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N Mishima

Publications and source records attributed to N Mishima.

53 records · Page 3Linked to original sources
PubMed1989

[Immunohistochemical study on distribution of transthyretin in normal human brain tissue and tumors].

Immunohistochemical examination of transthyretin (TTR), which is known to be synthesized in the epithelial cells of the choroid plexus as well as in the liver cells, was carried out on normal brain tissues and 84 human brain tumors, using a peroxidase-antiperoxidase (PAP) technique. TTR was demonstrated diffusely and strongly in the cytoplasm of normal choroid plexus cells, but not in ependyma and other tissues of normal brain. In all of 10 choroid plexus papillomas, TTR was found within the cytoplasm of tumor cells. In contrast, neither the two papillary ependymomas nor any other brain tumors contained TTR. Among the choroid plexus papillomas, some cases showed clear positive reactions in almost all tumor cells, while others had only a few TTR-positive cells. With these immunohistochemical findings, TTR proved a very useful marker of normal choroid plexus and choroid plexus papilloma.

Adult↗
PubMed1989

Preretinal membrane formation in rabbit eyes after intravitreal transplantation of cultured astrocytes.

Astrocytes were cultured from the cerebral cortices of newborn rabbits and were so confirmed by staining of the glial fibrillary acidic protein (GFAP). In Experiment I, the astrocytes of newborn rabbits of both sexes from one mother were pooled and suspended in a culture medium, and approximately 1-2 X 10(4) cells were injected into the vitreous cavity of one eye and the culture medium alone was injected into the fellow eye of the mother rabbit. In Experiment II, the astrocytes cultured from the cerebral cortex of a single newborn rabbit of known sex were injected into both eyes of the mother or father rabbit. In the 24 eyes receiving the astrocyte injection, 22 eyes developed preretinal membrane in 2.5 to 14 weeks: 11 eyes developed traction retinal detachment. In the 12 control eyes receiving the culture medium injection, preretinal membrane was seen only in one eye. The preretinal membrane consisted predominantly of spindle-shaped cells positively stained by the peroxidase-antiperoxidase method for GFAP staining. Electron microscopy showed that the major component cells of the preretinal membrane were astrocytes with characteristic intermediate filaments; no retinal pigment epithelial cells were observed. In Experiment II, the average frequency of sex chromatin detection was 4.6% and 55.2% in the male and female astrocyte cultures, respectively. Three groups of experiments were made, A) the female astrocytes injected into the mother's eyes, B) the male astrocytes injected into the mother's eyes and C) the female astrocytes injected into the father's eyes. The sex chromatin was found in the cells of the preretinal membrane at the average frequencies of 63.5%, 34.4% and 55.5% in Groups A, B and C, respectively. It was concluded that the astrocytes injected into the vitreous cavity proliferated and formed the preretinal membrane to a degree that caused traction retinal detachment, without involvement of the retinal pigment epithelial cells. It was also thought that the astrocytes from the retina of the adult host eyes participated to some extent in the preretinal membrane formation.

Animals↗
PubMed1989

[Analysis of activated lymphocytes and antigen-present macrophage in human brain tumors using double immunofluorescence staining].

Twenty-eight human brain tumors (18 gliomas and 10 metastatic brain tumors) were examined immunohistochemically using anti-Leu 1, -Leu 2 a, -Leu 3a + 3b, -LeuM 5, -HLA-DR, IL-2 receptor, -HLA-ABC and Ki-67 monoclonal antibodies (MoAb). Also, in the specimens, in which Leu 1+ cells and Leu M5+ cells infiltrate, simultaneous detection of Leu 2a, Leu 3a + 3b, or Leu M5 and HLA-DR, was performed by double immunofluorescence staining to analyze the T cell activation and antigen-present macrophage (M phi). Most of low-grade gliomas with low percentage of Ki-67+ cells showed only little lymphocyte and M phi's infiltration. THEre was a tendency toward a marked degree of T cell and M phi infiltration in malignant glioma with higher percentage of Ki-67+ cells. However, in metastatic brain tumors, M phi did not tend to infiltrate. IL-2 receptor+ cells was absent in the majority of brain tumors. Tumor cells and vascular endothelial cells also expressed HLA-DR antigens. The majority of tumor cells expressed HLA-A, B, C antigens. There were no correlation among the degree of T cell and M phi infiltration, MHC antigen expression, and percentage of Ki-67+ cells. Double immunofluorescence staining demonstrated that 42.4% of Leu 2a+ cells, 34.7% of Leu3a+ + 3b+ cells and 32.7% of M5+ cells are HLA-DR positive in glioma, and that 50.2% of Leu2a+ cells, 59.4% of Leu3a + 3b+ cells and 67.3% of LeuM5+ cells are HLA-DR positive in metastatic brain tumors.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1988

Distal CCAAT box deletion in the A gamma globin gene of two black adolescents with elevated fetal A gamma globin.

