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Biomedical subjects

N Nakamoto

Publications and source records attributed to N Nakamoto.

At least 19 recordsLinked to original sources
PubMed2001

Interferon regulatory factor 1 promoter polymorphism and response to type 1 interferon.

The clinical success of interferon-treatment has been found to vary in different individuals. To explain this, we hypothesized that responses to type 1 interferons could be partly determined by interferon regulatory factor-1 gene transcription, because the latter is an important transcription factor in the interferon system. We demonstrated that the antiproliferative effect of type 1 interferons on human liver cancer cells correlates with levels of transcription of the interferon regulatory factor-1 gene in parallel with those of p21(WAF-1) expression. Here, we investigated whether mutations in the interferon regulatory factor-1 gene cause different responses to type 1 interferons. DNA from several human liver cancer cell lines and peripheral blood mononuclear cells was investigated. Nucleotide sequences of the interferon regulatory factor-1 gene and polymerase chain reaction products of its upstream region were determined directly and after cloning. The promoter activity of the upstream region of this gene was measured by the luciferase reporter assay. We found 4 point mutations in the upstream (- 1 approximately - 495) region, and the luciferase promoter assay demonstrated that these mutations did modify promoter activity. Analysis of DNA from healthy volunteers showed that these mutations are single nucleotide polymorphisms. These results suggest that single nucleotide polymorphisms of the interferon regulatory factor-1 promoter contribute, at least in part, to determining responses to type 1 interferons. J. Cell. Biochem. Suppl. 36: 191-200, 2001.

Antineoplastic Agents↗
PubMed2001

Reduction of telomerase activity in human liver cancer cells by a histone deacetylase inhibitor.

The presence of telomerase has been demonstrated recently in many different malignancies. Several reports documented that in human hepatocellular carcinoma, the level of telomerase activity parallels its differentiation stage. In the present study, the effect of the differentiation-inducing agent sodium butyrate on telomerase activity in four human liver cancer cell lines was investigated using the telomeric repeat amplification protocol. We assayed telomerase activity before and after butyrate treatment and in cell cycle synchronized non-dividing quiescent cells. In addition, telomerase reverse transcriptase levels were measured at the mRNA level. All four cell lines possessed high but not identical levels of telomerase activity. Telomerase activity was significantly reduced by treatment with sodium butyrate as well as trichostatin A in a dose- and time-dependent fashion, paralleling the reduction of cell proliferation. Although methotrexate, hydroxyurea, and colchicine synchronized the cell cycle at G1, S, and G2/M, respectively, and thereby also caused proliferating cells to cease dividing and become quiescent, in this case telomerase activity remained essentially unaltered compared to the control cultures. Moreover, levels of mRNA encoding telomerase reverse transcriptase were not always significantly altered by either sodium butyrate treatment or cell cycle synchronization. These results suggest that sodium butyrate, as a histone deacetylase inhibitor, effectively reduces telomerase activity without affecting transcription levels of the reverse transcriptase component.

Antineoplastic Agents↗
PubMed2001

Reduction of c-myc expression by an antisense approach under Cre/loxP switching induces apoptosis in human liver cancer cells.

c-Myc has been documented to be both a positive and a negative signal for the induction of apoptosis. It is well known that overexpression of the c-myc gene induces apoptosis of normal cells, but the result of a reduction in its expression is not fully understood. We examined whether a reduction in c-myc expression would induce apoptosis in human liver cancer cells. Specifically, antisense and sense oligodeoxynucleotides (oligos) against the human c-myc mRNA were synthesized, mixed with a liposome reagent at various ratios, and were applied to the liver cancer-derived cell lines, HCC-T, HepG2, and PLC/PRF/5. To exclude effects resulting from using oligos, plasmid vectors expressing the full-length c-myc cDNA in both sense and antisense orientations under the control of the Cre/loxP system were generated. Monoclonal cell lines including these plasmid vectors were produced and Cre was supplied by adenovirus infection. Apoptosis was determined morphologically and c-Myc and Bcl-2 expression was examined by Western blotting. The antisense myc significantly inhibited the proliferation of the cells within two days, while neither the liposome reagent alone nor sense myc did so. Most of the cells were rounded up by the antisense-treatment and nuclear fragmentation and DNA ladder formation were detected after two days in antisense c-myc-treated cells. Antisense c-myc largely reduced c-Myc and partially Bcl-2 expression; overexpression of Bcl-2 partially rescued from apoptosis in HCC-T and HepG2 cells. These results suggest that the massive reduction in c-myc mRNA induces apoptosis in liver cancer cell lines and consequent decrease in Bcl-2 enhances the cell death. c-Myc reduction under the Cre/loxP switching system may be a useful tool for the clarification of c-myc-related cellular mechanisms in differentiation and proliferation.

Apoptosis↗
PubMed2000

Girl with accelerated growth, hearing loss, inner ear anomalies, delayed myelination of the brain, and del(22)(q13.1q13.2).

