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S Okano

Publications and source records attributed to S Okano.

At least 37 records · Page 2Linked to original sources
PubMed2000

Characterization of ferritin and ferritin-binding proteins in canine serum.

Ferritin and ferritin-binding proteins in canine serum were characterized. A certain percentage of ferritin in canine serum, but no tissue ferritin, was precipitated by centrifugation at 16,000 x g for 30 min. The precipitated ferritin was found to contain two subunits corresponding to the H and L subunits of canine liver ferritin by immunoblotting, the H subunit being predominant. More ferritin was precipitated from canine sera which had been incubated with anti-rat liver ferritin antibody than from untreated sera, and the H chain also predominated. To evaluate the possibility that the autoantibody was responsible for the precipitation of canine serum ferritin, the ferritin-binding activities of canine antibodies were examined using liver ferritin-coated microtiter plates and alkaline phosphatase-labeled antibodies specific for canine IgM, IgA, and IgG heavy chains. The results showed that IgM and IgA, but not IgG, had considerable ferritin-binding activities. Given these results, we suggest that there is H-chain-rich isoferritin in canine serum, and that ferritin exists as an immune complex.

Animals↗
PubMed2000

Biochemical properties of canine serum ferritin: iron content and nonbinding to concanavalin A.

A sandwich enzyme-linked immunosorbent assay using H-subunit-rich canine heart ferritin as a standard has been developed for measuring canine serum ferritin which is H-subunit-rich. Serum ferritin concentrations in 51 normal dogs ranged from 143 to 1766 ng ml(-1), with a mean value of 479 +/- 286 (SD) ng ml(-1). Serum ferritin iron concentrations as determined by an immunoprecipitation technique ranged from 30.4 to 115.9 ng ml(-1) in 15 normal dogs with serum ferritin protein levels of 298 to 959 ng ml(-1). There was a significant linear correlation between the serum ferritin iron and protein levels (r=0.9441, P<0.001), and the mean iron/protein ratio of serum ferritin was 0.112 +/- 0.017. When canine sera were incubated with concanavalin A-Sepharose 4B, we observed the apparent binding of serum ferritin to concanavalin A. However, ferritin obtained by heat-treating the sera at pH 4.8 to remove the ferritin-binding proteins did not bind to the lectin. These results suggest that canine serum ferritin contains a considerable amount of iron but no concanavalin A-binding G subunit present in human serum ferritin.

Animals↗
PubMed2000

Effects of aniracetam on impaired sleep patterns in stroke-prone spontaneously hypertensive rats.

The aim of the present study was to determine the pattern of sleep disturbances and the effects on sleep of aniracetam, a cognitive enhancer, in stroke-prone spontaneously hypertensive rats (SHRSP). Compared with normotensive control rats, SHRSP exhibited an impaired sleep pattern characterized by suppressed diurnal rapid eye movement (REM) sleep and excessive nocturnal non-REM sleep. At a dose of 30 mg/kg per day p.o., aniracetam increased REM sleep in the light period after administration for 5 consecutive days. Consequently, suppressed REM sleep in SHRSP was restored by repeated treatment with aniracetam. Aniracetam could be useful in improving REM sleep impairment associated with vascular dementia.

Animals↗
PubMed2000

Evaluation of intracranial pressure by transcranial Doppler ultrasonography in dogs with intracranial hypertension.

Transcranial Doppler ultrasonography (TCD) has been used to confirm changes in cerebral hemodynamics. In this study, we investigated whether the parameters for the basilar artery measured by TCD were correlated with the intracranial and cerebral perfusion pressures in extreme intracranial hypertension. An intracranial hypertension model was produced in seven dogs by inflating a balloon inserted into the epidural space. The resistance index was compared with the corresponding intracranial pressure and cerebral perfusion pressure values during intracranial hypertension. A significant correlation was recognized between the resistance index and cerebral perfusion pressure. Therefore, measurement of the basilar artery by TCD in the dog with intracranial hypertension is useful in estimating the intracranial circulation in cases where the measurement of intracranial pressure is not available or not indicated.

Animals↗
PubMed1999

The comparison between the cerebral blood flow directly measures and cerebral blood flow velocity in the middle and basilar cerebral arteries measured by transcranial Doppler ultrasonography.

