Search PubMed⌕ Search

Biomedical subjects

Y Hirota

Publications and source records attributed to Y Hirota.

At least 145 records · Page 8Linked to original sources
PubMed1996

Comparison of the therapeutic effects of the beta-blocking agent bisoprolol and the calcium-blocking agent diltiazem in patients with heart failure due to dilated cardiomyopathy.

Beta-blocking agents reduce mortality and improve symptoms in patients with dilated cardiomyopathy (DCM). There have been reports that diltiazem, a calcium-blocking agent, is also effective in such patients. We prospectively compared the effects of the beta-blocking agent bisoprolol with those of the calcium-blocking agent diltiazem in 18 patients (11 males and 7 females, age 14 to 68) with DCM. The 18 patients, (10 in New York Heart Association functional class III and 8 in class IV) were randomly assigned to 2 groups. Bisoprolol was administered as the first drug in 10 patients and diltiazem was administered in 8. Cross-over to bisoprolol was also performed in 3 patients. At the end of the study, among the 13 patients who had been given bisoprolol, 9 showed a good response (efficacy rate: 69%). In contrast, only 3 of the 8 patients who received diltiazem showed a good response (efficacy rate: 37.5%). Among the patients in NYHA class III, all 7 (100%) who were treated with bisoprolol responded but only 2 of the 4 (50%) treated with diltiazem responded (p < 0.05). Among the patients in class IV, 2 of 6 (33%) responded to bisoprolol and 1 of 4 (25%) responded to diltiazem (not significant). These results suggest that diltiazem, like bisoprolol, has a beneficial effect in patients with DCM, with a greater effect in class III patients. However, we conclude that diltiazem should usually be used as a second choice to improve heart failure in DCM, and as the first medication only in those with contraindications to beta-blocking agents.

Adolescent↗
PubMed1996

Production and characterization of polyclonal anti-canine interleukin-8 antibodies.

Polyclonal anti-canine interleukin-8 (cIL-8) antibodies were raised in rabbits immunized with cIL-8 expressed by E. coli. Polyclonal antibodies were purified by affinity chromatography. In the enzyme linked immunosorbent assay (ELISA), the resulting anti- cIL-8 antibodies showed relatively high reactivities with cIL-8 in the fusion proteins of glutathione-S-transferase/cIL-8 (GST/cIL-8) and maltose binding protein/cIL-8 (MBP/cIL-8), but negligible ones with MBP. Furthermore, Western blotting analysis using these polyclonal antibodies showed distinct bands for cIL-8, GST/cIL-8, and MBP/cIL-8. These antibodies also bound to recombinant human IL-8 (rhIL-8) in ELISA but not in Western immunoblotting. The rHIL-8 (50-800 ng/ml) was chemoattractant for canine neutrophils in a dose dependent manner, but the anti-cIL-8 antibodies did not show the inhibitory effect on the chemotactic activity of rhIL-8 of canine neutrophils, when tested by the chemotaxis assay using Boyden chambers. In addition, GST/cIL-8 and rhIL-8 induced strong and rapid shape change responses of canine neutrophils. However, the anti-cIL-8 antibodies inhibited shape change responses induced by GST/cIL-8 but not by rhIL-8.

ATP-Binding Cassette Transporters↗
PubMed1996

Anesthetic considerations of two sisters with Beckwith-Wiedemann syndrome.

Anesthetic considerations of 21-mo-old and 4-yr-old sisters with Beckwith-Wiedemann syndrome during surgical repair of cleft palate and reduction of macroglossia are presented and discussed. This syndrome is characterized by exomphalos, macroglossia, gigantism, hypoglycemia in infancy, and many other clinical features. This syndrome is also known as exomphalos, macroglossia, and gigantism (EMG) syndrome. Principal problems associated with anesthetic management in this syndrome are hypoglycemia and macroglossia. Careful intraoperative plasma glucose monitoring is particularly important to prevent the neurologic sequelae of unrecognized hypoglycemia. It is expected that airway management would be complicated by the macroglossia, which might cause difficult bag/mask ventilation and endotracheal intubation following the induction of anesthesia and muscle paralysis, so preparations for airway difficulty (e.g., awake vocal cord inspection) should be considered before induction. A nasopharyngeal airway is useful in relieving postoperative airway obstruction.

