Search PubMed⌕ Search

Biomedical subjects

J Ito

Publications and source records attributed to J Ito.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Dissecting aneurysm of the middle cerebral artery (M1-2 portion) with subarachnoid hemorrhage: a case report].

We report a SAH case of a ruptured dissecting aneurysm of the middle cerebral artery following parietooccipital subcortical hemorrhage. A 68-year-old woman was admitted to our hospital, complaining of headache. On admission she was alert with left homonymous hemianopsia. A CT scan disclosed subcortical hemorrhage in the right parieto-occipital lobe. An angiogram revealed no abnormal vessels. Seven days after admission, she suddenly lapsed into unconsciousness with left hemiparesis. A CT scan demonstrated subarachnoid hemorrhage with a right sylvian hematoma. A second angiogram revealed fusiform dilatation of the M2 branches and aneurysmal dilatation at the M1-M2 bifurcation. Following conservative therapy, she died 21 days after admission. The relationship between subcortical hemorrhage and the subsequent subarachnoid hemorrhage was not certain. We discuss and review the treatment of a dissecting aneurysm of the middle cerebral artery.

Aged↗
PubMed2000

L-152,804: orally active and selective neuropeptide Y Y5 receptor antagonist.

Neuropeptide Y (NPY) elicits food intake through the action of hypothalamic G-protein-coupled receptors. Previous publications indicate that the Y5 receptor may represent one of these postulated hypothalamic "feeding" receptors. Using a potent and orally available Y5 antagonist L-152,804, we evaluated the involvement of the Y5 receptor in feeding regulation. L-152,804 displaced [125I]peptide YY (PYY) binding to human and rat Y5 receptors with Ki values of 26 and 31 nM, respectively, and inhibited NPY (100 nM)-induced increase in intracellular calcium levels via human Y5 receptors (IC50 = 210 nM). L-152,804 did not show significant affinity for human Y1, Y2, and Y4 receptors at a dose of 10 microM. Intracerebroventricular (i.c.v.) (30 microg) or oral (10 mg/kg) administration of L-152,804 significantly inhibited food intake evoked by i.c.v.-injected bovine pancreatic peptide (bPP, 5 microg; a moderately selective Y4, Y5 agonist) in satiated SD rats. However L-152,804 did not significantly inhibit i.c.v. NPY (5 microg; a Y1, Y2, Y5 agonist)-induced food intake. These findings suggest that L-152,804 is a selective and potent non-peptide Y5 antagonist with oral bioavailability and brain penetrability. In addition, the anorexigenic effects of L-152,804 on bPP-induced feeding revealed participation of the Y5 receptor in feeding regulation, while i.c.v. administration of NPY does not appear to significantly contribute to Y5 stimulated food intake. We conclude that the potent and orally active Y5 antagonist, L-152,804, represents a useful tool to address the physiological role of the Y5 receptor.

Administration, Oral↗
PubMed2000

Characterization of the responsive elements to hormones in the rat aldolase B gene.

Transcription of the aldolase B gene, AldB, in the liver is regulated by hormones such as insulin and glucagon. To characterize the elements that are responsive to these hormones in the upstream region of AldB, plasmids carrying various length of the upstream region of this gene were constructed and transfected to primary cultured rat hepatocytes. The promoter activities were gradually increased by progressive deletion of the 5'-upstream region, and high activities were observed for constructs carrying the sequence between -408 and -85 bp, suggesting the presence of suppressive element(s) in the upstream region of -409 bp. The transcription activities of the mutants containing the sequences between -228 and -85 bp were enhanced by insulin, and glucagon suppressed the transcription activities of those containing the sequence between -764 and -85 bp. Two sequence elements similar to the cAMP-responsive element (CRE), one from -89 to -82 bp and another from +13 to +20 bp, were found in the upstream sequence of the gene. The latter element is not functional because its deletion did not affect either the transcription efficiency or glucagon response. However, the deletion of the former element diminished both functions. A gel retardation assay showed that the nuclear factor binds to the former element, which was competitive with authentic CRE oligonucleotide but not with the mutant CRE one. These results suggest that the CRE-like element in the promoter region is prerequisite for both fundamental transcription efficiency of the gene and suppression by glucagon in hepatocytes.

5' Untranslated Regions↗
PubMed2000

Inhibition of human plasma cholinesterase and erythrocyte acetylcholinesterase by nondepolarizing neuromuscular blocking agents.

