Biomedical subjects

A Oohira

Publications and source records attributed to A Oohira.

At least 73 records · Page 4Linked to original sources

PubMed1991

Zonal and age-related difference in the amounts of creatine kinase subunits in cartilage.

Energy metabolism in cartilage may affect the morphogenetic events of skeletal growth. Investigating enzymes responsible for energy metabolism in cartilage, such as creatine kinase (CK), can provide clues to an understanding of pathogenesis and treatment of osteochondrodysplasias. In this study levels of CK subunits M (muscle type) and B (brain type) were measured by a highly sensitive enzyme immunoassay system in growth and resting cartilages of the rat rib at various ages. CK-M was predominant, but there was no statistically significant difference in its quantity of CK among cartilages of various ages or between resting and growth cartilage. In contrast, although CK-B levels were low, they showed a significant decrease with advancing age and a significant increase in growth cartilage as compared with resting cartilage. The results of this study suggest that CK in cartilage, especially CK-B, may play an important role in skeletal growth.

Aging↗

PubMed1991

Inhibitory effects of brain chondroitin sulfate proteoglycans on neurite outgrowth from PC12D cells.

Soluble chondroitin sulfate proteoglycans (CSPGs), prepared from 10-d-old rat brain, were added to the culture medium of PC12D cells containing NGF to examine the effects on NGF-induced neurite outgrowth from the cells. PC12D cells, a flat-shaped variant of PC12 pheochromocytoma cells, are characteristic of prompt neurite formation in response not only to NGF, but also to cAMP-enhancing reagents such as forskolin. Brain CSPGs inhibited the neurite elongation irreversibly in a dose-dependent manner; complete inhibition was observed at a concentration of 50 nmol uronic acid/ml. Closely similar dose-dependent inhibition was observed in the forskolin-induced neurite outgrowth from PC12D cells. NGF-induced neurite outgrowth from conventional PC12 cells was also inhibited completely by 50 nmol uronic acid/ml CSPGs. Some brain CSPGs seemed to be inhibitory, but the cartilage-unique CSPG did not show any inhibitory effect. Chondroitin sulfate, a polysaccharide moiety of CSPGs, did not show any inhibitory effect even at a concentration of 250 nmol uronic acid/ml, while core proteins prepared from brain CSPGs by digestion with chondroitinase ABC exhibited inhibitory activity similar to that of intact CSPGs. This indicates that the site of the inhibitory activity exists in the core protein moiety of brain CSPGs. From these observations, it is conceivable that brain CSPGs are involved in the regulation of neuronal differentiation.

Adrenal Gland Neoplasms↗

PubMed1991

Disconjugate adaptation to long-standing, large-amplitude, spectacle-corrected anisometropia.

A 12-yr-old anisometropic patient had worn corrective eyeglasses (right eye, -0.50 +1.50 x 125; LE, -9.75 +2.50 x 60) for 7 yr, and then changed to contact lenses. Eye movements were recorded before and after the change to contact lenses using binocular search coils. In habitual spectacle viewing, the patient showed disconjugate adaptation. During monocular viewing, for example, ocular alignment changed by as much as 4 degrees during a 20 degrees saccade. Also, during monocular viewing, with either eye, placing the spectacle lens in front of the eye caused an increase in the disconjugate adaptive response compared with viewing without lenses. This finding emphasizes the context specificity of adaptive responses. After switching to contact lenses, the patient still wore his spectacles for 20-40 min each day. Although there was little residual disconjugate adaptation for vertical saccades, he showed considerable adaptation for horizontal saccades, especially for gaze changes that required divergence. The persistence of a partial state of disconjugate adaptation allowed the patient to use immediate, disparity-induced, horizontal vergence to aid ocular alignment in either the contact-lens-viewing or the spectacle-viewing condition. A more complete reversion to conjugacy occurred after nine days of exclusive use of his contact lenses. Then, in a short-term experiment, two minutes of binocular viewing through the eyeglasses induced a considerable reversion toward the previous state of disconjugate adaptation (up to 1.25 degrees of vergence change during monocular viewing). Finally, the waveform of the adapted (to spectacles) intrasaccadic vergence change with monocular viewing was similar to the waveform of the unadapted intrasaccadic vergence change during binocular refixations between targets that required a combined saccade and vergence. This finding suggests a common mechanism for adaptation to spectacle-corrected anisometropia and for normal binocular vergence-saccade interactions.

