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Biomedical subjects

N Adachi

Publications and source records attributed to N Adachi.

At least 19 recordsLinked to original sources
PubMed1997

Cell cycle-dependent regulation of the mouse DNA topoisomerase IIalpha gene promoter.

Expression of DNA topoisomerase (topo) IIalpha varies through the cell cycle with its peak in G2/M. To investigate the mechanism controlling the topo IIalpha gene expression, we cloned the 5' upstream region of the mouse topo IIalpha gene. Although there was no TATA-like sequence, two GC and seven CCAAT boxes were found in the upstream region 5' distal to the major transcription start sites, which were located 137, 124, and 105 bp upstream from the ATG start codon. Luciferase vectors with the upstream sequences were constructed and transfected into HeLa cells, followed by cell cycle arrest either in G1 by treatment with mimosine, in S with thymidine, or in G2/M with colcemid. We found that the topo IIalpha gene promoter has the cell cycle-dependent activity, which is low in G1, rises in S, and peaks in G2/M. We suggest that the level of topo IIalpha mRNA is determined by the cell cycle-regulated promoter.

Animals↗
PubMed1996

The epidemiology of human calicivirus/Sapporo/82/Japan.

Based on genome analysis of the RNA-dependent RNA polymerase region, it has been proposed that human caliciviruses (HuCV) can be classified into at least three genogroups: genogroup I is represented by Norwalk virus (NV), genogroup II by Snow Mountain agent (SMA) and genogroup III by HuCV/Sapporo/82/Japan (HuCV/Sa/82/J) virus. HuCV/Sa/82/J strain is genetically unique and more closely related to animal caliciviruses than are other known HuCVs, such as NV and SMA. HuCV/Sa/82/J strain was detected in four outbreaks of HuCV gastroenteritis occurring between 1977 and 1982 in an infant home in Sapporo. The HuCVs detected from these four outbreaks all showed a typical "Star of David" configuration by electron microscopy (EM), and they were identical antigenically and genetically. This strain has also been detected in other prefectures in Japan, as well as in the USA, UK, Saudi Arabia and Kenya. Seroepidemiological studies have shown a worldwide distribution of this virus, including Japan, USA, UK, Southeast Asia, Canada, China and Kenya. This virus has been circulating in Sapporo for at least 19 years (1977-1995). HuCV/Sa/82/J strain is thought to be one of the common causes of viral gastroenteritis worldwide. The HuCV/Sa/82/J strain has been detected mainly in infants. Age-related prevalence of antibody to this strain also shows that infections commonly occur in children less than 5 years old, although viruses in the NV and SMA genogroups commonly infect adults. The pattern of acquisition of antibodies to strain HuCV/Sa/82/J is similar to that of other common viral infections. HuCV/Sa/82/J strain is unique virologically and clinically among caliciviruses.

Age Factors↗
PubMed1996

Dot blot hybridization with a cDNA probe derived from the human calicivirus Sapporo 1982 strain.

A dot blot hybridization assay was developed for detection of human calicivirus/Sapporo/82/J (HuCV/Sa/82) or strains closely related to HuCV/Sa/82 in stool specimens. The cDNA derived from the RNA-dependent RNA polymerase (RDRP) region of HuCV/Sa/82 was used as a positive probe and the pBR322 DNA as a negative control probe. Both probes were labeled with digoxigenin and the products of hybridization reaction were detected with an anti-digoxigenin antibody-alkaline phosphatase conjugate. This assay was specific for HuCV/Sa/82 and for HuCV antigenically related to HuCV/Sa/82. The lower limit of sensitivity of this assay was estimated to be about 10(5) physical particles or 10 pg of cDNA, similar to that of the previously developed ELISA for HuCV. In 1273 stool specimens obtained from children with acute gastroenteritis in Sapporo, Japan, 110 (8.6%) contained small round structured viruses by EM and 23 (1.8%) were positive for HuCV antigenically related to HuCV/Sa/82 by either the hybridization assay or ELISA. A higher positive rate was obtained with the dot blot assay (21%) than by ELISA (10%), suggesting that the dot blot assay either detects HuCV more broadly than the ELISA or detects HuCV covered with fecal antibodies which interrupt antigen-antibody reactions in the ELISA. Negative results for detection of Norwalk virus (NV) cDNA and feline calicivirus (FCV) RNA by both this assay and the ELISA indicated that the HuCV/Sa/82 strain is distinct antigenically and genetically from NV and FCV.