Airway Obstruction↗
PubMed1996

The effects of the hypothalamus on hemodynamic changes elicited by vagal nerve stimulation.

To investigate the means by which neurogenic shock or syncope occur in dentistry, we determined the hemodynamic response to the activation of vagal tone in cats while they were under emotional stress. The hypothalamus and the vagal nerve were electrically stimulated to produce emotional stress and to activate vagal tone, respectively. Hemodynamic changes were recorded during vagal stimulation (Va group) and during vagal stimulation preceded by hypothalamic stimulation (AH + Va group). Although blood pressure decreased in both groups, the degree of hypotensive response in the AH + Va group was greater than the response in the Va group. Total peripheral resistance (TPR) was reduced in the AH + Va group but was increased in the Va group. The blood flow to the skeletal muscles in the AH + Va group was greater than that of the Va group. Reduced TPR, which could be due to vasodilation in the skeletal muscles, was the cause of intensified hypotension in the AH + Va group. Clearly, the hypotension produced by vagal stimulation was worsened when it was preceded by hypothalamic stimulation; this occurrence could be related to the tendency of blood to flow to the skeletal muscles.

Analysis of Variance↗
PubMed1996

[International trends in influenza control: preparing for the next pandemic and vaccination].

The prevention of influenza continues to be a major public health concern, and a program of vaccination has been promoted, especially to high-risk individuals such as the elderly. In addition, concerted efforts are being expended in many developed countries in order to better cope with the next influenza pandemic. These efforts include enhancing influenza virus surveillance, improving vaccine production and its delivery systems, centralizing vaccine distribution and establishing priorities, etc. In Japan, on the other hand, influenza is only considered a minor illness, and thus little attention has been give to measures against influenza. To disseminate information on recent international trends in influenza control to Japanese public health specialists, I herein outline the recommendations made at two recent international meetings: "Pandemic Influenza: Confronting a Reemergent Threat" held in the u.s., at Bethesda, Maryland, in December 1995; and "The 7th European Meeting of Influenza and Its Prevention" held in Berlin. Germany, in September 1993. Since a routine system capable of responding adequately to annual epidemics is considered to be the best defense against a pandemic, I also describe the present state of influenza control in other countries to contrast it with that in Japan: the target groups for special vaccination programs recommended by the U.S. Advisory Committee on Immunization Practices; the recommendations for influenza vaccination and reimbursement for the vaccination of recommended groups in developed countries: and influenza vaccine distribution in Japan and the U.S., 1980-1994. At present in Japan, the efficacy of the currently used inactivated vaccine is regarded as either very low or none at all. There is also no official national recommendations as to what groups should be targeted for active immunization, nor any system for vaccination reimbursement. Public health specialists in Japan, therefore need to fully understand Japan's peculiar situation and, as a result, better recognize the importance of influenza and its prevention.

Humans↗
PubMed1995

Adjacent upstream superhelical writhe influences an Escherichia coli promoter as measured by in vivo strength and in vitro open complex formation.

This work investigates the effect on transcription of superhelical writhe located in the region immediately upstream of the -35 consensus sequence of Escherichia coli promoters. A set of double-stranded oligonucleotides, each with an unique DNA configuration, were designed, synthesized and substituted into an area of naturally occurring right-handed superhelical curvature immediately upstream of the beta-lactamase promoter in plasmid pUC19. All the mutants showed reduced promoter activities in E. coli cells. However, rightward superhelical writhe clearly facilitated transcription when compared with the effect produced by a straight DNA segment. Leftward writhe greatly repressed transcription. A plane curve showed an intermediate effect. This phenomenon was due not only to the difference in the ability of the segment to drive an open complex formation, but also to the difference in the binding affinity of RNA polymerase to the promoter. The positive effect of rightward writhe was also observed in vivo for the promoter of the tetracycline resistance gene of pBR322. The sense and extent of superhelical writhe of a DNA curvature seem to determine its influence on promoter activity.