Adaptation, Ocular↗

PubMed1990

Calcified ligamenta flava in a patient with Coffin-Lowry syndrome: biochemical analysis of glycosaminoglycans.

Glycosaminoglycans in calcified cervical ligamenta flava from a male patient with Coffin-Lowry syndrome were analyzed biochemically. Hexuronate content based on the tissue dry weight was 8-fold and 5-fold concentrated in the calcified center as compared with the peripheral area and with age-matched, normal ligamenta flava, respectively. Two-dimensional electrophoresis of glycosaminoglycan preparations on cellulose acetate film revealed that, although dermatan sulfate was the major glycosaminoglycan in the normal ligamenta flava, chondroitin sulfate was the predominant glycosaminoglycan in the pathological tissue. Relative amounts of chondroitin sulfate disaccharide units were determined after digestion of glycosaminoglycans with chondroitinase, and the ratio of chondroitin 6-sulfate to chondroitin 4-sulfate tended to decrease with the distance from the calcified center to the peripheral area. These observations suggest that an alteration in glycosaminoglycan metabolism may be a contributing factor in calcification of ligamenta flava in Coffin-Lowry syndrome.

Abnormalities, Multiple↗

PubMed1990

Changes in glycosaminoglycans during the neuritogenesis in PC12 pheochromocytoma cells induced by nerve growth factor.

Previously, we had suggested that heparan sulfate (HS) makes some contribution to a flat-shaped morphology of PC12D cells. Therefore, we carried out quantitative and qualitative analyses of glycosaminoglycans (GAGs), the polysaccharide moiety of proteoglycans, during neuritogenesis in PC12 cells that is induced by nerve growth factor (NGF). (a) In PC12 cells, NGF induced a flat-shaped morphology with a few short processes after 3 days of culture, and then it elicited short and long neurites after 6 (in approximately 30% of cells) and 9 (in 60-70%) days of culture, respectively. (b) HS and chondroitin sulfate (CS) were detected in the cell layer at all times. Only CS was found in the medium at 3 and 6 days, whereas a low level of HS, in addition to CS, was detectable on day 9. (c) In the NGF-treated cultures, the amounts of cell-associated HS per cell were two to three times as high as those in the respective nontreated cultures at all times, whereas the amount based on phospholipid was about twofold higher after 3 days of culture. (d) The levels of HS labeled with [35S]sulfate during the last 48 h of the culture were 1.5- to twofold higher in the NGF-treated cultures than in the respective controls at any time. (e) The amount of cell-associated CS per cell (or per unit of phospholipid), but not of labeled CS per cell, was transiently enhanced at 3 days in culture with or without NGF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Gland Neoplasms↗

PubMed1990

Bioassay of chondrocyte differentiation by bone morphogenetic protein.

For sensitive bioassay of cartilage development in response to bone morphogenetic protein (BMP), the supernatant of interstitial fluid containing crud BMP was obtained from an implanted diffusion chamber, applied to a cellulose acetate film, and stained with Alcian blue. The optical density of the Alcian blue-stained spot was measured by a densitometer for quantitative analysis. Density of the Alcian blue-stained spot was markedly increased when cartilage developed outside the chamber. Occurrence of cartilage-specific proteoglycan-H (PG-H) and Type II collagen was seen in this intensely stained spot by dot-blot analysis. Electron microscopic examination revealed that the residue of interstitial fluid in the implanted diffusion chamber contained many collagen fibrils and proteoglycan granules.

Animals↗

PubMed1989

Three distinct molecular species of proteoglycan synthesized by the rat limb bud at the prechondrogenic stage.

To characterize proteoglycans in the prechondrogenic limb bud, proteoglycans were extracted with 4 M guanidine HCl containing a detergent and protease inhibitors from Day 13 fetal rat limb buds which had been labeled with [35S]sulfate for 3 h in vitro. About 90% of 35S-labeled proteoglycans was solubilized under the conditions used. The proteoglycan preparation was separated by DEAE-Sephacel column chromatography into three peaks; peak I eluted at 0.45 M NaCl concentration, peak II at 0.52 M, and peak III at 1.4 M. Peaks I and III were identified as proteoglycans bearing heparan sulfate side chains. The heparan sulfate proteoglycan in peak III was larger in hydrodynamic size than the proteoglycan in peak I. The heparan sulfate side chains of peak III proteoglycan were smaller in the size and more abundant in N-sulfated glucosamine than those of peak I proteoglycan. Peak II contained a chondroitin sulfate proteoglycan with a core protein of a doublet of Mr 550,000 and 500,000. The chondroitin sulfate proteoglycan was easily solubilized with a physiological salt solution and the heparan sulfate proteoglycan in peak I was partially solubilized with the physiological salt solution. The remainder of the proteoglycan in peak I and the heparan sulfate proteoglycan in peak III could be solubilized effectively only with a solution containing a detergent, such as nonanoyl-N-methylglucamide. This observation indicates the difference in the localization among these three proteoglycans in the developing rat limb bud.