Transcranial Doppler ultrasonography (TCD) may be useful for determining alterations in cerebral blood flow (CBF) during excessive hemodynamic changes by non-invasive measurement of the CBF velocity. The purpose of this study was to measure the correlation between CBF and the middle cerebral artery (MCA) and basilar artery (BA) flow velocities, as measured by TCD during excessive hemodynamic changes produced by hypertension and hypotension in adult dogs. The peak, diastolic, and mean flow velocities were measured by TCD. Arterial hypertension was induced by administration of dopamine at 5 and 15 microg/kg/min, and hypotension was induced by hemorrhage. During the hemodynamic changes, the BA velocity correlated more closely with the alteration in the CBF than the MCA velocity. In terms of percentages of the values during anesthesia, there was good correlation between CBF and the MCA and BA velocities. In conclusion, our findings indicate that MCA and BA velocity measurements, as a percentage of the values during anesthesia, both give an equally accurate indication of alterations in CBF during excessive hemodynamic changes.

Animals↗
PubMed1999

Effects of respiratory cycle on pulmonary venous flow and cardiac cycle on pulmonary venous diameter of dogs: a transesophageal echocardiography study.

We investigated 12 anesthetized normal dogs using transesophageal echocardiography to understand the effects of respiration on the pulmonary venous flow. Additionally, we observed whether the diameter of the pulmonary vein changes with the heart beat. The pulsed Doppler wave form of pulmonary venous flow predominantly demonstrated two backward flows, with one peak occurring during ventricular systole and another during ventricular diastole. Sometimes a small forward flow occurred during left atrial contraction. In comparison with expiration, the peak velocity and velocity-time integral of the flow wave under inspiration occurred during both systole and diastole were significantly smaller. The diameter of the pulmonary vein decreased during left atrial contraction and increased during left ventricular systole and diastole.

Animals↗
PubMed1999

A putative blue-light receptor from Drosophila melanogaster.

A gene encoding a 62.5 kDa homolog of Drosophila melanogaster photolyase was isolated. Purified recombinant protein contained a flavin adenine dinucleotide chromophore. The recombinant protein did not show photolyase activity for either cyclobutane pyrimidine dimers or 6-4 photoproducts in vitro as well as in vivo in Escherichia coli host cells, suggesting that the protein is not a DNA repair enzyme but a blue-light photoreceptor. Reverse transcription polymerase chain reaction analysis showed that the gene is more expressed in head than in body and that it is more expressed in antennae than in legs, wings and mouth appendages. In a phylogenetic tree of the photolyase family, the Drosophila photolyase homolog is located in a cluster containing 6-4 photolyases and mammalian photolyase homologs, which is only distantly related to the clade of higher plant blue-light photoreceptors. The mammalian photolyase homologs are more closely related to Drosophila 6-4 photolyase than to the Drosophila photolyase homolog, suggesting different roles of the photolyase homologs.

Animals↗
PubMed1998

Mutational analysis of the Jagged 1 gene in Alagille syndrome families.

Alagille syndrome (AGS) is an autosomal dominant disease characterized by five major abnormalities in the liver, heart, face, vertebrae and eye. The responsible gene has been recently identified as the human Jagged 1 (JAG1) gene, which encodes a ligand for the Notch receptor. We analyzed the JAG1 gene in eight AGS families, including affected and unaffected individuals, at the genomic DNA level, mainly by single-strand conformational polymorphism (SSCP) and DNA sequencing analysis. Four categories of mutations were identified: (i) four frameshift mutations in exons 9, 22, 24 and 26 were exhibited respectively in affected individuals of four AGS families, which resulted in moving the translational frame of JAG1; (ii) one nonsense mutation, a 1 bp substitution in exon 5 of the EGF-like repeat domain, was detected in two unrelated AGS families, which altered codon 235 from arginine to stop; (iii) one acceptor splice site mutation of exon 5 was revealed in a sporadic patient; and (iv) a 1.3 Mb deletion, which included the entire JAG1 gene, was found in another patient. Our results further demonstrate that AGS is a dominant disease and suggest that the JAG1 gene exerts a fundamental role in regulating genes involved in development.

