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Biomedical subjects

N Hirano

Publications and source records attributed to N Hirano.

At least 109 records · Page 6Linked to original sources
PubMed1991

[Activation of ras oncogene in myelodysplastic syndrome and acute myelogenous leukemia].

N-ras oncogenes activated by point mutation have been frequently detected in various types of human leukemias. Analysis of a large number of leukemias revealed that activated N-ras oncogenes were observed preferentially in AML, AMoL, T-ALL and Null-ALL but rarely in CML and B-cell leukemia. These results suggest that N-ras oncogene plays an important role in human leukemogenesis. Activated N-ras oncogenes were also detected in myelodysplastic syndrome (MDS) that is considered to be a preleukemic disease. MDS patients bearing an activated N-ras oncogene frequently showed leukemic progression of the disease, suggesting that an activated N-ras oncogene can be a critical factor for prognosis of MDS patients. Thus, detection of an activated N-ras oncogene is useful for diagnosis, prognostic evaluation and therapeutic decision. Recently, we demonstrated that detection of the minimal residual disease by analysis of N-ras oncogene can lead to improvement of the remission rate in leukemias. Moreover, we made it possible to screen N-ras oncogene by a sensitive non-radioactive method. Our research procedure seems to be a good model for clinical application of the molecular biological technique.

Base Sequence↗
PubMed1990

Osteoarthrosis induced by intra-articular hydrogen peroxide injection and running load.

Osteoarthrosis of the rat knee joint was induced successfully by intra-articular injection of 2% hydrogen peroxide (H2O2) and running load. In the group receiving two injections of physiological saline with running load, no histological osteoarthrotic knees were developed up to 8 weeks after the injection. In the group receiving two 2% H2O2 injections and running load, advanced osteoarthrosis occurred in all knees 8 weeks after the first injection, and the Mankin's score of osteoarthrotic knees appeared to be higher than the group receiving two 2% H2O2 injections without running load (p less than 0.004, Kruskal-Wallis H test). In the rats receiving a single 2% H2O2 injection with running load and a vitamin E-enriched diet, the inhibitory effect of vitamin E on the development of osteoarthrosis was statistically significant compared to the regular diet group (p less than 0.05, Wilcoxon rank test).

Animals↗
PubMed1990

Replication and plaque formation of swine hemagglutinating encephalomyelitis virus (67N) in swine cell line, SK-K culture.

Swine hemagglutinating encephalomyelitis virus (HEV), 67N strain, adapted to suckling mouse brain, grew readily in a porcine cell line, SK-K cell culture with cytopathic effect (CPE) consisting of syncytium formation and detachment of fused cells and round cells from glass surface. After further passages in SK-K cell monolayers with undiluted culture fluid, CPE developed earlier and became complete within 48 h postinoculation (p.i.). Viral specific antigen was detected in the cytoplasm of the infected SK-K cells by indirect immunofluorescence using rabbit antiserum against the mouse-passaged virus. The SK-K-passaged virus as well as the original mouse-passaged virus formed clear plaques on SK-K cell monolayers under simple overlay medium. The plaque assay system for HEV 67N was established by studying various factors influencing the plaque formation in the SK-K cell cultures. By this system more than 10(6) PFU/0.2 ml of the virus yield was detected in the fluid phase of the infected cultures at 48 h p.i. The SK-K-passaged virus caused fatal infection in 4-week-old mice by intracerebral inoculation, but was inhibited by rabbit antiserum against the mouse-passaged virus. Plaque formation and hemagglutinating activity of the virus were specifically inhibited by antisera against the mouse-passaged and SK-K-passaged 67N virus.

Animals↗
PubMed1990

Complications of lateral C1-2 puncture myelography.

