Biomedical subjects
Publications and source records attributed to T Hongo.
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Of the cytochrome P450 (CYP) family of carcinogen-activating enzymes, CYP3A is the major form found in human livers. The purpose of this study was to investigate the cytotoxic effects of dental resin monomers after being metabolized by CYP3A4 and CYP3A7, using a colony formation assay and a neutral red assay. Specimen wells were plated with transfected cells derived from the Chinese hamster lung at 100 cells well(-1). The experimental group consisted of CYP-producing 3A4-10 and 3A7-40 cells, while the control group consisted of non-CYP-producing CR-119 cells. Bisphenol A (BPA) and bisphenol A glycidyl methacrylate (Bis-GMA) and a positive control (Aflatoxine Bl) were added separately to each well and cultured for 7 days. After cultivation, the number of the colonies was counted and IC50 values were determined. The data were statistically analysed by a Student's t-test. The resultant of IC50 values indicated that the monomers were not metabolically activated by CYP3A4 or CYP3A7 as compared with the control (P < 0.05). We also confirmed that these monomers act neither as activators nor as inhibitors of CYP3A4 and CYP3A7.
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This study analyzed data on 35 infants with acute myeloid leukemia (AML) who were treated with intensive chemotherapy between 1995 and 1998 in Japan. The incidence of boys, younger age (< 6 months old), and hyperleukocytosis at onset was high in patients with the M4/M5 subtype (n = 23) in the French-American-British classification, compared with the non-M4/M5 subtype (n = 12). Thirteen (56%) and 16 (70%) patients with the M4/M5 subtype also showed 11q23 translocations and MLL gene rearrangements, respectively, whereas only one patient with the non-M4/M5 subtype had this rearrangement. All 35 patients were treated with the ANLL91 protocol consisting of etoposide, high-dose cytarabine, and anthracyclines. Overall survival and the event-free survival (EFS) rates at 3 years of all patients were 76% (95% confidence interval [CI], 61.3%-90.7%) and 72% (95% CI, 56.4%-87.9%), respectively. EFS showed no significant difference between 2 subgroups divided by age, gender, presence of the MLL gene rearrangements, and white blood cell count at onset; EFS in patients with the M4/M5 subtype tended to be better than those with the non-M4/M5 subtype. Although all 6 patients who underwent allogeneic stem cell transplantation (SCT) have been in complete remission, no benefit of SCT was confirmed. These findings suggest that the intensive chemotherapy with the ANLL91 protocol might have been responsible for the observed good outcome of infant AML, even without SCT. The presence of the MLL gene rearrangements or the age at onset had no impact on the outcome of infant AML.
Tandem duplication (TD) of the MLL or FLT3 gene in acute myeloid leukemia (AML) has been reported. We examined whether TD of these two genes occurs simultaneously. We analyzed 13 AML and 2 myelodysplastic syndrome patients, including 6 adult patients with trisomy 11 and 9 pediatric patients with TD of the FLT3 gene, using RT-PCR followed by sequencing. Among these, TD of the MLL and FLT3 genes was found in 5 and 10 patients, respectively. Notably, TD of both the MLL and FLT3 genes (coduplication) was detected in two AML patients, who died 6 and 14 months after diagnosis. TD of these two genes in AML is rare; thus, coduplication of these genes in the same patient is predicted to be very rare. Although the mechanisms of TD of both genes are different, development of TD of both genes may be related to an unknown similar etiology in leukemia because the frequency of coduplication of these genes in a single patient is considered to be very low. Further studies of the coduplication of these genes in AML patients may lead to the clarification of its mechanism and clinical implications.
We assessed the in vitro chemosensitivity of acute erythroblastic and megakaryoblastic leukemia cells from children with Down syndrome (DS) compared to non-DS children. We conducted in vitro tests using the MTT assay of bone marrow samples from 12 children with DS and 16 children without DS. Patients were newly diagnosed based on the morphology and expression of platelet-specific antigens. Induction failure occurred more frequently in the non-DS group (n = 4) than in the DS group (n = 0, P = .053). Children with DS had a superior event-free survival (EFS) probability of 0.750 at 4 years, compared to an EFS probability of 0.375 for non-DS children (P = .049). Blast cells from DS patients were significantly more sensitive to daunorubicin, melphalan, mitoxantrone, 4-hydroperoxy-cyclophosphamide, vincristine, etoposide, bleomycin, and pirarubicin than those from non-DS patients. Four of the 16 non-DS patients were found to have acquired an extra chromosome 21 in their leukemia cells: blasts from these patients also tended to have greater chemosensitivity than those from patients without an extra chromosome 21. Blast cells from DS patients are markedly sensitive to various drugs. These results suggest that the fragility of blast cells derived from DS patients may be related to an increased susceptibility to apoptosis.