Alagille Syndrome↗
PubMed1998

Relationship of the blood endotoxin concentration and prognosis in dogs with pyometra.

The blood concentrations of endotoxin in dogs with pyometra (n = 45) were compared with those in healthy dogs (n = 17). The blood endotoxin concentrations in the healthy dogs (n = 17), in those with good prognosis (n = 41) and those with poor prognosis (n = 4) were 3.4 +/- 2.8 pg/ml, 9.5 +/- 11.3 pg/ml and 74.2 +/- 18.3 pg/ml, respectively. The concentrations in the dogs with good prognosis and poor prognosis were significantly (p < 0.01) higher than those in the healthy dogs. The dogs with poor prognosis had significantly (p < 0.01) higher endotoxin concentrations than those with good prognosis. Blood endotoxin concentrations were measured in 9 dogs after surgery, and were found to be decreased. These results suggest the possible involvement of endotoxin in the pathophysiological changes due to pyometra in dogs, and also that the blood endotoxin concentration could be used as a marker to determine prognosis.

Animals↗
PubMed1998

Pulmonary venous flow in normal dogs recorded by transthoracic echocardiography: techniques, anatomic validations and flow characteristics.

To observe pulmonary venous flow in dogs, the echocardiographic imaging planes and the techniques for examination, and the validations of anatomic location were investigated. Then, the velocity pattern of pulmonary venous flow was recorded in normal conscious dogs. Six imaging planes were available for observing the right or left caudal lobe pulmonary venous flow with two-dimensional or pulsed Doppler echocardiography. Of these, the left lateral apical 4-chamber view can be applied as standard view, because the pulmonary venous flow and transmitral flow could be recorded in this view simultaneously with small sampling angle. The velocity pattern of pulmonary venous flow demonstrated two forward waves in 19 of 20 dogs examined, with one peak occurring during ventricular systole and another during ventricular diastole. A reversed flow during atrial contraction was also seen in 11 dogs. In the two forward waves, the mean peak velocity and velocity-time integral of ventricular diastolic forward flow were significantly higher than those of systolic forward flow (46.49 +/- 6.79 vs. 31.13 +/- 4.92 cm/s, p < 0.0001 and 8.18 +/- 1.84 vs. 5.14 +/- 0.82 cm, p < 0.0001, respectively). The deceleration time of diastolic forward flow shortened with the increase of heart rate (r = -0.87, p < 0.0001). Pulmonary venous flow in dogs can be observed under transthoracic two-dimensional or pulsed Doppler echocardiography.

Animals↗
PubMed1997

Infection with Mycobacterium avium-intracellulare with abscess, ulceration and fistula formation.

Infections caused by Mycobacterium avium-intracellulare complex are generally manifested as pulmonary disease, osteomyelitis or lymphadenitis, and cutaneous infection is rare. We describe a case of M. intracellulare infection of the skin in a 79-year-old man without apparent immunologically disabling disease or therapy. He had cutaneous infection of the right hand over 10 years, developing a fistula and, finally, an ulcer and abscess, 2 months before his death from heart failure. Mycobacterium intracellulare was identified by both microbiological characteristics and DNA-DNA hybridization.

Abscess↗
PubMed1997

Detection of hepatitis C virus RNA in bile.

OBJECTIVES: The infectivity of bile in patients with hepatitis C virus (HCV) infection remains to be clarified. The purpose of this study was to document the detection of HCV-RNA in bile of patients with HCV infection. METHODS: Bile and serum samples were tested for HCV RNA by a two-step polymerase chain reaction technique in 12 patients with HCV infection. RESULTS: HCV-RNA was detected in the serum of all 12 patients, whereas 6 of 12 bile samples (50%) tested positive. Comparison of laboratory data between patients with and without HCV-RNA in bile demonstrated statistically higher serum total bilirubin among those with positive bile HCV RNA than those without, but other clinical and biochemical variables as well as hepatitis activity scores were comparable between the two groups. CONCLUSIONS: Bile of HCV antibody-positive patients could be infectious.

Aged↗
PubMed1996

Cloning of a novel ubiquitin-conjugating enzyme (E2) gene from the ciliate Paramecium tetraurelia.