PURPOSE: The kinetics of the inhibition of human plasma cholinesterase (ChE) and erythrocyte acetylcholinesterase (AChE) by alcuronium, atracurium, d-tubocurarine, pancuronium, pipecuronium, and vecuronium were studied in blood drawn from 35 surgical patients. METHODS: The activities of plasma ChE and erythrocyte AChE were determined by the calorimetric method of Ellman et al., using acetylthiocholine as the substrate. Lineweaver-Burk plots and Dixon plots were used for the analysis of the kinetics of both enzymes. RESULTS: The dissociation constants (K(m)) of plasma ChE and erythrocyte AChE were 5.00 x 10(-5) M and 5.28 x 10(-5) M, respectively, indicating that both enzymes have similar affinity to acetylthiocholine. Both Lineweaver-Burk plots and Dixon plots indicated that the six nondepolarizing neuromuscular blocking agents (NMBAs) at different concentrations induce linear mixed-type inhibition. The apparent inhibition constants (K(i)) of pancuronium (8.72 x 10(-8) M) and vecuronium (3.53 x 10(-7) M) for plasma ChE inhibition were lower than that of neostigmine (7.36 x 10(-7) M), whereas those of the six nondepolarizing NMBAs for erythrocyte AChE were markedly higher than that of neostigmine. CONCLUSIONS: Both plasma ChE and erythrocyte AChE were inhibited by six nondepolarizing NMBAs, and the pattern of inhibition of both enzymes was of mixed type. The inhibitory potencies of pancuronium and vecuronium for plasma ChE were larger than that of neostigmine, whereas those of the six nondepolarizing NMBAs for erythrocyte AChE were markedly lower than that of neostigmine. The rank order of relative potency for plasma ChE was pancuronium > vecuronium > pipecuronium > alcuronium > d-tubocurarine > atracurium.

Journal Article↗
PubMed2000

Solitary myofibromatosis of the skull.

We present a case of solitary infantile myofibromatosis of the skull in a 3-month-old boy. A right parietal subcutaneous lump was found at birth, and it increased in size over the ensuing 3 months. Surgery was performed, and a diagnosis of myofibromatosis was confirmed histopathologically. Solitary myofibromatosis of the skull is extremely rare. The radiographical, CT, and MR appearances, as well as histopathological findings, are described in this article.

Humans↗
PubMed2000

Diffusion-weighted echo-planar MR imaging in differential diagnosis of brain tumors and tumor-like conditions.

We assess diffusion-weighted MR images in the differential diagnosis of intracranial brain tumors and tumor-like conditions. Heavily diffusion-weighted (b = 1100 or 1200 s/mm2) axial images were obtained with single-shot echo-planar technique in 93 patients with pathologically confirmed various intracranial tumors and tumor-like conditions with diffusion gradient perpendicular to the images. We compared signal intensity of the lesions with those of gray and white matter, and cerebrospinal fluid (CSF). In 29 cases (31.1%) the lesions were isointense to gray and/or white matter. However, 5 cases (5.4%) showed extremely increased signal intensity: two epidermoid cysts; two chordomas; and one brain abscess. The entire portion of a tumor was markedly hyperintense in 10 cases (10.8%): four malignant lymphomas; four medulloblastomas; one germinoma; and one pineoblastoma. A CSF-like hypointense signal was seen in many cystic tumors, and cystic or necrotic portions of tumors. A neurosarcoid granulation was the only solid lesion showing characteristically a hypointense signal like CSF. The combination of markedly hyperintense and hypointense signals was seen generally in hemorrhagic tumors. Diffusion-weighted echo-planar MR imaging is useful in the differential diagnosis of brain tumors and tumor-like conditions, and suggests specific histological diagnosis in some cases.

Adolescent↗
PubMed2000

Self-organized hierarchical structure in a plastic network of chaotic units.

Formation of a layered structure is studied in a globally coupled map of chaotic units with a plastic coupling strength that changes depending on the states of units globally and an external input. In the parameter region characterized by weakly chaotic and desynchronized dynamics, units spontaneously form a hierarchical structure due to the influence of the input. This hierarchical structure is not fixed in time, and is successively reorganized. It is found that the distribution of lifetimes of the structure obeys a power law. The possible relevance of the present result to information processing in the brain is briefly discussed.

