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Biomedical subjects

K Kishi

Publications and source records attributed to K Kishi.

At least 361 records · Page 20Linked to original sources
PubMed1994

Purification and characterization of human brain ribonuclease inhibitor.

Ribonuclease inhibitor (RI) was purified about 1300-fold from human cerebrum (including a small portion of midbrain) by a combination of ammonium sulfate precipitation, ribonuclease A-Sepharose chromatography, and high-performance anion-exchange chromatography. The purified RI appeared to be homogeneous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Using the same method, a homogeneous RI was also obtained from human hindbrain (brainstem and cerebellum). The cerebral RI appeared to be virtually identical with the hindbrain RI on the basis of the following properties: (a) Molecular mass was estimated to be 50 kDa on SDS-PAGE under reducing conditions. (b) Composition analysis revealed that the RI was rich in leucine and cysteine residues and included no amino sugars. (c) The N-terminus was blocked and probably modified by N-acetylation. After treatment with trifluoroacetic acid, it became susceptible to Edman degradation and was sequenced as Ser-Leu-Asp-Ile-Gln-Ser-Leu-Asp-Ile-Gln-(Cys)-Glu-Glu-. (d) The RI, which showed sulfhydryl-dependent inhibitory activity on both secretory-type and nonsecretory-type ribonucleases, bound tightly to ribonuclease to form a 1:1 complex on a molar basis. (e) The RI cross-reacted strongly with anti-human placental RI antibody. These findings also indicate that human brain RI is quite similar to human placental RI. In contrast to the abundance of RI in human brain tissue (about 0.08% (w/w) of total protein), RI was undetectable in human cerebrospinal fluid, suggesting that brain RI may not be a secreted protein.

Amino Acid Sequence↗
PubMed1994

Phosphorylation and activation of mitogen-activated protein kinase by kainic acid-induced seizure in rat hippocampus.

Injection of kainic acid into rat induced a limbic seizure and increased the activities of two protein kinases with Mrs of 42 kDa and 44 kDa in the hippocampus. These two protein kinases were identified as MAP kinases by an anti-MAP kinase antibody. These MAP kinases were phosphorylated at least at a tyrosine residue. The time course of the MAP kinase activation was roughly parallel with that of the seizure. These results indicate that the kainic acid-induced seizure induces MAP kinase activation in rat hippocampus.

Animals↗
PubMed1994

Mechanism of manganese peroxidase compound II reduction. Effect of organic acid chelators and pH.

The effect of oxalate, malonate, lactate, and succinate chelators on the reduction of Phanerochaete chrysosporium manganese peroxidase compound II by MnII was investigated using stopped-flow techniques. All rate data were collected from single-turnover experiments under pseudo-first-order conditions. With oxalate, the reduction of compound II by MnII exhibited saturation behavior when the observed pseudo-first-order rate constants were plotted against oxalate concentration. The plots passed through the origin, indicating that the reduction by MnII is irreversible at all concentrations of oxalate. Maximal stimulation of the rate of compound II reduction occurred at 2 mM oxalate, the concentration of oxalate found in the extracellular medium of agitated cultures of this fungus. In contrast, maximal stimulation of the reduction of compound II by MnII only was observed at high (> 20 mM) nonphysiological concentrations of malonate and lactate. Furthermore, at low concentrations of malonate and lactate, the reduction of compound II appeared to be reversible. These results suggest that at physiological concentrations oxalate chelates and stabilizes MnIII, enhancing its efficient removal from the enzyme. The rate constants for compound II reduction exhibited bell-shaped curves as a function of pH and had optima at pHs 5.0-5.4. In the presence of succinate, triphasic kinetics were observed for compound II reduction by MnII. In contrast to the reduction of compound II by MnII, various chelators had no observable effect on the formation of compound I. However, they did affect the steady-state oxidation of 2,6-dimethoxyphenol.

Basidiomycota↗
PubMed1994

Haplotype analysis at the FRAXA locus in the Japanese population.

