Search PubMed⌕ Search

Biomedical subjects

T Ota

Publications and source records attributed to T Ota.

At least 217 records · Page 12Linked to original sources
PubMed1994

[A successful surgical correction of the intermediate type of common atrioventricular orifice--report of an adult case].

A 42-year-old female was admitted to our hospital because of exertional dyspnea. Preoperative color Doppler echocardiogram revealed massive left to right shunt through the ostium primum defect, moderate mitral and tricuspid regurgitation, and trivial shunt via the small ventricular septal defect. Preoperative cardioangiogram also demonstrated goose neck deformity of the left ventricle. At the operation, the piece of atrioventricular valve fused on the summit of the small scooped ventricular defect was detected, and the total correction consisted of patch closure of the ostium primum defect and mitral and tricuspid valvuloplasty was performed. Postoperative course was uneventful. This is the first adult case reported in Japan who was operated on for the intermediate type of common atrioventricular orifice.

Adult↗
PubMed1993

Nucleotide sequence analysis of the human salivary protein genes HIS1 and HIS2, and evolution of the STATH/HIS gene family.

Human histatins are a family of low-M(r), neutral to very basic, histidine-rich salivary polypeptides. They probably function as part of the nonimmune host defense system in the oral cavity. A 39-kb region of DNA containing the HIS1 and HIS2 genes was isolated from two human genomic phage libraries as a series of overlapping clones. The nucleotide sequences of the HIS1 gene and part of the HIS2(1) gene were determined. The transcribed region of HIS1 spans 8.5 kb and contains six exons and five introns. The HIS1 and HIS2(1) genes exhibit 89% overall sequence identity, with exon sequences exhibiting 95% identity. The two loci probably arose by a gene duplication event approximately 15-30 Mya. The HIS1 sequence data were also compared with that of STATH. Human statherin is a low-M(r) acidic phosphoprotein that acts as an inhibitor of precipitation of calcium phosphate salts in the oral cavity. The HIS1 and STATH genes show nearly identical overall gene structures. The HIS1 and STATH loci exhibit 77%-81% sequence identity in intron DNA and 80%-88% sequence identity in noncoding exons but only 38%-43% sequence identity in the protein-coding regions of exons 4 and 5. These unusual data suggest that HIS1, HIS2, and STATH belong to a single gene family exhibiting accelerated evolution between the HIS and STATH coding sequences.

Amino Acid Sequence↗
PubMed1993

Surgical treatment for aneurysms of the descending aorta using temporary perfusion by a centrifugal pump: clinical analysis of 33 cases.

Since 1987, 33 patients have undergone surgery at Kobe University Hospital for aneurysm of the descending aorta using left heart bypass with a heparin-coated centrifugal pump and heparin-coated tubes. Sixteen patients had true aneurysms of the descending thoracic aorta, 7 had thoracoabdominal aneurysms, and 10 had aortic dissection (DeBakey's Type III). Heat exchangers and oxygenators were not included in the bypass circuit in any of the cases. Perfusion time was from 42 to 205 min (average 90 min). Left heart bypass was established with 1 mg/kg of systemic heparinization in 5 cases, 0.5 mg/kg in 5 cases, and 0 mg/kg in 23 cases. There were no complications such as perioperative embolism, acidosis, or hypothermia. During aortic cross-clamping, the arterial pressure of the lower extremity was maintained above 70 mm Hg, but there was no relationship between the distal perfusion pressure and bypass flow. The urine output during left heart bypass was related to the distal perfusion flow by centrifugal pump. Of 23 patients who underwent bypass with less than 40 ml/kg/min of distal perfusion flow, 7 showed transient renal dysfunction postoperatively, and 1 developed postoperative renal failure. The other patients who were bypassed with over 40 ml/kg/min of pump flow stayed in the normal range of renal function. Postoperative paresis occurred in 2 patients, who were also perfused with less than 40 ml/kg/min of bypass flow. It could be concluded that left heart bypass by centrifugal pump is safe and acceptable as a circulatory support in the surgical treatment of aneurysm of the descending aorta.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Experimental manufacture of a catheter for the measurement of blood flow rate.

