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Biomedical subjects

E Nakajima

Publications and source records attributed to E Nakajima.

At least 37 records · Page 2Linked to original sources
PubMed1996

First-trimester prenatal molecular diagnosis of infantile hypophosphatasia in a Japanese family.

We obtained a prenatal molecular diagnosis during the first trimester in a Japanese woman whose first child (the proband) had been a compound heterozygote for infantile hypophosphatasia. We examined chorionic villus DNA samples obtained at 10 weeks of gestation for the base substitutions detected in the proband DNA using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) and PCR-allele-specific oligonucleotide (ASO) analysis. The genotype of the fetus was the same as that of the proband. The same mobility shift patterns of single strand conformation polymorphism (SSCP) bands were observed in the fetus and the proband. This molecular approach to prenatal diagnosis appears to be more accurate than the enzymatic method and also more accurate and more rapid than the conventional RFLP method.

Alleles↗
PubMed1996

Recovery of active beta-lactamases from Proteus vulgaris and RTEM-1 hybrid by random mutagenesis by using a dnaQ strain of Escherichia coli.

Proteus vulgaris and RTEM-1 beta-lactamases that belong to molecular class A with 37% amino acid similarity were examined to find the relationship between amino acid residues and activity of enzymes. MICs of ampicillin were > 2,000 micrograms/ml for Escherichia coli cells producing these enzymes. We have made 18 hybrid genes by substituting the coding region of the P. vulgaris beta-lactamase gene with the equivalent portions from the RTEM-1 gene. Most of these hybrids produced inactive proteins, but a few hybrid enzymes had partial or trace activity. From one of the hybrid genes (MIC of ampicillin, 100 micrograms/ml), we recovered three kinds of active mutants which provided ampicillin MICs of 1,000 micrograms/ml by the selection of spontaneous mutations in a dnaQ strain of E. coli. In these mutants, Leu-148, Met-182, and Tyr-274 were replaced with Val, Thr, and His, respectively. These amino acids have not been identified as residues with functional roles in substrate hydrolysis. Furthermore, from these hybrid mutants, we obtained a second set of mutants which conferred ampicillin MICs of 1,500 micrograms/ml. Interestingly, the second mutations were limited to these three amino acid substitutions. These amino acid residues which do not directly interact with substrates have an effect on enzyme activity. These mutant enzymes exhibited lower K(m) values for cephaloridine than both parental enzymes.

Amino Acid Sequence↗
PubMed1996

Technical note: use of a PCR-single strand conformation polymorphism (PCR-SSCP) for detection of a point mutation in the swine ryanodine receptor (RYR1) gene.

We used the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis for screening the point mutation (C1843 to T) in the porcine ryanodine receptor (RYR1) gene. The PCR products (659 bp) were heat-denatured and separated by polyacrylamide gel electrophoresis. On silver-stained gels, the point mutation within the RYR1 gene could be detected clearly by mobility shifts. The best conditions for detecting the point mutation were by using a 5% polyacrylamide gel without glycerol and loading at 3 degrees C. The RYR1 genotypes diagnosed by PCR-SSCP were identical to the genotypes diagnosed by restriction enzyme fragment length polymorphism in all cases examined (n = 606).

Animals↗
PubMed1995

Loss of expression of the human MSH3 gene in hematological malignancies.

Human MSH3 (hMSH3), previously named human mismatch repair protein 1 (MRP1), is one of the human homologs of the bacterial DNA mismatch repair protein MutS. The hMSH3 gene is expressed at low level in most types of cells. Using the RT-PCR technique, we examined the expression of the hMSH3 gene in bone marrow cells from 40 patients with various hematological malignancies. The hMSH3 mRNA was not detectable in 7 cases including 3 of chronic myelogenous leukemia, 2 of acute myelogenous leukemia, and 1 of acute lymphocytic leukemia, and 1 of myelodysplastic syndrome. In addition, 17 cases showed significantly reduced expression of the hMSH3 gene. Southern blot analysis of genomic DNA demonstrated no remarkable changes in the structure and the copy number of the hMSH3 gene in all cases. These results suggest that inactivation of the hMSH3 gene may be involved in the development of hematological malignancies.