Animals↗
PubMed2000

Endonucleases.

Programmed cell death (PCD) involves hydrolysis of genomic DNA, which must be catalyzed by endonuclease(s) capable of digesting dsDNA. Plants have two major classes of endonucleases active towards dsDNA, Zn2+-dependent endonuclease and Ca2+-dependent endonuclease. Both classes are found among endonucleases nominated for machineries of PCD in plants. Survey of plant endonucleases in relation to PCD leads to a possibility that a different class of endonuclease reflects a different phase of PCD-associated DNA hydrolysis.

Amino Acid Sequence↗
PubMed2000

Immunohistochemical analysis of Ki-67, p53, p21, and p27 in benign and malignant apocrine lesions of the breast: its correlation to histologic findings in 43 cases.

We examined Ki-67, p53, p21, and p27 immunolocalization in 43 cases of apocrine lesions of the breast and correlated these findings with histologic parameters to understand their biologic significance. Twenty cases were benign, 1 case was borderline, and 22 cases were diagnosed as malignant, including 9 intraductal and 13 invasive apocrine carcinomas. Both the ratio of Ki-67-positive cases (17 of 21 [88.9%] versus 1 of 19 [5.3%]; P < .001) and the Ki-67 labeling index of positive cases examined (15.0% versus 2.7%; P < .005) were significantly higher in malignant than in benign apocrine lesions. None of the benign or borderline cases was immunohistochemically positive for p53, but 15 of 22 malignant cases (68.2%) demonstrated p53 (P < .001). In addition, the ratio of p53-positive cases was significantly higher in high nuclear grade cases (11 of 13 [84.6%]) than in intermediate nuclear grade cases (4 of 9 [44.4%]; P < .05). P53 immunoreactivity was also positively correlated with the nuclear grade of carcinoma cases examined in this study. Neither p21 nor p27 demonstrated any correlation with histologic parameters or findings of the apocrine lesions. Results of these studies suggest that Ki-67 and p53 may be good markers for differentiation between benign and malignant breast apocrine lesions.

Apocrine Glands↗
PubMed2000

Embryonal sarcoma of adult and pediatric kidneys: report of a case with localized submucosal invasion of the renal pelvis and long-term survival.

A case of cystic embryonal sarcoma of the kidney (CESK) with a rapidly fatal outcome was recently reported.1 Here, we report another case of a 12-year-old boy with a localized but ill-defined submucosal lesion of CESK in the right renal pelvis. The tumor consisted principally of small mesenchymal cells with oval to spindle nuclei and scanty cytoplasm, infiltrating in dense arrangements. Two growth patterns were distinguished in the tumor cells: (i) a diffuse infiltrating pattern without an epithelial component; and (ii) a foliated pattern with an epithelial lining over the surface. Foci of the diffuse pattern predominated over those that were lobular, infiltrating superficial layers of renal sinuses and along pyramids, in both of which remarkable intravenous invasion was evident. Foci of the foliated pattern invaded deeper portions of a few sinuses and frequently penetrated into their veins, producing together with their epithelial lining a characteristic foliated structure. Lining epithelial cells around lobular foci often appeared hob-nailed or eosinophilic in the cytoplasm. Despite the remarkable intravenous encroachment, the patient has remained well without a recurrence for more than 26 years after a simple nephrectomy. The present case report expands our understanding of the biological nature of CESK.

Child↗
PubMed2000

Suppressive effects of co-stimulatory molecule expressions on mouse splenocytes by anti-allergic agents in vitro.

The influence of anti-allergic drugs, epinastine hydrochloride (EP) and disodium cromoglycate (DSCG), on the co-stimulatory molecule expression was examined using in vitro cell culture technique. Spleen cells obtained from BALB/c mice 10 days after immunization with haemocyanin absorbed to aluminium hydroxide were cultured in the presence of 100.0 microg/ml haemocyanin and various concentrations of the agents. Low concentrations (<1.5 x 10(-4)M) of EP and DSCG did not influence spleen cell blastic activity induced by antigenic stimulation, whereas these agents caused significant inhibition of spleen cell activation when 2 x 10(-4) M of the agents were added to cell cultures. EP and DSCG also did not affect blastic activity of sensitized splenic T cells by anti-CD3 monoclonal antibody stimulation even when these cells were cultured in the presence of 2 x 10(-4) M of the agents. We next examined the influence of EP and DSCG on the expression of co-stimulatory molecules on spleen cells in response to antigenic stimulation. Sensitized spleen cells were cultured in the presence of 2 x 10(-4)M of the agents and the expression of molecules were examined by flow cytometer 24h later. EP and DSCG suppressed the expression of costimulatory molecules, CD40 and CD80, but not CD86, on splenic B cells which were enhanced by antigenic stimulation in vitro.