Acute Disease↗
PubMed1996

Outbreaks of nosocomial rotavirus gastro-enteritis in a paediatric ward.

UNLABELLED: Faecal samples were collected from patients with gastro-enteritis during two winter seasons on a paediatric ward. Three outbreaks of nosocomial rotavirus gastro-enteritis were identified by latex agglutination and the virus strains were characterized by polyacrylamide gel electrophoresis of the genome nucleic acid and by subgrouping and serotyping enzyme-linked immunosorbent assays (ELISA). One outbreak was caused by serotype 1 rotavirus, one by serotype 2 and the remaining outbreak was caused by a mixture of serotypes 1 and 4. Identical electrophoretic patterns of the rotavirus genome in each outbreak combined with the ELISA results indicate that these three outbreaks were hospital-acquired cases. The index cases in the three outbreaks were community-acquired and one of two index cases in the second outbreak was hospital-acquired. On each occasion, susceptible roommates were easily infected from the index cases and then cross-infection occurred in the paediatric ward. Possible vehicles were the medical staff, especially doctors, parents of infected patients and infected patients who were moved to other rooms. One patient who had been treated with a series of antitumour therapies excreted rotaviruses in faeces for a long time period and probably played a role as a source of the outbreak. Moreover, some patients still excreted rotaviruses in their normal stool 1 week after recovery from gastro-enteritis. These findings indicate that continual examination of stool samples for rotaviruses until they are negative may be important to prevent the spread of rotavirus infection. CONCLUSION: Nucleic acid analysis and serotyping ELISA are useful tools for analyzing nosocomial rotavirus gastro-enteritis and important to prevent the spread of rotavirus infection in institutions.

Child↗
PubMed1996

Histaminergic H2 action protects hippocampal CA1 neurons by prolonging the onset of the anoxic depolarization in gerbils.

The central histaminergic action on ischemia-induced neuronal damage was examined by evaluating the histological outcome and the direct current (DC) potential shift in the hippocampal CA1 region in gerbils. An intracerebroventricular administration of histamine (10-100 nmol) improved the delayed ischemic damage in hippocampal CA1 pyramidal cells produced by 3 min of transient forebrain ischemia. A high dose (75 nmol) of mepyramine, an H1 antagonist, aggravated ischemia-induced neuronal damage, but not a low dose (0.75 nmol). Administration of cimetidine (4 nmol) and ranitidine (3 nmol), H2 antagonists, aggravated the neuronal damage. An injection of histamine (100 nmol) prolonged the onset time of the ischemia-induced sudden shift in the extracellular DC potential (anoxic depolarization; AD) to 133% of that in control animals. Administration of mepyramine (75 nmol) did not markedly change the AD, whereas injections of cimetidine (40 nmol) and ranitidine (3 nmol) reduced the onset latency to 47 and 45%, respectively. These findings suggest that the central H2 action serves to protect neurons by delaying the onset of AD in gerbils.

Animals↗
PubMed1996

Purification, characterization, and cDNA cloning of ABP-2 (arylphorin gene-specific binding protein-2) that specifically binds to the ABP-1-binding sequence in the arylphorin gene of Sarcophaga peregrina.

