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Biomedical subjects

Y Okamura

Publications and source records attributed to Y Okamura.

At least 19 recordsLinked to original sources
PubMed1992

[Double valve replacement for secondary atrioventricular regurgitation due to dilated cardiomyopathy--a case report].

A successful surgical case of double valve replacement for a patient with dilated cardiomyopathy was performed. A 45-year-old man was admitted to our hospital with paroxysmal atrial fibrillation and congestive heart failure. Echo cardiogram and cineangiography showed dilatation and decreased contraction of the left ventricle. A diagnosis of dilated cardiomyopathy was established since neither coronary artery disease nor valvular disease were observed. He was treated with medication of diuretics and pacemaker implantation. However, mitral and tricuspid regurgitation occurred and progressed 7 years later. Since then, he repeated admission and discharge against the strong medication. He became medically uncontrollable at the age of 58. Because of this, surgical treatment had to be considered. Double valve replacement for mitral and tricuspid valve was performed on September, 1989. Avoidance of cardiopulmonary bypass was only possible with the aid of catecholamine. Poor left ventricular function and pleural effusion frequently shown on chest X-ray film complicated the postoperative course. And with hospital treatment, he discharged three months after the operation. He has been doing well without any significant complaint during the past two years and cardiomegaly has been decreasing as well.

Cardiomyopathy, Dilated↗
PubMed1992

[Comparative studies of various conduits for myocardial revascularization with Kawasaki disease].

Between October 1976 and December 1991, 36 patients with Kawasaki disease underwent coronary bypass surgery. Comparisons were made from the postoperative morphologic condition of 4 conduits; saphenous vein graft (SVG n = 27), left internal thoracic artery (LITA n = 22), right internal thoracic artery (RITA n = 5) and gastroepiploic artery (GEA n = 8). The patency rate of arterial grafts was 100% at 1 month after surgery, and kept as high as 94.7% at 1-3 years after surgery. On the other hand, the patency rate of SVG was 90% at 1 month, but decreased to 52% at 1-3 years postoperatively. Arterial grafts sometimes showed string sign at 1 month after surgery, but the length and the diameter increased during 1 year after surgery. The internal thoracic artery showed superior flow potential compared with GEA. Thus, the internal thoracic artery is the first choice and GEA is the second as the graft material with Kawasaki disease. Long-term result of SVG was very poor, so coronary revascularization only by the arterial grafts is recommended.

Adolescent↗
PubMed1992

[Study on the pharmacokinetics of cefepime (I)].

The pharmacokinetics of 14C-cefepime dihydrochloride (14C-CFPM), were studied in rats upon both single and repeated intravenous administration. 1. Blood level of radioactivity was 59.27 micrograms eq./ml at 5 minutes after single intravenous administration at a dose of 20 mg/kg, and declined biexponentially thereafter. The values of AUC and T 1/2 were 70.1 micrograms eq..hr/ml and 38.0 hours, respectively. 2. Blood level of radioactivity was 59.41 micrograms eq./ml at 5 minutes after administration on the 7th day of repeated intravenous administration at a daily dose of 20 mg/kg, and declined more slowly as compared to the case of single administration. The values of AUC and T 1/2 after repeated administration were 159.7 micrograms eq..hr/ml and 44.5 hours, respectively. 3. Urinary and fecal excretion rates after single administration were 93.3% and 3.3%, respectively. 4. Urinary and fecal excretion rates were almost constant throughout the repeated administration; 88.4-90.7% and 2.3-3.7%, respectively. 5. 14C-CFPM distributed rapidly to the whole body except to the central nervous system. Although the radioactivity was removed rapidly from tissues, high levels of radioactivity remained in the kidney and the spleen as compared to other tissues. 6. Tissue concentrations of radioactivity at 5 minutes after the final dose of repeated administration were about the same as those after single administration but they declined more slowly than those after single administration. High levels of radioactivity were found in the kidney and the spleen as were found upon single administration. The ratios of these levels between repeated and single dosing were 4.3 and 2.6 for kidney and spleen, respectively. 7. Data obtained with autoradiograms of the whole body were consistent with measured tissue distribution obtained in both cases of single and repeated administration.