Amino Acids↗

PubMed1989

Sulfated proteoglycans synthesized by Neuro 2a neuroblastoma cells: comparison between cells with and without ganglioside-induced neurites.

Mouse neuroblastoma Neuro 2a cells are known to extend neurite-like processes in response to gangliosides added to the culture medium. We compared the structural features of proteoglycans (PG) synthesized by conventional Neuro 2a cells with those of neurite-bearing cells. Two different proteoglycans labeled with [35S]sulfate, namely, chondroitin sulfate proteoglycan (CS-PG) and heparan sulfate proteoglycan (HS-PG), were found both in the cell layer and in the culture medium of the conventional cells. CS-PG isolated from the cell layer had a Kav value of 0.38 on Sepharose CL-6B, and had CS side chains with Mr of 27,000. HS-PG in the cell layer was slightly larger (Kav of 0.33) in terms of hydrodynamic size than CS-PG, and the apparent Mr of the heparan sulfate side chains was 10,000. The structural parameters of CS-PG and HS-PG isolated from the medium were almost identical to those of the PGs in the cell layer. In addition to these PGs, single-chain HS, with an average Mr of 2,500, was observed only in the cell layer and this component was the major sulfated component in the cell layers of both control and ganglioside treated cells. The neurite-bearing cells also synthesized both CS-PG and HS-PG which were very similar in hydrodynamic size to those synthesized by the conventional cells, but the size of HS side chains was greater. Radioactivity, as 35S, of each sulfated component from the ganglioside-treated culture seemed to be slightly less than that of the corresponding component from the control culture. These findings indicate that the marked morphological change in Neuro 2a cells, induced by gangliosides is not accompanied by major changes in the synthesis of PGs.

Animals↗

PubMed1989

Elevated accumulation of hyaluronate in the tubular bones of osteogenesis imperfecta.

The content and composition of glycosaminoglycans in the tubular bones of osteogenesis imperfecta were compared to those in the tubular bones of age-matched controls. Chondroitin sulfate was the major glycosaminoglycan (70-80% of total) both in the normal and pathological bones, and its level, based on the tissue wet weight, was slightly less in the pathological bones. The composition of chondroitin sulfate disaccharide units in the pathological samples was different from those of the control; a lower proportion of chondroitin 4-sulfate unit. Hyaluronate accounted for at most 7% of total glycosaminoglycans from the normal bones. The hyaluronate content of the pathological bones was 1.5- to 3-fold higher than that of the controls. Glycosaminoglycans have been shown to participate in the formation of a functional supramolecular complex in extracellular matrices. Therefore, it may be postulated that the abnormalities in glycosaminoglycan composition in the tubular bones of osteogenesis imperfecta is implicated in some clinical aspects of this connective tissue disorder such as the bony fragility.

Bone and Bones↗

PubMed1989

Glycosaminoglycan composition of PC12 pheochromocytoma cells: a comparison with PC12D cells, a new subline of PC12 cells.

PC12D cells, a new subline of conventional PC12 cells, respond not only to nerve growth factor but also to cyclic AMP by extending their neurites. These cells are flat in shape and are similar in appearance to PC12 cells that have been treated with nerve growth factor for a few days. In both cell lines, we have characterized the glycosaminoglycans, the polysaccharide moieties of proteoglycans, which are believed to play an important role in cell adhesion and in cell morphology. Under the present culture conditions, only chondroitin sulfate was detected in the media from PC12 and PC12D cells, whereas both chondroitin sulfate and heparan sulfate were found in the cell layers. The levels of cell-associated heparan sulfate and chondroitin sulfate were about twofold and fourfold higher in PC12D cells than in PC12 cells, respectively. Compared to PC12 cells, the amounts of [35S]sulfate incorporated for 48 h into chondroitin sulfate were twofold lower but those into heparan sulfate were 35% higher in PC12D cells. The amount of chondroitin sulfate released by PC12D cells into the medium was about a half of that released by PC12 cells. The ratio of [35S]sulfate-labeled heparan sulfate to chondroitin sulfate was 6.2 in PC12D cells and 2.2 in PC12 cells. These results suggest that there may be some correlation between the increase in content of glycosaminoglycans and the change in cell morphology, which is followed by neurite outgrowth.