Base Sequence↗
PubMed1995

Nine-bp repeat polymorphism in exon 1 of the hMSH3 gene.

We have identified a polymorphic 9-bp repeat sequence in exon 1 of the hMSH3 gene using polymerase chain reaction (PCR). Five alleles were observed in unrelated Japanese individuals with heterozygosity of 0.57.

DNA-Binding Proteins↗
PubMed1994

PreS1 deleted variants of hepatitis B virus in patients with chronic hepatitis.

Defective hepatitis B virus lacking 183 bases of the 3'-terminus part of the preS1 region was found in the sera of two patients with chronic hepatitis B virus infection. Results of sequencing analysis of samples with or without polymerase chain reaction yielded the same result, proving that this deletion was not due to an artifact obtained during polymerase chain reaction. One of the deletion ends lay in TCAGG that appeared five times in the genome of subtype adr and the other end was identified as TCAGG in direct repeats of the genome. The mutated hepatitis B virus became predominant in one patient's serum only after consecutive interferon therapy, suggesting that the deleted part might play a role in viral elimination from the circulation.

Base Sequence↗
PubMed1993

Significance of pre-S region-defective hepatitis B virus that emerged during exacerbation of chronic type B hepatitis.

A defective form of the hepatitis B virus has been found in a patient with chronic type B hepatitis. Sequence analysis of the viral DNA after polymerase chain reaction amplification revealed a 117-base pair deletion (nucleotides 3129-53, subtype adr). This deletion includes the initiation codon of the pre-S2 region and a newly created in-frame stop codon in the pre-S1 region (nucleotide 3055) located 230 base pairs downstream from the pre-S1 initiation codon. This virus coexisted with the wild-type virus during the exacerbation period, as evidenced by an elevation of serum transaminase levels. It was not detected in the stable period, and the blood chemistry results were normal. We assayed antibodies against the mutation-related region by enzyme immunoassay in serial serum samples to clarify the mechanism of the emergence of this variant virus. Antibodies against the pre-S2 region were negative; however, the antibody response against the pre-S1 epitopes coincided with the appearance of the variant virus. These findings suggest that an activated T-cell and B-cell response had developed against the pre-S1 region during hepatic inflammation in this patient and that, consequently, selection occurred for a pre-S antigen-defective mutant strain of the virus that might be resistant to such an immune response.

Adult↗
PubMed1993

Distribution of intrathecally administered ACNU in mongrel dogs: pharmacokinetics and quantitative autoradiographic study.

The pharmacokinetics of 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU) in the cerebrospinal fluid (CSF), were determined in dogs after ventriculolumbar perfusion (VLP, n = 6), and bolus injection into the ventricle (VB, n = 2), cisterna magna (MB, n = 5), and lumbar cistern (LB, n = 3), by high-performance liquid chromatography. The VLP method introduced effective amounts of ACNU into the lumbar cistern for cell kill in vitro. That is, the areas under the time concentration curve (AUC) of ACNU in the lumbar CSF for those receiving a 1.5 mg perfusion of ACNU were 481, 791, and 520 micrograms.min/ml and those receiving a 5 mg perfusion were 1,081, 2,048, and 1,215 micrograms.min/ml, respectively. These values were superior to 3-log cell kill condition of 9L gliosarcoma and 1.5-log cell kill of HU-126 human glioma cell line. Among the groups to which 5 mg of ACNU was administered, the VLP method attained significantly higher AUC values in the lumbar CSF than MB method. Quantitative autoradiography using an imaging plate system was performed in the VLP group (n = 2), VB group (n = 1), MB group (n = 2), and LB group (n = 2) using a 10 microCi/kg [ethylene-14C] ACNU dose which is thought to be related to the alkylating activity of ACNU. The VLP method attained a stable and abundant distribution of ACNU in the neural axis from the ventricular cavity to the lumbar cistern, but the cerebral convexity surface was devoid of a significant level of ACNU. When the MB method was used, the pharmacokinetic data varied in the cisterna magna and lumbar region, and again no significant level of ACNU was detected in the ventricular cavity. With the LB method, although a rich distribution was detected in the spinal cord, the concentration decreased abruptly at the upper cervical level. The VB method was unsatisfactory for obtaining an effective amount of ACNU in the lumbar region. The research and testing to date indicate that the VLP method is the procedure of choice in the treatment of meningeal dissemination.