Animals↗
PubMed1992

[Study on the pharmacokinetics of cefepime (II)].

The pharmacokinetics of 14C-cefepime dihydrochloride (14C-CFPM), was studied in dogs after single intravenous administration at a dose of 20 mg/kg. Protein binding was also investigated both in vitro and in vivo. 1. Blood level of radioactivity was 83.53 microns eq./ml at 5 minutes after single intravenous administration and declined biexponentially thereafter. The values of AUC and T1/2 were 229 microns eq.(.)hr/ml and 90 hours, respectively. 2. Urinary and fecal excretion rates were 95.1% and 2.7%, respectively. 3. The in vitro protein binding at 1 to 100 microns/ml of drug concentration was 7.9 to 12.7% in rat, 12.4 to 18.6% in human, and 12.5 to 14.5% in dog. In vivo protein binding, which increased with time after administration, was 10.8 to 92.9% in rat and 17.5 to 64.9% in dog at 5 minutes to 6 hours.

Animals↗
PubMed1992

[An emergency surgical case of double aortic arch with hemoptysis].

A 78-year-old man was admitted because of hemoptysis. CT and aortogram revealed double aortic arch. Bronchofiberscopy revealed intratracheal hemorrhage which was associated with right aortic arch. An emergency operation was performed to prevent massive intra-tracheal bleeding. The patient underwent ligation of the right aortic arch through median sternotomy. After operation, hemoptysis disappeared and the postoperative course was uneventful. Surgical cases of double aortic arch are rare, especially with critical hemoptysis in aged patients.

Aged↗
PubMed1992

[Intra-arterial infusion chemotherapy in locally recurrent breast cancer].

Intra-arterial infusion chemotherapy (IA) using implantable reservoir was performed in four locally recurrent breast cancers. The regimen consisted of several cycles of induction (1 cycle, 90-150mg: EPI) and the following maintenance infusion. The results were as follows. (1) D.F.I. of all cases were short and pre-treatment of 3 cases was not effective. (2) Clinical response was 2 CR and 1 MR. We confirmed that IA was an effective treatment for not only locally recurrence but also disseminated foci. (3) In 3 out of the four cases there was reduction of severe arm swelling. These findings suggested that IA using implantable reservoir was useful for the treatment of locally recurrent breast cancer in terms of anti-cancer effect and improved QOL.

Adult↗
PubMed1992

[A case report of thrombosed Björk-Shiley valve in aortic position diagnosed using transtelephone PCG monitoring].

We report a successful elective re-AVR and MVR 10 years after AVR with aortic root enlargement and OMC. The patient was a 41-year-old woman. The diagnosis of thrombosed Björk-Shiley (B-S) valve was first suspected by transtelephone PCG monitoring and reconfirmed by the frequency analysis of prosthetic valve sounds and the aortography preoperatively. The thrombosis was 15 x 8 x 6.5 mm in size and located at the minor orifice of B-S valve, extending to the strut. The transtelephone PCG was useful in analyzing prosthetic valve sounds for patients especially living away from the hospital.

Adult↗
PubMed1991

Spatial-temporal appearance of developing immunoreactive TRH neurons in the neuroepithelial wall of the diencephalon.