We report on an 18-month-old Japanese girl with 46,XX,del(22)(q13.1q13.2). To our knowledge, this is the first report of a case of interstitial deletion of a 22q13.1-q13.2 segment. Clinical features included hearing loss accompanied by inner ear anomalies, hypotonia and minor anomalies, such as a long philtrum, full eyelids, epicanthus, left transverse palmar crease and psychomotor developmental delay. Despite the chromosomal deletion, her physical growth was accelerated: her height was between the 75th and 90th percentiles for her age. Her brain MRI showed signs of delayed myelination. The three-dimensional MRI of the inner ear showed abnormalities of the cochlea and vestibule in both ears. Clinical features of the patient are similar to those of a patient with a del(22)(q13.1q13.33) karyotype previously reported by Romain et al.

Abnormalities, Multiple↗
PubMed2000

A patient of short stature with normal GH secretion, but a low serum IGF-I level.

We report the case of a 7-year-old patient of short stature who had normal GH secretion, but a very low serum IGF-I level. On admittance, his height and weight were 102.2 cm (-3.8S.D.) and 15.7 kg (-1.8S.D.), respectively. His bone age was 2 years and 8 months. The serum GH responses to insulin, glucagon and L-dopa were all normal. GH secretion during sleep was also normal, but the serum IGF-I level was very low (29 ng/ml). The serum IGF-I level was greatly increased by the administration of GH. No mutation was detected in the GH-1 gene. His height velocity was noticeably improved by GH treatment.

Age Determination by Skeleton↗
PubMed1999

Purification and characterization of rat liver naloxone reductase that is identical to 3alpha-hydroxysteroid dehydrogenase.

1. Rat liver cytosol produced exclusively 6beta-naloxol from naloxone in the presence of either NADPH or NADH at pH 7.4. The amount of 6beta-naloxol formed with NADPH was about four times that with NADH. The enzyme responsible for this reaction, termed naloxone reductase, was purified to a homogeneous protein by various chromatographic techniques. 2. The purified enzyme is a monomeric protein with a molecular weight of 34000 and an isoelectric point of 5.9, and it has a dual co-factor specificity for NADPH and NADH. The enzyme catalysed the reduction of various carbonyl compounds as well as naloxone analogues, and the dehydrogenation of 3alpha-hydroxysteroids and alicyclic alcohols. Indomethacin, quercetin and sulphhydryl reagents potently inhibited the enzyme, but pyrazole and barbital had no effect on the enzyme activity. 3. Identity of naloxone reductase and 3alpha-hydroxysteroid dehydrogenase in rat liver was demonstrated by comparing the elution profiles of the two enzyme activities during purification, the ratios of the two enzyme activities at each purification steps, and thermal stability and susceptibility to inhibitors for the two enzyme activities. 4. Amino acid sequences of five peptides obtained by proteolytic digestion of the purified enzyme were completely identical to the corresponding regions of previously reported 3alpha-hydroxysteroid dehydrogenase.

3-Hydroxysteroid Dehydrogenases↗
PubMed1999

[Pranlukast allows reduction of inhaled steroid dose without deterioration in lung function in adult asthmatics].

We undertook a community based case-control study to measure the effect of pranlukast on the reduction of inhaled steroid in adult asthmatics. Forty-one adults completed a run-in period of 4 weeks on 800 microgram of beclomethasone dipropionate (BDP) documenting twice daily peak expiratory flow (PEF) and symptom score and therapeutic score on a standard diary. Forced expiratory volume in one second (FEV1.0), V50, V25 was measured once during the run-in period. Patients were then randomized to receive either pranlukast with 400 microgram of BDP or 400 microgram alone for 8 weeks. There was no difference in the symptom score and therapeutic between the two groups at any time point. However, morning and evening % PEF run-in expressed as a % of the PEF average during the run-in period was significantly lower at 8 weeks in the groups without pranlukast. There were subjects in the group without pranlukast (35.3%) compared to those with (20.8%) who had a 10% or more reduction in % PEF from the run-in period. The patients with an FEV1.0 < 80% predicted who were randomized to the control group were more likely (5 of 7) to have a fall in % PEF run-in and those randomized to received pranlukast were less likely to have a fall in % PEF run-in though this was not significant (2 of 6). In this study, pranlukast has demonstrated steroid sparing effect. Severe asthmatics (FEV1.0 < 80%) who deteriorate after reduction of inhaled steroid may benefit most from pranlukast. Larger studies are now required to explore this important effect.

Administration, Inhalation↗
PubMed1998

[Screening test by statistically reducing the number of the State-Trait Anxiety Inventory (STAI) items].