Adrenal Gland Neoplasms↗

PubMed1989

Enhanced accumulation of hyaluronate in the culture of skin fibroblasts from two patients with Coffin-Lowry syndrome.

Cultured skin fibroblasts were prepared from two unrelated adult patients with full expressions of Coffin-Lowry syndrome. Glycosaminoglycans (GAGs) were isolated either from the medium or from the cell layer of cultured skin fibroblasts. Two-dimensional electrophoresis of GAG preparations on cellulose acetate film revealed that hyaluronate was the major component both in the medium and in the cell layer. Quantitative analysis of GAGs was carried out by measuring optical density at 615 nm of Alcian blue-stained GAG spots on electrophoretograms. Increase in the hyaluronate content was found both in the culture medium and in the cell layer of Coffin-Lowry fibroblasts. In addition, the incorporation of [14C]glucosamine into hyaluronate was similarly activated in skin fibroblasts from patients, suggesting the active biosynthesis and or the suppressed degradation of hyaluronate by cultured skin fibroblasts from Coffin-Lowry syndrome. The abnormal metabolism of hyaluronate in Coffin-Lowry fibroblasts may be implicated in some of the clinical aspects of this genetic disorder.

Abnormalities, Multiple↗

PubMed1988

Occurrence of three distinct molecular species of chondroitin sulfate proteoglycan in the developing rat brain.

More than 60% of brain chondroitin sulfate proteoglycans were extracted from 10-day-old rat brains by homogenization in ice-cold phosphate-buffered saline containing protease inhibitors. Although the soluble proteoglycan preparation was a mixture of chondroitin sulfate proteoglycans with a different hydrodynamic size as well as a different molecular density, each subfraction of the proteoglycans contained chondroitin sulfate side chains with virtually identical molecular weight (approximately 15,000) and chondroitin sulfate disaccharide composition (high content of 4-sulfate unit). Digestion of the purified proteoglycan preparation with protease-free chondroitinase ABC produced five core proteins with Mr = 250,000 (designated as 250K protein), 220,000 (220K), 150,000 (150K), 130,000 (130K), and 93,000 (93K). All these core proteins were obtained from chondroitin sulfate proteoglycan preparations extracted from various regions of the brain, but their composition varied among different brain regions. Analysis for amino acid composition of these core proteins and two-dimensional mapping of their proteolytic peptides revealed that three major core proteins (250K, 220K, and 150K proteins) were structurally different. These observations indicate that at least three distinct types of chondroitin sulfate proteoglycan occur in the developing rat brain.

Amino Acids↗

PubMed1988

Deletion of a single chromosome band 4q26 in a malformed girl: exclusion of Rieger syndrome associated gene(s) from the 4q26 segment.

We report a malformed girl with a single chromosome band deletion of 4q26 in peripheral lymphocytes. This patient is the fourth case reported with an interstitial deletion involving 4q26 and has the smallest deletion of those reported. Deletion mapping indicates that psychomotor retardation, coloboma, prominent forehead, epicanthus, broad based nose, and broad, thin upper lip are associated with monosomy 4q26, and that gene(s) associated with Rieger syndrome can be excluded from the 4q26 segment.

Abnormalities, Multiple↗

PubMed1988

Defective association between collagen fibrils and proteoglycans in fragile bone of osteogenesis imperfecta.

The relationship between collagen fibrils and proteoglycans in the bone matrices of three osteogenesis imperfecta (OI) patients was observed ultrastructurally to clarify the mechanism responsible for pronounced bony fragility. Collagen fibrils and noncollagenous components were prepared from the bone matrix of patients with osteogenesis imperfecta and a control sample, respectively. Compared with the control, a 95.2% decrease was found in the number of proteoglycan granules periodically associated with the cross-banding of collagen fibrils in one OI sample from a patient with severe bony fragility. Extractability of collagen fibrils and proteoglycans was high in this sample. However, proteoglycans and collagen fibrils could be reattached in vitro to reproduce the condition observed in the controls. There was no decrease in the number of proteoglycan granules attached to prepared collagen fibrils in a sample from a patient with predominantly bowing deformity of bones. Hypothetically, the separation of proteoglycans from collagen fibrils in OI may be associated with increased bony fragility. In osteogenesis imperfecta patients, the mechanism inducing bowing deformity appears to be different from that inducing fragility.

