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Biomedical subjects

T Miki

Publications and source records attributed to T Miki.

At least 775 records · Page 43Linked to original sources

[Towards cloning the gene responsible for myotonic dystrophy].

For the purpose of cloning the gene of myotonic dystrophy (DM) using the technique of reverse genetics, we have introduced new methods such as microdissection, a YAC library and a Not I linking library and cloned many DNA fragments derived from the region of 19q13.2. Then we have assigned these to chromosome 19 by linkage map (CEPH families and linkage disequilibrium) and physical map (PFGE and in situ hybridization). Here we have described these methods.

Chromosome Mapping↗

[Reconstruction of occlusal function with osseointegrated implant following mandibular resection].

We succeeded satisfactorily to restore the occlusal function by use of an osseointegrated implant following iliac bone grafting and partial mandibulectomy in 4 patients who underwent surgical resection of odontgenic cyst and benign or malignant tumor of the oral cavity. Case 1: The patient was a 19-year-old man. Partial resection of the mandible was carried out under the diagnosis of odontgenic keratocyst of the left lateral incisor to the 1st premolar region. Iliac bone grafting was performed as secondary surgery. After confirmation of the fusion of the grafted bone, the occlusal function was restored by use of an osseointegrated implant. Case 2: The patient was a 36-year-old man. After segmental resection of the mandible under the diagnosis of ameloblastoma of the left 2nd premolar to the right 2nd premolar region, mandibular reconstruction was carried out with an A-O plate. Iliac bone grafting was performed as secondary surgery. After fusion of the grafted bone had been confirmed, the A-O plate was remounted and the fixture was immediately implanted. Five months later, vestibuloplasty by free skin grafting and attachment of the abutment were carried out. A superstructure was mounted. Case 3: The patient was a 22-year-old woman. The histopathologically confirmed odontogenic myxoma in the right mandible posteriorly from the second premolar was resected. Immediate reconstruction of the mandible was carried out by use of an iliac bone graft. After confirmation of the fusion of the grafted bone, the occlusal function was restored by use of an osseointegrated implant. Case 4: The patient was a 57-year-old woman with carcinoma of the right lingual margin and mouth floor. The tumor was resected with the mandibular margin. Immediate reconstruction of the tongue and mouth floor with a major pectoral muscle skin flap was carried out. In the absence of evidence of recurrence, restoration of the occlusal function was attempted with an osseointegrated implant.

Adult↗

[Finite element analysis on physiological mobility of individual teeth].

The initial movement of the tooth was investigated by the finite element method. The mechanical properties of the periodontal membrane were estimated from the results of the simulation. The analysis was made by using an 8 point isoparametric finite element method. The upper central incisor with an axial directional load was simulated. The concept of the apparent elastic modulus was introduced to the stress-strain relation of the soft tissue, that is, soft tissue such as the periodontal membrane and the gingiva was considered to have stress dependent elastic moduli. At the first stage of the simulation, the stress and strain distributions in the paradentium were calculated by the conventional method. From the next stage, the apparent elastic moduli for the soft tissue were introduced to the calculation, that is, the elastic moduli for the soft tissue were computed from the calculated equivalent stresses of the previous stage. The calculations were repeated until the displacement values converged. The initial displacement of the tooth was not proportional to the applied load but showed a non-linear relationship. The relationship between load and displacement was approxiated by the n-th power equation. These results were in agreement with the clinical experimental results. The periodontal membrane is built up of different elastic moduli. The elastic moduli were low at the alveolar edge and the root apex. The equivalent stresses of the periodontal membrane were marked low in the alveolar edge and the root apex. In conclusion, the concept of the apparent elastic modulus is useful to investigate the initial movement of the tooth and estimate the mechanical properties of the periodontal membrane.

Computer Simulation↗

[Abnormalities in autologous mixed lymphocyte reaction-induced T cell activation cascade in rheumatoid arthritis and their possible correction by methyl-B12].

We have previously shown that when patients with active rheumatoid arthritis (RA) were examined for the ability of their lymphocytes to respond in the autologous mixed lymphocyte reaction (AMLR), profoundly reduced AMLR responses were found in the RA patients. The defects were mainly due to the impaired response of CD8+ and CD4+ Law8- subsets; however, both CD4+Leu8+ and CD4+ + Leu8- cells functioned normally as responding cells. The present study demonstrated that the abnormalities of RA CD8+ T cells in the AMLR were corrected when the AMLR cultures were set up in the presence of methyl-B12. In addition, a main target of the methyl-B12 effect observed was both CD8+Leu8+ and CD8+Leu8- cells. Thus, methyl-B12 may become a potential agent that would be able to control the pathophysiology of RA.