Animals↗
PubMed2000

Prevalence of mitochondrial gene mutations among hearing impaired patients.

The frequency of three mitochondrial point mutations, 1555A-->G, 3243A-->G, and 7445A-->G, known to be associated with hearing impairment, was examined using restriction fragment length polymorphism (RFLP) analysis in two Japanese groups: (1) 319 unrelated SNHL outpatients (including 21 with aminoglycoside antibiotic injection history), and (2) 140 cochlear implantation patients (including 22 with aminoglycoside induced hearing loss). Approximately 3% of the outpatients and 10% of the cochlear implantation patients had the 1555A-->G mutation. The frequency was higher in the patients with a history of aminoglycoside injection (outpatient group 33%, cochlear implantation group 59%). One outpatient (0.314%) had the 3243A-->G mutation, but no outpatients had the 7445A-->G mutation and neither were found in the cochlear implantation group. The significance of the 1555A-->G mutation, the most prevalent mitochondrial mutation found in this study of a hearing impaired population in Japan, among subjects with specific backgrounds, such as aminoglycoside induced hearing loss, is evident.

Aminoglycosides↗
PubMed2000

Role of the Y1 receptor in the regulation of neuropeptide Y-mediated feeding: comparison of wild-type, Y1 receptor-deficient, and Y5 receptor-deficient mice.

Neuropeptide Y (NPY) increases food intake through the action of hypothalamic NPY receptors. At least six subtypes of NPY, peptide YY (PYY), and pancreatic polypeptide (PP) receptors have been identified in mice. Although the involvement of Y1 and Y5 receptors in feeding regulation has been suggested, the relative importance of each of these NPY receptors and the participation of a novel feeding receptor are still unclear. To address this issue, we generated a Y1 receptor-deficient (Y1-/-) and a Y5 receptor-deficient (Y5-/-) mouse line in which we directly compared the orexigenic effects of NPY and its analogs after intracerebroventricular (icv) administration. The icv NPY-induced food intake was remarkably reduced in Y1-/- mice, but was not significantly altered by inactivation of the Y5 receptor. The Y1 receptor therefore plays a dominant role in NPY-induced feeding. Stimulation of feeding by moderately selective Y5 agonists [PYY-(3-36), human PP, and bovine PP] was reduced in Y5-/- mice, although food intake did not decrease to vehicle control levels. These results indicate that the Y5 receptor functions as one of the feeding receptors. In addition, the finding that Y5-preferring agonists still induce food intake in Y5-/- mice suggests a role for another NPY receptor(s), including the possibility of novel NPY receptors. Surprisingly, despite the limited efficacy of PYY-(3-36) and PPs at the Y1 receptor, food consumption induced by these agonists was significantly diminished in Y1-/- mice compared with that in wild-type controls. These observations suggest that the feeding stimulation induced by NPY and its analogs may be directly or indirectly modulated by the action of the Y1 receptor. We conclude that multiple NPY receptors, possibly including the novel feeding receptor, are involved in the feeding response evoked by NPY and its analogs. Among them, the Y1 receptor plays a key role in NPY-induced feeding in mice.

Animals↗
PubMed2000

Characterization of bovine and human lactoferrins as glycyrrhizin-binding proteins and their phosphorylation in vitro by casein kinase II.

The binding ability of bovine and human lactoferrins (bLF and hLF; LFs) to a glycyrrhizin (GL)-affinity column and their phosphorylation by casein kinase II (CK-II) in vitro were biochemically investigated. It was found that (i) both bLF and hLF are GL-binding proteins; (ii) purified both proteins function as phosphate acceptors of CK-II; and (iii) this phosphorylation is completely inhibited by two polyphenol-containing anti-oxidant compounds (quercetin and epigallocatechin gallate) at I microm, whereas a glycyrrhetinic acid derivative (oGA) inhibits it at one tenth the concentration of GL. The DNA-binding affinity of hLF was reduced by GL in a dose dependent manner. However, no significant effect of the CK-II-mediated hLF phosphorylation on its DNA-binding affinity was detected. These results suggest that the GL-induced inhibition of the DNA-binding affinity and the CK-II-mediated phosphorylation of hLF may be closely correlated with the anti-inflammatory effect of GL in the human body.

