practically sufficient for CEA extraction. A simple purification procedure for CEA after extraction with PI-PLC is proposed. The immunochemical properties of CEA thus obtained were found to be identical to those of CEA obtained by the usual method.

Adult↗
PubMed1991

Interleukin-1 inhibits in vitro decidualization of human endometrial stromal cells.

Interleukin-1 (IL-1), a critical cytokine for the initiation of the immune response to infection or antigenic challenge, is known to also possess a variety of biological functions outside the immune system. We examined whether IL-1 could affect the decidualization of human endometrial stromal cells (ESC), a conspicuous part in the process of implantation, by assessing PRL production and morphological transformation in an in vitro system. Purified human ESC were cultured in the presence of progesterone (P) with or without the addition of IL-1. IL-1 markedly suppressed the induction of PRL production by P in a dose-dependent manner. The morphological decidualization of ESC in response to P was also inhibited by IL-1. This report demonstrates for the first time the possibility that IL-1 blocks decidualization, the functional differentiation of human endometrial stromal cells in response to ovarian steroids.

Cell Count↗