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Biomedical subjects

S Tajima

Publications and source records attributed to S Tajima.

At least 181 records · Page 10Linked to original sources
PubMed1997

Displacements of eyeball in orbital blowout fractures.

Thirty-two cases of orbital blowout fracture, excluding those of linear fracture with trap-door variety, were selected to study the changes of the eyeball position: posterior displacement or enophthalmos, medial and inferior displacement. Two-millimeter slices of computed tomographic scans were taken, and the eyeball positions were measured with the contralateral eye as a control. Intraorbital edema, if present, at least 10 days after injury had little effect on the position of the eyeball, nor was there any evidence to suggest the late onset of enophthalmos. Enophthalmos remains around 1 mm before total orbital enlargement reaches 2 ml in volume, thereafter increases proportionally with total orbital enlargement until 4 ml, then remains on a plateau. Enophthalmos increases proportionally with the increase of medial orbital wall enlargement when the inferior orbital wall enlargement is less than 2 ml. With inferior wall enlargement more than 2 ml, 3 to 4 mm of enophthalmos is seen irrespective of the increase of medial wall enlargement. The medial displacement of the eyeball increases proportionally with the increase of medial wall enlargement when inferior wall enlargement is less than 2 ml. The inferior displacement of the eyeball has little proportional relationship with medial or inferior wall enlargement when the former exceeds 2 ml. Relatively good proportional relationship is found between the enophthalmos and the medial displacement of the eyeball, but not between the enophthalmos and the inferior displacement of the eyeball.

Adolescent↗
PubMed1997

Cultured human keratinocytes express tropoelastin.

We detected elastin mRNA in cultured normal human keratinocytes by RNase protection assay. The content of elastin mRNA was estimated at approximately one-twentieth of that of cultured skin fibroblasts. Tropoelastin polypeptide with a molecular weight of 68 kDa was detected in the preparation of culture medium of normal human keratinocytes by western blot assays using anti-tropoelastin antibody. Immunohistochemical studies also demonstrated positive staining in cultured normal human keratinocytes as well as in skin fibroblasts. The expression of elastin by normal human keratinocytes was found to reach a maximum level at the quiescent phase of keratinocyte growth. When normal human keratinocytes were cultured on tropoelastin-coated dishes, their growth potential was greatly suppressed compared with other matrix protein-coated dishes. These results suggest that cultured normal human keratinocytes can actively synthesize elastin and that keratinocyte elastin may act as a growth-regulator for keratinocytes.

Blotting, Northern↗
PubMed1997

Overexcretion of low-sulphated chondroitin sulphate in the urine of the patient resembling progeroid.

We report an unusual case with mental retardation, short stature, sparse scalp hair, prominence of scalp veins, atrophy of subcutaneous fat, pterygia of the neck and loose skin. The patient excreted greater amounts of low-sulphated chondroitin sulphate (LSC) in the urine than age-matched controls. The pattern of glycosaminoglycan in serum and its synthesis by the patient fibroblasts were normal. Collagen, elastin and decorin mRNA levels in the patient fibroblasts were also unaltered. These results suggest that this patient seems to be different from Lowe's syndrome and decorin-deficient progeroid. An abnormal LSC metabolism may be partially responsible for the pathology of these syndromes.

Abnormalities, Multiple↗
PubMed1997

Self-involuting atrophoderma of the lateral-upper arm. A new benign variant of morphea?

BACKGROUND: Atrophoderma of Pasini-Pierini and morphea are considered to be distinct clinical entities. However, some authors say that they are closely related diseases. We encountered 5 unique cases that did not fit the criteria for both diseases. OBJECTIVE AND METHODS: We report 5 cases with solitary atrophic lesions on the lateral-upper arm. They appeared as white to erythematous, non-indurated and slightly depressed lesions with a smooth surface, and the patients had no history of trauma or injection. RESULTS: Histological examinations showed slight to moderate lower dermal fibrosis without specific changes in adipose tissue. The lesions disappeared spontaneously within a year. CONCLUSION: Our cases may be a benign variant form of morphea. We propose the term 'self-involuting atrophoderma of the lateral-upper arm (SALA)' for these clinical features.

Adipose Tissue↗
PubMed1997

Increase in elastin gene expression and protein synthesis in arterial smooth muscle cells derived from patients with Moyamoya disease.

