Biomedical subjects

H Takechi

Publications and source records attributed to H Takechi.

16 recordsLinked to original sources

PubMed1992

Molecular cloning of a mouse 47-kDa heat-shock protein (HSP47), a collagen-binding stress protein, and its expression during the differentiation of F9 teratocarcinoma cells.

A 47-kDa heat-shock protein (HSP47) is a major collagen-binding stress protein residing in the endoplasmic reticulum, and is assumed to be a molecular chaperone specific to collagen. Two-dimensional gel electrophoresis and immunoprecipitation studies showed that the expression of HSP47 was significantly induced during the differentiation of mouse teratocarcinoma F9 cells by treatment with retinoic acid alone or with retinoic acid and dibutyryladenosine 3',5'-phosphate. The induction of type-IV collagen was also observed during F9-cell differentiation. For further analysis, we cloned cDNA encoding mouse HSP47 from a cDNA library of BALB/c 3T3 cells and performed Northern-blot analysis. The cDNA contained a signal sequence at the N-terminus and an endoplasmic-reticulum-retention signal, RDEL, at the C-terminus. An homology search revealed that mouse HSP47, as well as chick HSP47, belonged to the serine protease inhibitor superfamily. While chick HSP47 mRNA was 4.5 kb with a long (2-kb) 3' untranslated region, mouse and human HSP47 mRNA were 2.5 kb, with a 0.8-kb 3' untranslated region. Northern-blot analysis revealed that the concurrent induction of HSP47 and type-IV collagen during F9-cell differentiation, and the transient induction of HSP47 after heat shock was regulated at the level of mRNA accumulation. These results suggested that HSP47 was closely related to collagens in terms of its expression as well as in its functional relevance.

3T3 Cells↗

PubMed1992

Inhibition of the activation of heat shock factor in vivo and in vitro by flavonoids.

Transcriptional activation of human heat shock protein (HSP) genes by heat shock or other stresses is regulated by the activation of a heat shock factor (HSF). Activated HSF posttranslationally acquires DNA-binding ability. We previously reported that quercetin and some other flavonoids inhibited the induction of HSPs in HeLa and COLO 320DM cells, derived from a human colon cancer, at the level of mRNA accumulation. In this study, we examined the effects of quercetin on the induction of HSP70 promoter-regulated chloramphenicol acetyltransferase (CAT) activity and on the binding of HSF to the heat shock element (HSE) by a gel mobility shift assay with extracts of COLO 320DM cells. Quercetin inhibited heat-induced CAT activity in COS-7 and COLO 320DM cells which were transfected with plasmids bearing the CAT gene under the control of the promoter region of the human HSP70 gene. Treatment with quercetin inhibited the binding of HSF to the HSE in whole-cell extracts activated in vivo by heat shock and in cytoplasmic extracts activated in vitro by elevated temperature or by urea. The binding of HSF activated in vitro by Nonidet P-40 was not suppressed by the addition of quercetin. The formation of the HSF-HSE complex was not inhibited when quercetin was added only during the binding reaction of HSF to the HSE after in vitro heat activation. Quercetin thus interacts with HSF and inhibits the induction of HSPs after heat shock through inhibition of HSF activation.

Animals↗

PubMed1992

History of prostheses and orthoses in Japan.

Until the first contact with European civilization in 1543, prostheses and orthoses were not seen in Japanese medical history. Some physicians and surgeons who studied medicine in the Dutch language understood about prostheses and orthoses before the opening of the country in 1868. From 1868 to the end of World War II (1945), prostheses and orthoses were influenced by German orthopaedic surgery. From the latter half of the 1960s the research and development of these have been advanced, because of the establishment of a domestic rehabilitation system, international cultural exchange and economic development.

History, 16th Century↗

PubMed1991

HSP47: a tissue-specific, transformation-sensitive, collagen-binding heat shock protein of chicken embryo fibroblasts.

We report the isolation and characterization of a cDNA clone encoding HSP47, a transformation-sensitive heat shock protein that binds to collagen. A cDNA library was prepared from total RNA isolated from heat-shocked chicken embryo fibroblasts and screened by using oligonucleotide mixtures prepared on the basis of the N-terminal amino acid sequence of biochemically purified HSP47. The cDNA insert contained 3,278 bp, which encoded a 15-amino-acid signal peptide and a mature protein coding region consisting of 390 amino acid residues; it also included part of the 5' noncoding region and a long 3' noncoding region. The deduced amino acid sequence revealed an RDEL sequence at the C terminus, which is a variant of the KDEL retention signal for retention of proteins in the endoplasmic reticulum. Northern (RNA) blot analyses and nuclear run-on assays established that the induction of HSP47 by heat shock and its suppression after transformation of chicken embryo fibroblasts by Rous sarcoma virus are regulated at the transcriptional level. A homology search revealed that this protein belongs to the serpin family, the superfamily of plasma serine protease inhibitors. Although structurally homologous to the serpins, HSP47 lacks the active site thought to be essential for the inhibition of proteases and does not appear to bind to intracellular proteases. HSP47 is the first heat shock protein found to be a member of the serpin superfamily. Conversely, it is the first serpin family member that is not secreted from cells, which could be explained by acquisition of the RDEL retention signal during evolution.