The authors manufactured an experimental catheter to obtain blood flow rate, measuring not only the flow velocity but also the vessel diameter. This catheter consists of 3F Doppler and 7F external sheath catheters, and four thin wires 3 cm in length are attached to the catheters at both tips at a 90 degrees pitch. After the insertion of the catheter into the vessel, vessel diameter is calculated from the maximal width of the wires, which are expanded to a spindle shape inside the vessel; the maximal width is corrected with calibration metal markers also attached at the proximal site of the external sheath catheter. The flow velocity of the blood is calculated with the FFT (Fast Fourier Transform) analyzer. In experimental circuits as well as in the canine aorta, wires were adequately expanded, and the catheter was placed at the center of the tube or the aorta. The blood flow rate, which was calculated as a product of flow velocity and vessel diameter, was well correlated to that from the electromagnetic flowmeter, not only in the experimental circuits, but also in the canine aorta.

Animals↗
PubMed1993

Involvement of peanut agglutinin-binding sugar chains in experimental metastasis of B16 melanoma cells.

Involvement of PNA (peanut agglutinin)-binding sugar chains in experimental metastasis of B16M4 cells and their metastatic variants (B16F1, B16F10, and B16BL6) was investigated by using ginsenoside Rh2 (Rh2), which increased PNA binding to the cell surface without increasing concanavalin A or wheat germ agglutinin binding. The PNA binding to cell surface increased in parallel with the experimental metastatic ability in Rh2-treated B16M4 cells, and this increase in metastatic ability was suppressed when the cells were treated with PNA before i.v. injection of cells. Concanavalin A and wheat germ agglutinin did not have such inhibitory effects. Increased PNA binding was observed on glycoproteins of M(r) 75,000-85,000, and was suggested to be due to reduced sialylation of PNA-binding sugar chains on these glycoproteins. In Rh2-treated B16F10 and B16BL6 cells, the increase in experimental metastatic ability was also associated with increased PNA binding to cell surface and M(r) 75,000-85,000 glycoproteins. Although the mechanisms of these effects of Rh2 are unknown, these results suggested that the reduced sialylation of PNA-binding sugar chains on M(r) 75,000-85,000 is related to the increased experimental metastatic ability of Rh2-treated B16 melanoma cells.

Animals↗
PubMed1993

Evaluation of various mechanical heart values in the mitral and aortic positions.

To evaluate the function of various types of mechanical heart valves (Björk-Shiley = BS, Medtronic Hall = MH, St. Jude Medical = SJM, Duromedics = DM), hemodynamic studies were performed in 236 patients with valve replacement in addition to the evaluation of the clinical results. In 144 patients with mitral valve replacement including patients with double valve replacement, the degree of the postoperative improvements of clinical symptoms and hemodynamics were similar in patients with BS, DM and MH valves. There was a tendency for the effective orifice area calculated from pressure-half time obtained by continuous-wave Doppler (CWD) echocardiography to be larger in MH or DM valves than in BS valve of the same size on the average. In 115 patients with aortic valve replacement including patients with double valve replacement, there was no significant difference in the degree of postoperative reduction of the left ventricular hypertrophy among the patients with BS, MH and SJM valves. The mean value of the pressure gradient (PG) across the valve at rest obtained by CWD was less than 20 mmHg in each type of valve without significant difference among the valves. PG well correlated with cardiac output (CO) in each type and size of valve, and the rate of increase in PG with the increase in CO was smaller in the larger-sized valve of the same type and also smaller in MH valve than in BS valve of the same size. The frequency of valve-related complications was extremely low in each type of valve except for a higher incidence of occult hemolysis in SJM and DM valves. Overall, there were no significant differences in the clinical results among the patients with valvular prostheses examined. However, MH valve had advantages in hemodynamics and a lower incidence of hemolysis.

Adolescent↗
PubMed1993

[A case of surgical correction of sinus venosus atrial septal defect, mitral cleft, and interruption of inferior vena cava with azygos continuation in viscero-atrial heterotaxic syndrome].

A successfully corrected case of a 39-year-old female with viscero-atrial heterotaxic syndrome was reported. The cardiovascular anomalies were sinus venosus atrial septal defect, mitral cleft, and interruption of inferior vena cava with azygos continuation. She also had bilateral bilobed lungs, symmetric liver, right sided stomach, and malrotation of the bowel, indicating left isomerism. The atrial septal defect was closed with Teflon patch and mitral cleft was repaired with direct suture of the cleft. The postoperative course was uneventful and mitral regurgitation was trivial postoperatively.

Abnormalities, Multiple↗
PubMed1993

[Traumatic tricuspid regurgitation--report of two cases and review of operated cases].