BACKGROUND AND PURPOSE: Moyamoya disease is a progressive cerebrovascular occlusive disease that is rare in all ages but frequently presents in children. The etiology of the disease is unknown. We examined elastin gene transcripts and elastin synthesis in cultured arterial smooth muscle cells (SMCs) derived from moyamoya patients and compared them with those in SMCs from age-matched control subjects. METHODS: We used six cell strains from moyamoya patients and four from controls. The expression of elastin protein was observed by Western blot analysis and metabolic labeling with 3H-valine. Elastin gene transcripts were identified by Northern blot analysis. RESULTS: Elastin mRNA and protein levels were elevated in all SMCs from moyamoya patients compared with control SMCs. Although transforming growth factor-beta 1 (TGF-beta 1), a potent enhancer of the expression of elastin in arterial SMCs, upregulated elastin mRNA and protein levels in SMCs from both moyamoya patients and control subjects, the maximum levels of elastin synthesis and elastin gene transcripts in response to exogenous TGF-beta 1 were significantly greater in moyamoya SMCs than control SMCs. In addition, quiescent moyamoya SMCs secreted significantly more TGF-beta 1 into the culture medium than quiescent control SMCs (P < .01). CONCLUSIONS: Our findings suggest that moyamoya disease may result, at least in part, from an abnormal regulation of extracellular matrix metabolism that leads to increased steady state levels of elastin mRNA and elastin accumulation in the intimal thickening and that increased elastin accumulation is a stable marker of SMCs from patients with moyamoya disease.

Adolescent↗
PubMed1997

Purification and characterization of the NADP-malic enzyme from Bradyrhizobium japonicum A1017.

An NADP-malic enzyme [EC 1.1.1.40] was purified to homogeneity from Bradyrhizobium japonicum A1017, and the molecular and physiological characteristics were surveyed. The molecular mass of one subunit of the purified enzyme was evaluated to be 77,600 Da by SDS-PAGE, and the native enzyme was a tetramer in pH 7.0 and dimer in pH 8.0 conditions, showing complex oligomeric characteristics corresponding to pH value.

Amino Acid Sequence↗
PubMed1997

Keratinocytes cultured under hyperthermal conditions secrete factor(s) which can modulate dermal fibroblast proliferation and extracellular matrix production.

We have studied how keratinocytes cultured under hyperthermal conditions modulate skin fibroblast growth potential and their biosynthetic phenotypes in vitro. When keratinocytes were cultured at 30, 34, 37 or 39 degrees C, the conditioned medium of the keratinocytes cultured at 39 degrees C showed a greater inhibitory activity for fibroblast proliferation and greater synthetic activities of collagen and glycosaminoglycans than those incubated at 30, 34, or 37 degrees C. Transforming growth factor (TGF) beta 1 production in skin fibroblasts was also stimulated by the keratinocyte conditioned medium cultured at 39 degrees C. The stimulating activity of collagen and glycosaminoglycan syntheses of keratinocyte conditioned medium may be explained at least partly by enhanced TGF beta 1 production. The results indicate that keratinocytes cultured at a higher temperature (39 degrees C) may secrete factor(s) which modulate both fibroblast growth and matrix synthesis. This may provide evidence that under hyperthermal conditions epidermis can influence the functions of skin fibroblasts.

Cell Division↗
PubMed1997

Osteoblastoma of the nasal cavity invading the anterior skull base in a young child. Case report.

The benign osteoblastoma is rarely seen as a tumor of the facial bone in infancy or early childhood. Only five cases with nasal involvement have been reported in the literature. The authors present a case of osteoblastoma of the nasal cavity, the nasal bone, the ethmoid sinus, and the anterior cranial base. This 3-year-old girl presented with a tumor surrounding the left medial canthus. Imaging studies, including x-ray films, computerized tomography scans, magnetic resonance images, a (99m)Tc-scintigram, and angiograms, confirmed the location of the tumor. A biopsy specimen of tumor was obtained intranasally and the pathological diagnosis was an osteoblastic tumor suggestive of osteoblastoma. Although the tumor margin was well defined on the radiological images, it was difficult to determine the exact margin during the operation. Therefore, it is important to show how to excise the tumor completely under direct view. With the use of a "dismasking flap," it was possible to resect the benign osteoblastoma completely from the nasal cavity, even though it extended into the orbit, the maxilla, and the anterior cranial base.

