Search PubMed⌕ Search

Biomedical subjects

S Tajima

Publications and source records attributed to S Tajima.

At least 307 records · Page 17Linked to original sources
PubMed1993

Identification of two novel mouse nuclear proteins that bind selectively to a methylated c-Myc recognizing sequence.

The c-Myc recognizes the sequence CACGTG (Blackwell, T. K., Kretzner, L., Blackwood, E.M., Eisenman, R. N., and Weintraub, H. (1990) Science 250, 1149-1151), and its binding is inhibited by methylation of the core CpG (Prendergast, G. C. and Ziff, E. B. (1991) Science 251, 186-189). We identified two novel nuclear proteins, MMBP-1 and MMBP-2, that bound specifically and under physiological salt condition to the c-Myc binding motif of which cytidine in the CpG sequence was methylated. MMBP-1 was about 42 kD and MMBP-2 was about 63 kD. MMBP-1 was found in specific cells, while MMBP-2 was found in all the cell lines tested, suggesting that MMBP-1 may modulate the role of MMBP-2 in tissue specific manner. We propose that the two proteins play a role in the regulation of c-Myc function through stabilizing or destabilizing the methylation state of the c-Myc binding motif.

Animals↗
PubMed1993

Presence of the factor that inhibits collagen synthesis and stimulates cell proliferation in developing embryonic chick skin extracts.

The effects were studied of the extracts prepared from 10- and 18-day developing chick skins on collagen synthesis and proliferation of the monolayered fibroblasts established from 10-day skin. Cell proliferation was stimulated by both 10- and 18-day skin extracts at the concentration of 3.5 micrograms/ml. Collagen synthesis was suppressed by the treatment of extracts prepared from both 10- and 18-day skins at the concentration of 3.5 micrograms/ml, to a greater extent in 18-day extract. The results indicate that skin extracts possess factors exhibiting both a stimulating effect on cell proliferation and an inhibitory effect on collagen synthesis.

Animals↗
PubMed1993

Clinical application of a solid three-dimensional model for orbital wall fractures.

Orbital wall fractures have been diagnosed conventionally by plain X-rays, CT imaging, and more recently by three-dimensional CT imaging. However, it is not easy to know the three-dimensional appearances of orbital wall fractures. Anatomically precise reconstruction of the orbital wall is essential for the appearance and function of the eyes. Life-size solid models of fractured orbital walls and also solid models of bone grafts for the reconstruction were produced by milling polyurethane foam on the basis of CT data. These models are very valuable because they provide not only satisfactory understanding of the three-dimensional morphology, but the models at hand are the ideal guides during the operation, and the prefabricated bone grafts, based on the models make a complete surgical simulation.

Adolescent↗
PubMed1993

Successful reconstruction of a high-pressure injection injury of the hand using a first web flap of the foot.

High-pressure injection injury to the hand often results in loss of tissue and hand function. The successful reconstruction of a hand following high-pressure injection injury is reported. A free neurovascular flap was transferred from the first web space of the foot to cover a skin defect in the first web space area of the hand. The digital nerves of the thumb and index finger were repaired using sural nerve grafts.

Adolescent↗
PubMed1993

Low-density lipoprotein receptor mutation that deletes exons 2 and 3 by Alu-Alu recombination.

A deletion mutant in the low density lipoprotein receptor gene of a Japanese patient with heterozygous familial hypercholesterolemia was analyzed. Genomic Southern blotting showed abnormal size restriction fragments with BamHI (7.8 kb), EcoRI (3.8 kb), BglII (17 kb), KpnI (> 23 kb), EcoRV (13 kb), and XbaI (14 kb). The abnormal EcoRI fragment, 3.8 kb, was cloned into lambda phage vector, and the deleted region of 10 kb including exons 2 and 3 was identified. The nucleotide sequence around the deletion joint was determined. The sequence of the eight nucleotides in the deletion-joint region of the mutant gene was identical to the corresponding sequences of both introns 1 and 3 of the normal gene. The deletion seemed to occur by an unequal recombination between the Alu-like sequences in the same direction in introns 1 and 3.

Base Sequence↗
PubMed1993

Magnetic resonance imaging findings of craniofacial fibrous dysplasia.

There have been few reports in the literature concerning the magnetic resonance imaging (MRI) appearances of fibrous dysplasia. We reviewed MRIs of 4 patients with craniofacial lesions. Using a 1.5-T Signa Unit (General Electric, Milwaukee, WI), both T1- and T2-weighted MRI scans were performed. In our 4 patients, the fibrous dysplastic lesions were characterized by a decreased signal on both T1- and T2-weighted images. And all lesions had sharply demarcated borders. The fine image of fibrous dysplasia by MRI is extremely useful, not only as a diagnostic aid, but also as an invaluable guide to surgery.

