Search PubMed⌕ Search

Biomedical subjects

H Abe

Publications and source records attributed to H Abe.

At least 667 records · Page 37Linked to original sources
PubMed1995

[Changes of expression in matrix metalloproteinase and its inhibitor level in the sclera from axially elongated eyes].

We studied the gelatinolytic activity, caseinolytic activity and the level of tissue inhibitor of metalloproteinase-1 (TIMP-1) in the sclera from experimentally induced axially elongated eyes. The animal models were made by the injection of 250U alpha-chymotrypsin into the posterior chamber of young albino rabbits. Animals were killed with overdoses of intravenous pentobarbital and eyes were enucleated gently. Sclera from the equatorial area was then subjected to organ culture. The enzyme activity in the media was investigated by zymography using gelatin- or casein-containing gels together with an image analyzer system. TIMP-1 levels in each medium were measured by enzyme immunoassay (EIA). All samples showed three major bands of gelatinolytic activity at molecular weights of 87, 61, and 57 kDa. Gelatinolytic activity of 87 kDa increased 1.1 to 2.9 times compared with control sclera. All of the caseinolytic activity (87, 82, 52, and 50 kDa) was also elevated 1.8 to 6.6 times in samples from experimental eyes. TIMP-1 levels were mildly increased (up to 1.41 times) in the experimental eyes. These data suggest that degradation processes might be accelerated in the sclera from experimentally induced elongated eyes.

Animals↗
PubMed1995

[Collagen synthetic activity following filtration surgery in rabbits].

We evaluated collagen synthetic activity, which plays an important role in wound healing, following experimental filtration surgery in rabbits. Collagen synthetic activity was measured by immunohistochemistry for prolyl 4-hydroxylase beta-subunit and type I procollagen. Trabeculectomy was performed on albino rabbit eyes, with the filtering site harvested on postoperative days 1, 4, 7, 14, and 28. Samples were fixed with 10% buffered formalin for 12 hours and prepared for paraffin section, and each antigen was detected in filtering site tissue using avidin-biotinylated peroxidase complex. Immunoreaction of prolyl 4-hydroxylase beta-subunit or type I procollagen increased from day 4 to 14 and markedly decreased at day 28. These findings show that prolyl 4-hydroxylase and type I procollagen are markedly produced almost simultaneously, and collagen synthetic activity following filtration surgery continues for over 14 days in the process of wound healing.

Animals↗
PubMed1995

[Ultrastructural changes in the lamina cribrosa in experimental monkey glaucoma].

We examined the ultrastructural changes in the lamina cribrosa in monkeys with experimental chronic glaucoma. In normal monkey eyes, the extracellular matrix consists of tightly packed collagen fibers, elastic fibers and less ground substance in the beams, and basement membranes associated with vascular cells and astrocytes in the lamina cribrosa. In the experimental glaucomatous eyes there was a marked destruction of collagenous bundles. The empty spaces were expanded and filled with fine fibrillar materials. There were normal by appearing parts and clearly destroyed parts mixed in the same region. Elastic fibers looked isolated from the collagenous bundles around them. Basement membranes were generally thick, multi-laminated, and bent. In addition, basement membrane-like materials, separated from the cells, were often seen in the laminar beams. The lamina cribrosa in experimental chronic glaucoma showed evidence of both destruction and healing or remodeling. These changes might have a influence to the worse for the tissue characterization of the lamina cribrosa, such as resistence to intraocular pressure changes. In conclusion, this may be a factor related with the progression of glaucomatous optic nerve damage.

Animals↗
PubMed1995

[Comparison of nerve damage with alcohol and that with phenol in guinea pigs].

We compared the damaging effect on myelinated nerve of alcohol and that of phenol. Guinea pigs of approximately 300 g in weight were used. Right sciatic nerve was exposed after intraperitoneal administration of pentobarbital. Saline was used in the first group as control. The second group received perineural administration of 100% alcohol. The third group received 100% alcohol inside the epineurium. The fourth group received perineural administration of 5% phenol in aqua. The fifth group received 5% phenol in aqua inside the epineurium. The first group showed no change. Toe necrosis was found in 2 cases in the second group, 3 cases in the third, null in the fourth and 6 cases in the fifth group. We concluded that damage was larger with phenol than with alcohol when administered intraneurally, but the difference was not significant. Alcohol administered inside or outside of the epineurium made no significant changes, but phenol administered only inside the epineurium made a significant damage.