Adult↗

[Wallenberg's syndrome caused by a brain tumor--a case report and literature review].

we report a patient with Wallenberg's syndrome caused by glioma of the lateral medulla oblongata, and review the literature for Wallenberg's syndrome associated with neoplastic disease. A 46-year-old man was admitted because of progressive dysphagia and vertigo. Neurological examination revealed atypical symptoms and signs of Wallenberg's syndrome on the right side, hypalgesia on the second and third divisions of the left trigeminal nerve, paresis of the right palate and uvula, and ataxia of the right extremities. Although CT showed no abnormality in the posterior fossa, MRI demonstrated a mass with abnormal signal intensities in the right dorsolateral portion of the medulla. Biopsy specimens showed astrocytoma (grade III). Based on the present case and a review of 10 previously reported cases of Wallenberg's syndrome caused by neoplastic disease, the clinical features of this syndrome are characterized by gradual development and steady progression of symptoms, non-classical or atypical symptomatology, numerous additional symptoms and signs depending on the site and size of tumors, and poor prognosis.

Brain Neoplasms↗

[Acute myeloblastic leukemia and hepatocellular carcinoma following Waldenström's macroglobulinemia].

A 54-year-old man was admitted to our hospital for precise examination of pancytopenia in October 1988. He had been cut off his left femur and irradiated because of osteosarcoma in 1954. After 30 years, he was diagnosed as Waldenström's macroglobulinemia. Melphalan had been given 2 mg daily for 19 months until August 1988, when it was discontinued due to pancytopenia. Peripheral blood showed Hb 6.6 g/dl, platelet 40 x 10(3)/microliters, and WBC 2000/microliters with 33% blasts. Bone marrow showed normocellularity with 36% blasts. Although blasts were negative for peroxidase staining, surface marker analysis revealed myeloid (CD 13, CD 33) phenotypes. Chromosome analysis showed 45, XY, -7, inv (3). A CT scan of the liver showed a mass, 10 by 10 cm, compatible with hepatocellular carcinoma. He was treated with very low dose Ara-C without noticeable effect. Hepatic tumor gradually enlarged, and he died of hepatic failure. This is a rare case of quadruplicate malignancies. The chromosomal abnormality suggests that AML was secondary leukemia which might be associated with immunosuppression due to macroglobulinemia and/or melphalan therapy.

Carcinoma, Hepatocellular↗

[A case report of the reinforcing technique with collared prosthesis for the prosthetic valve endocarditis in mitral position].

A 58-year-old female was admitted to our hospital because of the prosthetic valve endocarditis in mitral position. In the past, this patient was undertaken double valve replacement in mitral and aortic position. Nevertheless, postoperative course was not in stable condition, showing persistent sign of the infection. The appearance of mitral regurgitant murmur and regurgitant signal by colour Doppler cardiography could make sure of the diagnosis for prosthetic valve endocarditis (PVE) in mitral position. The operation for PVE in mitral prosthesis was undertaken as follows. As there was extensive annular infection around the mitral valve, the new mitral prosthesis (Duromedics valve) with the Gore-tex flange, so called collared prosthesis, was revised. The collared prosthesis was implanted in the mitral annulus by using the suture ring of the Duromedics valve as well as possible, furthermore, the Gore-tex flange were sutured in the left atrial wall 2 cm above the mitral ring. Postoperatively, the infection sign and congestive heart failure were completely subsided. This patient has been in very healthy condition these days and restored to the daily life.

Endocarditis, Bacterial↗

[A case report of surgical treatment of prosthetic valve endocarditis in tricuspid position].

A case of right sided prosthetic valve endocarditis in tricuspid position was presented. This 38-year-old male underwent tricuspid valve replacement (TVR) with SJM (31 mm) prosthetic valve because of tricuspid valve endocarditis caused by staphylococcus epidermidis five years ago. At the beginning of this year, 1989, he was admitted with complain of high fever and bloody sputa. Doppler color imaging showed prosthetic valve was stenotic whose pressure gradient was 16 mmHg in peak pressure gradient, but vegetation was not identified. Following with gastrectomy perhaps due to AGML, re-TVR was done with Carpentier-Edwards vale (31 mm). He was discharged without any problems. It seems important to determine the timing of re-operation before leading any complications.

Adult↗

[Prophylactic use of DDAVP in a patient with von Willebrand disease during labor: a case report and a review].

A Case of delivery in a 23-year-old woman after a prophylactic infusion of DDAVP is described. She had a life-long history of easy bruising and frequent epistaxis, with the diagnosis of vWD being made when she was 14 years old. A hemostatic examination showed a prolonged bleeding time, a moderate reduction in the factor VIII level (VIII: C) and von Willebrand Factor Antigen (vWF: Ag), decreased platelet aggregation by ristocetin, and depletion of platelet retention. In April, 1988, in the 34th week of pregnancy, she was admitted to our clinic in order to avoid abnormal bleeding during labor. On admission, the level of factor VIII, ristocetin aggregation, and platelet retention were normal, but the bleeding time remained prolonged. The diagnosis of vWD type I was made on the normal multimeric structure. The DDAVP infusion test revealed a shortening of the bleeding time and an increase in the vWF: Ag. In the 41st week of pregnancy, labor was induced, accompanied by infusion of DDAVP, she gave birth to an infant without any abnormal bleeding. Since conventional treatments with human plasma derivatives may cause complicating viral infections, we propose the infusion of DDAVP is one of the treatments to prevent the abnormal bleeding of the patient with vWD during labor.