Ampicillin↗
PubMed1995

Empiric determination of the transition from concentric hypertrophy to congestive heart failure in essential hypertension.

OBJECTIVES: Our aim was to determine whether there is a final transition from left ventricular hypertrophy to congestive heart failure in the late stage of essential hypertension. BACKGROUND: A theoretic model using the concept of systolic transmural nonuniform wall thickening was applied to develop a concentric two-shell geometry allowing evaluation of the mechanics of circumferential midwall fibers. METHODS: We evaluated pressure-volume data from 46 normal control subjects (control group) and 70 patients with hypertension: 33 without hypertrophy (hypertension only group), 14 with hypertrophy (hypertrophy group) and 23 with heart failure in addition to hypertrophy (heart failure group). RESULTS: End-diastolic volume index was higher in the heart failure group than in the control group (p < 0.01). Although left ventricular wall thickness and mass index were increased in both the hypertrophy and the heart failure group, concentricity indexes as assessed by ratios of left ventricular wall thickness to dimension and mass index to end-diastolic volume index were maximal in the former. Although endocardial and standard midwall fractional shortening did not differ among the control, hypertension only and heart failure groups, that of the modified midwall by concentric two-shell geometry was decreased in the hypertrophy and the heart failure groups (p < 0.05). The Hotelling T2 test and Mahalanobis distance clearly discriminated the latter two groups with end-systolic stress and modified midwall fractional shortening relation. CONCLUSIONS: A fitting segmented regression model predicted a progression to hypertrophy and identified a transition from hypertrophy to heart failure by a combination of modified midwall fractional shortening and concentricity indexes.

Adult↗
PubMed1995

Long-term denopamine therapy for hemodialysis patients with chronic heart failure.

Denopamine was orally administered for more than 12 months to patients with chronic heart failure on maintenance hemodialysis. The plasma level in subjects treated with denopamine at 30 mg/day tended to be higher than that in subjects on 15 mg/day. There was no gradual increase in plasma level as the duration of therapy prolonged. Left ventricular end-diastolic and end-systolic diameters as well as ejection fraction on echocardiography showed a tendency to be improved by denopamine. Similarly, the cardiothoracic ratio was improved temporarily. No adverse effects were detected by electrocardiography and laboratory tests. These observations suggest that denopamine is safe and effective for hemodialysis patients with chronic heart failure.

Administration, Oral↗
PubMed1995

A new water-soluble camptothecin derivative, DX-8951f, exhibits potent antitumor activity against human tumors in vitro and in vivo.

CPT-11, a semisynthetic derivative of camptothecin, exhibited strong antitumor activity against lymphoma, lung cancer, colorectal cancer, gastric cancer, ovarian cancer, and cervical cancer. CPT-11 is a pro-drug that is converted to an active metabolite, SN-38, in vivo by enzymes such as carboxylesterase. We synthesized a water-soluble and non-pro-drug analog of camptothecin, DX-8951f. It showed both high in vitro potency against a series of 32 malignant cell lines and significant topoisomerase I inhibition. The anti-proliferative activity of DX-8951f, as indicated by the mean GI50 value, was about 6 and 28 times greater than that of SN-38 or SK&F 10486-A (Topotecan), respectively. These three derivatives of camptothecin showed similar patterns of differential response among 32 cell lines, that is, their spectra of in vitro cytotoxicity were almost the same. The antitumor activity of three doses of DX-8951f administered i.v. at 4-day intervals against human gastric adenocarcinoma SC-6 xenografts was greater than that of CPT-11 or SK&F 10486-A. Moreover, it overcame P-glycoprotein-mediated multi-drug resistance. These data suggest that DX-8951f has a high antitumor activity and is a potential therapeutic agent.

