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Biomedical subjects

M Honma

Publications and source records attributed to M Honma.

At least 109 records · Page 6Linked to original sources
PubMed1994

Demonstration by DNA fingerprint analysis of genomic instability in mouse BALB 3T3 cells during cell transformation.

We employed DNA fingerprint analysis to monitor DNA rearrangements in BALB 3T3 cells transformed spontaneously or by treatment with 3-methylcholanthrene (MCA) and UV-C. The effect of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in combination with MCA was also examined. Twenty-three spontaneously transformed cells, 28 induced transformed cells (18 by 1 microgram/ml MCA, six by 5 micrograms/ml MCA, and four by UV-C), and 31 non-transformed subclones were isolated from parental BALB 3T3 A31-1-1 cells. The DNAs were digested with HinfI and subjected to DNA fingerprint analysis with three multi-locus minisatellite probes, Per-6, Core, and Ins. Per-6 was the most effective probe for detecting DNA rearrangements. Rearranged bands detected by the Per-6 probe were observed in 9/31 (29%) of non-transformed subclones, 14/23 (61%) of spontaneously transformed cells, 16/18 (89%) of cells transformed by 1 microgram/ml of MCA, 6/6 (100%) of cells transformed by 5 micrograms/ml MCA, and 4/4 (100%) of UV-C-transformed cells. Higher numbers of DNA rearrangements (> or = 3) occurred most frequently in the induced transformed cells. TPA enhanced the frequency of DNA rearrangements in cells transformed by MCA. These data indicate that (1) genomic DNA in BALB 3T3 cells is unstable and susceptible to rearrangement, (2) its instability is elevated during cell transformation, and (3) MCA and UV-C induce DNA rearrangements, and TPA enhances the effect of the former, probably via the recombination process. DNA fingerprint analysis is valuable for monitoring genomic instability during cell transformation.

3T3 Cells↗
PubMed1994

Phenotypic heterogeneity of an adult form of adrenoleukodystrophy in monozygotic twins.

We describe genetically proven monozygotic twins with the adult form of adrenoleukodystrophy with significant phenotypic heterogeneity. Myeloneuropathy was common to both patients, but cognitive impairment and affective symptoms with extensive demyelination in the brain were prominent in the older twin, while adrenal insufficiency was predominant in the younger twin. The younger twin, however, exhibited affective symptoms similar to those displayed by his elder twin 10 years later. These findings suggest that nongenetic factors are important in determining the phenotypic variation of adrenoleukodystrophy gene.

Adrenoleukodystrophy↗
PubMed1994

Abdominal wall desmoid mimicking intra-abdominal mass: MR features.

A case of abdominal wall desmoid which enlarged toward the liver and mimicked an intra-abdominal tumor is presented. T*2-weighted MR images clearly demonstrated the tumor's continuity with the rectus abdominis muscle. The case presented suggests MRI may provide more valuable information concerning the origin of a right-upper-quadrant mass than CT does. However, the nature of the signals and attachment which this case showed were so unusual for desmoids that this case has not been diagnosed accurately.

Abdominal Muscles↗
PubMed1994

Molecular cloning and expression of an isomalto-dextranase gene from Arthrobacter globiformis T6.

The gene encoding an extracellular isomalto-dextranase, designated imd, was isolated from the chromosomal DNA of Arthrobacter globiformis T6 and cloned and expressed in Escherichia coli. A single open reading frame consisting of 1,926 base pairs that encoded a polypeptide composed of a signal peptide of 39 amino acids and a mature protein of 602 amino acids (M(r), 65,900) was found. The primary structure had no significant homology with the structures of any other reported carbohydrases, including two other dextranases. Transformed E. coli cells carrying the 2.3-kb fragment overproduced isomalto-dextranase into the periplasmic space under control of the promoter of the imd gene itself.

Amino Acid Sequence↗
PubMed1994

Effect of an oral gold compound, auranofin, on non-specific bronchial hyperresponsiveness in mild asthma.

BACKGROUND: A recent double blind clinical trial in Japan has shown that auranofin (6 mg/day) is a useful treatment for patients with moderate to severe asthma. To investigate the mechanism of action of auranofin the bronchial responsiveness to inhaled methacholine has been studied in well controlled asthmatic subjects. METHODS: Nineteen adult asymptomatic asthmatic subjects received auranofin (3 mg orally twice a day) or inactive placebo in random order for 12 weeks in a double blind fashion. Bronchial responsiveness to inhaled methacholine and pulmonary function tests were measured at the same time on different days before, and six and 12 weeks after, each treatment. RESULTS: Non-specific bronchial hyperresponsiveness 12 weeks after treatment with auranofin was decreased compared with that before treatment with auranofin and 12 weeks after treatment with inactive placebo, although the treatment did not improve pulmonary function tests. CONCLUSIONS: Non-specific bronchial hyperresponsiveness 12 weeks after treatment with auranofin is decreased in a group of mild asymptomatic asthmatic patients with normal lung function.