Two cases of nonpenetrating traumatic tricuspid regurgitation were reported. The first case, a 46-year-old man who had an episode of traffic accident 21 years ago, was admitted with complaints of peripheral edema and dyspnea on exertion. The second case was a 16-year-old man who noted to have cardiac murmur and cardiomegaly after 4 years of a traffic accident. In both cases, cardiac catheterization showed increased right atrial pressure with high v wave, and echocardiogram showed severe tricuspid regurgitation with ruptured chordae tendineae of the anterior leaflet. Tricuspid valve replacement was performed successfully in both the cases. Twenty-two operated cases of traumatic tricuspid regurgitation have been reported in Japan; 17 of ruptured chordae tendineae, 3 of ruptured papillary muscle, and 2 of primary laceration of anterior leaflet. The patients with ruptured papillary muscle were operated from 2 months to 7 years (average 4 years) after trauma, while those with ruptured chordae tendineae were operated from 5 months to 25 years (average 10 years) after trauma. Tricuspid valve replacement was performed in 17 of 22 cases. From the review of 22 cases, tricuspid valve replacement should be indicated for traumatic tricuspid regurgitation in consideration of the severity of valve destruction regardless of the interval after trauma.

Adolescent↗
PubMed1993

[Congenital extradural cyst causing a 30-year history of myelopathy with long-term remission].

We reported a peculiar case of a patient with a thoracic extradural cyst, who had a 30-year history of thoracic-myelopathy with a very long-term remission. A 42-year-old male was admitted to our hospital complaining of gait disturbance and hypesthesia of his bilateral lower limbs. Neurological examination revealed that he had spastic paraparesis and hypesthesia of all sensory modalities below Th11/12 dermatomes. Investigation of his past history disclosed that he had experienced gait disturbance due to paraplegia 29 years previously and had been able to move only with the aid of wheel-chairs. However these signs had resolved themselves gradually in a period of 3 years, and after that he had been able to live almost without any neurological handicaps until the recent appearance of weakness in both of his legs. Neuroradiological study revealed that plain X-Ps of the thoracic spine showed thinning of the pedicles and widening of the interpedicular distances between Th4-Th7 vertebrae. The old iodine contrast media injected 29 years previously for myelography in an other hospital was also observed. MRI showed a dorsal cystic mass compressing the thoracic spinal cord and subarachnoid space. Myelography showed also that the spinal cord and subarachnoid space were compressed anteriorly between the level of Th3 to Th7 by the dorsal mass. CT myelography disclosed that soon after the injection of contrast media a small part of the cyst was visualized as having direct communication with the subarachnoid space. The contrast media penetrated the major part of the cyst only 19 hours after its injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Rheumatoid factors--recent advances in measurement techniques, their fine specificities and mechanisms of their production].

Rheumatoid factors (RF) are autoantibodies directed to the Fc of IgG. RF are present in the blood and synovial fluid of most patients with rheumatoid arthritis, and are also commonly detected in Sjögren syndrome and other autoimmune diseases, in chronic infectious diseases such a viral hepatitis and subacute bacterial endocarditis, and even in healthy individuals at low titers. Although vast studies have been made so far, the precise mechanisms leading to RF production and the fine specificity of human RF have not been well delineated. In this report, we present recent observations of RF concerning the following items: 1) changes in measurement techniques, 2) biological significance of RF in diseased and healthy states, 3) analysis of specificity of RF, and 4) mechanisms inducing RF production.

Humans↗
PubMed1993

[131I-therapy of differentiated thyroid carcinoma with distant metastases--relation between absorbed dose by quantitative SPECT and outcome of the patients in thyroid carcinoma].

The correlation of absorbed doses of tumors in 18 patients of differentiated thyroid carcinoma with distant metastases, who were treated by 131I and followed over 5 years, with their outcome were analyzed and the clinical significance of determination of absorbed dose was discussed. Radioactivities of 131I in the tumors were measured by using SPECT at the time of therapy. Absorbed dose was calculated based on the MIRD equation. Outcome of 8 patients were evaluated as good and their absorbed dose was 10-630 Gy with 2-22 g of tumor volume, 1.2-3.5 days of effective half life (EHL) and follow-up term was 8.6 +/- 0.9 years. The absorbed dose of 10 patients whose outcome were evaluated as poor, was 5-81 Gy with 7-215 g of tumor volume, 1.3-5.3 days of EHL and follow-up term was 5.6 +/- 2.5 years. The initial treatment seemed to be important for 131I therapy, since the absorbed doses in the following therapy became reduced. When the absorbed dose of the tumor exceeded over 94 Gy at initial treatment, good clinical courses were obtained. These results indicate that the quantitative SPECT for 131I therapy is clinically valid and that the calculated absorbed doses correlate well with outcome of the patients.