Fragile X syndrome, one of the most common human genetic diseases, is characterized by a unique genetic mechanism which involves dynamic mutation in a heritable unstable DNA sequence, a p(CCG)n repeat, in the FRAXA locus. It has recently been suggested that a few founder chromosomes are responsible for most fragile X mutations in the Caucasian population. In order to investigate the origin of the fragile X mutations in the Japanese population, we analyzed haplotypes of the FRAXA locus in 40 unrelated fragile X chromosomes and 142 normal X chromosomes in Japanese males, by using two polymorphic AC repeats, FRAXAC1 and FRAXAC2, which flank the fragile site. This analysis provided evidence for founder fragile X chromosomes in the Japanese population, similar to that in Caucasians, although different haplotypes are involved. The distribution of normal allele size of the p(CCG)n repeat among the X chromosomes in the Japanese population is very similar to that reported for Caucasians, except that the most frequent copy number (n = 28) is one copy less than that in Caucasians and that there is an additional peak at 35 copies. There is significant correlation between FRAXAC alleles and the p(CCG)n repeat copy number in non-fragile X chromosomes, however, alleles with more than 31 copies of the p(CCG)n repeat do not segregate with either of the fragile X common FRAXAC haplotypes.

Asian People↗
PubMed1994

Preliminary crystallographic analysis of manganese peroxidase from Phanerochaete chrysosporium.

Manganese peroxidase from the white rot basidiomycete Phanerochaete chrysosporium has been crystallized in a form suitable for high-resolution X-ray structure determination. Crystals were grown from solutions containing 30% polyethylene glycol 8000, ammonium sulfate and cacodylate buffer at pH 6.5, using macroseeding techniques. A complete data set has been obtained to 2.06 A resolution. The data can be indexed in space group P1 with a = 45.96 A, b = 53.77 A, c = 84.87 A, alpha = 97.01 degrees, beta = 105.72 degrees and gamma = 90.1 degrees, with two peroxidase molecules per asymmetric unit, or in space group C2 with a = 163.23 A, b = 45.97 A, c = 53.72 A and beta = 97.16 degrees, with only one molecule in the assymetric unit. Lignin peroxidase, which shares about 57% sequence identity with manganese peroxidase, was used as a probe for molecular replacement. Unique rotation and translation solutions have been obtained in space groups P1 and C2. The structure has been partially refined in space group C2 to R = 0.22 for data between 10 and 2.06 A.

Basidiomycota↗
PubMed1994

[Self-expandable metallic stent therapy for inferior vena cava obstruction secondary to malignancy: clinical observations].

To evaluate the self-expandable metallic stent therapy for inferior vena caval obstruction (IVCO) secondary to malignant liver tumors, changes in caval pressure, the symptoms and hemobiochemical values were observed. Among 16 IVCO cases with higher caval pressure than 20 cmH2O at the peripheral caval lumen to the stenosis, nine cases consisting of five extracaval compression cases and four intravenous tumor thrombi cases subjected the stent therapy. Other three subjected radiotherapy and the other four cases inactive supportive care. Immediately after the Z-stent implantation, the averaged caval pressure distal to the stenosis decreased from 27.7 +/- 3.5 cmH2O to 14.7 +/- 2.6 cmH2O. One case developed 8 cmH2O increase of right atrial pressure but no lung edema. The urine excretion volume increased after stent. The decrease in caval pressure correlated with the urine volume of the day after the stenting (gamma = 0.83), symptomatic improvements of leg edema (gamma = 0.68), ascites (gamma v 0.51) and scrotal edema (gamma = 0.70). Five cases showed gradual increase in platelet number. All elevated LDH and elevated fibrinogen value decreased. These changes would suggest physiologic benefits of the IVC stent therapy. Compression cases showed better improvements and courses than the thrombi cases. Two thrombi cases endured severe conditions suspected of triggered by the procedure. Conclusively, the stent therapy to the IVC obstruction was thought to effect hemodynamically and hematobiochemically.

Aged↗
PubMed1994

[A twining method for struts connection in Z-stents].

