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Biomedical subjects

Y Honda

Publications and source records attributed to Y Honda.

At least 307 records · Page 17Linked to original sources
PubMed1997

Captopril reduced plasminogen activator inhibitor activity in patients with acute myocardial infarction.

Recent clinical trials have demonstrated that the administration of angiotensin-converting enzyme (ACE) inhibitors to patients with myocardial infarction reduces the incidence of recurrent myocardial infarction. It has also been reported that an elevated level of plasminogen activator inhibitor (PAI) appears to constitute a marker of the risk of recurrent coronary thrombosis. To determine whether the ACE inhibitor captopril reduces plasma PAI inhibitor activity, we measured changes in plasma PAI activity (IU/ml), tissue plasminogen activator (t-PA) antigen (ng/ml), and serum ACE activity (IU/L) in 14 survivors of myocardial infarction receiving captopril therapy (37.5 mg daily) and compared them with the values in 15 placebo-treated patients chosen at random. Blood sampling was performed at 07.00 h. In the captopril-treated group, serum ACE activity decreased significantly, from 14.0 +/- 0.8 to 11.5 +/- 1.2 IU/L 24 h after captopril therapy (p < 0.01), and those of PAI activity and t-PA antigen also decreased significantly-from 11.9 +/- 2.8 to 5.5 +/- 2.2 IU/ml (p < 0.02) and from 9.9 +/- 1.0 to 7.5 +/- 0.9 ng/ml (p < 0.05), respectively 48 h after captopril therapy. However, the levels of ACE activity, PAI activity, and t-PA antigen remained unchanged during the study period in the placebo group. Thus, our data indicate that the administration of captopril to patients with acute myocardial infarction may result in a reduced frequency of recurrent coronary thrombosis by increasing fibrinolytic capacity.

Aged↗
PubMed1997

Acute left ventricular dysfunction and left ventricular thrombus in a patient with cerebral hemorrhage.

A 66-year-old woman was admitted to the hospital with a cerebral hemorrhage. An echocardiogram showed severe left ventricular hypokinesis and a left ventricular thrombus. An electrocardiogram showed ST segment elevation in the precordial leads. The patient's creatine kinase level was elevated. A follow-up echocardiogram performed 1 month after admission showed normalization of left ventricular wall motion and disappearance of the thrombus. The results of thallium myocardial scintigraphy, coronary arteriography, and left ventriculography performed 1 month after admission were normal, and the patient was discharged without clinical sequelae. The cause of the patient's left ventricular dysfunction was believed to be not myocardial infarction or myocarditis, but a massive adrenergic discharge due to the cerebral hemorrhage.

Aged↗
PubMed1997

Effects of exposure to hypobaric-hypoxia on body weight, muscular and hematological characteristics, and work performance in rats.

The metabolic activities of skeletal muscles were studied in male rats exposed to hypobaric-hypoxia at about 550 Torr for 8 h per day for 2 weeks. Rats were divided into three groups; control (normoxic control), diurnal hypoxic (DH) exposure, and nocturnal hypoxic (NH) exposure groups. The changes in body weight and daily diet intake of the NH group were lower than the other groups (p < 0.01). The weights of fat in the abdominal cavity of both NH and DH groups were less than that of the control group. The red blood cell count, hemoglobin concentration, and hematocrit values were significantly increased in the hypoxic groups. The plasma glucose level in the NH group was significantly less than the control group (p < 0.05). The lactate dehydrogenase/citrate synthase (LDH/CS) activity ratios in the skeletal muscle tended to be lower in both hypoxic groups than in the control group. The swimming times to exhaustion at mild and high intensities that were measured after 2 weeks, loaded with a weight equivalent to 2.5% of the body weight, improved in the DH group. There were insignificant differences in the metabolic activity of skeletal muscles and blood characteristics between the NH and DH groups, but endurance swimming times in the DH group tended to be improved as compared to the NH group. We conclude that the DH group became competent in endurance work, which is believed to be driven from the combined effects of increased O2 transport capacity of the blood and enhanced O2 utilization capability by mitochondrial enzyme activity.

