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Biomedical subjects

M Ishizawa

Publications and source records attributed to M Ishizawa.

At least 19 recordsLinked to original sources
PubMed1998

Characterization of a newly established human chondrosarcoma cell line, CS-OKB.

A clonal cell line, CS-OKB, was derived from a human chondrosarcoma and characterized by cytogenetic study, immunocytochemical staining, and reverse transcriptase polymerase chain reaction (RT-PCR). Chromosomal abnormalities characteristic of malignant cartilaginous neoplasms were identified. CS-OKB cells were intensely stained with anti-type II collagen and anti-keratan sulphate antibodies. RT-PCR indicated that CS-OKB transcribes cartilage-specific genes such as type II, X procollagen, and aggrecan. This human chondrosarcoma cell line is stable and expresses well-differentiated chondrocyte-specific genes. It synthesizes well-differentiated chondrocyte-specific molecules in uncoated plastic dishes. CS-OKB may be useful for studies of human chondrocytes and in characterizing human chondrosarcomas.

Aged↗
PubMed1998

Alterations in insulin-induced postreceptor signaling in adipocytes of the Otsuka Long-Evans Tokushima fatty rat strain.

The Otsuka Long-Evans Tokushima fatty (OLETF) rat is a new spontaneous non-insulin-dependent diabetes mellitus (NIDDM) model rat strain developed in Tokushima, Japan. After 18 weeks of age, decreases of 45% and 40% respectively in insulin- and phorbol ester-stimulated [3H]2-deoxyglucose (DOG) uptake were observed, compared with those in Long-Evans Tokushima (LETO) rats (control). Insulin-specific binding and 95 kDa autophosphorylation of insulin receptor in OLETF rats were not different from those in LETO rats. Insulin-induced diacylglycerol (DG) production and Mono Q column-purified protein kinase C (PKC) translocation in adipocytes of OLETF rats were decreased compared with those of LETO rats. Insulin-induced PKC beta translocation from cytosol to membrane was also decreased in adipocytes of OLETF rats. Increases of the PKC beta I, beta II, epsilon and zeta isoforms in membranes of OLETF rats were markedly smaller than those of LETO rats. Analysis of mRNA levels of PKC isoforms in adipocytes of OLETF rats showed decreases of basal level and insulin-induced delayed responses of PKC beta I, beta II, epsilon and zeta mRNA in OLETF rats. On the other hand, insulin- or phorbol ester-induced phosphatidylinositol 3-kinase (PI 3-kinase) activation was decreased in adipocytes of OLETF rats compared with those of LETO rats. These results suggest that insulin resistance in OLETF rats, a spontaneous NIDDM model rat, may be associated with deterioration of insulin-induced DG-PKC signaling and subsequent decrease in PI 3-kinase activation.

Adipocytes↗
PubMed1997

Pubic osteolysis mimicking a malignant lesion: report a case with a fracture dislocation of the sacroiliac joint.

We report the case of a 67-year-old woman who presented to our institution with osteoblastic and osteolytic lesions of the pubis and fracture dislocation of the left sacroiliac joint. She had presented 7 months earlier to an outside institution with a left gluteal mass, which had been biopsied and had been believed to represent malignancy. A second biopsy at our institution showed no evidence of malignancy and was felt to represent fracture healing. A diagnosis of public osteolysis was made based on the radiographic and histologic findings. A follow-up radiograph 6 years after presentation revealed healing of the lesions, confirming its benignity.

Aged↗
PubMed1997

Effect of glucocorticoid receptor antagonist RU 38486 on acute glucocorticoid-induced insulin resistance in rat adipocytes.