Previously, we demonstrated that ABP-1 (arylphorin gene-specific binding protein-1), which is suggested to be the transcriptional activator of the arylphorin gene of Sarcophaga peregrina, is present in NIH-Sape-4 cells, which do not express arylphorin. As well as ABP-1, these cells were found to contain another protein (ABP-2) that probably binds to the same sequence as that to which ABP-1 binds [Adachi, N., Kubo, T., and Natori, S. (1993) J. Biochem. 114, 55-60]. We purified ABP-2 from a nuclear extract of NIH-Sape-4 cells and compared its DNA-binding activity with that of ABP-1. Both ABP-1 and ABP-2 were found to bind to the same sequence in the arylphorin gene with the same affinity and stability, but an ABP-2-specific hypersensitive site was detected by DNase I footprinting analysis. Analyses of proteolytic fragments suggested that both ABP-1 and ABP-2 have Zn fingers showing high similarity with that of AEF-1, a transcriptional repressor of the Drosophila melanogaster alcohol dehydrogenase gene that binds to a sequence very similar to that binding ABP-1 and ABP-2. We isolated a candidate cDNA for ABP-2, and the protein it encoded contained nine Zn fingers and regions rich in alanine, glutamine, serine/threonine, glycine, histidine, and asparagine.

Amino Acid Sequence↗
PubMed1996

Effects of pre- and postischemic administration of thiopental on transmitter amino acid release and histologic outcome in gerbils.

BACKGROUND: The mechanism by which barbiturates protect neurons against ischemia is unclear, particularly when they are given after ischemia or reperfusion begins. Because an excess release of excitatory neurotransmitters causes postsynaptic membrane depolarization, which triggers neuronal damage in ischemia, the effects of thiopental on histologic outcome, ischemia-induced amino acid release, and anoxic depolarization in gerbils were studied. METHODS: The effects of different doses of thiopental administered before or after ischemia were examined morphologically by assessing delayed neuronal death in hippocampal CA1 pyramidal cells produced by forebrain ischemia for 3 min in gerbils. The ischemia-induced changes in output of aspartate, glutamate, glycine, taurine, and gamma-aminobutyric acid were measured using a microdialysis-high-performance liquid chromatography procedure, and the differences among a halothane-anesthetized group, a thiopental-administered group, and a group given thiopental after a period of ischemia were evaluated. The changes induced in the direct-current potential in the hippocampal CA1 area by forebrain ischemia were compared in animals anesthetized with halothane and those given thiopental. RESULTS: Preischemic administration of thiopental at all doses decreased the risks for delayed neuronal death (P < 0.01). Post-ischemic administration at a dosage of 2 mg.kg-1.min-1 for 60 min protected neurons, but the same dose for 10 min did not ameliorate the cell injury. Forebrain ischemia produced marked increases in all amino acids 3 to 6 min after the start of recirculation in the halothane-anesthetized gerbils, whereas thiopental anesthesia (2 mg.kg-1.min-1) reduced these increases throughout the experimental period, except for glycine (P < 0.01). The initiation of thiopental after reflow did not markedly diminish these increases. Thiopental anesthesia prolonged the onset of anoxic depolarization and reduced its maximal amplitude. CONCLUSIONS: Thiopental helps protect the brain from ischemia, although treatment with this agent after ischemia requires a larger dose than that before ischemia. The effect of preischemic treatment may be related to the suppression of the excitatory amino acid release and the direct-current potential shift.

Animals↗
PubMed1996

Charles Bonnet syndrome in leprosy; prevalence and clinical characteristics.

Charles Bonnet syndrome (CBS) is diagnosed when a visually impaired patient without any mental disorder develops visual hallucinations. A survey of patients in a National Leprosarium revealed that the point prevalence of CBS in leprosy was 0.4%. This prevalence appears to be high, as few cases with CBS have been reported. The semeiology of visual hallucinations was typical of CBS. However, the clinical features were different from previous reported cases because of the history of leprosy and associated multi-sensory loss. Patients with leprosy appear to be at increased risk for CBS, due to frequent eye complications combined with sensory loss, ageing, and intact intellectual functions.