Animals↗
PubMed1997

Short-latency somatosensory evoked potentials in patients with brain stem tumor: study of N20 and N18 potentials.

Short-latency somatosensory evoked potentials (SSEPs) elicited by median nerve stimulation were studied in 17 patients with brain stem tumor. A total of 35 SSEP records were obtained and classified into five groups: 13 in Group I, central conduction time (CCT) < 7.56 msec (within the normal limits); eight in Group II, CCT > or = 7.56 msec; nine in Group III, N20 potential was abolished; four in Group IV, N20 and N18 potentials were abolished; and one in Group V, N20, N18, and P14 potentials were abolished. These SSEP groups were correlated with the size and location of the brain stem tumor on magnetic resonance images. N20 potentials were unchanged in latency in patients with small localized gadolinium (Gd)-enhanced lesions. In contrast, the N20 potentials were abolished in patients with tumors extending to the dorsal pons and the upper medulla oblongata. The extent of nonenhanced low-intensity lesion did not correlate with the changes of the N20 potentials. The degree of the impairment of the N20 potentials reflected the severity of the clinical symptoms. The N20 potential can evaluate brain stem dysfunction caused by brain stem tumor. The N18 potentials were abolished in four patients, in whom the tumor extension (one Gd-enhanced lesion, three low-intensity lesions) involved not only the pons but also the medulla oblongata. Therefore, the N18 potentials are probably generated from the medulla oblongata.

Adolescent↗
PubMed1997

Hemifacial spasm resulting from facial nerve compression near the internal acoustic meatus--case report.

A 61-year-old female presented with a rare case of hemifacial spasm (HFS) resulting from facial nerve compression near the internal acoustic meatus. She underwent a first surgery for microvascular decompression at the root entry zone of the facial nerve, but this did not achieve resolution of the HFS. During the second surgery, the meatal loop of the anterior inferior cerebellar artery (AICA) was found to be the offending artery near the internal acoustic meatus. When the AICA was dissected and separated from the facial nerve, abnormal muscle responses of the mentalis muscle due to electrical stimulation of the zygomatic branch of the facial nerve were abolished. Following surgery the patient was completely free of the HFS.

Decompression, Surgical↗
PubMed1997

The anti-inflammatory effects of ketoprofen in animal experiments.

The authors investigated the anti-inflammatory actions of ketoprofen using a battery of tests: in the rat paw oedema test induced by five different inciters, in the capillary permeability test, and in measuring the interleukin-8 (IL-8) production and superoxide dismutase (SOD) activity. The findings in these studies show that ketoprofen inhibits rat paw oedema, suppresses capillary permeability, reduces IL-8 production and increases SOD activity in the acetic-acid-induced inflammatory state. These results would seem to provide a clear rationale for exploring the usefulness of ketoprofen in the treatment of acute and chronic inflammatory diseases.

Acetic Acid↗
PubMed1997

Prednisolone, platelet-activating factor receptor antagonist, or superoxide dismutase reduced leukocyte entrapment induced by interferon alpha in retinal microcirculation.

PURPOSE: Interferon (IFN) alpha has been suggested as a possible treatment for choroidal neovascularization. However, the pathogenesis of retinal complications after IFN therapy still is unknown. Previously, we have shown that IFN alpha induced leukocyte entrapment in retinal microcirculation. The current study was designed to determine if leukocyte entrapment can be reduced by the agents that modulate leukocyte-endothelial adherence. METHODS: Interferon alpha was administered intravenously in rats. Simultaneously, prednisolone (PSL), platelet-activating factor receptor antagonist (CV-6209), or superoxide dismutase (SOD) was given to the rats. Leukocyte dynamics were observed with acridine orange (AO) digital fluorography, which uses a nuclear fluorescent dye of AO and scanning laser ophthalmoscopy. The number of trapped leukocytes in each group was assessed with a personal computer-based image analysis. RESULTS: Interferon alpha induced leukocyte entrapment in retinal microcirculation and increased leukocyte adherence to the vessel walls. The simultaneous administration of PSL, CV-6209, or SOD inhibited leukocyte adherence to the venous walls and significantly reduced the number of trapped leukocytes. CONCLUSIONS: Acridine orange digital fluorography was helpful to quantitate leukocyte-endothelial interactions in retinal microcirculation. The results suggested that increased leukocyte adherence after IFN alpha administration was reduced significantly by PSL, CV-6209, or SOD. These agents may be useful to prevent IFN-induced microcirculatory disturbances.