Animals↗
PubMed1995

Effect of administration and withdrawal of doxazosin on ambulatory blood pressure in patients with essential hypertension.

The effect of both administration and withdrawal of doxazosin on patients with essential hypertension was evaluated by twenty-four-hour ambulatory blood pressure (BP) monitoring. Six hypertensive men were treated with doxazosin starting at 1 mg/day, and the dosage was titrated at weekly intervals up to a maximum of 8 mg/day. The twenty-four-hour BP profile was monitored noninvasively before treatment, in the fourth week of treatment, and on days 2 and 7 after the discontinuation of doxazosin. The average twenty-four-hour systolic and diastolic BPs (SBP and DBP) were lowered by doxazosin treatment and returned to the pretreatment levels within two days of doxazosin withdrawal. Doxazosin treatment produced a significant decrease in the daytime SBP and DBP but not in the nighttime BP values. The daytime BP decrease was no longer detected on days 2 and 7 after drug withdrawal. The twenty-four-hour pulse rate was not influenced by either doxazosin administration or discontinuation. The plasma norepinephrine concentration and plasma renin activity were increased by doxazosin treatment and were decreased by drug withdrawal. There was no rebound hypertension following doxazosin withdrawal. Thus, the present study using twenty-four-hour BP monitoring showed that doxazosin treatment reduced the daytime BP in patients with essential hypertension and that this reduction was abolished within two days after doxazosin discontinuation.

Adult↗
PubMed1995

Effects of nicorandil on left ventricular systolic and diastolic function in patients with hypertrophic cardiomyopathy.

Various evidence suggest that myocardial ischemia is a major factor in the progression of hypertrophic cardiomyopathy (HCM). In this study, we investigated the effects of nicorandil on left ventricular (LV) systolic and diastolic function in 12 symptomatic patients with HCM using echocardiography and radionuclide angiography. Nicorandil (6 mg), when administered intravenously, produced no significant changes in any parameter, including LV filling dynamics. However, accelerated LV peak early filling velocity (0.51 +/- 0.13 to 0.59 +/- 0.14 m/sec, p < 0.01), and reduced peak velocity in atrial contraction (0.54 +/- 0.17 to 0.50 +/- 0.15 m/sec, p < 0.05) were observed by Doppler echocardiography after 4 weeks of oral administration of 10 mg nicorandil 3 times daily. This oral administration did not affect heart rate, blood pressure, LV outflow gradient, or LV systolic function. The same favorable results were observed in a wall motion analysis with radionuclide angiography: peak filling rate (PFR) in global LV (3.21 +/- 0.76 to 3.52 +/- 0.87 end-diastolic volume (EDV)/sec, p < 0.02), and apical (4.73 +/- 1.18 to 5.42 +/- 1.55 EDV/sec, p < 0.01) and lateral (4.78 +/- 1.60 to 5.52 +/- 1.51 EDV/sec, p < 0.05) segments was increased, and the time to peak filling rate (TPF) in septal (245 +/- 31 to 203 +/- 40 msec, p < 0.01) and lateral (222 +/- 54 to 193 +/- 34 msec, p < 0.05) segments was reduced. These findings indicate that nicorandil has beneficial effects on LV diastolic function in HCM. These favorable effects may be due to the improvement of subendocardial ischemia.

Adult↗
PubMed1995

Effects of 6-Hydroxydopamine on the antibody response to the hapten dinitrophenyl in the chicken.