We examined the mechanism of acute glucocorticoid-induced insulin resistance in rat adipocytes using the glucocorticoid receptor antagonist RU 38486. Pretreatment with dexamethasone (DEX) and prednisolone for 60 minutes resulted in 50% inhibition of insulin-induced [3H]2-deoxyglucose (DOG) uptake at 10(-8) and 10(-7) mol/L, respectively, in rat adipocytes and 20% and 25% inhibition of insulin-induced [3H]2-DOG uptake, respectively, in soleus muscles. Our previous experiments indicated that DEX and prednisolone alone stimulate protein kinase C (PKC) in rat adipocytes. Accordingly, we examined [3H]DEX binding to PKC from MonoQ column-purified rat brain cytosol. Specific [3H]DEX binding to MonoQ column-purified PKC was observed (kd, 56.8 nmol/L; Bmax, 725 fmol/mg protein). Thus, insulin-induced PKC translocation from the cytosol to the membrane was suppressed by pretreatment with 10(-7) mol/L DEX and 10(-6) mol/L prednisolone for 80 minutes. During treatment with RU 38486 for 60 minutes, there was no change in the glucocorticoid-induced inhibitory effect on insulin-induced [3H]2-DOG uptake and PKC translocation from the cytosol to the membrane. Moreover, pretreatment with RU 38486 for 120 minutes slightly prevented the DEX-mediated inhibition of insulin-induced glucose uptake. These results suggest that acute glucocorticoid-induced insulin resistance may be mainly mediated through the other non-glucocorticoid receptor pathway.

Adipocytes↗
PubMed1997

Acute effects of phorbol ester and insulin on insulin-induced glucose uptake and protein kinase C activation in rat adipocytes.

We examined the acute effect of pretreatment with phorbol ester and insulin on insulin-induced glucose uptake and protein kinase C (PKC) translocation from cytosol to the membrane in rat adipocytes. Adipocytes were preincubated with 1 microM tetradecanoylphorbol 13-acetate (TPA) and 10 nM insulin for 60 min and then stimulated with 10 nM insulin for 10 and 30 min to measure PKC activity in cytosol and membrane fractions using a Mono Q column connected onto an HPLC system and [3H]2-deoxyglucose (DOG) uptake, respectively. Pretreatment with 1 microM TPA and 10 nM insulin for 60 min resulted in the marked decreases of insulin-induced [3H]2-DOG uptake. Translocation of Mono Q column-purified cytosolic PKC enzyme activity and PKC beta immunoreactivity from cytosol to the membrane was suppressed by pretreatment with TPA and insulin for 60 min. These results indicate that acute treatment with TPA and insulin which are PKC activators suppress translocation/activation of PKC, and accordingly inhibit insulin-induced glucose uptake. We suggest that a decrease of cytosolic PKC activity may mainly-contribute to the impaired responsiveness of the glucose transport system after acute TPA and insulin treatment.

Adipocytes↗
PubMed1996

Insulin regulated PKC isoform mRNA in rat adipocytes.

Insulin and 12-O-tetradecanoyl phorbol-13-acetate (TPA) induce both glucose uptake and translocation of protein kinase C (PKC) from cytosol to membrane in insulin-sensitive tissues as previously reported by several investigators. We examined insulin-mediated PKC beta I, beta II, and epsilon translocation from cytosol to cytoskeleton, and expression of PKC alpha, beta I, beta II, gamma, and epsilon isoforms using the reverse transcription polymerase chain reaction (RT-PCR) method during treatment with insulin for 240 min in rat adipocytes. Insulin-induced increases in PKC beta I, beta II, and epsilon were greater in the cytoskeleton fraction than those in the membrane fraction. Insulin induced time-dependent increases in PKC alpha, gamma, epsilon and zeta mRNA levels for up to 240 min (555%, 117%, 236% and 138% increase, respectively). TPA also induced time-dependent increases in PKC alpha and gamma (34% and 500% increase, respectively) but not in PKC zeta. However, PKC beta I mRNA was decreased for up to 60 min and then maintained at under the basal level during stimulation with insulin and TPA. On the other hand, PKC beta II mRNA was markedly increased for up to 240 min. These results suggest that insulin-regulated PKC alpha, gamma and epsilon mRNA levels and PKC beta mRNA alternative splicing may occur in rat adipocytes.

Adipocytes↗
PubMed1996

Inhibitory action of 5-hydroxytryptamine on propulsive activity of the guinea-pig isolated colon.

