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Biomedical subjects

H Yajima

Publications and source records attributed to H Yajima.

At least 73 records · Page 4Linked to original sources
PubMed1998

Vascularized bone grafts to the upper extremities.

From 1979 to 1995 in our clinic, vascularized bone grafting was performed in 29 patients with large bone defects, established nonunion, congenital pseudoarthrosis, or avascular necrosis in the upper extremity. Four patients had traumatic bone defects, six had posttraumatic nonunions, two had congenital pseudoarthroses, five had amputations, nine had defects following tumor resection, and three had other lesions. Reconstructed sites were the humerus in 7 patients, the radius in 12, the ulna in 2, both radius and ulna in 1, and the metacarpal and phalangeal bones in 7. Donor bones were fibula in 19 cases, radius in 6, scapula in 2, and medial condyle of the femur in 2. Postoperative circulatory disturbances and venous thrombosis resulted in revision surgery in two patients. Thrombectomy and reanastomosis to other veins were performed, and these flaps took successfully. No patients required additional bone grafts. The mean period required to obtain radiographic bone union was 4 months (fibula, 4.5 months; scapula, 3.5 months; radius, 2.6 months; medial condyle of the femur, 4 months). Vascularized fibula graft is indicated in patients with large bone defects in the humerus, radius, and/or ulna. The scapula is easy to transfer to the proximal humerus on its pedicle. This donor is indicated in young women because operative scars can be hidden. The radius is usually harvested with skin, and its use is indicated in patients with bone loss in the hand including thumb amputations. Thin corticoperiosteal graft from the femur is indicated in patients with established nonunion of the humerus and radius without significant bony defects.

Adolescent↗
PubMed1998

Results of opening-wedge osteotomy for the treatment of a post-traumatic varus deformity of the ankle.

We performed a one-stage opening-wedge valgus osteotomy in nine patients to correct a post-traumatic progressive varus deformity of the ankle. The osteotomy site was stabilized with two, three, or four Kirschner wires or with a plate and screws (in one patient). The site of the osteotomy united within two months after the operation in eight patients and at six months in one patient who was fifty-nine years old. The average duration of follow-up was seven years and four months (range, two years and four months to thirteen years and two months). Postoperatively, the range of motion of the ankle was decreased in six patients and remained unchanged in three. However, none of the patients reported any limitation in the activities of daily living, and the four adolescent patients were able to participate in sports activities. The result was graded as excellent for four ankles, good for two, and fair for three.

Activities of Daily Living↗
PubMed1998

[A case of rectal cancer metastatic to the tonsil].

Metastatic tumors of the tonsils are rarer than primary tumors. Few cases of metastatic tonsillar tumor have been reported. A 51-year-old man expectorated a portion of a tumor from the left side of the pharynx after an operation for cancer metastatic to the lung. Biopsy revealed that the pharyngeal tumor was rectal cancer (adenocarcinoma) metastatic to the tonsil. To our knowledge, this is the first case of primary rectal cancer metastatic to the tonsil to be reported in Japan. The clinical features of metastatic tonsillar tumor are discussed.

Adenocarcinoma↗
PubMed1998

[Case of multiple posterior mediastinal and retroperitoneal neurinomas].

We report a case of multiple neurinomas arising in the posterior mediastinum and the retroperitoneum. A 49-year-old man was admitted to our department for operation after an abnormal shadow appeared on routine chest X-ray film. A left adrenal tumor was found incidentally with ultrasonography at the time of a previous thoracic surgery. First, the posterior mediastinal tumor was surgically removed. Histologic diagnosis was neurinoma. After resection, endocrinologic findings were within normal limits. A left adrenal tumor was diagnosed, and surgery was performed. The tumor was separated from the adrenal gland; the histologic diagnosis was neurinoma. Neurinomas are usually solitary; multiple neurinomas are extremely rare.

Humans↗
PubMed1997

Carbohydrate analysis of porcine thyroglobulin isoforms with different iodine contents.

To further validate the relationship between thyroid hormone formation and the carbohydrate structure of thyroglobulin (Tg), we reinvestigated the relationship between the iodine content and the asparagine-linked oligosaccharide structures of porcine Tg. Purified porcine Tg was further separated into isoforms (Tg-F1, -F2 and -F3) with a DEAE-cellulose ion-exchange chromatography column. The iodine residues, neutral sugar and sialic acid were analyzed for the separated Tg isoforms and their asparagine-linked oligosaccharide structures were analyzed. The asparagine-linked oligosaccharides were released from Tg-F1, -F2 and -F3 by hydrazinolysis and each oligosaccharide was labeled with p-aminobenzoic acid octyl ester (ABOE). The ABOE-labeled oligosaccharides from Tg-F1, -F2 and -F3 were analyzed for their relative content in oligosaccharides of each structure type by chemical methods and DEAE- and ConA high-performance liquid chromatography (HPLC) columns. As a result, it was revealed that the Tg fraction eluted at higher ionic strength from a DEAE-cellulose column is apt to contain more of each iodoamino acid, as well as total content of iodine, larger negative zeta-potential, conforming to sialic acid content in the Tg molecule and to a higher content of di-sialo-bi-antennary complex and to high mannose type oligosaccharides. These results support the conclusion that iodine organification of the Tg molecule is correlated with asparagine-linked oligosaccharide completion.