To compose Gianturco Z-stents without welding, a twining method was applied. The link portion of the struts of were spirally entwined by a thin stainless steel wire of 0.1 mm in diameter. The directional balance of spring force of the twined stents compared favorably with that of the conventionally welded stents. This twining method has theoretical benefit of less susceptible to corrosion than soldering. Then the twining method was thought to be beneficial in composing Z-stents.

Equipment Design↗
PubMed1994

Use of antibodies against synthetic peptides for analysis of molecular multiplicity: human deoxyribonuclease I polymorphism.

Eight different antibodies were raised in rabbits and chickens by injecting them with two synthetic N- and C-peptides, which corresponded to the N- and C-terminal 15 residues of human deoxyribonuclease I (DNase I). These two peptides were used as immunogens, both free and conjugated with keyhole limpet hemocyanin (KLH). A rabbit antiserum against the C-peptide conjugated with KLH (rabbit anti-C/KLH) and two chicken antisera against the C-peptide itself (chicken anti-C) and conjugated with KLH (chicken anti-C/KLH) reacted well with purified DNase I, blotted onto a transfer membrane after isoelectric focusing in a polyacrylamide gel. A clear isoenzyme pattern identical to that detected with a rabbit antiserum against the parent enzyme (rabbit anti-DNase I) was observed. Surprisingly, the chicken anti-C antiserum was found to be a powerful and highly specific tool for the determination of urinary DNase I phenotypes (Kishi et al., Hum. Genet. 1989, 81, 295-297) and was not inferior in any respect to the rabbit anti-DNase I. These findings show that the selection of immune animal is one of the most important factors for producing an effective anti-peptide antibody. Unfortunately, the anti-peptide antisera obtained in this study neither blocked DNase I enzyme activity nor did it bind to the enzyme.

Animals↗
PubMed1994

Genetically polymorphic alpha-L-fucosidase (FUCA1) isozymes detected in blood plasma.

The main isozyme patterns of desialylated blood plasma or serum alpha-L-fucosidase (FUCA) were found to be almost identical to those of semen, urine, placental extracts, and leukocyte lysates, when detected by polyacrylamide gel isoelectric focusing, and activity staining using the fluorogenic substrate 4-methylumbelliferyl-alpha-L-fucopyranoside. Three phenotypes (1, 2-1, and 2) determined from plasma samples were identical to the phenotypes from urine and leukocyte lysates from the same individuals. A population study of plasma samples collected from 485 Japanese individuals indicated that the frequencies of the FUCA1*1 and FUCA1*2 alleles were 0.7505 and 0.2495, respectively. The mean plasma enzyme activities (+/- SD) of the three phenotypes were 318.8 +/- 116.7 nmol/ml per h for type 1, 268.0 +/- 108.3 nmol/ml per h for type 2-1, and 233.2 +/- 84.4 nmol/ml per h for type 2. The mean activities of types 1 and 2 suggest that, on average, the FUCA1*1 gene product in plasma has about 1.4 times the activity of FUCA1*2.

Adult↗
PubMed1994

Immunocytochemical survey of the neuroepithelial endocrine system in the respiratory tract of the Tokyo salamander, Hynobius nebulosus tokyoensis TAgo.

The epithelial lining of the respiratory tract of urodeles has been shown to harbor an innervated system of neuroepithelial endocrine (NEE) cells. Even between phylogenetically closely related species, large differences have been reported in the appearance and chemical coding of the NEE system. Although urodeles are well suited for the purpose, none of the prior studies have provided an immunocytochemical survey of the NEE system in all parts of the respiratory tract. In the present study, many bioactive substances and a general marker were immunocytochemically demonstrated in serial sections of the entire respiratory tract of the Tokyo salamander, Hynobius nebulosus tokyoensis, a species in which neuroepithelial bodies (NEBs) were previously characterized at the electron microscopic level. In the current study, serotonin-immunoreactive solitary NEE cells were observed in variable numbers in the larynx, in all parts of the trachea, and in areas of the lungs covered with ciliomucous epithelium. Serotonin-containing NEBs, however, were detected in small cranial areas of the lung only. Solitary NEE cells were seen in the trachea and lungs of H. nebulosus tokyoensis by immunocytochemical staining for somatostatin, calcitonin, calcitonin gene-related peptide, and bombesin, but the number, localization, and appearance of the labeled NEE cells differed considerably. Only calcitonin-like immunoreactivity was also noted in some NEB-like cell clusters in the cranial parts of the lungs. Unlike many other vertebrates, neuron specific enolase was found to be a poor marker for the NEE system in the salamander species used in this investigation. It may be concluded that the NEE system of H. nebulosus tokyoensis contains at least five different bioactive substances.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Effect of penicillin on GABA-gated chloride ion influx.