Acridine Orange↗
PubMed1997

Protective effects of methylcobalamin, a vitamin B12 analog, against glutamate-induced neurotoxicity in retinal cell culture.

PURPOSE: To examine the effects of methylcobalamin on glutamate-induced neurotoxicity in the cultured retinal neurons. METHODS: Primary cultures obtained from the fetal rat retina (gestation days 16 to 19) were used for the experiment. The neurotoxicity was assessed quantitatively using the trypan blue exclusion method. RESULTS: Glutamate neurotoxicity was prevented by chronic exposure to methylcobalamin and S-adenosylmethionine (SAM), which is formed in the metabolic pathway of methylcobalamin. Chronic exposure to methylcobalamin and SAM also inhibited the neurotoxicity induced by sodium nitroprusside that release nitric oxide. By contrast, acute exposure to methylcobalamin did not protect retinal neurons against glutamate neurotoxicity. CONCLUSIONS: Chronic administration of methylcobalamin protects cultured retinal neurons against N-methyl-D-aspartate-receptor-mediated glutamate neurotoxicity, probably by altering the membrane properties through SAM-mediated methylation.

Animals↗
PubMed1997

Early detection of left atrial thrombus in acute cardiogenic cerebral embolism by transesophageal echocardiography.

Re-embolization tends to occur during the first 14 days after the onset of cardiogenic cerebral embolism. The usefulness of early transesophageal echocardiography (TEE) was investigated in 64 patients (33 men and 31 women, mean [+/-SD] age 70.1 +/- 12.6 years) who underwent TEE within 30 days of the onset of cardiogenic cerebral embolism. Patients were retrospectively classified into two groups based on the time from the onset of the embolism to performance of TEE: group A consisted of 33 who underwent TEE within 4 days of the onset and group B consisted of 31 who underwent TEE 5 to 30 days after the onset. Transthoracic echocardiography visualized a left atrial thrombus in two patients, and TEE detected thrombi in 14 patients: 11 in group A and 3 in group B. Lethal re-embolization occurred in two patients in group A who had highly mobile thrombi. Early TEE may be useful for detecting left atrial thrombi and predicting the risk of re-embolization in patients with acute cardiogenic cerebral embolism.

Acute Disease↗
PubMed1997

[A case of meningioma of the jugular foramen without disturbance of lower cranial nerves].

We report a case of meningioma with extracranial extension via the jugular foramen not accompanied by any disturbances of the lower cranial nerves. A 32-year-old female suffered from a headache without any other neurological abnormalities. She had no particular family or past history. The extracranial extending meningioma was removed at the first operation. The meningioma of the jugular foramen was removed at the second staged operation by transcondylar approach. A meningioma of the jugular foramen is rare, and the meningioma with extracranial extension via the jugular foramen without showing disturbances of lower cranial nerves has not been reported so far.

Adult↗
PubMed1997

Surgical reconstruction for angle-closure glaucoma due to a flat anterior chamber following trabeculectomy.

In cases in which filtration surgery such as trabeculectomy is necessary, a flat anterior chamber postoperatively due to overfiltration may cause severe problems in the control of intraocular pressure. Once a broad synechia has formed between the iris and the corneal endothelium, this type of refractory, surgically induced angle closure can be difficult to manage. This article details a case of refractory angle-closure glaucoma secondary to a flat anterior chamber following trabeculectomy. Multiple surgical treatments were performed to control intraocular pressure and to reconstruct the anterior segment of the eye.

Anterior Chamber↗
PubMed1997

Role of P-selectin in endotoxin-induced uveitis.