Adult↗
PubMed1994

[Double blind trial of pulse methylprednisolone versus conventional oral prednisolone in lupus nephritis].

A double blinded clinical trial was conducted in which the efficacy and safety of pulse methylprednisolone (400 mg/day) was compared with oral prednisolone (50 mg/day), a control drug for a period of 3 months. One-hundred and two (102) patients were enrolled in the study, of which 91 patients were determined as eligible for analysis of efficacy. Patients on pulse methylprednisolone had more favorable response to therapy with regard to laboratory value changes from baseline such as CH50 and anti-DNA antibody titers. In terms of anti-DNA antibodies, a significant difference was detected at one week after treatment. With regard to time course changes in laboratory values, CH50 at one and two weeks after treatment showed a significantly higher elevation in the pulse methylprednisolone group than in the control group. There was no significant difference noted in incidence of adverse reactions between both treatment groups. No serious adverse reaction was encountered in the pulse methylprednisolone group. The physician's assessment of final global improvement significantly favored the pulse methylprednisolone-treated group. The above results suggest that the pulse therapy with methylprednisolone leads to more rapid onset of drug effect than the conventional oral prednisolone in the treatment of lupus nephritis.

Administration, Oral↗
PubMed1993

Immortalization of normal human fibroblasts by treatment with 4-nitroquinoline 1-oxide.

Normal human fibroblasts (the OUMS-24 strain), derived from a 6-week-old human embryo, were transformed (into the OUMS-24F line) and immortalized by repeated treatments (59 times) with 4-nitroquinoline 1-oxide (4NQO). Treatment began during primary culture and ended at the 51st population doubling level (PDL). At the 57th PDL (146 days after the last treatment), morphologically altered, epithelial-type cells appeared, began to grow and became immortal (now past the 100th PDL). However, the control fibroblasts, which were not treated with 4NQO, senesced at the 62nd PDL. The finding that extensive, repeated treatments with 4NQO are required for the immortalization of normal human cells, indicates that multiple mutational events are involved in the immortalization of human cells in general. In other words, immortalization itself seems to be a multi-step process. Karyotypic analysis showed that many cells were hypodiploid before immortalization, but that afterwards chromosomes were distributed broadly in the diploid to tetraploid regions. The immortalized cells showed amplification and enhanced expression of c-myc. Two-dimensional electrophoretic analysis showed that the number of disappearing cellular proteins was greater than the number of the newly appearing ones after the cells became immortalized. Since the immortalized cells showed neither anchorage-independent growth nor tumorigenicity, they are useful for studying factors that can contribute to multi-step carcinogenesis in human cells. In addition, genetically matched normal (OUMS-24) and immortalized (OUMS-24F) cells will be useful for analyzing the genes related to cellular mortality and immortalization.

4-Nitroquinoline-1-oxide↗
PubMed1993

Detection of recombinational mutations in cultured human cells by Southern blot analysis with minisatellite DNA probes.

Using the human acute monocytic leukemia cell line, THP-1, a hypermutability of minisatellite loci was demonstrated in cell culture by Southern blot analysis with minisatellite DNA probes. DNA was isolated from 98 subclones and hybridized to a panel of minisatellite probes consisting of three multilocus minisatellite probes (ML probes) and seven locus-specific minisatellite probes (LS probes). The Southern blot patterns of the hybridized subclones were compared with those of the parental THP-1. Four mutated bands with two ML probes and two mutated bands with two LS probes were detected. The mutation frequency was estimated roughly at 0.1% based on the total number of bands analyzed, and it was much higher than that expected for other DNA regions. Four of these mutations were thought to be alterations of repetitions caused by insertion or deletion of tandem repeats, and one mutant lost a complete minisatellite allele. The nature of the sixth mutant was unclear. Because of the hypermutability of minisatellite DNA, Southern blot analysis using minisatellite DNA probes can be used as a mutation assay system directly based on the DNA.

Base Sequence↗
PubMed1993

The effect of an oral leukotriene antagonist, ONO-1078, on allergen-induced immediate bronchoconstriction in asthmatic subjects.