We describe the prevalence of community-acquired M. pneumoniae pneumonia diagnosed by culture methods in a single institute in Japan from January 1979 to December 1999. Cultures were performed in 2971 pneumonia cases and yielded M. Pneumoniae in 508 cases. The epidemic peaks recurred regularly at 4-year intervals (1980, 84, 88 and 91-2). Although a large epidemic has not occurred since 1992, traces of epidemic periodicity have still persisted from 1992 to 1999 at 3-year intervals.
We describe the successful treatment of a 20-year-old patient with chronic granulomatous disease (CGD), by unrelated bone marrow transplantation (UBMT). The patient is relatively old compared to other CGD patients treated with BMT. He had had repeated serious infections from early childhood and was diagnosed as CGD, gp91-phox deficiency. Prolonged antibiotic-resistant pneumonitis worsened when the patient was 18 years old. In addition, he suffered Aspergillus osteomyelitis and acute renal failure due to amphotericin B. He received 94 granulocyte transfusions from 94 adult donors and the infections gradually improved. In September 1998, at 20 years of age, he underwent UBMT from an HLA 6 antigen-matched male donor, with CY and TBI conditioning. He received MTX and CsA as prophylaxis against GVHD. No serious complications occurred and rapid engraftment was achieved. Acute GVHD (grade 2, at day 19) and chronic GVHD (limited, at day 192) occurred. However, both were easily controlled. The patient is alive and well with no late rejection 26 months after UBMT.
To determine the clinical relevance of in vitro drug chemoresistance in childhood acute myeloid leukemia, we used an MTT assay to test leukemic cells from 132 newly diagnosed children. Patients were diagnosed according to the French-American-British (FAB) classification as follows: M0 (n = 12), M1 (n = 16), M2 (n = 53), M4 (n = 17), M5 (n = 19) and M7 (n = 15). The results revealed that, compared to leukemic cells from complete-responders (n = 107), those from non-responders who failed induction therapy (n = 17) were 1.4 to 5.0 times more resistant in vitro to cytarabine (P = 0.005), melphalan (P = 0.003), etoposide (P = 0.011), L-asparaginase (P = 0.017), aclarubicin (P = 0.026) and dexamethasone (P = 0.039). For seven other drugs tested, the median lethal dose of 70% and leukemic cell survival of non-responders were higher than those of complete-responders, but the difference was not statistically significant. We sought correlations between FAB subtypes and in vitro drug resistance. Leukemias of the FAB M4 and M5 subtype were more sensitive to L-asparaginase (P = 0.01, P = 0.0036) than those of the FAB M2 subtype. FAB M5 leukemia was more sensitive to etoposide than were the FAB M2, M4 and M7 subtypes (P = 0.001, P = 0.034, P = 0.023, respectively). By contrast, FAB M5 leukemia was significantly more resistant to prednisolone and dexamethasone than were the FAB M0, M1, M2, M4 and M7 subtypes. We sought correlations between in vitro drug resistance and long-term clinical outcome, but found no associations in this case. These results suggest that in vitro resistance to cytarabine, melphalan, etoposide, L-asparaginase, aclarubicin and dexamethasone might represent factors that can predict response to the early course of therapy. Selecting an appropriate anti-cancer drug according to the FAB classification together with drug sensitivity testing may contribute to improved prognoses in childhood acute myeloid leukemia.
Sucrose-negative colonies were isolated on TCBS agar plate from otorrhea specimens from otitis media patient in the Adult Diseases Examination Center, Hirosaki Medical Association. The isolate was identified as Vibrio vulnificus by nested PCR method which amplify V. vulnificus-specific sequences directed against 23S rRNA genes. The PCR method was applied to identify 6 strains originally isolated from septicemia patients in Kurashiki Central Hospital and formerly identified as V. vulnificus by phenotypic characteristics. When examined by the API20E system, the above PCR confirmed-V. vulnificus isolates were correctly identified as V. vulnificus with % ID 99.8, though this gave 3 different profiles. Cytotoxin-hemolysin gene was detected in otorrhea strain as well as septicemia strains by PCR method. The above results suggest that PCR method targeted cytotoxin-hemolysin gene is suitable for rapid and accurate identification of the isolate, because the result is obtained in less than 4 h. To our knowledge this is the first report on the V. vulnificus infection in Aomori Prefecture and the isolation from otorrhea.
