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Biomedical subjects

Y Ando

Publications and source records attributed to Y Ando.

At least 19 recordsLinked to original sources
PubMed1992

Site-directed mutation makes rabbit calcyclin dimer.

Unlike human, rat and mouse calcyclin, purified rabbit calcyclin did not form a dimer on Tricine SDS-PAGE under non-reduced conditions. Based on the internal peptide sequence of rabbit calcylin, we isolated and sequenced a cDNA clone encoding calcyclin. The sequence of this clone (pCalC) is 629 bp long and codes 90 amino acid residues of a protein with a molecular mass of 10,153 Da. By Northern blot analysis, a major band of 0.9 kbp and a minor band of 2.6 kbp were detected in the lung. The recombinant calcyclin mutated serine at the third position to cysteine was expressed in E. coli and made dimer formation under non-reduced conditions on SDS-PAGE. Whether or not this type of mutation which prevents dimer formation of calcyclin plays a physiological role in the rabbit lung is the subject of an ongoing study.

Amino Acid Sequence↗
PubMed1992

Full sequence of neurocalcin, a novel calcium-binding protein abundant in central nervous system.

We determined the cDNA sequence for neurocalcin, a novel calcium-binding protein in bovine brain. This clone (pCalN) has 582 nucleotides in the open reading frame including the termination codon TGA, 11 nucleotides of the 5' leader and 1251 nucleotides of the 3' noncoding region. The deduced amino acid sequence revealed that neurocalcin is composed of 193 amino acids, has a molecular mass of 22,284 daltons, and contains three putative calcium-binding sites (EF-hand motifs). By Northern blot analysis, 3.8kbp mRNA was detected in brain. The deduced amino acid sequence had a strong homology to visinin (46.5%) and recoverin (51.6%) in retina, suggesting that neurocalcin may play a visinin- or recoverin-like role in brain.

Amino Acid Sequence↗
PubMed1992

Identification of immuno-reactive lipocortin 1-like molecules in serum and plasma by an enzyme immunoassay for lipocortin 1.

A two-site enzyme immunoassay for lipocortin 1 (LC1) has been developed. The detection limit of LC1 was 0.2 ng/tube and the optimal assay range was 1 to 100 ng/tube. The assay system enabled us to identify immunoreactive lipocortin 1-like molecules (IR-LC1) in human serum and plasma. Normal human serum and plasma IR-LC1 concentrations were 44.6 ng/ml for males and 43.1 ng/ml for females with no significant difference between both sexes. The age-related analysis among nine age groups from newborn to 69 years old revealed that the serum or plasma level was high in infants (77.5 ng/ml for newborn and 75.6 ng/ml for 1 month-1 year group), and the 40-year-old (52.2 ng/ml) and 50-year-old (51.3 ng/ml) groups. The major population of plasma IR-LC1 was of 70 kDa in size corresponding to that of the LC1 homodimer. The present enzyme immunoassay system is sufficiently sensitive for the clinical study of LC1 in human body fluids, tissues and organs.

Adolescent↗
PubMed1992

Role of autonomic nerve functions in patients with familial amyloidotic polyneuropathy as analyzed by laser Doppler flowmetry, capsule hydrograph, and cardiographic R-R interval.

Laser Doppler flowmetry (LDF) was conducted on familial amyloidotic polyneuropathy (FAP) patients and asymptomatic carriers of FAP. Vasoconstrictive responses in the 11 FAP patients tested, induced by deep inspiration, were markedly depressed compared with those of the healthy controls. The responses decreased with the progression of FAP, with no responses being elicited from the 7 patients in stages 2 (moderate) to 4 (terminal). Interestingly, vasoconstrictive responses following deep inspiration also were depressed in 3 of 4 asymptomatic carriers of FAP who showed no clinical sign of FAP, and who had normal sensory nerve conduction velocity. Patients who had such diseases as Shy-Drager's disease, spinocelebellar degeneration, and pandysautonomia showed no decrease in blood flow for various stimulations. In contrast, patients with primary amyloidosis, who had no autonomic dysfunction, showed a normal pattern. Detection of the autonomic functions in FAP patients and asymptomatic carriers by capsule polyhydrography and computer analysis of the cardiographic R-R interval revealed that the asymptomatic carriers of FAP, as well as the FAP patients, had disordered peripheral autonomic functions. Our results suggest that the autonomic nervous system is first affected during the very early stage of FAP.