Animals↗
PubMed1997

Ligand-dependent heterodimerization of thyroid hormone receptor and retinoid X receptor.

The thyroid hormone receptors (TR) bind to cis-acting DNA elements as heterodimers with the retinoid X receptors (RXR). These heterodimers display distinct specificities in mediating the hormonal response to target gene transcription. We characterized the interaction between TRalpha1 and RXRalpha via their ligand binding domains (LBDs) and the effect of ligands on the interaction using a yeast two-hybrid system. The DNA binding domain (BD) of yeast Gal4 fusion to the LBD of TRalpha1 had no transcriptional activity on its own, but when it was coexpressed with the activation domain (AD) of yeast Gal4 fusion to LBD of RXRalpha conferred activation to a reporter gene harboring a Gal4 binding site, indicating that LBDs of TRalpha1 and RXRalpha interact with each other in solution. Furthermore, T3 and 9-cis-RA increased the reporter activity, and an additive effect was observed when both ligands were added, indicating that the TRalpha1.RXRalpha heterodimerization is augmented by their respective ligands in vivo. Using an in vitro pull-down experiment, we confirmed the ligand-dependent interaction observed in the yeast system. Matrix-bound glutathione S-transferase-RXRalpha specifically coprecipitated the 35S-labeled TRalpha1 above the control, and associated 35S-labeled TRalpha1 was increased by the addition of T3 and 9-cis-RA. These results imply a complex, sensitive cross-talk in vivo among nuclear receptors and their respective ligands through distinct hormonal signaling pathways.

Alitretinoin↗
PubMed1997

Inhibition of peroxisome proliferator signaling pathways by thyroid hormone receptor. Competitive binding to the response element.

Peroxisome proliferators (e.g. clofibric acid) and thyroid hormone play an important role in the metabolism of lipids. These effectors display their action through their own nuclear receptors, peroxisome proliferator-activated receptor (PPAR) and thyroid hormone receptor (TR). PPAR and TR are ligand-dependent, DNA binding, trans-acting transcriptional factors belonging to the erbA-related nuclear receptor superfamily. The present study focused on the convergence of the effectors on the peroxisome proliferator response element (PPRE). Transcriptional activation induced by PPAR through a PPRE was significantly suppressed by cotransfection of TR in transient transfection assays. The inhibition, however, was not affected by adding 3,5,3'-triiodo-L-thyronine (T3). Furthermore, the inhibition was not observed in cells cotransfected with retinoic acid receptor or vitamin D3 receptor. The inhibitory action by TR was lost by introducing a mutation in the DNA binding domain of TR, indicating that competition for DNA binding is involved in the molecular basis of this functional interaction. Gel shift assays revealed that TRs, expressed in insect cells, specifically bound to the 32P-labeled PPRE as heterodimers with the retinoid X receptor (RXR). Both PPAR and TR bind to PPRE, although only PPAR mediates transcriptional activation via PPRE. TR.RXR heterodimers are potential competitors with PPAR.RXR for binding to PPREs. It is concluded that PPAR-mediated gene expression is negatively controlled by TR at the level of PPAR binding to PPRE. We report here the novel action of thyroid hormone receptor in controlling gene expression through PPREs.

Animals↗
PubMed1997

Binding of the N-terminal 63 kDa portion of connectin/titin to alpha-actinin as revealed by the yeast two-hybrid system.

Connectin/titin is a 3000 kDa protein which links the myosin filament to the Z-line in vertebrate striated muscle sarcomeres. To search for the Z-line proteins to which connectin binds, the yeast two-hybrid system was applied using cDNA coding the N-terminal 63 kDa fragment of connectin. Two clones coding the C-terminal half region of alpha-actinin (amino acids, 343-897 and 446-897) were obtained. Enzyme-linked immunosorbent assay clearly demonstrated the interactions of alpha-actinin and the N-terminal 63 kDa fragment of connectin in vitro. Thus it is concluded that the N-terminal 63 kDa portion of connectin binds to alpha-actinin in the Z-line of myofibrillar sarcomeres.

Actinin↗
PubMed1997

Vascularized fibular graft for reconstruction of the wrist after excision of giant cell tumor.