To investigate the mechanism of penicillin-induced convulsions, we have studied the effects of penicillin G (PC-G) on GABA-gated chloride ion influx in brain 'microsac' preparations of mice. In the presence of 10(-4) M GABA, PC-G inhibited GABA-gated chloride ion influx in a dose-dependent manner. The dose-response curve for GABA in the presence of 10(-3) M PC-G was shifted rightward and there was a decrease in maximum response. The inhibitory effects of PC-G were not reversed by RO 15-1788, an antagonist of benzodiazepine (BZ) receptors, but were reversed by washing the 'microsac' membranes. Therefore, PC-G probably exerts its proconvulsant effect by inhibiting GABA-gated chloride ion influx. However, it appears not to act through the BZ receptor of the GABA/BZ receptor complex.

Animals↗
PubMed1994

Immunohistochemical characterization of undifferentiated carcinomas of the ovary.

Immunohistochemical characteristics of undifferentiated carcinomas of the ovary were examined using formalin-fixed, paraffin-embedded tissues with an avidin-biotin staining approach. Eight cases were collected from the pathology files of our Institute from a total of 214 recorded malignant ovarian tumors. For immunostaining, antibodies reacting with epithelial membrane antigen (EMA), pankeratin, vimentin, CA 125, CA 19-9, carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), alpha-1-antitrypsin (AT), epidermal growth factor receptor (EGFR), c-erbB-2, bcl-2 and p53 proteins were used. All the cases examined were positive for EMA and pankeratin, specific markers for epithelial tumors, negative for the non-epithelial tumor marker, vimentin, and also positive for EGFR. Interestingly, only one case was positive for CA 125, despite it being one of the commonest reported indicators of ovarian cancer. CA 19-9 was positive in 7 cases, CEA in 5, AFP in 2, AT in 6 and c-erbB-2 protein in 4. Two cases were positive for p53 protein, and in 1 of these positive staining for bcl-2 was also observed. These results indicate that the epithelial nature is well preserved in undifferentiated ovarian carcinomas, although consistently positive reactions were not observed within the cases for some antigens. They further clearly show that a negative signal for CA 125 can not be considered to exclude the possibility of a primary ovarian tumor.

Biomarkers, Tumor↗
PubMed1994

A cavernous hemangioma of the rectum treated as a hemorrhoid for 1 year prior to its diagnosis: report of a case.

We report herein the case of a 28-year-old woman with a rectal cavernous hemangioma in whom recurrent rectal bleeding and marked anemia were interpreted as being caused by her coexisting internal hemorrhoids, resulting in a delay in the correct diagnosis for 1 year. Digital examination revealed a walnut-sized, wide-based, and elastic soft mass, 3 cm proximal from the anal verge, in addition to the internal hemorrhoids. Colonofiberscopy revealed a bluish submucosal lesion with superficial capillary dilatation at the same site. A transanal local resection was performed and the histological diagnosis of the tumor was cavernous hemangioma. The patient has been well without any recurrence of rectal bleeding for 2 years and 6 months since her operation. Thus, although rectal cavernous hemangioma is rare, a lack of awareness of this condition could lead to misdiagnosis as hemorrhoids and subsequent inappropriate therapy.

Adult↗
PubMed1994

Significance of distributed representation in the output layer of a neural network in a pattern recognition task.