New antitumor agents must be added to the current neuroblastoma treatment regimens to improve the clinical results. We investigated whether recombinant human endostatin (rhEndostatin), an antiangiogenic agent, is effective against human neuroblastoma in the human neuroblastoma xenograft model designated TNB9. When tumors on the back of nude mice grew to a weight of 90-95 mg, rhEndostatin 10 mg/kg/day was administered subcutaneously every day for 10 consecutive days. Mean relative tumor weight in mice administered rhEndostatin (n=5) was significantly less than that in controls (n=12) on days 2, 4, and 6 after the start of administration (p<0.01 on day 2, p<0.05 on days 4 and 6), and regression of tumor growth (TRW<1.0) was marked on day 2. The maximum inhibition rate (MIR) by rhEndostatin was 46.4%, indicating inefficacy, but it may not be appropriate to apply Battelle Columbus Laboratories criteria to this experimental model because rhEndostatin is a protein. After day 8, tumors in the experimental group increased in weight and were not statistically significantly different from those in controls. Recombinant human endostatin was used in tumors in the arterial system of the mouse in this experiment because eventually rhEndostatin, not recombinant mouse endostatin, may be used to treat advanced neuroblastoma in the clinical setting. The results show that there is little cross-reactivity of rhEndostatin with the human and mouse models and indicate that rhEndostatin could become an effective agent for the treatment of human neuroblastoma.
The Japanese recommended dietary allowances (RDA) for major and some minor nutrients were revised in 1999, and included those for trace elements such as selenium. The requirement of selenium in animals was first recognized in 1957. It has been shown that cellular glutathione peroxidase (GPx) contains selenium but it was subsequently revealed that selenium has diverse biochemical effects, rather than simply functioning in the enzyme. At least twelve different selenoproteins have been identified. The role of selenium has been known as antioxidant, and non-antioxidant mediated through these enzymes. Now, selenium is well recognized as a preventive factor for cancer and cardiovascular diseases. Several dietary studies have shown that the selenium intake in Japan is adequate. One study estimated daily selenium intake to be 104.2 micrograms/day for adults. This value was 2 or 3 times higher than the lower limit of the safe range of dietary selenium (40 micrograms/day for men and 30 micrograms/day for women) estimated by WHO, and also exceeded the newly established RDA of 55-60 micrograms/day for men and 45 micrograms/day for women by the Japanese Public Health Council. However, the established RDA for selenium is tentative because of a lack of information on the 1) chemical forms of selenium in food, 2) differences in absorption rate and bio-availability in the chemical forms, and 3) interactions with other metals and trace elements. There are two potential problems concerning selenium nutrition in Japan. The first problem is that rice, which is the Japanese staple food, contains less than 0.05 microgram/g selenium whereas U.S. rice contains more than 0.3 microgram/g, probably due to differences in soil chemistry. The second problem is that although studies have shown that seafood, fish, shellfish and oysters, contain high levels of selenium (0.4-0.5 microgram/g), these being the main selenium source for Japanese, the bio-availability in fish is low. Thus, it is likely that the selenium status of those Japanese who eat an imbalanced diet is not sufficient or is not optimal even if the intake exceeds the RDA. Further studies are needed so that community health care specialists have available appropriate knowledge on the role of trace nutrients, including selenium, in human nutrition and health, to promote proper nutritional practices in the community.
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Four cultures of monkey kidney cell line, JTC-12, were flown on the Spacelab-J (SL-J) mission during 8 days. The results of the present study showed that the space flight gave no essential effect on morphology, cell cycle, glucose consumption and urokinase production of the mammalian culture cell. However, the cell proliferation slightly decreased under microgravity. Moreover, the lack of gravity induced the trypsin-treated dissociated cells to keep floating in the culture medium. Therefore, the attachment of the cells onto the substratum was delayed, and that caused difficulties in subculturing the cells. The present research also offered some important information on techniques for establishment of cell cultures in space laboratories.