Seven patients with a giant-cell tumor involving the distal end of the radius were treated with en bloc resection and reconstruction with a free vascularized fibular graft. Two patients with stage 2 disease of Enneking's surgical staging and grade 2 of Campanacci's radiographic grading system were reconstructed with an articular fibular head graft. Five patients with stage 3 and grade 3 disease underwent wrist arthrodesis using fibular shaft transfer. There was radiographic evidence of bone union at the host-graft junctions in all cases. No local recurrence was seen in any of the patients at the most recent follow-up examinations. There were six good and one excellent functional results. Wrist arthroplasty using a vascularized fibula head graft is the best procedure for a stage 2 or grade 2 giant-cell tumor of the distal end of the radius. In cases of stage 3 or grade 3 disease, wrist arthrodesis using a vascularized fibular shaft graft is indicated.

Adolescent↗
PubMed1997

Characterization of IKI1 and IKI3 genes conferring pGKL killer sensitivity on Saccharomyces cerevisiae.

The Saccharomyces cerevisiae iki mutants show an insensitive phenotype to the pGKL killer toxin, and we have cloned some IKI genes by complementation of this phenotype [Kishida et al., Biosci. Biotech. Biochem., 60, 798-801 (1996)]. Here, we identified and characterized the IKI1 and IKI3 genes. DNA sequencing of the genes showed that both have 100% identity with hypothetical genes identified by the yeast genome project, YHR187w (481,911-480,985 in chromosome VIII) for IKI1, and YLR384c (888,852-892,898 in chromosome XII) for IKI3. Both are novel genes with no significant identity with other known genes and they do not belong to any homology domain group, gene family, or superfamily. The disruption of IKI1 is not lethal, but growth of the disruptant was slower than that of the wild type at all temperatures examined. The disruptant was the killer-insensitive phenotype. The sequence of the IKI1 gene predicted a hydrophilic protein with a molecular mass of 35 kDa (309 amino acids). A 35-kDa protein band was also detected by immunoblotting the 25,000 x g pellet fraction of the wild type yeast cell lysate. Disruption of the IKI3 gene is also non-lethal and it has the killer-insensitive phenotype. Iki3p may contain a transmembrane domain near the NH2-terminal region (97-113 residues in a total of 1349 amino acids).

Blotting, Northern↗
PubMed1997

[A case of asymptomatic posterior mediastinal pheochromocytoma diagnosed during the procedure of video-assisted thoracic surgery (VATS)].

The patient was a 20-year-old male. On routine check-ups, a posterior mediastinal tumor was found radiologically and referred to our hospital for the operation. During the Video-Assisted Thoracic Surgery (VATS), sudden elevation of the blood pressure up to 270 mmHg was observed by the tumor palpation. At once we diagnosed as pheochromocytoma. Changing the VATS to usual thoracotomy the tumor was completely removed and histologically confirmed. After the operation the patient was uneventful and the value of norèpinephrine reduced to normal range from 2912 pg/ml. The posterior mediastinal pheochromocytoma is rare and this report is the 6 th case in Japan. Clinical characteristics were discussed in addition to the review of the literature.

Adult↗
PubMed1997

[Reliability of Amplicor Mycobacteria test for detection of Mycobacterium tuberculosis complex. M. avium and M. intracellulare: a cooperative study among 9 laboratories].

The Amplicor Mycobacteria, a PCR-based assay, is a rapid test for the detection of Mycobacterium tuberculosis, Mycobacterium avium and Mycobacterium intracellulare in clinical samples. To estimate the reliability and reproducibility of the method, a cooperative blind study was conducted among 9 laboratories. Materials used for testing consisted of 105 sputum and 30 water samples containing known numbers of M. bovis BCG, M. avium, M. intracellulare, and samples without bacteria. Only 2 out of the 9 laboratories correctly identified the presence or absence of mycobacterial DNA in all 135 samples. In sputum samples, 6 out of the 9 laboratories detected mycobacterial DNA in all positive samples, and 4 out of the 9 laboratories correctly reported the absence of DNA in the negative samples, indicating the need for good laboratory practice and development of reference reagents to monitor the performance of the whole study, including pretreatment of clinical samples. The main problem was lack of specificity rather than lack of sensitivity. From about half of the laboratories, false-positive results were reported, however, the ratio was below 6%; 1% (1/106 sputum samples) in 3 laboratories, 1.9% (2/105) in 2 laboratories, and 5.7% (6/105) in one laboratory, respectively. These results indicate that the Amplicor Mycobacteria is quite useful for a rapid diagnosis of tuberculosis.

DNA, Bacterial↗
PubMed1997

Expression of adhesion molecules on mononuclear cells from individuals with stable atopic asthma.