Point mutations in G gamma and A gamma globin gene promoters are associated with increased production of G gamma and A gamma globin, respectively. To determine whether an upstream promoter mutation could account for elevated A gamma in a Black adolescent with A gamma-beta+-HPFH and sickle cell trait, we cloned the 13 kb BglII fragment containing both gamma genes into phage lambda vector EMBL3. For one clone, the A gamma upstream promoter showed no hybridization to a 19 bp oligonucleotide whose sequence centered at -117. A gamma promoter sequence data for this mutant clone revealed a 13 bp deletion which eliminated the A gamma distal CCAAT box. Amplified A gamma genomic DNA of this and a similar case showed hybridization to both deletion-mutant and normal oligonucleotide probes. We propose that this 13 bp deletion removes part of the binding site for a repressor protein which is abundant in adult erythroid cells.

Adolescent↗
PubMed1988

Four base-pair DNA deletion in human A gamma globin-gene promoter associated with low A gamma expression in adults.

Fetal haemoglobin (alpha 2 gamma 2) is predominant in red cells of the fetus and newborn baby, and is largely replaced after birth by adult haemoglobin (alpha 2 beta 2). The two types of gamma chains (A gamma and G gamma) are generally less than 1% of total beta-like chain in adults, and the G gamma: A gamma ratio is typically 40:60. Higher G gamma values (greater than 50% of gamma chain) are frequently associated with a T for C nucleotide substitution 158 base pairs 5' of the G gamma Cap site (-158). The first exception to this rule was a beta o-thalassaemia in a Black family that was associated with about 60% G gamma in heterozygotes. A DNA fragment containing the G gamma and A gamma genes of the high G gamma haplotype of this case has now been cloned. DNA sequencing from -383 to the Cap site showed no differences from normal for the G gamma gene, except for C at -158. For the A gamma gene, however, a deletion of four base pairs (AGCA) at -222 to -225 was found. It is hypothesized that this deletion causes reduced A gamma globin gene expression in adults, which suggests that promoter elements important for the regulation of fetal haemoglobin expression in adults extend upstream at least to -225.

Adult↗
PubMed1988

Upstream promoter mutation associated with a modest elevation of fetal hemoglobin expression in human adults.

In hereditary persistence of fetal hemoglobin, Hb F (alpha 2 gamma 2) is elevated after birth. Screening of sickle cell patients has revealed a family with elevated Hb F and high A gamma values. The propositus was a sickle cell patient with approximately 25% Hb F and 68.4% A gamma. He was heterozygous for the Benin (#19) and Mor beta S haplotypes. Five AS relatives with the Mor haplotype had 2.5% +/- 0.9% fetal hemoglobin and 92.8% +/- 2.8% A gamma, whereas two with the Benin haplotype had normal fetal hemoglobin (0.5%). The Mor haplotype is thus associated with the elevated Hb F in this family. The 13-kilobase (kb) Bg/II fragment containing the G gamma and A gamma genes of the Mor haplotype was cloned, and the G gamma and A gamma promoters sequenced from -383 to beyond the Cap sites. The Mor G gamma gene was normal, but the A gamma gene had a unique C----T mutation at -202. A different mutation at -202 of G gamma (C----G) was previously detected by other researchers in association with considerably higher Hb F in AS cases (15% to 25%). These data suggest either that -202 mutations affect the G gamma and A gamma promoters differently or that different nucleotide substitutions at -202 have divergent effects. Alternatively, additional unknown mutations could cause the differences in gene expression.

Adolescent↗
PubMed1986

Sex differences in appetitive learning of mice.

Learning abilities of male and female ddY mice were compared in two appetitive tasks (a lever-press task and an 8-arm radial maze task), and two avoidance tasks (a shuttle box task and a light-dark discrimination T-maze task). In the two types of appetitive learning, male mice were significantly superior to female mice. Sex differences were particularly apparent in the acquisition process. In contrast, there was no significant sex difference in learning of the two avoidance tasks. A sex difference in appetitive learning was not found in juvenile mice prior to sexual maturation, and the mice which had established a lever-press response as juveniles did not show any significant difference in the performance level when tested as adults. Thus, a sex difference appeared only in the acquisition stage of adult mice. These results suggest that there exists a sex difference in motivation level for hunting food but not for feeding, and that it causes a sex difference in appetitive learning.

Aging↗
PubMed1986

Iodinated proteins in normal human thyroid gland. Thyroid albumin.

