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Biomedical subjects

H Sakakibara

Publications and source records attributed to H Sakakibara.

At least 19 recordsLinked to original sources
PubMed1992

Ultrastructural and ultracytochemical differences between megakaryoblastic leukemia in children and adults. Analysis of 49 patients.

BACKGROUND: Acute megakaryoblastic leukemia (AMKL) has two peaks in distribution of incidence (in adults and children 1 to 2 years of age) and is frequently seen in children with Down syndrome. The current study was undertaken to disclose whether there were any differences between these groups. METHODS: Electron microscopic and ultrastructural cytochemical features of 49 children and adults with a AMKL or chronic myelogenous leukemia (CML) in megakaryoblastic crisis were compared. RESULTS: Blast cells from children with AMKL, including those with and without Down syndrome, had immature features lacking typical alpha granules and a demarcation membrane system (DMS). However, blast cells from patients with AMKL with Down syndrome had more theta, electron-lucent, and basophil-like granules, suggesting that the blast cells had more potential to differentiate into other cell lines than megakaryocytes. The AMKL blast cells of adult patients showed a higher percentage of platelet peroxidase (PPO) positivity than other subgroups, and they occasionally contained typical alpha granules and DMS. This indicated that the blast cells of adults with AMKL were more mature than those of children and CML in megakaryoblastic crisis. CONCLUSIONS: By electron microscopic analysis, leukemic megakaryoblasts differed between children with AMKL with and without Down syndrome, adults with AMKL, and patients with CML in megakaryoblastic crisis.

Acid Phosphatase↗
PubMed1992

Three-headed outer arm dynein from Chlamydomonas that can functionally combine with outer-arm-missing axonemes.

A procedure was developed for isolating Chlamydomonas outer-arm dynein that can functionally combine with the axoneme of an outer-arm-missing mutant, oda1. Previous studies showed that the outer-arm dynein of this organism, containing three heavy chains (alpha, beta, gamma), dissociates upon extraction with a high-salt-concentration buffer solution into an 18-S particle containing the alpha and beta heavy chains and a 12-S particle containing the gamma heavy chain. It was found, however, that the three heavy chains did not dissociate if the high-salt extract was centrifuged in the presence of Mg2+; the three chains constituted a single species (23-S dynein) sedimenting at about 23 S and displayed a three-headed bouquet configuration in electron micrographs. Furthermore, the 23-S dynein had the activity to bind to the axonemes of oda1 and increase the reactivated motility of detergent-extracted cell models; its addition increased the beat frequency from 28 Hz to 53 Hz, a frequency comparable to that of wild-type axoneme. The 18-S and 12-S dyneins, on the other hand, were unable to increase the motility of oda1 axonemes even when added together. The new protocol thus enables purification of outer-arm dynein that retains its functional activity. It will provide a useful experimental system with which to study the mechanism of outer-arm function.

Animals↗
PubMed1992

11;13 translocation in acute nonlymphocytic leukemia.

In this paper, we report on a 9-year-old girl with acute nonlymphocytic leukemia (FAB-M5) with a rare chromosome abnormality, t(11;23)(q21;p11). Peripheral blood showed Hb 7.5 g/dl, WBC 3,600 cells/microliters (10% blasts), and platelet count 110 x 10(3) cells/microliters. The bone marrow aspirates showed normal cellularity with 36.7% blasts. On morphological characteristics, micromegakaryocytes were observed, and on chromosome examination the karyotype was shown to be 46,XX,t(11;13)(q21;p11) in all metaphases.

Bone Marrow↗
PubMed1992

Effect of sympathetic nerve stimulation on lung vascular permeability in the rat.