The effects of 5-hydroxytryptamine (5-HT) and its receptor subtype agonists on spontaneous propulsive activities of the segment, and on changes in tension of the muscle strips were examined in the guinea-pig isolated distal colon. 5-HT, 5-carboxamidotryptamine (5-CT), alpha-methyl-5-HT and t-methoxytryptamine (5-MeOH), applied to the serosal side of the segment, inhibited spontaneous propulsive activities, but 2-methyl-5-HT did not. On the indomethacin-treated segment, 5-HT and its receptor subtype agonists all stimulated propulsive activity. 5-HT, 5-CT, alpha-methyl-5-HT and 5-MeOH relaxed circular muscle strips, which were inhibited in the presence of tetrodotoxin. However, these agonists showed contractile effects on the indomethacin-treated circular muscle strips. These results suggest that 5-HT may inhibit spontaneous propulsive activities of the colonic segment via release of endogenous PGs (e.g., E and I types) in the circular muscle cells mediated by an inhibitory neurotransmitter, which release was stimulated by 5-HT1-like 5-HT2 and 5-HT4 receptors on the myenteric neurones in the circular muscle layer.

5-Methoxytryptamine↗
PubMed1996

Use of preoperative autologous blood donations and erythropoietin for treatment of giant cell tumor of the ischium.

A 24-year-old man with an osteolytic lesion of the ischium was referred to the authors' institution. Computed tomography and magnetic resonance imaging studies showed that the lesion extended to and involved the subchondral bone of the acetabulum. Histologic examination of the biopsy specimen revealed giant cell tumor of bone. Following the biopsy, autologous blood was collected 4 times with recombinant human erythropoietin treatment definitive surgery was performed. Three weeks after the biopsy, the lesion was curetted and bone cementation was performed. The total blood loss during surgery was 3100 ml, which was replaced successfully with stored autologous blood without the need for homologous blood transfusion. The authors believe that without the erythropoietin treatment, autologous blood could have been collected only 3 times instead of 4 times, and the patient would have needed homologous blood.

Adult↗
PubMed1996

Glomus tumor of the musculotendinous junction of the rotator cuff. A case report.

A rare case of glomus tumor of the rotator cuff is presented. A 35-year-old man had a 20-year history of left shoulder pain. Through physical examination, muscular atrophy in the supraspinatus and infraspinatus muscles and restriction of shoulder motion was seen. Magnetic resonance imaging showed an abnormal oval shadow in the supraspinatus musculotendinous junction, and postcontrast computed tomographic scanning showed a small calcification focus in the tumor. Surgical excision of the tumor and rotator cuff reconstruction using Debeyre's procedure were done. Microscopic examination of the tumor showed a typical glomus tumor. It was difficult to diagnose glomus tumor in this patient before surgical intervention. Retrospective consideration indicated that the history of the present illness, computed tomographic scanning, and magnetic resonance imaging were critical for differential diagnosis.

Adult↗
PubMed1996

Analysis of the presence of osteocalcin, S-100 protein, and proliferating cell nuclear antigen in cells of various types of osteosarcomas.

Osteosarcomas are characterized by different histologic subtypes that are composed of heterogeneous tumor cells. Although the histological origin of the malignant cells is unknown, it has been speculated that osteoblasts lead to the malignant cells. In the current study, the osteosarcoma cells in 27 lesions were assessed by means of immunohistochemical staining for osteocalcin (OC), S-100 protein (S-100) and proliferating cell nuclear antigen (PCNA). PCNA labeling indices were the highest in osteoblastic and stromal areas, and significantly lower in chondroblastic areas (p < 0.01). Cells that were positive for both PCNA and OC were abundant in osteoblastic and stromal areas, while cells that were positive for both PCNA and S-100 were rarely observed. These results were almost similar for conventional, parosteal and periosteal osteosarcomas. In contrast, OC reactivity was poor in fibroblastic osteosarcoma, in osteosarcoma with giant cells, and in telangiectatic osteosarcoma. Pulmonary metastatic osteosarcoma lesions weakly expressed OC (p < 0.01), but showed high values for the PCNA labeling indices. In conclusion, immunohistochemical staining for OC, S-100, and PCNA are useful to analyze the proliferating cells in osteosarcomas. The main proliferating cells in most osteosarcomas are mature osteoblast-like cells. OC-negative tumor cells predominate in some of osteosarcoma subtypes, and these tumors therefore probably represent a distinct osteosarcoma variant. OC expression in pulmonary metastatic lesions may be suppressed.

Adolescent↗
PubMed1995

Anaplastic large cell Ki-1 lymphoma with bone involvement: report of two cases.