This study reviewed the technical complication of 112 cases of lateral C1-2 puncture myelography for cervical spinal cord disorders. Spinal cord puncture and contrast injection, puncture between the occiput and C1, and blood vessel puncture were the main complications. These principally depended on the positioning of the patient's neck (hyperextension) and misdirection of the x-ray beam. For preventing major arterial puncture, the authors also reviewed 164 vertebral angiograms and determined the pathway of the vertebral arteries and the incidence of anomaly.

Female↗
PubMed1990

Plaque assay and propagation in rat cell line LBC cells of rat coronavirus and 5 strains of sialodacryoadenitis virus.

Various factors influencing the plaque formation of rat coronavirus (RCV) and sialodacryoadenitis virus (SDAV) in LBC cell monolayers were studied to develop the practical method for plaque assay. By this method, 4 Japanese isolates of SDAV also produced clear plaques. In one-step growth experiments of these viruses, newly formed virus was first recognized within 7.5 h postinfection and showed subsequently a rapid exponential increase. The virus was released rapidly from the infected cells. By indirect immunofluorescence virus specific antigen was detected as perinuclear granules in the cytoplasm of the cells at 5-6 h postinfection, and all the cells revealed fluorescence at 12 h postinfection.

Animals↗
PubMed1990

Natural infection of nude mice with low-virulent mouse coronavirus.

The outbreak of wasting disease of nude mice occurred in the laboratory colony of a Pharmaceutical Company. The viruses producing cytopathic effect with syncytium formation were isolated from the wasted nude mice by DBT cells, and were identified as mouse coronavirus by direct immunofluorescence. The nude mouse colony was closed and all the nude mice (about 500) were killed by the reason of disease control. At autopsy about 60% of nude mice showed necrotic hepatitis. By the virus isolation to see the source of contamination, viruses were isolated from the feces of apparently healthy mice of ICR, CDF1, DBA/2 and C3H, and from human cancer cell line stocked in liquid nitrogen. In experimental infection, the isolates produced only mild hepatitis in ICR mice treated with cortisone. By cross-neutralization test, the nude isolate reacted closely with the virus from C3H mice but not with the virus from cancer cell line. The isolates from nude and C3H mice produced experimentally wasting disease with necrotic hepatitis in nude mice. These findings suggest that wasting disease in nude mice might be caused by low-virulent mouse coronavirus shed in feces from C3H mice introduced before the outbreak of disease.

Animals↗
PubMed1990

Vacuolar degeneration in mice infected with a coronavirus JHM-CC strain.

Vacuolar degeneration was constantly induced in the CNS of 4-week-old ICR mice by intracerebral or intranasal inoculation of JHM-CC virus, a small plaque mutant of mouse hepatitis virus (JHM). Most animals showed no symptoms or only mild hindlimb paresis. Irrespective of clinical manifestations, the virus was isolated from the CNS up to days 14 to 16. Viral antigen expression in the CNS tissue was most extensive around days 5 to 7 and became undetectable on day 14. Viral antigens were localized almost exclusively to neurons, and the temporal sequence of viral antigen distribution after intranasal inoculation clearly indicated the virus spread through the olfactory and limbic systems into the brainstem and spinal cord, and possible cell-to cell transmission of the virus within the CNS. Vacuolar changes, most conspicuous in the brainstem and spinal cord, were steadily progressive up to 4 weeks after infection, but became indistinct by 4 months. Although the distribution of vacuolar lesions largely agreed with that of viral antigen-positive cells, the severity of vacuolation did not correlate with that of inflammation. Intramyelinic splitting, periaxonal edema, and swollen neurites were major ultrastructural substrates for vacuolar changes. This model could provide a better understanding of new types of neurologic disorders associated with viral infections, including vacuolar myelopathy in AIDS.

Animals↗
PubMed1990

Ceramic interspinous block (CISB) assisted anterior interbody fusion.