Antibody responses to the hapten dinitrophenyl (DNP) and the concentration of catecholamine in chickens received a single injection of 6-Hydroxydopamine (6-OHDA) into the chorioallantoic cavity at the embryonal stage were evaluated. A significantly enhanced anti-DNP IgA response and a markedly decreased level of noradrenaline in the peripheral blood were observed in chickens treated with 400 micrograms of 6-OHDA at 14 days of incubation. These results suggested the immunomodulatory influence of the sympathetic nervous system.

2,4-Dinitrophenol↗
PubMed1995

Flow cytometric analysis and immunohistochemistry of delayed-type hypersensitivity responses in mice immunized with rat hepatocytes.

Delayed-type hypersensitivity (DTH) responses to rat hepatocytes (HCs) in mice were investigated by flow cytometric analysis and immunohistochemistry with monoclonal antibodies directed against murine class II, CD4, and CD8 antigens. Mice were immunized subcutaneously (s.c.) with 10(6) rat HCs (referred to as s.c.-immunized mice), and control mice were injected s.c. with sterile Hanks' solution (non-immunized mice). Four days later, 10(5) rat HCs were injected into the footpad of s.c.-immunized mice and non-immunized mice. The DTH response in s.c.-immunized mice significantly increased after challenge when compared to that in non-immunized mice. The numbers of class II+, CD4+, and CD8+ cells in the footpad, and CD4+ and CD8+ cells in the inguinal lymph node of s.c.-immunized mice significantly increased during the DTH response. An increase in the number of CD4+ cells in the footpad of s.c.-immunized mice after challenge was more significant than that of non-immunized mice. The number of CD4+ cells increased more markedly in the footpad of s.c.-immunized mice as compared to that of CD8+ cells. Furthermore, immunohistochemical studies of the footpad of s.c.-immunized mice showed more severe infiltration of CD4+ cells rather than CD8+ cells at the injection site of rat HCs. These results suggest that the DTH response in the footpad of mice immunized with rat HCs is associated with severe infiltration of CD4+ cells.

Animals↗
PubMed1995

Detection of the chemotactic factor for canine peripheral blood mononuclear cells and polymorphonuclear cells in the culture supernatant of Cos7 cells transfected with canine interleukin-8 cDNA.

Chemotactic activities in the culture supernatants of Cos7 cells transfected with a cloned canine IL-8 cDNA (pcIL-8SR alpha 14) were evaluated by using mononuclear cells (MNC) and polymorphonuclear cells (PMN) from the peripheral blood of dogs. The culture supernatants of Cos7 cells were collected 66 hr after the transfection of pcIL-8SR alpha 14 (Cos7/cIL-8). Chemotactic activities in the culture supernatants for MNC and PMN were determined as migration distances in Millipore membrane filters in a modified Boyden's chamber method. Peroxidase staining for MNC was effective not only for cells in cytospun smears but also for cells migrated in the filters. PMN in cytospun smears were well stained by peroxidase staining, whereas migrated PMN in the filters were stained weakly. Chemotactic activities in the culture supernatant of Cos7/cIL-8 cells for both MNC and PMN were significantly higher than those of control Cos7 cells. In addition, the culture supernatant of Cos7/cIL-8 cells was chemotactic for peroxidase negative nonadherent MNC (lymphocytes), but not for peroxidase positive adherent MNC (monocytes). This Cos7/cIL-8 supernatant also showed chemotactic activities for neutrophils in a dose dependent manner. These results suggest that the culture supernatant of Cos7/cIL-8 is chemotactic for lymphocytes as well as for neutrophils.

Animals↗
PubMed1995

Enhancing effects of chicken egg white derivatives on the phagocytic response in the dog.