Adult↗
PubMed1996

Differential diagnosis of scalp trichilemmal cyst on MRI.

The characteristic MRI of scalp trichilemmal cysts is reported. The feature of an iso-intense area on T1-weighted images is unique to trichilemmal cysts. MRI is helpful in diagnosing the trichilemmal cyst and useful in distinguishing cystic tumors on the median scalp from a cranial malformation, meningo- or encephalocele.

Adult↗
PubMed1996

[Cardiac impairment of elderly patients with diabetes mellitus as studied with non-invasive myocardial scintigraphy and signal-averaged electrocardiography].

In patients more than 65-year-old with diabetes mellitus, positive late potentials on signal-averaged electrocardiograms were more common than in normal subjects (p < 0.05). This suggests that aged patients with diabetes mellitus are at risk for micromyocardial impairment. Myocardial scintigraphy with 123I-metaiodobenzylguanidine showed abnormally low uptake, in parallel with the data on SA-ECG. Thus, both methods may be clinically useful ways to noninvasively reveal micromyocardial impairment in aged patients with diabetes mellitus. Moreover, trimetazidine hydrochloride may be effective as therapy for micromyocardial impairment: the uptake of 123I-metaiodobenzyl guanidine had increased in some patients when measured 1 year after administration of trimetazidine hydrochloride (18 mg/day) and the late potential changed from positive to negative.

3-Iodobenzylguanidine↗
PubMed1996

[Mouth mask method for fiberoptic tracheal intubation in difficult intubations].

We tried 72 fiberoptic tracheal intubations (FTI) using a mouth mask in difficult intubation cases. In this method, ventilation is performed via only the mouth using a mask applied over the mouth (mouth mask) and FTI can be done via a nostril with no hindrance from the mask in anesthetized patients. We have been using an infant or child type Seal Mask (Gibeck Respiration) for the mouth mask or a specially made mouth mask. An oral airway is usually inserted and the nostril of one side is plugged with cotton. FTI is performed by another anesthesiologist. An endotracheal (ET) tube capped with a rubber diaphragm is passed through another nostril, and a fiberscope is inserted through the ET tube. The subsequent technique is the same as that of the usual FTI for awake patients. Intubations were successful in all cases except 2; in one, ventilation was impaired even with oral airway in place, and in the other, bleeding in upper airway due to jaw injury from traffic accident hindered the sight of the scope. Mouth mask method for FTI is safe, useful and practical in difficult intubations with little discomfort to the patient.

Adolescent↗
PubMed1996

Decreased DNA topoisomerase II alpha expression and cold-sensitive growth in a mouse mammary cancer cell line resistant to etoposide and doxorubicin.

A mouse mammary carcinoma FM3A cell line resistant to the DNA topoisomerase (topo) II-targeting agent, etoposide (VP-16), FM3A/VP-2B, had a markedly reduced growth rate at a low temperature (33 degrees C). The cells had the following properties: (a) FM3A/VP-2B, which had 24-fold higher resistance to VP-16 than its parental line, FM3A, was cross-resistant to doxorubicin, but not to a camptothecin derivative, CPT-11. (b) Cold-resistant revertants from FM3A/VP-2B, R-6 and R-11, remained 8- to 9-fold more resistant to VP-16 and 2- to 3-fold more resistant to doxorubicin. (c) FM3A/VP-2B had one-fourth the level of topo II activity and one-third of the topo II alpha content and mRNA of FM3A. R-6 and R-11, however, had levels similar to FM3A. (d) FM3A/VP-2B and FM3A had a 3-base deletion at position 4170 on one allele on the topo II alpha cDNA, but expression of the wild-type and the deletion allele was not appreciably changed in both cell lines. Decreased topo II alpha expression might have led to the acquisition of drug resistance to etoposide in FM3A/VP-2B, and appeared to be linked with the cold-sensitive growth. We also present a corrected mouse topo II alpha cDNA sequence.