Iodinated proteins in normal thyroid tissue extracts were analyzed immunochemically, immunohistochemically and physicochemically after isoelectric focusing. An albumin-like protein ranging from pI 4.80 to 5.21 was found in normal human thyroid tissue extracts, and its pI range was not compatible with that of serum albumin ranging from pI 4.85 to 6.16. An immunodiffusion study suggests that T3 loosely combines with the albumin-like protein, and that this compound is so-called thyroid albumin. Amino acid analysis revealed a difference in the basic amino acid composition of thyroid albumin and serum albumin, and our immunohistochemical study showed that thyroid albumin and T3 were localized in follicular epithelial cells, but not in the colloid. Based on these results, thyroid albumin may be described as consisting of T3 and an albumin-like protein which is distinguishable from serum albumin and distinct from thyroglobulin immunochemically. It appears that a low molecular weight hormone like T3 can be detected when it combines with a protein molecule. Recently, DeGroot et al. (1975) suggested a collateral pathway of hormone metabolism through the thyroid albumin in thyroid follicular cells. Our results seem to support the existence of this pathway.

Albumins↗
PubMed1982

Reversible depression of spontaneous brain electrical activity induced by actinomycin D and 7-aminoactinomycin D in rats.

Various types of actinomycin (C,D,S2, I and V) and 7-amino-analogue of actinomycin D were injected into the right lateral ventricle of the brain through a chronically implanted cannula. In rats but not in mice actinomycin D, actinomycin S2 and 7-aminoactinomycin D caused depression of EEG, while cardiac and respiratory activity were maintained. This effect of the EEG was reversible and a normal EEG pattern reappeared at least 3 h after administration.

Animals↗
PubMed1981

An immunohistochemical study of lens development in a mutant small eye and cataractous mouse.

The immunohistochemical method was used to study lens formation in a new dominant mouse strain with a small eye and lens cataract (gene symbol Cs). Antisera to pure alpha- and gamma-crystallins were used. In the homozygotes, the eyes have cataractous lenses about half the size of normal lenses. In the heterozygotes, the eyes show opacities of the lens but the lens itself is normal in size. The mouse strain has two genes in the same autosome which cause the phenogenetical characteristics of small eyes and cataracts. One reflects the defect of the gamma-crystallin synthesis in the secondary lens fibers in the equatorial zone. This is a recessive gene and it may cause the small lens. The other gene is responsible for the swollen, granular and misshaped fiber cells. This is a dominant gene like that in the Fraser's cataract and it may cause the cataract lens.

Animals↗
PubMed1980

An immunohistochemical study of the Müller cells of the chicken retina.

The immunohistochemical specificity of the Müller cell of the chicken retina was studied by the indirect immunoperoxidase bridge method with glial acidic protein antiserum. The immunohistochemical result indicates that the Müller cell contains the acidic protein characteristic of astrocytes, oligodendroglia and the Bergmann cell. However, the ependymal cell does not contain the glial acidic protein. This evidence supports the concept that the Müller cell derived from the glioblast is not a modified ependymal cell but is more closely related to astrocytes and oligodendroglia.

Animals↗
PubMed1977

Impairment of acquisition of learning by inhibitors of RNA or protein synthesis.

The effects of inhibitors of RNA or protein synthesis (cycloheximide, puromycin and actinomycin D) on acquisition of learning in mice were investigated using various types of shock avoidance tasks. Mice having uniform and superior learning ability were used as subjects. Drugs were injected into the lateral ventricle 1 hr before training for avoidance tasks in three different shapes of maze and in a one-way shuttle box and for those based on light-dark discrimination. In all cases of training, the drugs were found to impair the acquisition of learning. The impairment was pronounced in a relatively complicated task such as H-maze learning as compared to a simple task such as T-maze learning. The drugs never affected the performance of pretrained animals. During the discussion, the acquisition of learning would be related to some specific process of RNA and protein synthesis in the brain.

Animals↗
PubMedDate not supplied

Insertion of stabilizing loci in vectors of T7 RNA polymerase-mediated Escherichia coli expression systems: a case study on the plasmids involving foreign phospholipase D gene.

Plasmids carrying stabilizing loci were used in the expression of phospholipase D (PLD) gene fused with pelB signal sequence by a recombinant strain of Escherichia coli BL21 (DE3) using T7 RNA polymerase mediated expression system. By checking the living cell number and the percentage of the plasmid-bearing cells, it was found that the plasmids involving PLD gene were not stable under noninduced conditions and that, after the induction, the number of plasmid-bearing cells were rapidly decreased to almost zero. Then, a biologically stabilizing locus such as par B, ccd, or par was inserted into the plasmids. The newly constructed plasmids were maintained very stably in the recombinant cells until the cells were induced. However, after the induction, almost all the recombinant cells were rapidly killed due to highly toxic PLD. Using the best one of the stabilized PLD-expressing plasmids, PLD production was improved 2-fold.

Amino Acid Sequence↗