The present study was undertaken to evaluate the role of sympathetic nerves in increasing lung vascular permeability. An isolated rat sympathetic nerve-lung preparation was used. Three minutes after an increase in lung weight was induced by elevating the intravascular pressure, stimulation of sympathetic nerves was performed in the presence of papaverine, which further increased the lung weight in a graded manner. After the nerve stimulation, deposits of carbon were observed in alveolar macrophages and perivascular walls, indicating an increase in vascular permeability. The response of lung weight to the sympathetic nerve stimulation was altered, depending on the magnitude of intravascular pressure change as well as on the voltage and frequency of electrical stimulation. Furthermore, these responses were prevented by tetrodotoxin. Calculation of the relationship between the maximal slope of the graded lung weight gain and the slope obtained just before the nerve stimulation gave a slope ratio at a frequency of 30 cps in normal rats of 4.47 +/- 0.21. Treatment with phentolamine diminished the value to 1.93 +/- 0.15, and with reserpine, to 1.43 +/- 0.14. In reserpinized rats, the slope ratio was restored by an administration of norepinephrine to 2.11 +/- 0.05 at 30 cps, being further increased by propranolol and blocked partially by phentolamine. The capillary filtration coefficient was not affected by either of the agents. In capsaicin-treated rats, sympathetic nerve stimulation did not cause any response in terms of lung weight (slope ratio = 1.0).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

The gap between mitral leaflets as a cause of mitral regurgitation: relationship to mitral valve prolapse.

The gap between the tips of the anterior and posterior mitral leaflets was studied to assess the significance of this gap in the diagnosis of mitral valve prolapse. The subjects were 39 patients in whom the gap was seen and the mitral valve did not exceed the mitral annular line in systole on two-dimensional echocardiography. Forty eight healthy subjects, in whom phonocardiography disclosed no abnormalities, served as controls. The site of the gap as well as the site and severity of mitral regurgitation were assessed with two-dimensional echocardiography and Doppler flow imaging. The incidence of mitral regurgitation was 82%, which was comparable to that in the controls (67%). The site of the gap was consistent with that of regurgitation. The gap was also seen in a low percentage of healthy subjects, but clinically significant mitral regurgitation did not accompany the gap in healthy subjects including the gap-carrying controls. On the other hand, many of the gap-carrying patients showed clinically significant mitral regurgitation. Also the fact that a gap between the tip of the anterior and posterior mitral leaflets was found to be frequently accompanied by phonocardiographical features corresponding to mitral valve prolapse indicates that the presence of a gap is a significant finding.

Adolescent↗
PubMed1992

[Analysis of lymphocyte surface markers in childhood acute lymphoblastic leukemia during maintenance chemotherapy].

In this study we investigated T-cell subsets, HLA-DR and IL2 receptor (IL2R, CD25) expression on T-cells in peripheral blood lymphocytes from the patients with childhood acute leukemia undergoing maintenance chemotherapy with 6-MP and MTX, and compared them with those in the healthy controls. There were decrease of relative number of CD4 positive (CD4+) cells and the increase of relative number of CD8 positive (CD8+) cells in comparison with those in controls; thus the ratio of CD4+ cells to CD 8+ cells decreased. HLA-DR and IL2R expression on T-cells increased in the patients. Increased HLA-DR expression was detected on both CD4+ cells and CD8+ cells, but the increased IL2R expression was related only to CD4+ cells. IL2R expression in the patients with side effects was higher than in controls. Methotrexate (MTX)-induced increase of HLA-DR and IL2R expression was observed in 2 of every 3 patients undergoing intensive chemotherapy.

Antigens, Surface↗
PubMed1992

Establishment of a monocytoid cell line (DOP-M1) from an infant with acute monocytic leukemia.

A monocytoid cell line (DOP-M1) was established from mononuclear cells separated from the cerebrospinal fluid of a 1-year-old girl with acute monoblastic leukemia (AMoL) (French-American-British; FAB-M5a). Judged by morphological, cytochemical, and immunological criteria, the DOP-M1 cells showed immature monocytoid characteristics. They were positive for alpha-naphthyl butyrate esterase, the expression of which was inhibited by NaF, and for myeloperoxidase (MPO). Positive MPO findings in nuclear envelope were detectable by electron microscopy. The cell surface was positive for CD15, CD33, and CDw65, but negative for CD4, CD14, and HLA-DR. HLA-DR expression was detected after treatment with IFN-gamma. Chromosome analysis of DOP-M1 cells revealed 47,X,-X,-13,+19,+20,+mar. Our established cell line, DOP-M1 appears to be a cell line which will be a useful tool for studying the phenotype, morphology, and function of monocytoid cells.