Amino Acid Sequence↗
PubMed1995

Molecular cloning and sequencing of the hcs gene, which encodes 3-hydroxy-3-methylglutaryl coenzyme A synthase of Schizosaccharomyces pombe.

We have cloned and sequenced the hcs gene, which is thought to encode a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase consisting of 447 amino acids, from the fission yeast Schizosaccharomyces pombe. The predicted amino acid sequence of the hcs product of S. pombe has homology with the HMG-CoA synthase of rat (47.8%), chicken (49.2%), hamster (47.1%) and human cells (46.9%). One of the hcs genes was replaced with a marker gene in the diploid cell. No viable hcs-disrupted haploid was isolated after tetrad dissection, suggesting that the hcs gene is essential for growth. However the hcs-defective mutant could be grown on a medium containing 5 mg/ml mevalonate. These results strongly support that the hcs gene encodes HMG-CoA synthase and S. pombe contains a single copy of the hcs gene.

Amino Acid Sequence↗
PubMed1995

Fatal cytomegalovirus myocarditis in a seronegative ALL patient.

Fatal cytomegalovirus (CMV) myocarditis occurred in a 2 year old boy with acute lymphoblastic leukemia (ALL) in remission. The patient showed mild hepatic dysfunction and a rapid progress of pancytopenia after complete remission had been achieved. At the fifth week of complete remission, he presented signs of heart failure such as tachycardia, S4 gallop on auscultation and decreased ejection fraction on echocardiography. However, no significant electrocardiographic changes were recognized. In addition to the cardiac dysfunction, the patient presented a marked tachypnea and dyspnea associated with hypoxemia. These were dramatically improved by methylprednisolone pulse therapy (30 mg/kg per day, for 3 days) and CMV high titer immunoglobulin (400 mg/kg per day, for 3 days). On the sixth day after signs of respiratory failure were improved, the patient suddenly presented a paroxysmal atrial tachycardia followed by a fatal ventricular fibrillation. Although we could detect neither a specific IgM antibody, a significant increase of IgG antibody, nor CMV genome by DNA hybridization techniques during the course of the illness, microscopic examination of necropsy specimens of the heart showed a marked disruption and disintegration of muscle bands associated with cytomegalic inclusion bodies. Polymerase chain reaction (PCR) yielded a 305 bp amplification product in the heart and lung tissues, supporting the view that myocarditis was caused by CMV.

Antibodies, Viral↗
PubMed1995

A late-appearing Philadelphia chromosome in acute lymphoblastic leukemia confirmed by expression of BCR-ABL mRNA.

We report two cases of acute lymphoblastic leukemia (ALL) with a late-appearing Philadelphia chromosome (Ph1), confirmed by the expression of BCR-ABL mRNA, using the reverse transcriptase/polymerase chain reaction (RT/PCR) technique. The first patient was a 10-year-old boy with precursor B cell type ALL-L1 (FAB classification). At diagnosis, no metaphase cells were found by chromosome analysis and BCR-ABL mRNA was not observed. At the beginning of relapse, which occurred after 7 months of complete remission, a normal karyotype was observed. At the terminal stage, leukemic cells with Ph1 and BCR-ABL mRNA for the P190 variety were observed. The second patient was a 12-year-old boy with immature T cell type ALL-L1. The metaphase cells showed a 9p- chromosome at diagnosis and Ph1 appeared in addition to 9p- at relapse. Hybrid mRNA for the P210 variety was detected only when Ph1 had developed. The blast cells with Ph1 were derived from the original leukemic clone through clonal evolution, since the same clonal rearrangements of IGH or TCRB were detected in leukemic cells obtained both at diagnosis and relapse in both patients. Thus, in both cases, Ph1 was detected only in the course of ALL along with expression of BCR-ABL mRNA. This observation also confirmed that, as in de novo Ph1-positive ALL, both the P190 and P210 varieties of BCR-ABL mRNA are observed in ALL with late-appearing Ph1.

Base Sequence↗