Adult↗
PubMed1992

Ocular microangiopathy in familial amyloidotic polyneuropathy, type I.

To obtain precise information on ophthalmological manifestations in patients with familial amyloidotic polyneuropathy (FAP), we performed ophthalmological and histopathological studies on 18 FAP patients and 6 asymptomatic individuals with a mutant transthyretin (TTR) gene. The incidence of vascular abnormalities of the conjunctiva and retina was surprisingly high in FAP patients. Abnormal conjunctival vessels were found mainly in the limbal area of FAP patients, but not in asymptomatic individuals with a mutant TTR gene. Conjunctival biopsy of 5 FAP patients and autopsy of another 2 FAP patients revealed that a significant amyloid deposit could be recognized in the superficial substantia propria of the conjunctiva and wall and perivascular area of the conjunctival vessels in all cases, a finding that is of diagnostic value. As for the retinal vessels, an abnormal arteriovenous ratio (A/V ratio), tortuous retinal vessels, cotton wool exudates and retinal hemorrhages were found in FAP patients. However, histopathological analysis of the retina in two autopsied cases revealed only a trace amount of amyloid deposit around the retinal vessels. Ophthalmological examination of three patients with pandysautonomia revealed that the appearance of both the conjunctival and retinal vessels of these patients was similar to that in FAP patients. These results indicate that in FAP patients ocular microangiopathy may be related to autonomic dysfunction as well as amyloid deposit.

Adolescent↗
PubMed1992

The relationship of estrogen receptor status to DNA ploidy in breast cancer.

The relationship of estrogen receptor (ER) status to DNA ploidy was investigated in 121 patients with breast cancer who underwent surgery. Lymph node status was evaluated histologically and ER levels were determined by the dextran-coated charcoal method, with a level of 3 fmol/mg.protein being considered positive. Flow cytometric DNA content was analyzed using paraffin-embedded tissue blocks. Sixty-three percent of the specimens were ER+, while 37 percent were negative. Sixty-one patients (50.4 percent) were diploid and 60 aneuploid. A statistically significant correlation between the ER positivity rate and diploid DNA was found. Higher ER levels were seen in the postmenopausal patients with diploid tumors than in those with aneuploid tumors and there was a significant tendency for ER levels to be higher in the diploid tumors. Nodal status was not correlated with ER positivity or ploidy pattern. The present results indicate that ER levels are correlated with DNA ploidy, and reflect the degree of functional differentiation.

Biomarkers, Tumor↗
PubMed1992

The role of folates in the development of methotrexate resistance in human leukemia cell line K562.

The effect of reduced and oxidized folates on the development of methotrexate (MTX) resistance has been examined in human leukemia cell line K562 (K562/S). K562/S cells were made resistant to MTX by soft-agar cloning either in RPMI-1640 medium (K562/MTX-PGA) or in folic-acid-free RPMI-1640 medium containing 10 nM leucovorin (K562/MTX-LV). The optimal concentrations of leucovorin for the growth of K562/S, K562/MTX-PGA and K562/MTX-LV cells were 1 nM, 5 nM and 10 nM respectively. K562/MTX-PGA cells were 24-fold resistant to MTX as noted by impaired MTX transport. In contrast, K562/MTX-LV cells were 26-fold resistant to MTX as noted by gene amplification of dihydrofolate reductase. Furthermore cross-resistance to cytosine arabinoside was only demonstrated in K562/MTX-PGA, while the K562/MTX-LV cells showed no significant cross-resistance to cytosine arabinoside. These results suggest that the type and level of folates used during the development of MTX resistance may play a role in the mechanism for MTX resistance. Leukemia cells that are grown in leucovorin might serve as a model for acquired MTX resistance in vivo.