Animals↗
PubMed1995

[A case report on a reconstructive operation of a traumatic tricuspid regurgitation with a congenital defect of the left pericardium].

We reported a successful tricuspid valve replacement in a 58-years old man, who had easy fatiguability after 14 years of a blunt chest trauma. The preoperative examination revealed a marked cardiomegaly with deformation of both ventricles and grade 4 tricuspid regurgitation caused by the prolapse of the anterior leaflet. The operative inspection revealed a left pericardial defect with a diameter of 10 cm and a torn anterior papillary muscle. Since a usual plastic procedure did not improve the regurgitation, a Carpentier-Edward bioprosthetic valve was implanted in the supra annular position. Atrioventricular conduction was preserved. The tricuspid valve was not resected to preserve the ventricular function. The patient recovered his own activity.

Heart Injuries↗
PubMed1995

[99mTc pertechnetate scintigraphy for malignant soft-tissue tumors].

The purpose of this study was to investigate the accumulation of technetium-99m pertechnetate (99mTc) in malignant soft-tissue tumors. Twenty-one patients with malignant soft-tissue tumors were subjected to 99mTc scintigraphic studies. In 19 of 21 patients (90%), 99mTc accumulated extensively in the tumors. 99mTc accumulation was especially thorough in all cases of MFH and liposarcoma. Therefore, 99mTc is useful for the local evaluation of malignant soft-tissue tumors.

Adolescent↗
PubMed1995

Functional magnetic resonance imaging of the primary visual cortex: evaluation of human afferent visual system.

The authors evaluated signal changes in the human primary visual cortex during visual stimulation using functional magnetic resonance imaging (MRI) scanner at 1.5 Tesla. Experiments were performed on 10 normal volunteers and 2 patients with homonymous hemianopsia. In the normal volunteers, a signal increase was observed on the bilateral primary visual cortex during hemifield stimulation. In one patient with homonymous hemianopsia after cerebral infarction, the signal change was clearly decreased on the affected side. In the other patient, who was recovering from multiple sclerosis to an almost normal visual field, the fMRI results were within normal limits. These results suggest that it is possible to map noninvasively the activation of the visual stimulation with a clinical MRI system, and that this test might be useful as an objective method of visual field examination.

Adult↗
PubMed1995

[Surgical treatment for syringomyelia associated with Chiari malformation].

Two major surgical procedures, i.e., foramen magnum decompression (FMD) and syringo-subarachnoid shunt (S-S shunt) have been performed as the treatment for syringomyelia with Chiari malformation in our department. FMD was done principally in patients with symptoms due to Chiari malformation and for small size or localized syrinx, and S-S shunt was applied to patients with main symptoms due to syringomyelia, especially with local pain and for large syrinx in size. Eighty patients of syringomyelia with Chiari malformation were surgically treated. FMD was performed in 38 patients, and S-S shunt in 39 patients as the first operation. FMD were done with craniectomy of posterior fossa, C1 laminectomy and resection of epidural band, but without opening dura, and S-S shunt were done with hemipartial laminectomy and DREZtomy. The clinical outcome was evaluated, comparing the two major surgical procedures. Satisfactory neurological improvement was obtained in the two groups, but S-S shunt group took better improvement than FMD group. These results suggest that both procedures are effective, but should be selected by preoperative clinical and radiological findings.

Adolescent↗
PubMed1994

Induction of ischaemic tolerance in gerbil hippocampus by pretreatment with focal ischaemia.

We investigated the induction of ischaemic tolerance in the hippocampal CA1 neurones to transient forebrain ischaemia following pretreatment with unilateral middle cerebral artery occlusion (MCAO) in gerbils. Histological evaluation was carried out after 5 min bilateral carotid artery occlusion (5BCO) in the gerbils with no MCAO pretreatment, MCAO pretreatment 3 days prior to 5BCO (MCAO-3d-5BCO), MCAO pretreatment 7 days prior to 5BCO and sham MCAO pretreatment 3 days prior to 5BCO. CA1 neurones were preserved at > 40% of normal controls only in the left hippocampus in the MCAO-3d-5BCO gerbils. CA1 neurones in the right side of MCAO-3d-5BCO gerbils as well as in both sides of animals in the other pretreatment groups almost completely disappeared after 5BCO. While the exact mechanism remains to be resolved, pretreatment with focal ischaemia seems to induce ischaemic tolerance in neurones outside of the primary ischaemic lesion.

Adaptation, Physiological↗
PubMed1994

Activation mechanism of NADPH oxidase by SDS in intact guinea pig neutrophils.