The purpose of the study is to find a method of mental examination which can be simply performed concurrently with physical examination during a regular check-up. On a regular check-up, the state-trait anxiety inventor (STAI) was administered to 264 construction workmen engaged in reconstruction work for the Hanshin Awaji Great Earthquake. Data on a total of 40 STAI items, i.e., 20 state anxiety (A-State) items and 20 trait anxiety (A-Trait) items were subjected to multiple regression analysis and five items were extracted from A-State and five from A-Trait items as a practical tool for a simple screening test. The contribution rates of the respective five items for the total score were 90.0% for A-State and 88.5% for T-State. The correlation coefficients, r, between predicted and observed values were 0.949 (p < 0.01) for A-State and 0.940 (p < 0.01) for A-Trait. Because of certain degrees of validity and reliability of each five-item system, it is considered that this method is useful as a simple screening test to roughly grasp the mental health of subjects and can be utilized for mental health care at offices.

Adult↗
PubMed1998

[A case report of acute encephalitis with neuro-psychiatric side-effects of acyclovir].

We reported a 5-year-old boy with acute encephalitis due to suspected herpes simplex infection, who developed confusion, agitation and insomnia during intravenous administration of acyclovir. He recovered from these neuro-psychiatric symptoms two days after the cessation of acyclovir. The same symptoms recurred two days after its re-administration and resolved on the next day of the second cessation of the drug. Electroencephalogram (EEG) showed periodic lateralized epileptiform discharges (PLEDs) on hospital day 16, which disappeared on hospital day 27, suggesting that neurotoxicity of acyclovir may induce PLEDs. Although acyclovir is useful for the treatment of herpes simplex and varicella-zoster virus infections, we have to pay attention to its neurotoxicity.

Acute Disease↗
PubMed1997

[Cousins with X-linked recessive myotubular myopathy].

We describe two cousins with severe infantile form of myotubular myopathy. In Japan this disease has previously been reported in only three families. Case 1. The propositus, a 2-year-5-month-old boy, had been on a respirator since birth. He had a history of severe neonatal asphyxia and sequential hypotonia with dyspnea. Findings diagnostic of congenital myotubular myopathy, such as central nuclei and peripheral halo of muscle fibers, were demonstrated in his biopsied muscle. Case 2. A male the cousin of case 1 had congenital myopathy and died at 3 months of age due to respiratory failure. His muscle biopsy disclosed the identical findings as had been seen in case 1. These two cases were born to twin mothers, suggesting X-linked recessive inheritance. Early diagnosis and proper treatment of myotubular myopathy are important, because this condition may be erroneously-interpreted as the sequelae of neonatal asphyxia.

Child, Preschool↗
PubMed1995

[A case of rubella encephalitis: rubella virus genome was detected in the cerebrospinal fluid by polymerase chain reaction].

We studied a 2-year-old boy who had been diagnosed as having rubella encephalitis by detection of rubella virus genome in his cerebrospinal fluid with the reverse transcription-polymerase chain reaction (PCR). PCR was considered to be very useful not only to make an early diagnosis of rubella encephalitis but also to be applied generally to that of various viral encephalitis.

Cerebrospinal Fluid↗
PubMed1995

[A case of acute disseminated encephalomyelitis with lesions in the cerebral gray matter on MRI in the acute phase].

We reported a case of acute disseminated encephalomyelitis (ADEM) after Streptococcus infection. Brain MRI (T2-weighted image) showed high intensity lesion in the gray matter in the acute phase. The high intensity pattern of the lesion was different from those in previously reported cases. The boy, aged 14, had fever late in August 1993. He had lumbago and back pain since September 3 and also leg weakness developed since September 7. He became unable to urinate on September 10 and was admitted on September 12. His consciousness became indistinct. We considered ADEM on the basis of high CSF level of myelin basic protein, clinical course, symptoms and MRI findings and began to administer steroid hormone on the second day after admission. He rapidly recovered. We reported here an atypical case of ADEM as to the antecedent infection and MRI lesion.

Adolescent↗
PubMed1991

[Study of influence of respiratory rate to airway resistance in patients with pulmonary emphysema].

Application of the panting method is very difficult for patients with pulmonary emphysema (PE). We attempted to measure airway resistance (Raw) during quiet breathing and changing respiratory rate step by step in patients with PE using a pressure-type body plethysmograph system (BX-82) correcting measured values by temperature and humidity. Influence of the respiratory rate to Raw was studied at 0.5l/sec of inspiratory and expiratory flow. Whenever the respiratory rate was going up, the Raw increased in spite of the increase of the thoracic gas volume. Raw (2Hz) was about one and a half times as high as Raw (quiet breathing). On the other hand, when the respiratory rate was going up, elevation of the peak flow was always able to be recognized. It seemed that the state of the airway varied during the panting method. The Raw measured during 0.5 Hz breathing (nearly quiet breathing) had small variability. Because the airway state during 0.5 Hz breathing was nearly the same as that during quiet breathing, measurement of Raw (0.5Hz) can be regarded as a practical method in patients with PE.

Aged↗