Cell Cycle↗
PubMed1992

The role of radiotherapy in the treatment of primary mediastinal seminoma.

Nine patients with primary mediastinal seminoma were treated with radiotherapy. All patients achieved complete response on chest radiography. None of the three patients treated with whole mediastinal irradiation relapsed. Four of the six patients with involved-field irradiation had marginal relapses, suggesting the efficacy of the whole mediastinal irradiation.

Adolescent↗
PubMed1992

User and manufacturer's requirements for IMAC standardization in Japan.

Many radiologists and radiological technologists understand that Picture Archiving and Communication Systems (PACS) are useful not only for image management but also for improving the quality of patient care. However, such systems have not yet been widely installed in hospitals. In order to determine why radiologists have not installed a PACS in their hospitals, we carried out a written survey of 400 Japanese hospitals asking them to describe the current image management activities, the problems inherent in PACS and the problems related to standardization. 216 hospitals responded, and the following suggestions were compiled concerning possible improvements to PACS. (1) PACS benefit needs to be improved with respect to patient care. (2) The cost of PACS should be reduced. (3) The system should be easier to operate and should save time. (4) Standardization is needed to allow simplified, cost-effective networking. We also carried out a written survey of 25 PACS and related equipment manufacturers asking them to describe the opinions inherent in current PACs and the problems related to standardization. Ten manufacturers responded, and the various suggestions were compiled concerning possible improvements to the PAC system.

Japan↗
PubMed1992

Current status of Image Save and Carry (IS&C) standardization.

Image Save And Carry (IS&C) was planned to be an off-line information system for transmission and exchange of medical images and information between a medical facility's different divisions as well as between other hospitals. The IS&C committee defines file format for magneto-optical disk, the data format and representation, media compatibility and data security and technological assessment. A 'zone management method' which contributes to a rapid access of data in the recording media is used for IS&C file management. The IS&C standard holds as much conformation as possible in order to coordinate with ACR-NEMA (American College of Radiology-National Electrical Manufacturers' Association) and MIPS (Medical Information Processing Systems) standards. The IS&C data format is based upon the ACR-NEMA/MIPS standard. A major difference between the ACR-NEMA/MIPS standard and IS&C standard is that the IS&C standard is expected to serve for recording all kinds of medical information (e.g., diagnostic reports, endoscopic images and electrocardiograms), including X-ray images. Applications to PACS, teaching files, personal electronic health and medical records are promising. The booklet of IS&C standard will be published in the spring of 1992 by the IS&C committee.

Computer Communication Networks↗
PubMed1992

Auditory-evoked response of the cortex after yohimbine administration: phase advance effect of central noradrenergic activation.

The effects of central noradrenergic activation on an auditory-evoked cortical response were studied using systemic administration of yohimbine (2 mg/kg intravenously, IV), a noradrenergic stimulant, in 13 anesthetized rats. To analyze changes of the response, surface and intracortical evoked potentials (EP) as well as extracellular single-unit recordings with tungsten microelectrodes were employed. It was noted that the initial-positive wave of the surface EP corresponded to unit firing responses in a restricted area of the auditory cortex, where the surface EP was largest and a polarity inversion of the intracortical EP was observed. The following effects were produced by yohimbine: 1) The initial-positive surface potential (n = 10) and corresponding intracortical potential with inverted polarity (n = 6) both showed an increase in amplitude and a decrease in peak latency; 2) the unit firing response (n = 10) tended to show an increase in peak frequency and a decrease in peak firing latency; and 3) yohimbine produced an earlier ending of the firing period, and in paired stimulation experiments (n = 7) it prolonged the period during which the second response was suppressed, indicating an augmentation of postexcitation inhibition. Later histological examination suggested that most of the units recorded were pyramidal cells. These findings indicate that chemical stimulation of the central noradrenergic system by yohimbine enhances both the initial excitatory and following inhibitory processes in the auditory-evoked response of the cortical units (probably pyramidal cells), resulting not only in amplification of the response but also in advancement of the response phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Cerebral arterial and venous flow-velocity measurements in post-haemorrhagic ventricular dilatation and hydrocephalus.