Activated mononuclear cells (lymphocytes and monocytes) (MNCs) circulate in peripheral blood and accumulate in the airways of individuals with steady-state asthma. The expression of adhesion molecules on MNCs of 10 patients with steady-state atopic asthma and 10 non-atopic control subjects was measured by flow cytometry. The mean fluorescence intensity of CD23 (P = 0.0003), CD11a (P = 0.034), and very late antigen-4 (VLA-4) (P = 0.016) was increased on lymphocytes of asthmatic patients relative to those of controls. Although the expression of CD16 (P = 0.002) and CD23 (P = 0.002), which are associated with differentiation into macrophages, was increased on monocytes of patients relative to those of controls, monocyte expression of VLA-4 (P = 0.006) and sialyl Lewis x (P = 0.005) was reduced. The concentration of interleukin-4 (IL-4) in serum was significantly higher in asthmatic patients than in normal subjects (P = 0.023), and a significant correlation was apparent between the serum concentration of IL-4 and the expression of VLA-4 on lymphocytes (p = 0.71, P = 0.03) or on monocytes (p = -0.72, P = 0.03) in asthmatic patients. Results suggest that IL-4 may contribute to the priming of adhesion molecule expression on lymphocytes even in steady-state conditions in individuals with chronic allergic inflammation.

Adolescent↗
PubMed1996

Construction and characterization of a recombinant adenovirus vector carrying the human preproinsulin gene under the control of the metallothionein gene promoter.

A new adenovirus vector carrying human-preproinsulin (h-PPI) genomic DNA, which was placed under the control of the mouse metallothionein gene promoter, was constructed. In the recombinant virus-infected cells, h-PPI gene expression increased as a function of ZnSO4 concentration. Reversed-phase high-performance liquid chromatography analysis revealed that the recombinant adenovirus-infected cells secreted immature insulin containing proinsulin and incorrectly processed insulin. Tyrosyl phosphorylation of human insulin receptor substrate 1 occurred when HepG2 cells were treated with the cultured medium, indicating that the h-PPI gene product was functionally active in vitro. We also examined the biological activity of the product using diabetic severe combined immunodeficient mice and confirmed that the h-PPI gene product reduced the blood glucose concentration in vivo. This study suggests that the adenovirus vector can be used to express a foreign gene under the control of an external promoter in various human cells.

Adenoviridae↗
PubMed1996

A 11.5-kb 5'-terminal cDNA sequence of chicken breast muscle connectin/titin reveals its Z line binding region.

A partial 5'-region cDNA (11.5 kb) of chicken breast muscle connectin/titin encoding 3752 amino acids was sequenced. The predicted amino acid sequence contains 31 immunoglobulin C2 motifs and 10 interdomains. The sequence suggests a skeletal muscle type of connectin isoforms. Immunoelectron microscopic studies using antisera raised against several products of the cDNA fragments expressed in E. coli revealed that a region of some 800 amino acids from the N terminus of connectin is involved in its binding to the Z line in a sarcomere.

Animals↗
PubMed1996

Purification and characterization of virus-like particles and pentamers produced by the expression of SV40 capsid proteins in insect cells.

Three capsid proteins of SV40 (VP1, VP2, and VP3) were expressed in insect cells using recombinant baculoviruses. When the VP1 capsid protein was expressed alone or co-expressed with VP2 and VP3, virus-like particles (VLP) were produced. In the latter case, the minor capsid proteins, VP2 and VP3, were incorporated into the VLP. VLPs with and without VP2 and VP3, and the wild type SV40 virions were indistinguishable under electron microscope. The sedimentation coefficient, S20,w' obtained for the VLP consisting of VP1 alone (VP1-VLP) was 170 S, and that for the VLP consisting of all of the capsid proteins (VP1/2/3-VLP) was 174 S. Treatment of the VP1-VLP with a calcium ion chelating agent and a reducing agent caused dissociation of the VP1-VLP. The dissociated and purified VP1 proteins were identified as pentamers of VP1 based on the molecular weight determination by sedimentation equilibrium. The pentamers were shown to possess the ability to re-assemble into VLP which had the S20,w of 141S. The results are discussed in relation to the morphogenesis of SV40.

Animals↗
PubMed1996

Selective Isolation of DNA or RNA Using Single-Stranded DNA Affinity Latex Particles.

We developed latex particles with a diameter of about 0.22 µm on which single-stranded (ss) DNA was covalently coupled to select or enrich its complementary DNA or mRNA. DNA was first covalently coupled to the latex particles in the double-stranded (ds) form with both blunt and protruding ends. More than 80% of the dsDNA was coupled through the ssDNA stretch at its protruding end. The presence of NaCl in the immobilization reaction severely inhibited DNA from coupling to the particles. The particles were then treated with alkali or heated to denature the dsDNA and sedimented by a brief centrifugation to yield ssDNA immobilized particles. They allowed the selective and efficient isolation of a desired RNA from total cellular RNA.

Journal Article↗