Adenocarcinoma↗
PubMed1992

Interactions between recombinant human erythropoietin and serum factor(s) on murine megakaryocyte colony formation.

We investigated the interactions between human erythropoietin (hEpo) and serum factor(s) on murine megakaryocyte (MK) colony formation. Serum-free cultures supported the growth of a large number of murine MK colonies in the presence of murine interleukin-3 (mIL-3). The addition of fetal calf serum (FCS) to mIL-3-containing cultures resulted in only a minimal increase in the number of murine MK colonies. In contrast, hEpo alone had no murine MK colony-stimulating activities in serum-free cultures. hEpo required the presence of FCS, murine serum, or human serum in cultures to promote murine MK colony growth and synergized with these sera to stimulate murine MK colony formation. Furthermore, sera from patients with aplastic anemia showed higher synergistic activities with hEpo than sera from hematologically normal persons (normal human serum). When normal human serum was fractionated by gel-filtration chromatography, two peaks with the synergistic activity were observed in the eluent. However, serum did not show any synergistic effects with hEpo on the growth of murine GM colonies or murine colony-forming unit-erythroid-derived colonies. Although human serum synergized with hEpo to stimulate murine MK colony formation, human cytokines such as IL-3, IL-4, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte-CSF (G-CSF) failed to induce murine MK colony formation in Epo-containing cultures. In cultures containing human IL-1 alpha + human IL-6 + hEpo as well as in cultures containing hEpo, human IL-3 and human GM-CSF failed to show stimulatory effects on murine MK colony formation. Moreover, the synergistic activity of human serum with hEpo could not be neutralized by antibodies such as antihuman IL-1 alpha, antihuman IL-3, antihuman IL-4, antihuman IL-6, antihuman G-CSF, and antihuman GM-CSF. Our data show that serum contains a growth factor(s) that synergizes with Epo to stimulate the proliferation and differentiation of MK precursors, and strongly suggest that this factor(s) is an unique growth factor(s) that is distinct from IL-1 alpha, IL-3, IL-4, IL-6, G-CSF, and GM-CSF.

Anemia, Aplastic↗
PubMed1992

Isolation and characterization of a low metastatic variant from EL-4 mouse T-lymphoma.

A variant cell line (EL-4ad) which adhered to a tissue culture dish was isolated from highly metastatic EL-4 murine T-lymphoma. The experimental and spontaneous metastatic ability of EL-4ad was lower than that of the EL-4 parent cell line. The cell surface phenotypes of both cell lines were CD2+3+4-8-45+TCR alpha beta+TCR gamma delta-, but the level of CD2 expression of EL-4ad was much lower than that of EL-4. Furthermore, EL-4ad had higher binding ability to fibronectin and expressed more PNA receptors on the cell surface than EL-4. These differences indicated that either the maturation stage of the less metastatic variant was lower than that of the parent cell line or the activation state of the two cell lines differed. EL-4ad showed higher in vitro invasiveness and adhesiveness to liver cells, and these characters were not consistent with the reduced metastatic ability of this variant. Neuraminidase-releasable cell surface sialic acid levels did not differ significantly between the cell lines. Neither cell line was adhesive to laminin, type IV collagen or reconstituted basement membrane. These metastasis-related properties could not explain the decreased metastatic ability of EL-4ad. On the other hand, EL-4ad was more sensitive to NK activity than EL-4 in vivo, and this was thought to be a major cause of its decreased metastatic ability. The molecules or mechanisms involved in the differentiation or activation of T-cells may be responsible for the sensitivity of tumor cells to NK activity.

Animals↗
PubMed1992

Paraganglioma associated with hypoglycemia.

A 63-year-old female had frequent attacks of palpitations with sweating and occasional loss of consciousness for 7 years before admission. These symptoms and documented hypoglycemia (blood glucose: 46 mg/dl) suggested insulinoma, but computed tomography demonstrated a retroperitoneal tumor which was diagnosed as a paraganglioma by histological examination of the resected specimen.

Adrenal Glands↗