Immunostimulative effects of chicken egg white derivatives (EWD) on phagocytic responses of peripheral blood mononuclear cells (MNC) and polymorphonuclear cells (PMN) in dogs were evaluated by flow cytometric analysis. Peripheral blood leukocytes (PBL) cultured with EWD showed the enhanced phagocytic response. The response was maximal when PBL were cultured with 100 - 400 micrograms/ml of EWD for 3 - 12 hr. Furthermore, significantly increased phagocytic responses were also induced even when PBL were cultured with protein components (200 micrograms/ml) of EWD such as conalbumin, flavoprotein and ficin-papain inhibitor for 3 hr. In addition, the enhancing effect of EWD on the phagocytic responses was also observed in MNC cultured with EWD (200 micrograms/ml) for 4 hr but not in PMN cultured with EWD in the same procedures. The supplement of the supernatant (20%) of MNC cultured with EWD (200 micrograms/ml) for 24 hr at 37 degrees C to PBL and MNC resulted in the enhancement of their phagocytic responses. In contrast, the supernatant of PMN cultured with EWD for 24 hr at 37 degrees C did not show any significant enhancing effect on the phagocytic responses of PBL, MNC and PMN. These results suggest that EWD has an enhancing effect on phagocytosis of MNC and PMN, which may be mediated through active humoral substances produced by EWD-stimulated MNC.

Adjuvants, Immunologic↗
PubMed1995

Establishment of a bovine macrophage cell line from a fetal thymus.

A cell line, FBM-17, was established from a fetal bovine thymus and passaged for more than a year. Electron microscopic examination revealed that the cytoplasm contained many phagosomes and a significant amount of rough endoplasmic reticula. In addition, FBM-17 cells showed non-specific esterase, phagocytosis and surface expression of Fc receptors for IgG and classes I and II MHC antigens. These observations confirmed that this cell line had the morphologic and functional features as a macrophage. MHC expression markedly increased by treatment with recombinant bovine gamma-interferon, showing the cell line to be sensitive to bovine gamma-interferon and functional. These present results suggest that the FBM-17 is a functional bovine macrophage cell line. This line gamma-interferon, showing the cell line to be useful for clarification of roles of macrophages in immunoregulation in cattle.

Animals↗
PubMed1995

[Characterization of intraoperative rupture of epithelial ovarian cancer at early stage].

OBJECTIVE: To investigate whether intraoperative rupture of epithelial ovarian cancer. influences the prognosis. METHODS: Between 1984 and 1994, 46 patients with stage Ia and Ic epithelial ovarian cancer were treated at Oita Medical University Hospital. Of 46 patients, 20 had stage Ia tumors, 16 stage Ic secondary to capsular invasion-serosal disease or positive ascites or washings (stage Ic-ascites), and 10 stage Ic secondary to intraoperative rupture (Ic-rupture). Survival analysis was performed to compare the three groups of patients. RESULTS: The ages (mean +/- SD) of patients with stage Ia, Ic-ascites and Ic-rupture at the first diagnosis were 40.1 +/- 17.0, 47.6 +/- 13.4 and 52.8 +/- 15.7, respectively. The age of the stage Ia group tended to be lower than those of the Ic-ascites and Ic-rupture groups. At operation, ovarian tumors of all patients in the Ic-rupture group were firmly adhered to surrounding organs, had markedly thin weak cyst walls and were easily ruptured during operation. Fourteen of 20 patients in the Ia group (70%), 5 of 16 patients in the Ic-ascites group (31.3%) and 3 of 10 patients in the Ic-rupture group (30%) showed signs of mucinous cystadenocarcinoma. The incidence of mucinous cystadenocarcinoma in Ia group was significantly lower than in the Ic-ascites (p < 0.025, chi 2-test) and Ic-rupture (p < 0.05, chi 2-test) groups. The Kaplan-Meier survival plot for stage Ia, Ic-ascites and Ic-rupture patients revealed a probability of 5-year survival of 100%, 87.5% and 63.5%, respectively. The probability of 5-year survival in the Ic-rupture group tended to be lower than that in other groups. CONCLUSIONS: The results of our study suggest that intraoperative rupture of a malignant ovarian cystic tumor may worsen the prognosis of patients with the FIGO stage I epithelial ovarian cancer.

Adolescent↗