Female↗
PubMed1992

Analysis of factors related to hypertension in Japanese middle-aged male workers.

A total of 789 Japanese male transport service workers between the ages of 35 and 50 were used as subjects in an analysis of daily lifestyle factors related to hypertension. Multiple logistic analysis showed positive dose-response relations between hypertension and age, obesity and alcohol consumption. Age and obesity were factors having a linearly increasing odds ratios for hypertension (including borderline cases and those under treatment). Alcohol consumption of 56 g ethyl alcohol per day or more had an odds ratio about double that of those who did not drink. Smokers had 1/2 the odds ratio of non-smokers. Subjects working a 24-hr shift comprised mostly of standby duty showed a slightly lower rate of hypertension, but it was statistically insignificant.

Adult↗
PubMed1991

Molecular cloning and characterization of complementary DNA encoding for ferredoxin-dependent glutamate synthase in maize leaf.

The sequence of ferredoxin-dependent glutamate synthase (EC 1.4.7.1) mRNA from maize has been determined. Complementary DNAs were isolated from a cDNA library of light-induced leaf poly(A)+ RNA constructed in an expression vector. An open reading frame beginning at an ATG codon at nucleotide 328 of the longest cDNA (5617-bases long) encoded 1616 amino acid residues. The amino terminus of the purified mature enzyme coincided with the cysteine residue at position 98 of the predicted sequence. This enzyme is homologous with the large subunit of Escherichia coli NADPH-dependent glutamate synthase having about 42% identical residues between the two proteins. The enzyme also contains a short region similar to a potential FMN-binding region of yeast flavocytochrome b2. The cDNA hybridizes to an RNA band about 5.5 kilobases whose steady-state level is markedly increased upon illumination of etiolated maize seedlings. Analysis of genomic DNA indicates the presence of a single-copy gene for ferredoxin glutamate synthase in maize.

Amino Acid Sequence↗
PubMed1991

Circulatory disturbances of the foot in vibration syndrome.

Circulatory disturbances of the foot in patients with vibration syndrome were studied by measuring the skin temperature of both index fingers and great toes through a 3-min immersion of the right foot in cold water at 10 degrees C. Subjects included 11 patients with vibration-induced white finger (VWF) [VWF(+) group], 12 patients without VWF [VWF(-) group], and 20 healthy referents not exposed to vibration. Patients were all male chain saw operators who had scarcely been exposed to vibration of the foot. The prevalence of coldness felt in the upper and lower extremities was greater than 90% in the VWF(+) group, about 60% in the VWF(-) group, and less than 10% in the referents. The extent of the coldness was greatest in the VWF(+) group. The skin temperature of both fingers and toes was lowest in the VWF(+) group, somewhat higher in the VWF(-) group, and highest in the referents both before and after immersion. These findings indicate that patients with vibration syndrome, especially those with VWF, have circulatory disturbances in the foot as well as in the hand. The disturbances in the foot may be related to long-term repeated vasoconstriction in the foot induced by hand-arm vibration through the sympathetic nervous system.

Aged↗
PubMed1991

Effect of vibration frequency on finger blood flow.

A total of 18 healthy subjects (9 men and 9 women) 20-35 years of age were used to study the effect of vibration frequency on finger blood flow. Seven vibration frequencies of 16, 31.5, 63, 125, 250, 500 and 1,000 Hz, at vibrational accelerations of 10 m/s2 (rms: root mean square) or 50 m/s2 (rms), with the exception of 16 Hz, which was measured at only 10 m/s2 (rms), were randomly applied to the palm of the right hand for 1 min at intervals of about 3 min. Finger blood flow was measured simultaneously in both the right and the left middle fingers with a blood flowmeter using a thermal diffusion method and in the left middle finger with a laser Doppler flowmeter. The experiments were performed in an artificial climate chamber set at 23 degrees C air temperature and 50% humidity. Relatively great responses were observed at frequencies of 31.5-63 and 250-500 Hz on the exposed and unexposed sides, respectively, as measured with a blood flowmeter using a thermal diffusion method and at 31.5-63 as well as 500 Hz on the unexposed side with a laser Doppler flowmeter. These results may be related to Meissner's and pacinian corpuscles.