BACKGROUND: Cysteinyl leukotrienes are potent contractile agonists for airway smooth muscle. To examine the relative role of cysteinyl leukotrienes in immediate airway obstruction in human subjects with asthma after allergen challenge, we investigated the effect of ONO-1078, a potent receptor antagonist of cysteinyl leukotrienes, on the response. METHODS: ONO-1078 and an inactive placebo, in 150-mg capsule form, were administered every 12 hours for 1 week, in a double-blind, cross-over fashion. To examine the effect on the early part of the response, total respiratory resistance (Rrs) was continuously evaluated for 10 minutes after the start of a 1-minute exposure to an appropriate concentration of allergen. Rrs and FEV1.0 were estimated every 10 minutes for 60 minutes after the exposure. RESULTS: ONO-1078 significantly reduced percent changes in Rrs and FEV1.0 from 20 to 60 minutes after the exposure, as well as percent maximum changes in these indices, although the treatment did not alter the time from the start of allergen exposure to the beginning of elevation of Rrs, the time from the start to the point at which total respiratory conductance decreased by 35% from its baseline value, or percent changes in Rrs or FEV1.0 10 minutes after the exposure. CONCLUSIONS: Therefore, we conclude that cysteinyl leukotrienes primarily mediate a later part of immediate airway obstruction after allergen exposure.

Administration, Oral↗
PubMed1993

Effects of fixation and varying target length on the sensitivity of polymerase chain reaction for detection of human T-cell leukemia virus type I proviral DNA in formalin-fixed tissue sections.

In this study, the fixation condition most suitable for maintaining the sensitivity of the polymerase chain reaction (PCR) was investigated by using the alpha-tubulin gene sequence, and the PCR procedure most effective for detecting human T-cell leukemia virus type I (HTLV-I) proviral sequences in fixed, embedded tissues of adult T-cell leukemia patients was explored. First, the sensitivity of the PCR targeting a 286-bp alpha-tubulin sequence was studied in tissue sections fixed in several fixatives for various periods at 25 or 4 degrees C. For histological examination, fixation with 10% buffered formalin at a lower temperature for a shorter period was found to be preferable to retain the sensitivity. And the HTLV-I sequence was detected in only 7 of 18 specimens (38.9%) when the 374-bp sequence of the gag region was targeted, but the rate increased to 77.8% (14 of 18 specimens) when the length of the target sequence was reduced to 120 bp within the same region. Therefore, the one-round PCR targeting a shorter sequence is preferable for application of PCR to archival fixed tissue specimens, the fixation condition of which may not be ideal for DNA preservation.

Base Sequence↗
PubMed1993

Identification of the reactive sulfhydryl group of 1-aminocyclopropane-1-carboxylate deaminase.

1-Aminocyclopropane-1-carboxylate (ACC) deaminase, a pyridoxal phosphate enzyme that catalyzes cyclopropane ring-opening and deamination of ACC, formed a quinoid intermediate with D-alanine, as shown by the appearance of a 510-nm absorption band. The presence of D-alanine also stimulated the inactivation of ACC deaminase with iodoacetamide. The increase of absorbance at 510 nm and the stimulation of the enzyme inactivation were temperature-dependent with a critical point at around 20 degrees C, indicating a conformational change of the enzyme. To identify a reactive thiol group, this stimulated inactivation and an iodoacetamide derivative, N-(iodoacetamidoethyl)-1-aminonaphthalene-5- sulfonic acid were used. The residue that was modified by the specific reagent was monitored by absorbance at 350 nm through the digestion by lysylendopeptidase and the fractionation of peptides, and it was located at Cys-162 near the midpoint of the whole peptide chain of the ACC deaminase.

Alanine↗
PubMed1993

Influence of exogenously administered oxytocin on prolactin-producing cells in adult male rats as revealed by immuno-electron microscopy.

Prolactin-producing cells (PRL cells) identified by immuno-electron microscopy were studied in male rats with chronic intraperitoneal injection of synthetic oxytocin (OT). The PRL cells are usually classified into three types: the immature type containing round secretory granules about 100 nm in diameter with poorly developed cell organelles; the intermediate type containing medium-sized (150-250 nm in diameter) secretory granules with moderately developed cell organelles; and mature type containing large pleomorphic secretory granules ranging from 300 to 700 nm in diameter with well-developed cell organelles. In male rats, the intermediate type comprises typical PRL cells that constitute about 50% of all immunoreactive PRL cells. Chronic intraperitoneal OT administration to rats caused morphologically hypertrophic and hyperfunctioning PRL cells which are identified as mature type PRL cells. The frequency of occurrence of the mature type PRL cells increased after treatment. The contents of pituitary and serum PRL as measured by radioimmunoassay essentially paralleled the morphological results. These data indicate that OT may play a physiological role in PRL secretion as a releasing factor, and that OT administration causes the interconversion of the three types of PRL cells, indicating the mature type to be at the most activated state of secretory function.