Bone and Bones↗

PubMed1987

Developmental change in the amount of polysialosyl glycopeptides isolated from the rat brain.

Polysialosyl glycopeptides were coisolated with glycosaminoglycans by Pronase digestion of the whole brains of perinatal rats and could be separated from known glycosaminoglycans by two-dimensional electrophoresis on cellulose acetate film. The polysialosyl glycopeptides could not be obtained from fetal rat brain on day 13 of gestation, but began to be detected on day 14. The amount of polysialosyl glycopeptides was estimated from the dye concentration of the Alcian blue-stained spot in the electrophoretogram. The glycopeptide content increased almost linearly, on the basis of brain DNA, up to 10 days after birth. Thereafter, the content decreased rapidly, and hardly any polysialosyl glycopeptides could be isolated from the brain at approximately 30 days. This developmental change may be involved in morphogenesis and maturation of the brain. The polysialosyl glycopeptides could be isolated from the cerebellum, from the cerebrum, or from the brainstem of the neonatal rat. However, each region of the brain had a postnatal developmental change in glycopeptide content different from those of the other regions.

Animals↗

PubMed1987

Deficiency of density-dependent regulation of cell growth in the culture of skin fibroblasts from patients with mucolipidosis III.

Cultured skin fibroblast cells were prepared from two patients with mucolipidosis III (ML III), which is a genetic disorder characterized by low activities of multiple lysosomal enzymes in fibroblasts. Genetic complementation analysis of fused fibroblast hybrids revealed that the patients were classified in different complementation groups. Growth curves of fibroblasts of ML III patients in culture were compared with those of fibroblasts of Sanfilippo's syndrome patients as well as of the normal fibroblasts. Normal and Sanfilippo fibroblasts gave essentially the same sigmoid curve of cell growth. However, although both ML III cell lines grew at the normal rate in the initial logarithmic phase, they continued to proliferate actively even after the cultures reached confluency. This is the first report to demonstrate the deficiency of density-dependent regulation of cell growth in the culture of nontransformed cell types. Therefore, the culture of skin fibroblasts of ML III patients may serve as a useful experimental model for investigating the regulation of cell proliferation in vitro.

Adult↗

PubMed1987

Levels of creatine kinase activity in cartilage of tubular and nontubular bone in relation to pathogenesis of achondroplasia.

For the purpose of investigating events of energy metabolism in growing cartilages of human tubular and nontubular bones, measurements of creatine kinase (CK), lactate dehydrogenase (LDH), and aldolase of freshly excised cartilages in normal and pathologic conditions were performed. The level of cartilage CK of the normal phalanges (tubular bone) and exostosis was significantly less than those of the normal iliac bones (nontubular bone) and the achondroplasia tubular bone. A similar difference was also found between the tubular and the nontubular bone of an autopsy subject with achondroplasia. There was no statistical difference in the levels of LDH and aldolase in the cartilage between the tubular and the nontubular bone. These observations together with results obtained from iliac and limb cartilages of the newborn rat suggest the hypothesis that CK activity of cartilage of the tubular and the nontubular bone is different; cartilage of achondroplasia tubular bone has CK activity similar to that of normal nontubular bone cartilage.

Achondroplasia↗

PubMed1986

Congenital bowing of long bones: clinical and experimental study.

The mechanism responsible for prenatal bowing of long bones was investigated based on the results of morphological observation and biochemical analysis of glycosaminoglycans of the autopsied bone from a newborn patient with classic campomelic dysplasia and the result of an experiment which produced a similar deformity in rat fetuses. An excised bone with postnatal bowing from a patient with osteogenesis imperfecta was also examined for comparison. In the case of campomelic dysplasia, marked hypertrophic change of the cambium layer of the periosteum at the concave side of the bone was noted. Parallel rays of the periosteal bone extended from the concave (posterior) side toward the apex of the bowing at the anterior side. Increased amounts and differences in composition of glycosaminoglycans were found in the diaphyseal bone on the concave side, suggesting the existence of bone with maturity retardation. In contrast, there were no such differences in the case with postnatal bowing and in the control. Congenital bowing of long bone in the patients with multiple malformations such as campomelic dysplasia is probably manifested as early as the cartilaginous model as the experimental result suggested.

Animals↗