Two cases of anaplastic large cell Ki-1 lymphoma involving bone as the most prominent and initial manifestation are reported. The first patient was a 20-year-old male who had back pain and incomplete paraparesis due to vertebral involvement. The second was a 14-year-old girl, whose first clinical signs were fever of unknown origin and sternal bone pain. Radiologically, skeletal lesions were lytic and destructive. Histopathologically, the tumour cells had pleomorphic bizarre nuclei and abundant basophilic cytoplasm. Immunohistochemically, Ki-1(CD30) reactivity was strongly positive in both cases. Tumour cells were also CD3, CD4, epithelial membrane antigen and interleukin-2 receptor positive in the first case, and CD10, HLA-DR positive in the second case. The former tumour was considered to be of T-cell lineage and the latter of lymphoid progenitor cell origin. Radiation and chemotherapy were temporarily effective. However, both patients died 14 and 7 months after diagnosis, respectively, due to systemic lymph node involvement. These observations suggest that the prognosis for Ki-1 lymphoma involving bone is poorer than indicated in previous reports.

Adolescent↗
PubMed1995

A distinct mRNA encoding a soluble form of ICAM-1 molecule expressed in human tissues.

A soluble form of ICAM-1 (sICAM-1) have been observed in normal human serum (Rothlein et al., J. Immunol. 147, 3788-3793) and at elevated levels in inflammatory and tumor bearing status (Seth et al., Lancet, 338, 83-84; Giavazzi et al., Canc. Res. 52, 2628-2630; Harning et al., Canc. Res., 51, 5003-5005). However, the mechanism to produce the sICAM-1 has been still unknown. In this report we presented evidence for the presence of the mRNA specifically encoding sICAM-1, which is probably generated by alternative splice donor site selection. A 19-base deletion occurred right upstream of the transmembrane region gave rise to reading frameshift and eliminate the entire transmembrane and cytoplasmic domains, resulting in incapability of ICAM-1 molecules to reside in the membrane. A reverse transcription-polymerase chain reaction (RT-PCR) using a primer pair specific to sICAM-1 revealed a positive expression in all tissues analyzed, though the amount and the ratio to the conventional species varied slightly from tissue to tissue. Inflammatory cytokines displayed a complex pattern in the ICAM-1 mRNA expression depending on the combination of cytokines and the cultured cell lines used.

Alternative Splicing↗
PubMed1995

The identity of proliferating cells in bone tumors with cartilaginous components: evaluation by double-immunohistochemical staining using proliferating cell nuclear antigen and S-100 protein.

S-100 protein (S-100) appears to be a marker for bone tumors of cartilaginous origin. Any analyses of proliferative activity in S-100-positive tumor cells, however, has not yet been presented. This study assessed the proliferative activity of those cells by means of a double-immunohistochemical staining method using proliferating cell nuclear antigen (PCNA) and S-100. The most intense reactivity for S-100 was found in the well-differentiated chondrocytes of enchondromas, osteochondromas, and osteosarcomas. On the contrary, the more immature the tumor cells were, the more intensely positive they were for PCNA. In parosteal chondrosarcoma, exceptionally, PCNA-positive as well as S-100-positive cells were abundant, suggesting that these proliferating cells produced S-100. In periosteal osteosarcoma, however, the proliferating cells labeled by PCNA revealed little reactivity for S-100. This immunohistochemical method is potentially useful to know the identity and origin of proliferating cells and may sometimes be diagnostic for bone tumors containing cartilaginous elements.

Adolescent↗
PubMed1994

Contractile responses of longitudinal muscle strip to 5-HT and influences of divalent cations in the guinea-pig isolated colon.