Animals↗
PubMed1993

[Effect of AS-35 aerosol on bronchoconstriction induced by specific antigens in macacus rhesus monkeys].

In a previous in vitro study, 9-[(4-acetyl-3-hydroxy-2-n-propylphenoxy) methyl]-3-(1H-tetrazol-5-yl)-4H- pyrido[1,2-a]pyrimidin-4-one (AS-35) was shown to have an inhibitory effect on antigen-induced mediator release and an antagonistic effect on leukotriene C4 and D4 receptors. In the present study, therefore, we investigated the effect of AS-35 aerosol on allergen-induced bronchoconstriction, using 6 female Macacus rhesus monkeys sensitized with DNP-Ascaris extracts (DNP-As). After treatment with an inactive placebo, inhalation challenge with DNP-As increased total lung resistance and decreased dynamic lung compliance dose-dependently 1 week after sensitization with DNP-As. Treatment with AS-35 aerosol, however, significantly inhibited allergen-induced bronchoconstriction dose-dependently 2 weeks after the sensitization. The inhibitory effect was about ten times more potent than that of DSCG. Because we confirmed that DNP-As evoked almost the same bronchoconstriction 1 and 2 weeks after sensitization and also that AS-35 did not inhibit histamine-induced bronchoconstriction at all, we inferred that AS-35 diminished allergen-induced bronchoconstriction by inhibiting allergen-induced mediator release from the cells in the airway.

Aerosols↗
PubMed1992

Peritoneal mesothelioma: hypertrophic gastroepiploic and omental arteries identified by radioimmune angiography.

We report a first case of malignant peritoneal mesothelioma examined by radioimmune (RI) angiography with technetium-99m human serum albumin. The RI angiography clearly demonstrated the characteristic findings including hypertrophic gastroepiploic arteries and dilated omental branches. These findings may be very helpful in distinguishing malignant peritoneal mesotheliomas from peritoneal carcinomatosis.

Adult↗
PubMed1992

A new DNA profiling system for cell line identification for use in cell banks in Japan.

Using the polymorphic DNA probes, ChdTC-15, ChdTC-114, pYNH24, and lambda TM-18, a DNA profiling system was developed that verified identities of individual cultured cell lines collected in the Japanese cell banks, JCRB, RCB, and IFO. These highly polymorphic DNA probes include both VNTR (Variable Number of Tandem Repeats) sequences and substantial lengths of unique regions. In the mixed probe system, several distinct bands from four to eight can be used for cell line identification. These bands were widely spread in a range of molecular sizes, and were stable and reproducible under stringent conditions of Southern blot hybridization. Because the DNA profile was specific for each individual human cell line, it is useful not only to authenticate many existing cultured cell lines but also to monitor their identity during propagation in a laboratory, and to confirm newly established lines as unique.

Blotting, Southern↗
PubMed1992

Sensitivity of the polymerase chain reaction for detecting human T-cell leukemia virus type I sequences in paraffin-embedded tissue. Effect of unbuffered formalin fixation.

Recently, the application of the polymerase chain reaction (PCR) to formalin-fixed paraffin-embedded tissue has been reported. But formalin, especially unbuffered formalin, is known to break DNA into small fragments. DNA extracted from MT-2 cells fixed in unbuffered formalin for various periods of time were subjected to the PCR and the effect of unbuffered formalin fixation on the ability of the PCR to detect exogenous sequences; i.e., human T-cell leukemia virus type I (HTLV-I) proviral DNA, was examined. The sensitivity of the PCR decreased as a function of both the duration of fixation and the length of the expected DNA products. When the expected length of the PCR product was about 200 bp, a slight decrease in the sensitivity was observed after 4-day fixation. When it was about 300 bp, a similar decrease was observed following 4-h fixation. In the case of a 500 bp product, the sensitivity began to decrease after 30-min fixation and a 100-fold decrease was observed after 10-day fixation. A decrease was not observed, however, with a 100 bp product. The appropriate design of primers, especially with regard to the length of the amplified product, is essential to keep the sensitivity of the PCR, particularly when the target tissues have been fixed in unbuffered formalin.

Base Sequence↗