Adult↗

[A case of constrictive pericarditis due to traumatic pericardial hematoma].

Although the cause varies widely, we recently experienced a case of constrictive pericarditis of which cause seemed to be traumatic as described below. The patient was a 62-year-old man having a history of epigastric trauma about 20 years ago. Since then, palpitation appeared and he was recently hospitalized in our department for the purpose of receiving an operation under the diagnosis of constrictive pericarditis. At operation, a hematoma was found in the pericardial region, which was considered to have been caused by trauma in the past. Less reports have so far been available concerning trauma-induced constrictive pericarditis and this case thus seemed to be of rarity as well.

Constriction, Pathologic↗

IgA myeloma complicated by fractures of the bones and hyperviscosity syndrome--report of an autopsied case.

A case of IgA (kappa type) myeloma complicated by fractures of the bones and hyperviscosity syndrome is presented. A 56-year-old woman who had been followed as an outpatient with diabetes mellitus for about 16 years, developed multiple myeloma. She also showed symptoms and signs of hyperviscosity syndrome; hemorrhagic diathesis, blurred vision and episodes of transient ischemic attacks of the brain, and fractures of the bones by small powers of trauma. At autopsy, almost all bones showed infiltration of multiple myeloma of IgA-kappa type and severe osteoporosis accompanied with proliferation of osteoclasts. The association of IgA myeloma with hyperviscosity syndrome and/or bone destruction was discussed. The "serum hyperviscosity syndrome" has been described clinically as the triad of bleeding, visual signs and symptoms, and neurologic manifestations. And this syndrome has been associated frequently with macroglobulinemia of Waldenström, occasionally with immunoglobulin (Ig) G myeloma, rarely with IgA myeloma, and with other dysproteinemia. Myeloma is also characterized by extensive bone destruction and is accompanied by susceptibility to fracture, although Waldenström's macroglobulinemia, acute leukemia or chronic leukemia are rarely associated with bone resorption. The present report describes a patient with IgA myeloma complicated by hyperviscosity syndrome and multiple bone fractures.

Blood Viscosity↗

[Experimental evaluation for tricuspid annular constriction with the model of tricuspid annular dilatation].

We have obtained the good result about tricuspid annular constriction (TAC) for secondary tricuspid insufficiency. The purpose of this study is to investigate the effectiveness of TAC for the experimental model of tricuspid annular dilatation. First of all, tricuspid annular dilatation was made surgically in 8 mongrel dogs by placing 8 incisions to tricuspid annulus except septal cusp under the condition of heart-lung preparation. On clinical evaluation, septal annulus was kept to be intact in many cases compared with the two other areas. This experimental model of tricuspid annular dilatation was considered to be substituted to the clinical model of tricuspid annular dilatation. TAC suture was surrounded circumferentially around the dilated tricuspid annulus. And then, TAC suture was pulled out from the right atrial wall, and the circumferential length of tricuspid annulus was completely accommodated by pulling the TAC suture. The hemodynamic status was observed by right atrial pressure (V wave and mean) and right ventricular end-diastolic pressure (RVEDP). After heart resuscitation and gradual increase of preload, right atrial pressure was significantly elevated especially right atrial pressure (V wave) compared with control values. When 2 cm of circumferential length of tricuspid annulus on an average was constricted by shortening of TAC suture, right atrial pressure was significantly decreased, and then RVEDP tended to decrease. It was shown that TAC was an effective operative technique for the secondary tricuspid annular dilatation and tricuspid insufficiency from the standpoint of experimental aspect as well as clinical results.

Animals↗

[Mitral valve prolapse as an initial clinical feature of dilated cardiomyopathy: report of two cases].