Ceramic interspinous block (CISB) assisted anterior fusion system was developed. The system is recommended for patients with symptomatic disc degeneration and destructive lesions of the lumbar spine. One hundred and six patients who underwent CISB-assisted anterior fusion by one doctor (H.T.) from 1981 to 1987 were followed-up 2-6 years after the operation. A comparative study of the results between the CISB-assisted group and the CISB-unassisted anterior fusion group, performed by the same doctor during 1979-1981 for deranged disc, was also done. Satisfactory relief of back and leg pains, marked ADL recovery and early bone union were obtained in all of the CISB-assisted anterior fusion cases. The union rate was 98.9% in the CISB-assisted anterior fusion group, whereas in the CISB-unassisted group, it averaged 79%. The efficacy of CISB for anterior interbody fusion was also verified using a computer simulation. CISB implementation appears to create equalization of stress distribution on the graft-vertebra interface.

Adolescent↗
PubMed1990

Motion characteristic of the normal lumbar spine in young adults: instantaneous axis of rotation and vertebral center motion analyses.

To determine the motion characteristic of the normal lumbar spine, 61 of 612 optimal radiographs of healthy young Japanese adults in the neutral erect, active maximum flexion and maximum extension positions were carefully selected. The coordinates of the instantaneous axis of rotation (IAR) and vertebral center from L1 to L5 vertebra were analyzed. The directional shifts in IAR in the x-axis and the y-axis closely reflected translational and rotational movements of the vertebra. The IAR showed qualitative values with very large, 95%, probability ellipses in the normal lumbar spine. Analysis of coordinates of the vertebral center provided quantitative data of the extension-to-flexion motion of each vertebra. In extension-to-flexion motion, the L4 vertebra showed a translation-predominant motion characteristic. The L5 vertebra had a rotation-predominant motion characteristic. The patterns of motion of the L1-L4 vertebrae were correlated to the intervertebral disc height and the inclination angle of the facet joint. The L5 vertebra alone showed some specific patterns suggestive of the involvement of a separate ligamentous stabilizer, the iliolumbar ligaments, which reduces translation.

Adolescent↗
PubMed1989

Electron microscopic immunocytochemistry of prolactin secreting cells (PRL-cells) and growth hormone secreting cells (GH-cells) in the anterior pituitary gland of partially hepatectomized rats.

After 60% hepatectomy in rats, prolactin secreting cells (PRL-cells) and growth hormone secreting cells (GH-cells) of the anterior pituitary gland were distinctly identified by the protein A-gold procedure combined with electron microscopy. The animals were sacrificed by the decapitation at midnight at intervals of about 28, 76 and 124 h after the operation. The principal changes can be summarized as follows; (1) Hypertrophy of the Golgi complex, (2) Dilation of the rough endoplasmic reticulum (RER), (3) Increased numbers of secretory granules (markedly in GH-cells), and occurrence of granule extrusion or exocytosis, (4) Increased numbers of lysosomes, which were mostly seen at 124 h after the operation. These ultrastructural changes were remarkably observed in both PRL and GH-cells. Especially, the noticeable changes in PRL-cells after partial hepatectomy in the rat were new findings in this study. The above results suggest that hepatectomy induced synthesis and release of GH and PRL in cells from pars distalis.

Animals↗
PubMed1989

Water, fixed charge density, protein contents, and lysine incorporation into protein in chymopapain-digested intervertebral disc of rabbit.

Chymopapain (Discase) was injected at a dose of 0.125 nanokatal unit into the intervertebral discs of rabbits, and sequential changes in the metabolism of water, proteoglycan, collagen, and noncollagenous protein were investigated separately in the nucleus pulposus, anterior, and posterior anulus fibrosus. One week after chymopapain injection, the water and proteoglycan content was lower in all of the fractionated tissues of the anterior and posterior anulus and nucleus pulposus of the discs than in the control discs. In the anterior and posterior anulus, the proteoglycan content recovered after 12 weeks, but there was no recovery in the nucleus pulposus. The collagen content continued to increase up to the 12th week in the nucleus pulposus, while the noncollagenous protein content decreased in all tissue fractions after 1 week. In the anterior and posterior anulus, the content of noncollagenous protein recovered after 3 to 6 weeks, but there was no recovery in the nucleus pulposus. The lysine incorporation in collagen and noncollagenous protein was inhibited in all tissue fractions after 12 weeks, suggesting a decrease in synthetic activity. The intradiscal pressure calculated from proteoglycan hydration at 1 to 6 weeks after chymopapain injection showed a marked decrease to 0.8 to 0.9 atm, but it recovered to 1.6 atm after 12 weeks.