Acoustics↗
PubMed1991

A Chlamydomonas outer arm dynein mutant missing the alpha heavy chain.

A novel Chlamydomonas flagellar mutant (oda-11) missing the alpha heavy chain of outer arm dynein but retaining the beta and gamma heavy chains was isolated. Restriction fragment length polymorphism analysis with an alpha heavy chain locus genomic probe indicated that the oda-11 mutation was genetically linked with the structural gene of the alpha heavy chain. In cross-section electron micrographs, the oda-11 axoneme lacked the outermost appendage of the outer arm, indicating that the alpha heavy chain should be located in this region in the wild-type outer arm. This mutant swam at 119 microns/s at 25 degrees C, i.e., at an intermediate speed between those of wild type (194 microns/s) and of oda-1 (62 microns/s), a mutant missing the entire outer dynein arm. The flagellar beat frequency (approximately 50 Hz) was also between those of wild type (approximately 60 Hz) and oda-1 (approximately 26 Hz). These results indicate that the outer dynein arm of Chlamydomonas can be assembled without the alpha heavy chain, and that the outer arm missing the alpha heavy chain retains partial function.

Cell Movement↗
PubMed1991

Mixed blasts crisis following extramedullary involvement with the cytogenetic evidence of clonal evolutions in Philadelphia chromosome-positive chronic myelocytic leukemia.

We describe a unique case of a young girl with adult type chronic myelocytic leukemia (CML). Clinically she had an extramedullary blastic crisis (BC) prior to that in peripheral blood and in bone marrow. The blasts were primitive cells and always CD7, CD33, CD34 and HLA DR-positive. During the course of illness the blasts became negative for CD5 and positive for CD41a and for platelet-peroxidase. Additional chromosomal appearances and subsequently clonal evolution were seen during the clinical course. Surface antigen modulation and morphological changes, which were observed by microscopic examination and flow cytometry, were induced by in vitro incubation. Surface antigen modulation was more induced in the presence of phytohemagglutinine-conditioned media (PHA-CM) but the effects of PHA-CM on morphological changes were not clear.

Antigens, CD↗
PubMed1991

Lung vascular permeability enhanced by sympathetic nerve stimulation in rats.

Role of sympathetic nerves in increasing the lung vascular permeability was investigated in the presence of papaverine using an isolated rat lung perfusion preparation. Sympathetic nerve stimulation was performed at different time points before and after pressure-induced weight gain. When stimulated at 3 or 7 min after the pressure associated increment, stimulation evoked a further increase in lung weight, particularly in the former case. In contrast, stimulation performed before or 15 min after the pressure increment elicited no such response. The histological finding of carbon particles in the perivascular wall after sympathetic nerve stimulation also provided direct evidence of increased lung vascular permeability.

Animals↗
PubMed1991

The deterioration of visual acuity by exercise under a mesopic vision environment.

Visual acuity deteriorated following 15-minute bicycle ergometer pedaling under the condition of a mesopic vision environment. Visual acuity decreased sharply as the load increased. The visual functions which changed significantly after the exercise in the mesopic vision environment were visual acuity (deterioration) and accommodative near point distance (extension).

Accommodation, Ocular↗
PubMed1991

Effects of color CRT display on pupil size in color-blind subjects.

The effects of color cathode ray tube (CRT) display on the pupil size in color-blind subjects were studied experimentally. Red, magenta, green, cyan, yellow, and white were presented on the CRT. Five protan subjects, five deutans, and five normal subjects were tested using infrared pupillography. In the protan group, the pupils were significantly less sensitive to red (wavelength: 600 nm) targets compared to the other colors. In the deutans and the control group, there were non-significant changes in pupil size in response to the colors. Dominant wavelengths above 600 nm in color CRTs should be avoided in routine work presentation because of less sensitivity in protanopias.

Adult↗