Oocytes of the starfish, Asterina pectinifera, are arrested at the G2 phase of meiosis I and possess a prominent germinal vesicle in which maternal stores of nuclear proteins which are destined for use primarily by the early embryo are stored. Germinal vesicle breakdown and subsequent oocyte maturation is triggered by activation of the p34(cdc2)/cyclin B complex, which is present as the preform in the cytoplasm. The aim of the present study was to identify and biochemically characterize in vivo substrates of the kinase. Two nucleic acid binding nuclear proteins designated NAAP1 and NAAP2 were found, both of which contain 345 amino acid residues with pI 3. 6 and which serve as substrates. The only difference between the two proteins was in the primary amino acid sequence at position 51, which is Asn in NAAP1 but Thr in NAAP2. NAAPs are phosphorylated in vivo during oocyte maturation but not at the meiotic G(2) stage. NAAPs are phosphorylated in vitro by the cdc2 kinase on the same site as in vivo. Although there are other evolutionarily conserved consensus sequences for phosphorylation by mitotically active cdc2 kinase in NAAPs and NAAP-derived fragments containing the sequences were efficiently phosphorylated in vitro, these sites in the intact NAAPs were not phosphorylated either in vivo or in vitro. These results suggest that the tertiary structure of NAAPs affects the target specificity of the cdc2 kinase.
CREB-binding protein (CBP) is a transcriptional co-activator which is required by many transcription factors. Rubinstein-Taybi syndrome (RTS), which is an autosomal dominant syndrome characterized by abnormal pattern formation, is associated with mutations in the human CBP gene. Various abnormalities occur at high frequency in the skeletal system of heterozygous Cbp-deficient mice, but some features of RTS such as cardiac anomalies do not, suggesting that some symptoms of RTS are caused by a dominant-negative mechanism. Here we report the characterization of homozygous Cbp-deficient mice. Homozygous mutants died around E10.5-E12.5, apparently as a result of massive hemorrhage caused by defective blood vessel formation in the central nervous system, and exhibited apparent developmental retardation as well as delays in both primitive and definitive hematopoiesis. Cbp-deficient embryos exhibited defective neural tube closure which was similar to those observed in twist-deficient embryos. However, a decrease in the level of twist expression was not observed in Cbp-deficient embryos. Anomalous heart formation, a feature of RTS patients and mice mutated in the CBP-related molecule, p300, was not observed in Cbp-deficient embryos. Since both Cbp and p300 are ubiquitously expressed in embryonic tissues including the developing heart, these results suggest that cardiac anomalies observed in RTS patients may be caused by a dominant negative effect of mutant CBP.
In response to 1-methyladenine, a maturation-inducing substance, starfish oocytes undergo reinitiation of meiosis with germinal vesicle breakdown through activation of p34cdc2-cyclin B, which results in the dispersal of the nucleolus. Little information has been elucidated thus far on nucleolar proteins that are phosphorylated by p34cdc2-cyclin B during meiotic maturation. Here, we describe a novel nucleolar protein of the starfish Asterina pectinifera oocyte, which is designated ANO39 and which is phosphorylated during meiotic maturation. A full-length ANO39 cDNA of 2106 base pairs encodes a polypeptide of 346 amino acids having a calculated Mr of 39 005. The amount of ANO39 is kept nearly constant during oocyte maturation and embryogenesis up to the midgastrula stage. The transcript encoding ANO39 was present in growing oocytes but not in full-grown ones, as evidenced by Northern blot hybridization. Ser145 is specifically phosphorylated when ANO39 is incubated in vitro with purified starfish p34cdc2-cyclin B. This phosphorylation site corresponds to that is phosphorylated during meiotic maturation in vivo. Immunoblot analysis using phosphoserine145-specific antibody as a probe revealed that some populations of ANO39 of the immature oocytes at the G2 stage have been already phosphorylated on Ser145 and Ser145 is maximally phosphorylated during meiotic maturation.
Mouse newborns find their mother's nipples and suckle milk by themselves. It has been argued which sense organ they use when locating their mother's nipples to suckle milk. Olfactory or tactile sensory systems are primary candidates. In the present study, we investigated the trigeminal-whisker sensory and olfactory systems in genetic arhinencephaly mouse embryos (Pdn/Pdn). Pdn/Pdn newborns do not suckle milk and die within 1 day after birth. Dysfunction of nipple-searching behavior was clear in Pdn/Pdn newborns. Pdn/Pdn newborns had a complete developmental failure in the olfactory nerve projection to the central nervous system and no olfactory bulb architecture. The trigeminal-whisker system was intact in this strain. From the results of these experiments, it was suggested that the olfactory system is essential for nipple-searching behavior and suckling milk and that the trigeminal-whisker system is not able to substitute for the lack of olfactory input in mouse newborns.