Animals↗
PubMed2000

Biochemical characterization of 60S acidic ribosomal P proteins from porcine liver and the inhibition of their immunocomplex formation with sera from systemic lupus erythematosus (SLE) patients by glycyrrhizin in vitro.

The three casein kinase II (CK-II) phosphate acceptors (p35, p17 and p15) in the Superdex CK-II fraction prepared from a 1.5 M NaCl extract of porcine liver were selectively purified by glycyrrhizin (GL)-affinity column chromatography (HPLC) as a heterocomplex associated with CK-II. Determination of the N-terminal amino acid sequences and immunological tests confirmed that these three CK-II phosphate acceptors belong to the family of 60S acidic ribosomal proteins (P0, P1 and P2). Three polyphenol-containing anti-oxidant compounds [catechin, epigallocatechin gallate (EGCG) and quercetin] inhibited CK-II activity (phosphorylation of these ribosomal P proteins) in a dose-dependent manner in vitro. Quercetin (ID50 = approx. 50 nM) was found to be an effective CK-II inhibitor. In contrast, CK-II activity was significantly stimulated by lower doses (0.3-3 microl) of GL, but was inhibited at high doses above 30 microM. As expected, GL at high doses above 200 microM inhibited the immunocomplex formation of 60S acidic ribosomal P proteins with their specific antibodies in the sera from patients with systemic lupus erythematosus (SLE). These results suggest that (i) a GL-affinity column is useful for effective purification of 60S acidic ribosomal P proteins from various mammalian cells as a heterocomplex associated with CK-II; and (ii) a relative high dose of GL may prevent the immunocomplex formation of 60S acidic ribosomal P proteins with their specific antibodies in the sera of SLE patients.

Amino Acid Sequence↗
PubMed2000

Purification, characterization, and molecular cloning of acidophilic xylanase from penicillium sp.40.

Penicillum sp. 40, which can grow in an extremely acidic medium at pH 2.0 was screened from an acidic soil. This fungus produces xylanases when grown in a medium containing xylan as a sole carbon source. A major xylanase was purified from the culture supernatant of Penicillium sp. 40 and designated XynA. The molecular mass of XynA was estimated to be 25,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. XynA has an optimum pH at 2.0 and is stable in pH 2.0-5.0. Western blot analysis using anit-XynA antibody showed that XynA was induced by xylan and repressed by glucose. Also, its production was increased by an acidic medium. The gene encoding XynA (xynA) was isolated from the genomic library of Penicillium sp. 40. The structural part of xynA was found to be 721 bp. The nucleotide sequence of cDNA amplified by RT-PCR showed that the open reading frame of xynA was interrupted by a single intron which was 58 bp in size and encoded 221 amino acids. Direct N-terminal amino acid sequencing showed that the precursor of XynA had a signal peptide composed of 31 amino acids. The molecular mass caliculated from the deduced amino acid sequence of XynA is 20,713. This is lower than that estimated by gel electrophoresis, suggesting that XynA is a glycoprotein. The predicted amino acid sequence of XynA has strong similarity to other family xylanases from fungi.

Amino Acid Sequence↗
PubMed2000

Morphological evaluation of the baboon hind limb muscles based on relative weight.

Morphological features of the hind limb muscles reflect the muscular function correlating with the locomotion. In this study, the muscles of the baboon hind limb were weighed and the relative muscle weights were compared with those of the human lower extremity. In the baboon, the biceps femoris was the largest (11.60%) and the vastus lateralis (10.67%) was placed second. The gluteus medius (8.55%) among the hip muscles and the gastrocnemius (4.38%) among the leg muscles were predominant in each segment. The relative weights of the gluteus medius and the biceps femoris were especially larger in the baboon than in the human, while the gluteus maximus and the soleus were larger in the human. The baboon gluteus medius and biceps femoris chiefly generate the propulsive power during quadrupedal locomotion and the human soleus is essential for the erect bipedalism.

Animals↗