It is well known that sodium dodecyl sulfate (SDS) activates NADPH oxidase in a cell-free system independently of protein kinase C (PKC). However, in intact neutrophils, direct evidence has never been presented to show that O2- production by SDS is actually due to the NADPH oxidase activation observed in the cell-free system. So, in this paper, we investigated the activation mechanism by SDS in intact guinea pig neutrophils. We previously reported that hypotonic treatment reversibly enhanced O2- production stimulated by PKC activators in intact neutrophils (M. Hiura et al., 1991, Arch. Biochem. Biophys. 291, 31-37). In this paper, SDS also significantly stimulated O2- production in the intact cells under the hypotonic condition. This enhancement was gradual and was PKC inhibitor resistant. Furthermore, phosphorylation of the 46-kDa protein, one of cytosolic activation factors, was not detected by autoradiography of two-dimensional electrophoresis. Translocation of cytosolic activation factors was demonstrated by a decrease in the activity of the factors remained in the cytosol. In the presence of SDS, addition of 1-oleoyl-2-acetylglycerol, a PKC activator, further enhanced O2- production and translocation of the cytosolic activation factors. On the other hand, SDS remarkably increased membrane fluidity in intact neutrophils as well as in the cell-free system. These results indicate that activation of NADPH oxidase by SDS in intact neutrophils seems to be partly due to the same mechanism observed in cell-free activation, and that SDS alone slightly activates the oxidase and other stimulation, such as hypotonic and/or PKC activator treatments, is required for significant activation. The increase in the membrane fluidity may be one of the activation mechanisms of NADPH oxidase by SDS.

Animals↗
PubMed1994

Postnatal development of [D-Ala2]deltorphin-I-like immunoreactive structures in the rat brain.

[D-Ala2]deltorphin-I, a highly selective ligand for delta opioid receptors, is a heptapeptide originally purified from frog skin. Previous immunohistochemical studies indicate that [D-Ala2]deltorphin-I-like molecule(s) may be present in adult rat brain, including specific neuronal cells and fibers partially overlapping with the mesocortical and nigrostriatal dopaminergic systems. Here, we examined the developmental aspect of such immunoreactive brain structures in early postnatal rats. In newborn to 21-day-old rats, positive staining in the brain occurred mainly in subpopulations of neurons and occasionally in tanycytes. On postnatal day 0, neuronal cell bodies containing [D-Ala2]deltorphin-I-like immunoreactivity were found in various brain regions, including the olfactory tubercle, ventral pallidum, hippocampus, ventral tegmental area, pars compacta of the substantia nigra, supramammillary nucleus, and dorsal raphe nucleus. Immunoreactive nerve fibers were observed in the main and accessory olfactory bulbs, olfactory tubercle, prelimbic area, anterior cingulate cortex, neostriatum, accumbens, lateral septal nucleus, lateral habenular nucleus, and superior colliculus. As pups grew, positive staining of cell bodies decreased gradually in both density and intensity, and those in the olfactory tubercle and ventral pallidum were no longer visible on postnatal day 14. On postnatal day 21, positive cells were found only in the ventral midbrain, including the pars compacta of the substantia nigra, ventral tegmental area, A8 region, and supramammillary nucleus. Positive fibers also decreased in density with age except in the accessory olfactory bulb, olfactory tubercle, prelimbic area, and anterior cingulate cortex.

Amino Acid Sequence↗
PubMed1994

Simultaneous determination of D- and L-amino acids in the nervous tissues of crustaceans using precolumn derivatization with (+)-1-(9-fluorenyl)ethyl chloroformate and reversed-phase ion-pair high-performance liquid chromatography.

After the derivatization of D- and L-amino acids with (+)-1-(9-fluorenyl)ethyl chloroformate, nineteen amino acids were separated into their D- and L-enantiomers and from other physiological amino compounds by reversed-phase ion-pair high-performance liquid chromatography. The separation was performed by three separate runs differing in mobile phase compositions and gradient profiles. Tyrosine, tryptophan and cysteine could not be detected because of their weak reactions with the derivatization reagent. Of seven D-amino acids found in the crustacean nervous tissues and eyes, D-alanine, D-arginine and D-aspartate were the most abundant and widely distributed.

Amino Acids↗
PubMed1994

Characterization of a novel cofilin isoform that is predominantly expressed in mammalian skeletal muscle.