Using an anti-pro-thyrotrophic hormone-releasing hormone (TRH) serum for immunohistochemical analysis, we examined the ontogenesis of TRH-producing neurons in the rat diencephalon, and distinguished three waves in the neurogenesis corresponding to the time and place of their origin. The first wave started on day 12.5 of embryonic age (E12.5); the neurons appeared within the neuroepithelium in both the anterior and posterior walls of the optic recess. These cells then migrated anteriorly into the marginal layer of the developing preoptic area (group 1 cells) and posteriorly into the hypothalamus (group 2 cells). The second and third waves occurred on E13.5-14.5 and E16.5-17.5, respectively. We named the cells that appeared in the neuroepithelium of the anterior portion of the hypothalamus as group 3 and 5 cells, and those in the posterior portion as group 4 and 6 cells. Group 1 and 3 cells generated the lateral and medial preoptic TRH neurons, and group 2 and 4 cells generated the cells in the lateral hypothalamic nucleus. Group 6 cells were involved in the development of the dorso-medial hypothalamic nucleus. Group 5 cells gave rise to the hypophysiotrophic secretory neurons in the parvocellular paraventricular nucleus. The cells derived from each cell group showed distinct morphological characteristics. These findings suggest that the ventricular wall of the hypothalamus is protomapped in a spatial-temporal manner to generate TRH neurons with distinct functional properties.

Amino Acid Sequence↗
PubMed1991

Anti-bilirubin monoclonal antibody. III. Preparation and properties of monoclonal antibodies to unconjugated bilirubin-IX alpha.

Anti-bilirubin-IX alpha monoclonal antibodies exclusively specific for unconjugated bilirubin-IX alpha are prepared and characterized. Using modified MBS (metamaleimidobenzoyl-N-hydroxysuccinimide ester) method, bilirubin-IX alpha was covalently coupled to bovine serum albumin (BSA) retaining its intramolecular hydrogen bonds as well as three-dimensional structure. Somatic cell fusion was performed between murine spleen cells immunized with the bilirubin-IX alpha-BSA and murine myeloma P3-X63-Ag8-U1 cells. After screening assay, 58 clones were identified which were producing antibodies not to albumin nor MBS, but to haptenic bilirubin-IX alpha. In inhibition analysis, the antibodies in the culture supernatant reacted only with bilirubin-IX alpha to a varying degree, but did not react with conjugated bilirubin-IX alpha, including bilirubin-IX alpha monoglucuronide, bilirubin-IX alpha diglucuronide, and ditauronic bilirubin-IX alpha.

Animals↗
PubMed1991

Further evidence of the presence of rat embryonic hypothalamic factors that induce the differentiation of gonadotrophic hormone-releasing hormone-containing secretory neurons.

We examined the presence of factor(s) in the embryonic medial basal hypothalamus (MBH) that may influence nasal placode (NAP)-derived luteinizing hormone-releasing hormone (LHRH) neurons in determining their secretory phenotype. In this study, we performed organotypic culture and transplantation of the NAP from 12.5-day-old embryos of rats and vomeronasal organ (VNO) from 14.5-day-old embryos. Surgical operations, however, were performed on 16.5-day-old embryos. The NAP and VNO were cultured singly or with the MBH obtained from the embryos of the same age and, further, in a medium with a nerve growth factor or fibroblast growth factors. Although LHRH neurons were derived from the NAP and VNO in all the cultures, judging from numbers and cellular morphologies, the MBH was most effective. The VNO was transplanted into the third ventricle of adult female rats singly or with the cerebral cortex, the mesencephalon-myelencephalon complex, or the MBH from 14.5-day-old embryos. All the grafts gave rise to LHRH neurons, but the number of the neurons was far greater in the grafts cotransplanted with the MBH, in which the neurons projected long processes to blood capillaries and formed neurovascular complexes, the feature of which may suggest the occurrence of the secretory activity in the fibers. The animals were examined 5 days after the surgical operations. In rhinoectomized embryos, LHRH neurons were distributed throughout the brain in the same pattern as found in intact rats, showing normal cellular morphology. In the encephalectomized rats, immunoreactive LHRH cells were present only in the terminal ganglia. These findings indicate that the embryonal MBH has a factor (s) that is essential to the development of secretory LHRH neurons.

Animals↗
PubMed1991

Developmental changes in delayed rectifier K+ currents in the muscular- and neural-type blastomere of ascidian embryos.