Two cases with mitral valve prolapse (MVP), without any other cardiac abnormalities at the initial evaluation, developed the clinical features mimic to dilated cardiomyopathy (DCM) during follow-up period. Case 1. A 40-year-old man visited our hospital in May 1982 to evaluate a heart murmur. A standard 12-lead electrocardiogram (ECG) showed an abnormal Q wave in lead III. Echocardiography revealed MVP, but neither dilatation nor wall motion abnormality of the left ventricle (LV) were observed. Thallium-201 scintigraphy revealed an abnormal thallium uptake at the apex and inferior wall. He had no episode of acute myocardial infarction or myocarditis, but complete right bundle branch block developed, thus, he was hospitalized in October 1984. He had no coronary artery lesions, and had only mild mitral regurgitation on left ventriculography. The motion of the interventricular septum and apex was reduced on echocardiogram and a persistent perfusion defect was observed at the inferior wall and the interventricular septum on Tl-201 scintigrams. In December 1985, he experienced an Adams-Stokes attack due to complete atrioventricular block. Echocardiographically, the left ventricle enlarged, and the wall motion abnormalities and a perfusion defect on Tl-201 scintigrams were relatively severe. Case 2. A 46-year-old woman occasionally experienced palpitation of short duration and chest oppression since 1977. She was admitted to our hospital because of cardiac symptoms in 1982. A heart murmur of Levine II was heard and a standard 12-lead ECG showed single supraventricular extrasystole and T wave inversion in lead III and aVF. Echocardiography revealed MVP and mild mitral regurgitation, but neither dilatation nor wall motion abnormality of the LV was observed. During 6-year follow-up period, permanent atrial fibrillation developed and LV developed dilatation and wall motion abnormalities progressed. Thus, during follow-up periods, DCM-like features developed in two cases who had had MVP as a sole echocardiographic abnormality with systolic murmur and non-specific ECG changes. We consider that these two may be important cases who may show a relation between cardiomyopathic process and MVP.

Adult↗

[A study of tricuspid-tailoring annular constriction in autopsy cases--cases which appear to embody limitation of tricuspid-tailoring annular constriction].

We our department have performed tricuspid-tailoring annular constriction (T-TAC) as salvage operation for secondary tricuspid regurgitation (TR) with gratifying results. Of those cases undergoing MVR and T-TAC for mitral valve regurgitation (MR) and secondary TR with an associated severe cardiac cachexia, 2 autopsy cases in which an associated severe cardiac cachexia, 2 autopsy cases in which residual tricuspid regurgitation culminated in patient's death long after operation were investigated. In Case 1, the patient was discharged asymptomatic 2 months after operation, but later developed severe left heart failure and marked tricuspid regurgitation as precipitated by upper respiratory tract infection and died from exacerbation of LOS before undergoing a scheduled reoperation. T-TAC was found successful on autopsy. In Case 2, the patient died of long-persisting left heart failure and severe residual tricuspid regurgitation after following a similar postoperative course to that in Case 1. On autopsy stitches made through the tricuspid anterior leaflet, septum and posterior leaflet were found untied and loosened and the tricuspid annulus diameter increased. In severe valvular heart disease, even if T-TAC has proven successful, aggravation of cardiac failure may lead to the development of TR. Because of the fragility of myocardial tissue due to severe myocardial damage in such compromised patients, sophisticated operative techniques need to be devised. Cases illustrative of a limited long-term success of T-TAC used alone are presented.

Constriction↗

An efficient directional cloning system to construct cDNA libraries containing full-length inserts at high frequency.

We have developed a high efficiency cDNA cloning system which can direct the orientation of inserts in lambda-plasmid composite vectors with large cloning capacities. Cleavage of the vector DNA by SfiI creates two different nonsymmetrical 3' extensions at the ends of the vector arms. Using a linker-primer and an adaptor, cDNA is prepared so it has two different sticky ends which can be ligated to those of the vector arms. When the cDNA fragments and the vector arms are mixed, both the molecules can assemble without self-circularization due to base-pairing specificity. Ligation of the cDNA-vector mixture produces the concatemers from which phage clones carrying a single cDNA insert in the desired orientation can be formed very efficiently by in vitro packaging. This system provides: (1) high cloning efficiency [10(7)-10(8) clones/micrograms poly(A)+ RNA], (2) low background (more than 90% of the clones contain inserts), (3) directional insertion of cDNA fragments into the vectors, (4) presence of a single insert in each clone, (5) accommodation of long inserts (up to 10 kb), (6) a mechanism for rescue of the plasmid part from the lambda genome, and (7) a straightforward protocol for library preparation. Screenings of cDNA libraries constructed by this method demonstrated that cDNAs of up to 6.4 kb, containing complete coding sequences, could be isolated at high efficiency. Thus, this cloning system should be useful for the isolation of cDNAs of relatively long transcripts, present even at low abundance, in cells.

Bacteriophage lambda↗

Human KGF is FGF-related with properties of a paracrine effector of epithelial cell growth.

Keratinocyte growth factor (KGF) is a human mitogen that is specific for epithelial cells. The complementary DNA sequence of KGF demonstrates that it is a member of the fibroblast growth factor family. The KGF transcript was present in stromal cells derived from epithelial tissues. By comparison with the expression of other epithelial cell mitogens, only KGF, among known human growth factors, has the properties of a stromal mediator of epithelial cell proliferation.

Amino Acid Sequence↗