Animals↗
PubMed1989

Water diffusion pathway, swelling pressure, and biomechanical properties of the intervertebral disc during compression load.

The behavior of water in the intervertebral disc of pig tail and its physiologic and biomechanical properties were investigated in relation to compression load. The water content, chemical composition, and swelling pressure in the intervertebral disc were measured, and the mechanism of the generation of the swelling pressure in relation to compression load stress was studied. The swelling pressure, through regulation of the water content of the disc and the resistance of the external load, differs with the region of the intervertebral disc. In the nucleus pulposus and the inner layer of the anulus fibrosus, the swelling pressure rises in proportion to the load, but few changes occur in the outer layer of the anulus fibrosus, and the constant pressure environment is thus maintained. The tritiated water (3H2O) uptake of the disc under various loads was measured. The molar partition coefficient of tritiated water is almost equal to 1 even under a compression load, which suggests that water is freely exchangeable. The diffusion of 3H2O in the intervertebral disc was traced using two pathway models: the perianular route and the end-plate route. The diffusion of water in the unloaded disc for both uptake and washout was about 2 to 3 times larger in the perianular route than in the end-plate route. Under load, the water diffusion was inhibited in both pathways. The relation between the load and displacement revealed viscoelastic properties indicating creep and stress relaxation. Young's modulus and the stiffness increased with a rise in load speed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Analysis of rabbit intervertebral disc physiology based on water metabolism. I. Factors influencing metabolism of the normal intervertebral discs.

Basic factors influencing the metabolism of intervertebral discs of rabbits were quantitatively analyzed based on the water metabolism. The blood flow surrounding the intervertebral disc was calculated using pharmacokinetic concepts from the data obtained by time-related tritiated water distribution analyses. The blood flow was estimated as 0.056 (mg/min/mg tissue) in the anterior annulus, 0.106 in the posterior annulus, 0.120 in the lateral annulus, and 0.084 in the nucleus pulposus, respectively (Experiment 1). Water content and fixed charge density in the intervertebral disc fractions also were measured (Experiment 2). The cations and uncharged small solutes transported into the disc tissue ranged in descending order from nucleus pulposus, lateral annulus, posterior annulus, to anterior annulus. The authors also calculated theoretically the swelling pressure of the proteoglycan in the intervertebral disc fractions from the results of Experiment 2. It was concluded that swelling pressure was highest in the nucleus pulposus, and lowest in the anterior annulus. The water in the posterior annulus is less exchangeable than in the other disc tissue fractions.

Animals↗
PubMed1988

Analysis of rabbit intervertebral disc physiology based on water metabolism. II. Changes in normal intervertebral discs under axial vibratory load.

Metabolic changes induced by axial vibratory load to the spine were investigated based on water metabolism in normal intervertebral discs of rabbits with or without pentobarbital anesthesia. Tritiated water concentration in the intervertebral discs of unanesthetized rabbits was reduced remarkably by axial vibration for 30 minutes using the vibration machine developed for this study. Repeated vibratory load for 18 and 42 hours duration showed the recovery of 3H2O concentration of the intervertebral disc without anesthesia. Computer simulation suggested a reduction of blood flow surrounding the intervertebral disc following the vibration stress. However, no reduction of the 3H2O concentration in the intervertebral disc was noted under anesthesia. Emotional stress cannot be excluded as a factor in water metabolism in the intervertebral disc.

Animals↗