PURPOSE: P-selectin is one of the early-reactive adhesion molecules that play a part in the rolling phase of leukocytes in cellular infiltration. The study objective was to determine whether P-selectin is involved in the development of endotoxin-induced uveitis (EIU). METHODS: Endotoxin-induced uveitis was initiated in male Lewis rats by injecting 200 micrograms lipopolysaccharide (LPS) into the foot pad. Expression of P-selectin in the iris-ciliary body was studied by immunohistochemistry using wholemounts and paraffin embedded sections of iris-ciliary body prepared at various time intervals. A monoclonal antibody (mAb) against P-selectin and a ligand for P-selectin, sialyl Lewis X oligosaccharide (SLeX-OS), was intravenously injected to evaluate the effects of selectin inhibition. The effect of treatment was evaluated by the number of infiltrated cells and protein concentration in the aqueous humor at 24 hours after LPS treatment. RESULTS: P-selectin immunoreactivities were observed in the vessels of the iris in whole iris-ciliary body mounts and on the surface of the microvascular endothelium in paraffin-embedded sections. Activity was most prominent at 15 minutes and at 5 to 7 hours after LPS treatment and was moderate from 1 to 4 hours after treatment. The selective inhibition of P-selectin significantly blocked the cellular infiltration into aqueous humor, but this infiltration was even more effectively inhibited by SLeX-OS. Protein concentration in the aqueous humor was not inhibited by selectin as much as was cellular infiltration. CONCLUSIONS: In the early phase of EIU, P-selectin may be expressed on the vascular endothelium in the iris in a biphasic pattern that modulates the rolling phase of leukocytes. The expression of this molecule may be essential for succeeding processes of cellular infiltration and may determine the subsequent states of ocular inflammation.

Animals↗
PubMed1997

[Coronary microvascular dysfunction in coronary artery disease associated with glucose intolerance].

Coronary flow reserve is used as an indicator to assess coronary microvascular function in the absence of obstructive coronary atherosclerosis. Diabetic patients, even with angiographically normal coronary arteries, show significantly reduced coronary flow reserve. This study evaluated coronary microcirculation in coronary artery disease complicated by glucose intolerance. Thirty-three patients with coronary artery disease were divided into three groups: Fourteen patients without glucose intolerance (control group), 8 with impaired glucose tolerance (IGT group), and 11 with noninsulin dependent diabetes mellitus (DM group). A Doppler guide wire was used to measure phasic coronary blood flow velocity in the left anterior descending artery without significant stenosis (> or = 40% diameter narrowing). Coronary flow reserve was determined by intracoronary 10 mg papaverine hydrochloride administration which induced maximal hyperemia. Coronary flow reserve was decreased in the DM group compared with the control group (2.1 +/- 0.6 vs. 3.1 +/- 0.9, p = 0.004), and that in the IGT group (2.5 +/- 0.9) did not show a significant difference compared with the other two groups. Vessel characteristics, such as infarct- or noninfarct-related artery and previous coronary angioplasty, did not have an influence on the results. Other coronary risk factors, left ventricular function, and hemodynamic findings were comparable in the three groups. This study demonstrates that diabetes mellitus may cause functional microvascular abnormalities in coronary artery disease.

Aged↗
PubMed1997

Trabeculotomy combined with phacoemulsification and implantation of an intraocular lens for the treatment of primary open-angle glaucoma and coexisting cataract.