Amino Acid Sequence↗

PubMed1991

Gait analysis of slope walking: a study on step length, stride width, time factors and deviation in the center of pressure.

Determination was made of step length, stride width, time factors and deviation in the center of pressure during up- and downslope walking in 17 healthy men between the ages of 19 and 34 using a force plate. Slope inclinations were set at 3, 6, 9 and 12 degrees. At 12 degrees, walking speed, the product of step length and cadence, decreased significantly (p less than 0.01) in both up- and downslope walking. The most conspicuous phenomenon in upslope walking was in cadence. The steeper the slope, the smaller was the cadence. The most conspicuous phenomenon in downslope walking was in step length. The steeper the slope, the shorter was the step length.

Adult↗

PubMed1989

Amplification of both c-myc and c-raf-1 oncogenes in a human osteosarcoma.

Fourteen human bone and soft part tumor tissues were screened by Southern blot hybridization using five oncogene probes (c-myc, c-K-ras, c-fos, c-raf-1, and N-myc). Amplification of c-myc was found in two osteosarcomas and one malignant fibrous histiocytoma. One of these osteosarcomas had amplified c-raf-1 gene. Rearrangement of the amplified gene was not observed. This is the first report of c-raf-1 amplification in human cancer tissues.

Adolescent↗

PubMed1986

Follow-up study of cartilaginous bone tumors.

A series of clinical and pathological studies were performed on 74 cartilaginous bone tumors including osteochondromas, multiple cartilaginous exostoses, chondromas, chondromatoses, benign chondroblastomas and chondrosarcomas. Resection was adequate for the osteochondromas, and no recurrence was observed. Out of 14 multiple cartilaginous exostoses, three, all in flat bones showed malignant change. The predominant sites of chondroma were the finger and toe bones, and curettage and bone graft was adequate treatment. Neither recurrence nor malignant change was observed. Two cases of chondromatosis, one of Ollier's disease and one of Maffucci's syndrome, were included in our series. Leg length discrepancy and pathologic fracture were common problems in chondromatosis. Moreover, malignant change was suspected in a hemangioma of the Maffucci's syndrome patient. Benign chondroblastoma was treated by curettage and bone graft, with no recurrence. In our series, 4 primary and 3 secondary chondrosarcomas were observed. Metastasis was seen in only one case. Because of the discrepancy between the biological behavior and histological findings of cartilaginous bone tumors, the malignancy of tumors should be evaluated by clinical signs and symptoms as well as by histological findings.

Adolescent↗

PubMed1985

Electromyographic kinesiology of lower extremity muscles during slope walking.

To investigate the phasic activity of the lower extremity muscles during up- and downslope walking, five muscles of ten healthy men were examined by telemetered electromyography (EMG). The muscles were the tibialis anterior (TA), gastrocnemius (Gc), rectus femoris (RF), semitendinosus (St) and gluteus maximus (GM). The inclination of the slope was 3, 6, 9 and 12 degrees. EMG of the muscles and the time factors of a walking cycle were recorded by a 12-channel polygraph simultaneously. In upslope walking, the duration of TA, St and GM activity was longer and that of RF activity was shorter than in level walking. The phasic pattern of Gc in upslope walking was the same as in level walking. In downslope, the duration of Gc and RF activity was longer than on the level. St showed biphasic activities. The phasic pattern of TA and GM was nearly the same as in level walking. The phasic activity of the muscles altered with an inclination over 6 degrees in upslope, and over 3 degrees in downslope. The findings indicate that the muscles stabilize the knee and ankle joint much more in slope walking than in level walking, and in slope walking they also exert themselves to elevate or lower the body weight.

Adult↗

PubMed1978

Malignant fibrous histiocytoma with skeletal involvement.

Malignant fibrous histiocytoma of soft part is rather common but malignant fibrous histiocytoma of the bone is rarely encountered clinically. Authors present five cases of malignant fibrous histiocytoma with skeletal involvement and discuss their clinical course, x-ray findings and histological features. This tumor has marked tendency for local recurrence and metastasis. Other bone tumors such as giant cell tumor, aneurysmal bone cyst, non ossifying fibroma, osteosarcoma, fibrosarcoma of bone and metastatic cancer can be excluded by several characteristic findings observed in x-rays as well as histopathological features. All information on the patient should be carefully analysed, because it is difficult to decide whether bone involvement is primary or secondary. Four out of five cases definitely originated within the bone.

Bone Neoplasms↗

PubMed1977

Trabecular architecture of the knee joint.

The trabecular architecture of the human knee joint was studied three dimensionally by microradiography. The trabecular arrangement of the two condylar wheels of the femur was divided into five types. The trabeculae are so arranged that both condyles are able to adjust to mechanical compression and rotary movement. In the tibia, each trabecular arrangement has a different mechanical function. The epiphyseal line can be considered a laminated structure interposed between the compressive forces acting from the articular surface and the forces supporting the architecture of the metaphysis. The mechanics and kinematics of the traecular architecture are discussed.

Adult↗

PubMed1972