Adolescent↗
PubMed1993

Microvascular reconstruction of nose and ear defects using composite auricular free flaps.

Two cases using composite auricular free flaps, based on the superficial temporal vessels, in the reconstruction of full-thickness defects of the nose and ear are reported. This composite free flap can be based on either the superficial temporal or the posterior auricular vessels depending on the defect to be reconstructed. The superficial temporal vessels can also be used in reversed flow to obtain a vascular pedicle of sufficient length for microvascular anastomosis. The anatomical vascular features of the flap make it possible to reconstruct various facial defects with freedom of design.

Adult↗
PubMed1993

[Measurement of normal eyeball position and its application for evaluation of exophthalmos in craniofacial synostosis].

The chronologic changes in eyeball position in relation to bony landmarks were studied by CT scans. The results were applied to the preoperative evaluation in 16 craniofacial synostosis patients. Ten subjects from each age group were selected from more than 2000 subjects who underwent CT scanning of the skull without any brain and skull diseases. These age groups ranged from birth to 20 years of age. The following four distances were measured on the CT section incorporating lenses: (1) the distance from the dorsum sellae to the lenses, (2) the distance between the lateral orbital rim and the lenses, (3) the distance from the nasal root to the lenses, and (4) the width between the lenses. These distances also were measured in 16 craniofacial synostosis patients preoperatively, and the results were compared with those of the healthy individuals in the same age group. The distances of the lenses from the nasal root and from the lateral orbital rim were larger than in the healthy individuals in almost all craniofacial synostosis patients. However, the distance from the dorsum sellae to lenses was the same as that in healthy individuals on the whole.

Adolescent↗
PubMed1993

Human plasma free activin and inhibin levels during the menstrual cycle.

The role of inhibin in gonadal function and reproduction has been confirmed by the measurement of plasma inhibin levels, but there has been no clinical data available on activin because of the lack of a good assay method. We measured plasma free activin levels during the normal menstrual cycle using a newly developed competitive protein binding assay with follistatin as the binding protein. Plasma inhibin levels were measured simultaneously using an alpha-subunit N-terminal fragment RIA with recombinant inhibin as the reference standard. Four normal women, aged 23-29 years, were investigated by obtaining plasma at 3-day intervals. Plasma inhibin levels showed some variation during the follicular phase, but a parallel rise in inhibin and progesterone was observed during the luteal phase. These findings confirmed those of previous studies. In contrast, plasma free activin levels did not show any substantial changes during the menstrual cycle. This study suggests that activin has no endocrine role in modulating the pituitary-gonadal axis during the normal menstrual cycle, while changes of inhibin reflect cyclic gonadal function and indicate an endocrine role for this protein in modulating gonadal activity.

Activins↗
PubMed1993

Activin and inhibin secretion by cultured porcine granulosa cells is stimulated by FSH and LH.

Follistatin-free activin and inhibin levels were measured in the culture medium of porcine granulosa cells by a competitive protein binding assay and N-fragment RIA, respectively. Cultures were maintained for 6 days in MEM containing 10% fetal calf serum. FSH and HCG (1-1,000 IU/L) were added on day 2 to cultures containing 1 x 10(5) cells/ml and the medium was changed every 2 days. Granulosa cells secreted a large amount of progesterone, which indicated their luteinization. Activin and inhibin were both secreted throughout the 6 day culture period. Both of them increased equally in response to FSH and HCG in a dose-dependent manner on day 4, but their responses became discrepant on day 6, when the activin response decreased while the response of inhibin increased. This study demonstrated that cultured porcine granulosa cells secrete both activin and inhibin under the control of FSH and LH. The activin response was lost before that of inhibin, suggesting the role of activin at an earlier stage of luteinization.

Activins↗
PubMed1992

A point mutation of low-density-lipoprotein receptor causing rapid degradation of the receptor.

The exons of the low-density-lipoprotein-(LDL)-receptor gene from a Japanese patient with homozygous familial hypercholesterolemia were amplified by the polymerase chain reaction (PCR), and their nucleotide sequences were determined. A point mutation from G to C was found in exon 9, which was expected to change Asp at position 412 to His. This amino acid change occurred within the epidermal-growth-factor-precursor homology domain of the LDL receptor, slightly impairing the processing from the precursor to the mature form and causing rapid degradation of the mature form in the fibroblasts of the patient. The mutant LDL-receptor gene transfected into COS-1 cells expressed a LDL-receptor protein with the same properties as the protein expressed in the fibroblasts of the patient; impaired processing and rapid degradation of the synthesized receptor protein. The mutation was identified in family members of the patient by dot-blot hybridization of PCR-amplified DNA with the mutant oligonucleotide. The family members carrying the mutant gene showed higher serum cholesterol levels than the others. However, their cholesterol levels were also greatly influenced by the apolipoprotein-E phenotype.

Base Sequence↗