1. Developmental changes in the amplitude, kinetic properties, tetraethyl-ammonium (TEA) sensitivity, and ion selectivity of the delayed rectifier K+ currents were investigated in differentiating muscular-type (M) and neural-type (N) blastomeres isolated from the early cleavage-arrested ascidian embryos, using conventional two-microelectrode voltage clamp techniques. 2. No voltage-sensitive outward K+ currents were found in either type of blastomere during the first 35 h of development at 9 degrees C. Thereafter the delayed rectifier K+ current became apparent. The peak amplitude of the K+ current in the M-blastomere increased abruptly from 50 to 60 h and tended to plateau after 60 h, while in the N-blastomere it continued to increase after initial emergence at around 35 h. 3. The threshold potential level of the K+ current in the M-blastomere was initially about -10 mV in a standard external solution (1 mM-K+ solution), but shifted towards the hyperpolarized direction until it reached a steady level at 45 h after fertilization. At the fully differentiated stages, the threshold was around -32 mV and -26 mV in the M- and N-blastomeres, respectively. 4. Throughout development, the reversal potential of the tail current changed with the external K+ concentration in both M- and N-blastomeres as expected for a K(+)-electrode. There was no significant difference in the selectivity ratios for the K+ channel between the two types of blastomeres. The relative selectivities were K+ (1.000): Rb+ (0.774): NH4+ (0.122): Na+ (0.074) and K+ (1.000): Rb+ (0.724): NH4+ (0.155): Na+ (0.074) in the M- and N-blastomeres, respectively. 5. Modified Scatchard plots of TEA-sensitivity data indicated a one-to-one reaction between TEA and the K+ channel. These plots revealed the presence of TEA-resistant K+ channels in addition to TEA-sensitive K+ channels in the M-blastomere, but revealed only TEA-sensitive K+ channels in the N-blastomere. The dissociation constant (Ki) values of these three types of K+ channel did not change during development. In the M-blastomere, the Ki of the TEA-sensitive K+ channel was 1.29 +/- 0.05 mM (mean +/- S.E.M., n = 31) and that of the TEA-resistant K+ channel was 1.4 +/- 0.1 M (mean +/- S.E.M., n = 31) at a test potential of 45 mV. The Ki value of the neural-type K+ current was 1.38 +/- 0.03 mM (mean +/- S.E.M., n = 20) at 45 mV.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Expression of blood group A and B antigens in nuclear heterochromatin in mucous cells of human cervical glands.

Using a post-embedding immunogold labeling procedure, we found that monoclonal antibody against A (MAb-A) or B antigen (MAb-B) reacted with nuclear heterochromatin regions, as well as secretory granules, in mucous cells of human cervical glands. Systematic and critical observation of specimens from 24 individuals of different blood groups revealed that the labeling pattern with MAb with strictly dependent on the blood group (A,B, or O) of the donors, i.e., MAb-A reacted with the heterochromatin from blood group A and AB but not with B and O individuals. Labeling with MAb-B was also specific for the heterochromatin from blood group B donors. On the other hand, MAb against H antigen did not react with the heterochromatin from any individuals examined, despite the fact that H antigens were detected by the MAb in secretory granules. Such specific reactions provide evidence that certain types of blood group-related antigens exist in the nuclear heterochromatin in mucous cells of human cervical glands. In contrast to the secretory granules in which ABH antigens were recognized by blood group-specific lectin, heterochromatin regions had little or no affinity for these lectins. Furthermore, the secretory status of individuals affected the staining intensity with MAb in secretory granules but not in the heterochromatin. These results suggest that the blood group substances found in the heterochromatin may have different molecular properties from those in the secretory granules, although both have the same determinant structures of ABH antigens.

ABO Blood-Group System↗
PubMed1991

[Disorder of serum electrolytes following CAP therapy].