In the cerebral cortex, it is assumed that information is represented by the activity pattern of an assembly of neurons and the synaptic efficacies among them. A distributed representation of pattern is incorporated in the output layer of a neural network with an error back-propagation algorithm, in order to study its technological merits. The network has three layers, which consist of a 32 x 32 array of units (1024) for the input layer, 6-25 units for the hidden layer and 12 units for the output layer. 12 triangular patterns with a variety of parameters are presented to the input layer. Three output-layer units are assigned to each input figure. After initial learning, the network responds to the learned pattern with high accuracy. In addition, it responds with high accuracy to similar but unpresented patterns, showing a generalisation for patterns. The network shows resistance to unit de-activation procedures. When the input layer is exposed to the learned pattern, the hidden-layer units show associative activation pattern. These results indicate that the organisation of information representation in the output layer in a neural network strongly influences both the performance of the whole network and information representation in the hidden layer.

Association↗
PubMed1994

Detection of deoxyribonucleases I and II (DNases I and II) activities in reproductive organs of male rabbits.

Deoxyribonucleases (DNases) I and II activities in 13 different organs and body fluids from healthy male rabbits were measured using the single radial enzyme diffusion method. We now show that testis, epididymis, ampulla, seminal vesicle, vesicular gland, prostate, and semen have both of the DNases I and II activities, whereas spermatozoa do not. DNase I activities were highest in epididymis and seminal vesicle, whereas DNase II activities were highest in epididymis and prostate among the reproductive organs. The presence of these two enzyme activities outside the digestive system suggests that they have another biological function in addition to their digestive roles.

Animals↗
PubMed1994

Leukemic cell membrane from acute myelogenous leukemias with massive mast cell infiltration has a mast cell differentiation activity under culture condition containing interleukin 3.

Five cases of acute myelogenous leukemia with massive mast cell infiltration in bone marrow and leukemic tumors of the soft tissue were examined to elucidate the relationship between leukemic cells and mast cells. Leukemic cells in each case showed no basophil/mast cell features and differentiated to neutrophil-like cells in liquid culture. Isolated mast cells failed to proliferate with or without growth factors used irrespective of culture conditions. Mononuclear cell fraction obtained from all patients gave rise to relatively numerous mast cells in interphase culture using IL-3 but not in other culture systems. The simultaneous addition of leukemic cell membrane and IL-3 or delayed addition of leukemic cell membrane produced more numerous and mature mast cells in the upper layer of interphase culture using IL-3. However, addition of leukemic cell membrane alone failed to increase the number of mast cells. Similar results were obtain using mononuclear cells obtained from volunteers and cord blood cells. These results indicate that a cell to cell contact or interstitial substance together with IL-3 are essential requirements for growth and maturation of mast cell precursors and that the cell membrane itself in some cases of leukemia has the ability to induce maturation of mast cell precursors.

Adolescent↗
PubMed1994

Characterization of newly established adriamycin resistant human leukemic cell lines (KY-ADR1 and KY-ADR2).

New adriamycin (ADR) resistant human leukemic cell lines (KY-ADR1 and KY-ADR2) have been established. KY-ADR1 was selected from a cytosine arabinoside (Ara C) resistant cell line by gradually increasing the concentration of ADR and KY-ADR2 from the parental cell line, KY-821, by the same method. The IC50s of both cell lines were 4.3 x 10(-5) and 3.6 x 10(-5) M ADR, respectively. Both lines revealed a similar cross resistance to various anticancer drugs, but KY-ADR1 was resistant to Ara C, whereas KY-ADR2 was sensitive. MDR1 gene was over-expressed and P-glycoprotein was expressed on the cytoplasmic membrane in both lines. Neither verapamil nor cyclosporin A could completely reverse ADR resistance. In addition, no significant changes in topoisomerase II and glutathione-s-transferase levels were detected. These findings indicate that ADR resistance in both cell lines is mainly mediated by P-glycoprotein and some other mechanism may be present. Interestingly, growth of both cell lines was stimulated by natural IL-1 and not affected by TNF alpha and IFN gamma, whereas growth of parental KY-821 was inhibited by these factors. These cell lines will provide new biological aspects on drug resistant leukemic cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