The contractile effects of 5-hydroxytryptamine (5-HT) and influences of several kinds of divalent cations were investigated on longitudinal muscle strips of the guinea-pig isolated distal colon. 5-HT (10 nM-10 microM) produced phasic contractions which were partially inhibited by atropine (1 microM) and markedly inhibited by tetrodotoxin (1 microM), indicating that 5-HT acts mainly on the myenteric plexus and releases transmitters to cause contraction of the longitudinal muscle. The contractile response to 5-HT (3 microM) was almost completely inhibited by spantide (10 microM), a substance P antagonist, in the presence of atropine (1 microM), while spantide alone did not block 5-HT-induced contraction. Of several divalent cations including Cd2+, Co2+, Mg2+, Mn2+, Ni2+, Sr2+ and Zn2+, Cd2+ ions (10 mu-100 microM), which block L- and N-type Ca2+ channels, were most effective inhibitor of the 5-HT-induced contractions. While Sr2+ and Co2+ at a concentration of 100 microM did not have a significant effect. The order effectiveness of inhibition was Cd2+ >> Mn2+ > Mg2+ = Ni2+ = Zn2+. Bay K 8644 (1 microM), a L-type Ca2+ channel activator, did not influence the contractile response of the longitudinal muscle strip to 5-HT (3 microM). The present results suggest that 5-HT may mainly act on N-type Ca2+ channels in the myenteric neurones and cause the release of at least acetylcholine and substance P to induce contractions of the longitudinal muscle in the guinea-pig distal colon.

Acetylcholine↗
PubMed1994

Periosteal osteosarcoma and parosteal chondrosarcoma evaluated by double immunohistochemical staining. Report of 2 cases.

Differentiation of periosteal osteosarcoma and parosteal (periosteal) chondrosarcoma by conventional histology may be difficult. One case each of clinically and histologically proven periosteal osteosarcoma and parosteal chondrosarcoma were evaluated by a double-immunohistochemical staining method using proliferating cell nuclear antigen (PCNA) and S-100 protein (S-100). Conventional histology showed proliferation of both osteoblastic and chondroblastic cells in the periosteal osteosarcoma, while there was a growth of only chondroblastic tumor cells in the parosteal chondrosarcoma. Immunohistochemical studies indicated that the nuclei of chondroblastic cells recognized by S-100 were PCNA-negative, while osteoblastic stromal cells were PCNA-positive in the periosteal osteosarcoma. In contrast, chondroblastic cells in the parosteal chondrosarcoma were both S-100- and PCNA-positive. Our findings suggest that periosteal osteosarcoma is characterized by the proliferation of osteoblastic stromal cells, whereas parosteal chondrosarcoma is characterized by the proliferation of chondroblastic cells. This method of double immunohistochemical staining, using PCNA and S-100, may be useful in differentiating these chondroblastic tumors.

Adolescent↗
PubMed1993

Thymidine phosphorylase activity associated with platelet-derived endothelial cell growth factor.

Partial complementary DNA (cDNA) for thymidine phosphorylase (dThdPase) was cloned by means of a polymerase chain reaction. There was complete sequence identity between the amino acid sequence deduced from the nucleotide sequence of a clone (288 nucleotides) and the residues of platelet-derived endothelial cell growth factor (PD-ECGF). The amino acid sequence of all four peptide fragments from purified human dThdPase could be aligned with that of PD-ECGF. Our data indicate that residues 125-244 of PD-ECGF are identical to the sequence of human dThdPase. The molecular weights of human dThdPase and recombinant PD-ECGF (rPD-ECGF) that lacks 10 amino acids at the amino terminal were 55 and 52 kDa, respectively. Anti-PD-ECGF antibody recognized dThdPase, and anti-dThdPase antibody recognized rPD-ECGF. rPD-ECGF had dThdPase activity and its specific activity was similar to that of purified human dThdPase. dThdPase activity and molecules were detected in COS cells transfected with human PD-ECGF cDNA, but not in nontransfected cells. The sizes of PD-ECGF and dThdPase in the transfected COS cells were identical. These data suggest that human dThdPase is identical to PD-ECGF.

Amino Acid Sequence↗
PubMed1993

Osteosarcoma of the talus. A case report.

A 20-year-old man complained of increasing pain and swelling in the right ankle joint. Radiographs of the ankle demonstrated an ill-defined osteolytic lesion in the talus associated with a small, round bone formation just proximal to the neck of that bone. Histologic examination of the lesion showed osteoblastic osteosarcoma originating in the talus. Below-knee amputation was performed because of the peripheral location of the tumor and the close anatomic confines of the foot. A literature review demonstrated that the calcaneus and metatarsals are favorite sites of this tumor in the foot, with only one case in the talus. A second case of osteosarcoma in the talus seems to have not been previously reported.

Adult↗