Combination chemotherapy with Cyclophosphamide, Adriamycin and Cisplatin (CAP) is one of the most effective chemotherapies for ovarian cancer. Severe vomiting induced by this treatment may cause a disorder of the serum electrolytes. Severe hyponatremia was observed in one patient who complained of convulsions and unconsciousness. Accordingly we studied the disorder of serum electrolytes in 158 courses of CAP treatment (44 patients) during the five years from 1984 to 1988. The serum electrolytes were influenced by the amount of vomiting in this study. Consequently frequent examination of serum electrolytes is necessary during this treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

[Evaluation of chest wall resection in the patients with breast cancer involving chest wall].

Twenty-three patients with advanced or recurrent breast cancer involving bony chest wall were treated by extended full-thickness chest wall resection and immediate reconstruction. The results were as follows: 1) Distant metastases were found concurrently or subsequently in more than half of the patients. Therefore, we should regard chest wall lesions as a systemic disease. 2) Long term result was encouraging, with 73.9% local control rate. 3) Post-surgical prognosis of the patients with sternal metastasis and solitary chest wall lesions were favorable, in that order. 4) Both local control rate and survival of the patients with mediastinal invasion, however, were fairly poor. 5) Disease-free interval (D.F.I.) after mastectomy longer than 5 years correlated significantly with a long survival after chest wall resection. As a result, we confirmed that chest wall resection was the treatment of choice for the patients with long D.F.I. and solitary chest wall lesion without mediastinal invasion nor metastasis, but the postoperative systemic therapy was indispensable to improve the patient's survival.

Adult↗
PubMed1991

[A case of successful surgical repair for congenital corrected transposition of the great arteries associated with Ebstein's malformation and diverticulum of atrialized ventricle].

Congenital corrected transposition of the great arteries (C-TGA) is frequently associated with VSD and PS. Systemic atrioventricular valve regurgitation is also sometimes present in patients with C-TGA. It is though that left-sided A-V valve regurgitation is caused by the deformities of the tricuspid valve (TV) or intolerance of TV and the right ventricle (RV) against systemic pressure load. We had a patient with C-TGA associated with Ebstein's malformation. The patient suffered from congestive heart failure due to left-sided A-V valve regurgitation. In this case, the septal and posterior leaflets were displaced below the atrioventricular annulus. The edges of all valves were thickened and partially calcified. Focal agenesis was found in the septal leaflet. There was a distinct atrialized ventricle which had a thin wall and no trabeculae. It shaped like a diverticulum of 3 cm in depth toward the diaphragm. Preoperative cardiac catheterization showed that the functional RV had an adequate size (RVEDVI 162% of normal) and ejection fraction was 53%. Left-sided valve replacement was performed using SJM 31M with preservation of TV. Left-sided atrioventricular annulus was so deformed due to the diverticulum that the prosthetic valve was sutured at the ventricular wall below the atrioventricular annulus to which TV had attached. Good clinical result was obtained after surgical treatment.

Diverticulum↗
PubMed1991

[Clinical significance of a tumor marker NCC-ST-439 in breast cancer--a comparative study with CA 15-3, CEA and TPA].

We compared a new tumor marker NCC-ST-439 (ST-439) with CA 15-3, CEA and TPA for its clinical usefulness in 600 patients with breast cancer (81, primary; 49, recurrent; 470, non-recurrent), and confirmed the following results. The sensitivity of ST-439 (41.5%) was significantly higher (p less than 0.05) than that of CA 15-3 (26.2%), CEA (28.5%) and TPA (26.9%). The specificity of ST-439 (84.5%), however, was considerably lower (p less than 0.01) than these other three markers. In primary cases, the positive rate of ST 439 (34.6%) was significantly higher (p less than 0.05) than that of the other markers, and was remarkable in the early stage. As to the positive rate at the various metastatic sites, there were a few differences among these four markers. Because of no significant correlation among these markers, combination assay with ST-439, CA 15-3 and CEA showed an excellent sensitivity (57.7%). These results suggest that ST-439 is a useful tumor marker not only in monitoring the recurrence, but also in the diagnosis of primary cancer.

Antigens, Tumor-Associated, Carbohydrate↗