Animals↗
PubMed1992

Gly145 to Arg substitution in HBs antigen of immune escape mutant of hepatitis B virus.

A Japanese child born to an HBeAg-positive carrier mother received anti-HBs immunoglobulins and a plasma-derived HBs vaccine with a poor anti-HBs-antibody response. The child, who is now 3 years old, is presently suffering from chronic hepatitis with unusual serological findings that are positive for HBsAg, anti-HBs and HBeAg, since being infected with a measles virus at 12 months of age. The nucleotide sequences of the S region of HBV DNA obtained from the patient, the mother and an HBeAg-positive brother were completely identical except for one nucleotide at position 587 (mother and brother: guanosine, patient: adenosine), giving an amino acid change: Gly - greater than Arg at position 145 of the major HBs protein.

Amino Acid Sequence↗
PubMed1992

[Detection of the deletion of interferon-alpha and beta genes in lymphoblastoid cells by PCR].

The HuIFN-alpha and beta genes were examined by the PCR method in the 11 human lymphoblastoid cell lines. The results showed that the homozygous deletion of HuIFN-alpha and beta genes was detected in 5 of 11 cell lines and in 5 of 11 cell lines, respectively. The deletions of both the HuIFN-alpha and beta genes were observed in 4 of 11 cell lines. One T cell leukemia cell line deleted only HuIFN-alpha gene, while the other T cell leukemia line deleted only HuIFN-beta gene. This suggests that the deletions of HuIFN-alpha and beta genes may be related the development of leukemia or lymphoma.

Burkitt Lymphoma↗
PubMed1991

Detection of influenza viruses in throat swab by using polymerase chain reaction.

An assay protocol based on exploiting the polymerase chain reaction (PCR) for the direct detection of influenza virus in throat swab is described. By use of the mixture of H1 and H3 primers, it was possible to determine the subtype of the influenza A viruses simultaneously. No visible band was detected after PCR of influenza B or A (H2N2) viruses with a pair of H1 or H3 primers. The dilution experiment showed that the influenza viruses, as few as 1.3-6 plaque-forming units, were sufficient for detecting the HA gene by PCR. All throat swab samples from which influenza viruses had been isolated by conventional method were also positively detected by PCR method.

Electrophoresis, Agar Gel↗
PubMed1991

[Intrathecal distribution of ACNU by various modes of its administration analyzed by HPLC and autoradiography].

Various modes of administration of ACNU (nimustine hydrochloride) were tried to make clear which mode is the best method to obtain intrathecal diffuse distribution of ACNU to match the condition of killing of glioma cells (10 micrograms/ml; greater than 30 min.). Tried modes of administration included 1)bolus injection into ventricular cavity, 2)bolus injection into cisterna magna, 3)bolus injection into lumbar subarachnoid space, 4)ventriculo-lumbar perfusion, 5)chiasmatic cistern-lumbar perfusion. Used dose of ACNU was 5 mg/body for all modes of administration. ACNU level in CSF was measured by HPLC method specially developed by authors. To make clear intrathecal distribution of ACNU, autoradiography using 14C-ethylene-ACNU was studied after administration of 10 muCi/Kg of radioactive ACNU. The images were studied by image analyzer system (BAS-2,000 system developed by Fuji Film Co. Ltd). Among the modes of administration tried, ventriculo-lumbar perfusion method gave the best results in terms of lumbar, ventricular, cisterna magna, and basal cistern distribution of ACNU to match the cell kill condition experimentally ascertained. Although, bolus injection of ACNU into cisterna magna gave sufficient amount of ACNU in lumbar region, the initial level of ACNU was too high in cisterna magna, and administration of ACNU once a week for three times in a canine cisterna magna resulted in considerable deterioration of brain stem and basal structure. In addition to it, the level of ACNU in ventricular cavity was not detectable. Lumbar bolus injection resulted in also too much ACNU accumulation at the injected lumbar area, and at the cisterna magna region, ACNU was not detectable.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Polymerase chain reaction to detect hepatitis B virus DNA and RNA sequences in primary liver cancers from patients negative for hepatitis B surface antigen.