Simultaneous anterior cerebral artery (ACA) and internal cerebral vein (ICV) flow-velocities were measured in 18 babies with post-haemorrhagic ventricular dilatation (PHVD) and hydrocephalus (PHH). Compared with a control group matched for post-conceptional age, the resistance index of the ACA was increased. This was shown to occur at an early stage of PHVD in a longitudinal study of seven of the babies. There were no significant changes in ACA or ICV time-averaged velocities. Eight babies with PHH had ventricular taps on 18 occasions to relieve raised intracranial pressure. There was a significant decrease in the resistance index of the ACA, accompanied by an increase in the ACA time-averaged velocity, but no change in the ICV time-averaged velocity.

Blood Flow Velocity↗
PubMed1992

[Frequency of the development of RNA-rich reticulocytes in allogeneic bone marrow transplant recipients].

We measured appearance rates of RNA-rich reticulocytes in 8 patients undergoing allogeneic bone marrow transplantation, using a Sysmex R-1000 reticulocyte counter which utilizes laser flow cytometry. The changes in proportion of RNA-rich reticulocytes (high fluorescence ratio: HFR) and maturation index (MI: HFR + middle fluorescence ratio/low fluorescence ratio) were compared with those of WBC, neutrophil or reticulocyte counts. Engraftment was defined as an HFR of greater than or equal to 5% or a MI of greater than or equal to 15%. Engraftment was confirmed significantly earlier by HFR (13.5 +/- 2.4 days) and MI (13.1 +/- 2.9 days) than by neutrophils (17.1 +/- 3.2 days) or reticulocytes (20.4 +/- 6.2 days). The maturation of reticulocytes would be a useful indicator for engraftment or recovery from marrow aplasia in cases of bone marrow transplantation.

Adolescent↗
PubMed1992

[The significance of determination of human herpesvirus-6 (HHV-6) antibody during pregnancy].

HHV-6 which was detected in peripheral blood lymphocytes of lymphocytic patients is now said to be an agent causing exanthema subitum. We investigated the titer of HHV-6 antibody in 100 primigravida and 30 patients with spontaneous abortion by means of the indirect immunofluorescence method (IF method). The positive incidence in which the titer of HHV-6 antibody was more than 10 times in 100 primigravida was 82%. That of HHV-6 IgM antibody was 3% in those who had no complication during pregnancy. This supposes that there may be some women who were infected or were reactivated while they were pregnant. The positive incidence in 30 spontaneous abortion patients was 90%. 3 of them had IgM antibody to HHV-6, and HHV-6 antigen was detected on the epitherium of the chorionic villi by the IF method with HHV-6 monoclonal antibody in two of them. This suggests that the infection or reactivation of HHV-6 may be one of the causes of spontaneous abortions.

Abortion, Spontaneous↗
PubMed1992

[Diagnostic value of measurement of RNA in platelets by fluorescence flow cytometry].

We analyzed the RNA in platelets by fluorescence flow cytometry after staining with thiazole orange(TO) in whole blood samples from hematologically normal subjects and patients with thrombocytopenia. The percentage of TO-positive platelets and their mean fluorescence channel number in 32 control subjects were 6.2 +/- 2.5% (mean +/- SD) and 6.9 +/- 0.7, respectively. In 11 patients with idiopathic thrombocytopenic purpura, the percentage of fluorescently labeled platelets was significantly elevated (p less than 0.05) to 21.5 +/- 14.3%. By contrast, the proportion of positively stained platelets in 14 patients with thrombocytopenia due to impaired platelet production did not significantly differ from that of the controls, whereas the absolute counts of TO-positive platelets were significantly lowered (p less than 0.05). In both patient groups, the mean fluorescence channel numbers of TO-positive platelets were significantly elevated to 16.1 +/- 16.8 and 6.9 +/- 0.7, respectively (p less than 0.05, 0.005). We conclude that flow cytometric analysis of platelets after staining with TO provides information on the thrombopoietic activity in thrombocytopenic disorders. The main advantages of this method for clinical use are its simplicity and the rapidity.

Blood Platelets↗