We isolated a 1.7 kb gene (UbcP1) for a ubiquitin-conjugating enzyme from a P. tetraurelia cDNA library and sequenced it. Its deduced polypeptide sequence consists of 425 amino acid residues (48 kDa). The UbcP1 protein contains novel N- and C-terminal extensions in addition to a UBC domain, and within the UBC domain it shares low identity with sequences of other known E2s. A constructed phylogenetic tree suggests that the UbcP1 protein may represent a member of a distinct subfamily of E2s. Southern blot analysis showed that the N-terminal extension of the UbcP1 is conserved in P. multimicronucleatum.

Amino Acid Sequence↗
PubMed1996

A 19-kb CpG island associated with single-minded gene 2 in Down syndrome chromosomal region.

To help in isolating the genes involved in Down syndrome, we sought CpG islands in 4 Mb cosmid/PAC contigs spanning most of the 21q.22.2 band using seven rare cutting enzymes. A striking feature was observed upstream of hSIM2 where at least 41 rare-cutting sites were clustered within a 20-kb region. To investigate the structure of the cluster, a cosmid containing hSIM2 was submitted to shotgun sequencing. Sequence analysis revealed that the cluster was a long CpG island extending 19, 128 nucleotides which includes in the first and second exons of hSIM2. Taken together with our observation in which the CpG islands were concentrated within 1.2 Mb around hSIM2, we propose that this region functions as an R-band, and the cluster provides a unique element for marking of DNA for the spatial and temporal expression of the hSIM2 locus.

Amino Acid Sequence↗
PubMed1996

An integrated map with cosmid/PAC contigs of a 4-Mb Down syndrome critical region.

The major phenotypic features of Down syndrome have been correlated with partial trisomies of chromosome 21, allowing us to define the candidate gene region to a 4-Mb segment on the 21q22.2 band. We present here a high-resolution physical map with megabase-sized cosmid/PAC contigs. This ordered clone library has provided unique material for the integration of a variety of mappable objects, including exons, cDNAs, restriction sites, etc. Furthermore, our results have exemplified a strategy for the completion of the chromosome 21 map to sequencing.

Bacteriophage P1↗
PubMed1996

A new model of transient cerebral ischemia in neonatal rats.

A new model of transient cerebral ischemia in 10-day- old rats is described. Under microscopic guidance, the right external and internal carotid arteries were electrically coagulated. A solid 0.47 mm diameter nylon thread was inserted into the right common carotid artery toward the ascending aorta up to 10-12 mm from the upper edge of the sternomastoid muscle (preischemic rats). A 60-min cerebral ischemia was induced by clamping the left external and internal carotid arteries (ischemic rats), followed by 3-h recirculation. 31P magnetic resonance (MRS) spectroscopic studies revealed that severe intracellular acidosis occurred and ATP disappeared completely for a least the last 20 min of ischemia. Cerebral blood flow (CBF), measured by the hydrogen clearance technique, decreased to approximately 11% of the preischemic level in the frontal cortex soon after the induction of ischemia. On resuscitation, ATP recovered completely and the preischemic intracellular pH level was restored within 180 min. CBF has recovered to approximately 30% of the preischemic level at 5 min after resuscitation. The CBF recovery was not compete even at 180 min after resuscitation. With this model, the effects of pure ischemia without hypoxia on the neonatal brain and the process of recovery from transient ischemia can be studied.

Adenosine Triphosphate↗
PubMed1996

[Experience in administration low dose all-trans retinoic acid for a child with acute promyelocytic leukemia].

Ten year old boy with acute promyelocytic leukemia (APL) was treated with all-trans retinoic acid (ATRA). Immediately after the oral administration of ATRA (nine mg/m2 three times a day), DIC was controlled, and complete remission was achieved at day 39. The patient received ATRA therapy for 47 days, and then followed by conventional chemotherapy. Plasma ATRA level after 90 minutes of drug administration was 84.6 ng/ml. The superoxide generating activity of neutrophils in the bone marrow and peripheral blood was measured by chemiluminescence. The phagocytic function of neutrophils was markedly reduced in the ATRA-induced remission period, and was normal in the chemotherapy-induced remission. APL could be induced complete remission by three divided small doses of ATRA, and the ATRA-induced differentiated neutrophils might have lower phagocytic function.

Child↗