Cofilin is an actin-modulating protein of 20 kDa, which is widely distributed throughout muscle and non-muscle cells. By means of immunoblotting combined with two-dimensional gel electrophoresis, we found that two cofilin variants, muscle type (M-type) and non-muscle type (NM-type), exist in mammals, while a single isoform exists in chickens. During in vitro myogenesis of mouse C2 cells, expression of the M-type cofilin was upregulated. To better understand the nature of the M-type cofilin, we cloned cDNAs encoding M-type cofilin from the cDNA library of C2 myotubes and determined the entire sequence. The deduced peptide sequence contained a nuclear localization signal and a putative actin-binding sequence as reported in NM-type cofilin. The sequence showed 81% identity in the amino acid residues with the mouse NM-type cofilin sequence and, interestingly, higher homology (96% identity) with that of chicken cofilin. The mRNA encoding M-type cofilin, though it contains two variants that differ in the size of their 3'-non-coding sequences, was detected predominantly in heart, skeletal muscle, C2 myotubes, and testis by Northern blotting, while the mRNA for NM-type cofilin was seen in a variety of non-muscle tissues. The presence of the muscle type isoform of cofilin strongly suggests that cofilin is deeply involved in the regulation of actin function not only in non-muscle cells but also in muscle cells.

3T3 Cells↗
PubMed1994

Effect of nafamostat mesilate, a synthetic protease inhibitor, on tissue factor-factor VIIa complex activity.

Nafamostat mesilate (NM), a synthetic protease inhibitor, is frequently used for the treatment of disseminated intravascular coagulation (DIC) in Japan. NM inhibits several proteases which may be importantly involved in the pathophysiology of DIC. Since tissue factor (TF) plays a critical role in DIC associated with septicemia, inhibition of the extrinsic pathway of coagulation by coagulation inhibitors may be useful for the treatment of DIC. NM inhibited extrinsic pathway activity (TF-F.VIIa mediated-F.Xa generation) in a concentration dependent manner; the IC50 was 1.0 x 10(-7) M. F.Xa was not inhibited by NM at the concentrations used in the experiment, suggesting that NM might inhibit TF-F.VIIa complex activity. When incubated with TF-F.VIIa complex, NM inhibited the complex activity with an IC50 of 1.5 x 10(-7) M, the same value that found for inhibition of extrinsic pathway activity. A Lineweaver-Bulk's plot of the inhibition demonstrated that NM inhibited TF-F.VIIa complex in a competitive fashion, with an inhibition constant (Ki) of 2.0 x 10(-7) M. These findings suggested that NM may be a potent inhibitor of TF-F.VIIa complex and the therapeutic effect of NM in DIC patients could be partly explained by inhibition of the extrinsic pathway of the coagulation system.

Amino Acid Sequence↗
PubMed1994

Glutamate release in the gerbil hippocampus after middle cerebral artery occlusion.

In a modified version of the unilateral middle cerebral artery occlusion (MCAO) model in gerbils, both sides of hippocampus are spared from direct ischaemic insult. Using this newly employed left MCAO model in gerbils, we investigated the concentrations of extracellular amino acids in the left hippocampus by microdialysis and histological changes in both sides of hippocampus one month after ischaemia. The concentrations of glutamate and aspartate were significantly increased by more than 3.5 times basal levels after MCAO. Glutamate maintained this peak level for 40 to 120 min after the onset of ischaemia. However, hippocampal neurones were well preserved one month after MCAO. While the exact mechanism of the survival of hippocampal neurones remains to be elucidated, we suggest it may be crucial that the hippocampus be protected from ischaemic insult.

Amino Acids↗
PubMed1994

Circadian rhythms in the release of vasoactive intestinal polypeptide and arginine-vasopressin in organotypic slice culture of rat suprachiasmatic nucleus.

Temporal profiles of the amount of vasoactive intestinal polypeptide (VIP) were examined in the medium of organotypic suprachiasmatic nucleus (SCN) slice cultures over a 2-day period. Arginine-vasopressin (AVP) level was also measured in the same medium. The slices of the SCN were obtained from 7-8-day-old rats and cultured individually in tubes on a roller drum for 14 days. The VIP amount in the medium of SCN culture showed a circadian rhythm with a approximately 22-h period. Circadian rhythms with identical periods were also observed in AVP amount of the same culture. However, the peak time of the VIP rhythm was slightly ahead of that of the AVP rhythm. Furthermore, the total VIP amount in the medium over a 24-h period was six times as large as that of AVP. These results suggest that there is a circadian rhythm of VIP which is released from the ventrolateral SCN.

Animals↗