Angiography↗
PubMed1997

Point mutation of p53 tumor suppressor gene in bovine leukemia virus-induced lymphosarcoma.

To elucidate the mechanism of leukemogenesis induced by bovine leukemia virus (BLV), the abnormality of p53 tumor suppressor gene was examined using the sequencing method of polymerase chain reaction (PCR)-amplified DNA from peripheral blood lymphocytes (PBL) and tumors from BLV-infected cattle that showed evidence of different stages during the progression of enzootic bovine leukosis (EBL). Mutations of the p53 gene were found in tumor cells from cattle with EBL, but not in PBL from BLV-free normal cattle or BLV-infected cattle without any evidence of tumor, suggesting mutation of p53 gene occurred specifically at the lymphoma stage of the disease. Twelve of eighteen cattle with EBL had seven missense and five silent mutations. The mutations were mapped to the highly evolutionarily conserved regions of p53 gene, and were involved in the DNA binding of p53. Thus, it appeared that the p53 point mutation is one of the critical events leading from the asymptomatic stage to the lymphoma stage.

Animals↗
PubMed1996

Analysis of interleukin 6 receptor and gp130 expressions and proliferative capability of human CD34+ cells.

We recently demonstrated that stimulation of gp130 by a combination of soluble interleukin 6 receptor (sIL-6R) and IL-6 but not IL-6 alone significantly stimulates the ex vivo expansion of primitive hematopoietic progenitors and the generation of erythroid cells from human CD34+ cells in the presence of stem cell factor (SCF). Here, we show that gp130 is found low positively on most CD34+ cells, whereas IL-6R is expressed on only 30-50% of these cells. Although most of the colonies generated from FACS-sorted CD34+IL-6R+ cells were granulocyte/macrophage (GM) colonies, CD34+IL-6R- cells gave rise to various types of colonies, including erythroid bursts, GM, megakaryocytes, and mixed colonies in methylcellulose culture with a combination of IL-6, sIL-6R, and SCF. Similar results were obtained in culture supplemented with a combination of IL-3, IL-6, SCF, granulocyte colony-stimulating factor, erythropoietin, and thrombopoietin. A limiting dilution analysis of long-term culture-initiating cells (LTC-IC) showed that the CD34+IL-6R- cells contained a larger number of LTC-IC than did the CD34+IL-6R+ cells. In a serum-free suspension of CD34+IL-6R- cells, the addition of sIL-6R to the combination of IL-6 and SCF dramatically increased the total and multipotential progenitors, whereas CD34+IL-6R+ cells failed to do so under the same conditions. These results indicate that most of the erythroid, megakaryocytic, and primitive human hematopoietic progenitors are included in the IL-6R- populations, and the activation of gp130 on these progenitors can be achieved by a complex of IL-6-sIL-6R, but not by IL-6 alone. The present culture system using IL-6, sIL-6R, and SCF may provide a novel approach for ex vivo expansion of human primitive hematopoietic progenitors.

Adult↗
PubMed1996

Erythropoietin-independent erythrocyte production: signals through gp130 and c-kit dramatically promote erythropoiesis from human CD34+ cells.

Erythropoietin (EPO) is the primary humoral regulator of erythropoiesis and no other factor has previously been reported to support proliferation and terminal maturation of erythroid cells from hemopoietic stem cells. Here we show that stimulation of glycoprotein (gp130) by a combination of recombinant human soluble interleukin 6 receptor (sIL-6R) and IL-6 but not sIL-6R or IL-6 alone can support proliferation, differentiation, and terminal maturation of erythroid cells in the absence of EPO from purified human CD34+ cells in suspension culture containing stem cell factor (SCF). A number of erythroid bursts and mixed erythroid colonies also developed in methylcellulose culture under the same combination. The addition of anti-gp130 monoclonal antibodies but not anti-EPO antibody to the same culture completely abrogated the generation of erythroid cells. These results clearly demonstrate that mature erythroid cells can be emerged from hemopoietic progenitors without EPO in vitro. Together with the previous reports that human sera contain detectable levels of sIL-6R, IL-6, and SCF, current data suggest that gp130 signaling in association with c-kit activation may play a role in human erythropoiesis in vivo.

Antigens, CD↗