BACKGROUND AND METHODS: The role of hepatitis B virus (HBV) in the course of patients with primary liver cancer who are negative for hepatitis B surface antigen has been debated. We used the polymerase chain reaction to evaluate 28 such patients for the presence of DNA and RNA sequences of the virus; 22 of these patients had associated cirrhosis. The patients were from areas with different prevalences of HBV infection (South Africa, Italy, France, and Japan). RESULTS: Antibodies to the surface and core antigens of HBV were detected in 10 of the 23 patients tested. HBV DNA sequences were detected in 17 of the 28 patients, including 8 of the 10 with HBV antibodies and 6 of 13 without HBV serologic markers. HBV RNA molecules were found in four of five tumors tested. CONCLUSIONS: Our investigation indicates that transcriptionally active HBV genomes are present in various geographic areas among patients with liver cancer who are negative for hepatitis B surface antigen. This observation is consistent with an etiologic role for the virus in the development of these tumors.

Adult↗
PubMed1990

S-adenosyl-L-methionine ameliorates reduced local cerebral glucose utilization following brain ischemia in the rat.

The average values of the local cerebral glucose utilization (LCGU) were approx. 35-110 mumols/100 g/min in various nuclei in the brain of sham-operated animals. The values, however, were decreased by 25-75% in all areas examined at 24 hr after 4-vessel occlusion (forebrain ischemia) for 0.5 hr. Particularly, the LCGU values in the forebrain nuclei such as the cerebral cortices and thalamus were severely reduced, while that in the nuclei in the midbrain and hindbrain such as the red nucleus, chochlear nucleus and vestibular nucleus were slightly reduced. In rats treated with S-adenosyl-L-methionine (SAM, 100 mg/kg, i.p.) every 1 hr for 6 times from the recirculation, however, the LCGU values were increased in all brain structures by 35-195% in the forebrain ischemic rat. A significant increase was observed in the cerebral neocortices, caudate-putamen, lateral septal nucleus, thalamic nuclei, substantia nigra, cerebellum and some other nuclei. In some forebrain structures whose LCGU were mildly reduced to approx. 60-70% by the ischemia, SAM recovered the LCGU to more than 90% of the value in the sham-operated group. Thus it was concluded that SAM ameliorated widely ischemia-induced reduction of LCGU in the rat.

Animals↗
PubMed1989

Studies on the techniques of topical application with fluoride gel. 2. Standardization on the amounts of gel applied.

In the previous report, the results of an experiment for utilization of the practically available tray in our effort to introduce a new technique for the application of fluoride gel products to patients were described. Through the experiment, it was found that the groove in the sponge tray is too shallow for the application of gel, and the need for standardization of the proper amount of fluoride gel for application was felt. In the present study, an experiment using an improved version of a ready-made sponge tray was conducted. Simultaneously, the standardization of the amount of gel for application using cotton pellets, sponge tray and custom-fitted tray was attempted with good results. However, problems still remain concerning the way of accommodating the standardized amount of gel in a tray, and how to apply the gel intraorally using the cotton pellets.

Dental Instruments↗
PubMed1988

Transmission of hepatitis B from hepatitis-B-seronegative subjects.

The polymerase chain reaction (PCR) was used to identify and characterise serum HBV DNA sequences in 3 patients negative for all HBV serological markers. HBsAg determinants were detected in 1 individual by monoclonal anti-HBsAg immunoradiometric assay. By use of sets of primers on the S and pre-S parts of the HBV genome the presence of HBV DNA was demonstrated in the serum of all 3 patients. Inoculation of human sera to 2 chimpanzees induced acute hepatitis in both animals; 1 became positive for HBsAg and anti-HBcAg and the other only for anti-HBsAg. Cloning of DNA sequences from viral isolates from 1 chimpanzee and 1 patient was accomplished after amplification of the 3' region of the S gene. Comparison of the partial nucleotide sequence with that of known HBV subtypes showed 0 and 1 point mutation, respectively, in the highly conserved 3' end of the S gene. Therefore the results show that PCR with HBV primers may unambigously identify HBV infectious particles among non-A, non-B viruses and is a potentially useful diagnostic test for detection of HBV DNA sequences in serum.

Animals↗