BACKGROUND AND OBJECTIVE: The authors previously reported the usefulness of trabeculotomy ab externo for the treatment of primary open-angle glaucoma in adult patients. In an attempt to elucidate the long-term risk-to-benefit ratio of this surgical modality in combination with cataract surgery, the authors conducted a retrospective study of the surgical effects and complications of a triple procedure: phacoemulsification, implantation (of an intraocular lens), and trabeculotomy (PIT). PATIENTS AND METHODS: The authors conducted a retrospective study of patients treated with PIT at multiple hospitals. Intraocular pressure (IOP) and visual function data were obtained from patients after PIT as an initial surgical treatment in cases where antiglaucoma medications failed to resolve uncontrolled IOP (higher than 21 mm Hg). Included in this study were 96 eyes of 64 patients with primary open-angle glaucoma and coexisting cataract. The mean follow-up period was 22.6 +/- 14.7 months (range 3-56 months). RESULTS: In 94 (98%) of the 96 eyes, the IOP was well controlled, having achieved a level of 21 mm Hg or lower at the final examinations. The mean preoperative IOP of the 33 eyes that underwent the triple procedure using a single flap method (PIT-I) was 24.3 +/- 3.9 mm Hg, with an average of 2.1 +/- 1.1 medications. At the final examinations, the mean IOP had dropped to 16.0 +/- 1.2 mm Hg, with an average of 1.2 +/- 1.2 medications. The mean preoperative IOP of the 63 eyes that underwent the triple procedure using a double flap method (PIT-II) was 26.2 +/- 6.2 mm Hg, with an average of 1.9 +/- 1.2 medications. At the final examination, the mean IOP for this group was 15.6 +/- 2.9 mm Hg, with an average of 1.0 +/- 0.9 medications. CONCLUSION: The long-term results from this multicenter study showed that the triple procedure, PIT, can be useful and effective as an initial surgical treatment for open-angle glaucoma in glaucoma patients with coexisting cataract.

Adult↗
PubMed1997

Pharmacokinetic study on acetaminophen: interaction with a Chinese medicine.

To know the influences of a Chinese traditional medicine (KAKKONTO) on the metabolism of acetaminophen (APAP), we have carried out pharmacokinetic studies on APAP under KAKKONTO coadministration in humans and rats. In humans, the pharmacokinetic parameters were calculated from the blood APAP concentration-time curves of each volunteer. The parameters did not show any significant differences between the KAKKONTO-coadministration group (group K) and the APAP-administration group (group A). KAKKONTO, when given at two different doses, did not show any significant effects on blood APAP level. In rats, the blood APAP level was significantly higher than that of group A (p < 0.01) only in the 100 mg/kg of group K at 0.25 h after APAP administration. There were no other significant differences.

Acetaminophen↗
PubMed1997

Fluorophotometric quantitation of oxidative stress in the retina in vivo.

PURPOSE: To establish a new fluorophotometric method to quantitate oxidative stress in the retina in vivo with a hydrogen peroxide (H2O2)-sensitive fluorescent dye. METHODS: For in vitro fluorophotometric study, nonfluorescent 2',7'-dichlorofluorescein (DCFH) was incubated with H2O2 (10 pM to 100 nM), and the production of fluorescent 2',7'-dichlorofluorescein (DCF) was measured with fluorophotometric analysis. The inhibitory effect of catalase was also examined. For in vivo fluorophotometric study, rabbit eyes received vitrectomy and were perfused with 5 microM 2',7'-dichlorofluorescein diacetate (DCF-DA) or 2',7'-dichlorofluorescein diacetate (DCFH-DA). For oxidative stress, 300 microM H2O2 was infused after perfusion of DCFH-DA. Fluorophotometric measurements of the chorioretinal peak were performed. The eyes were enucleated for fluorescent microscopic examination to determine the localization of DCF fluorescence. RESULTS: H2O2 converted DCFH to DCF in a dose-dependent manner, which was inhibited by catalase dose dependently. In vivo fluorophotometric study showed DCF-DA and DCFH-DA caused production of 2006 +/- 274 picomole/ml (mean +/- SD, n = 5) and 8.35 +/- 1.11 picomole/ml (n = 5), respectively, in the chorioretinal peak. DCFH-DA with stimulation by H2O2 induced 30.7 +/- 13.1 (n = 4) picomole/ml DCF. Fluorescent microscopy showed DCF production in the retina was significant in the eye treated with DCF-DA and minimal in the eye treated with DCFH-DA. Moderate DCF production in the nerve fiber layer was observed in the eye treated with DCFH-DA and H2O2. CONCLUSIONS: This new fluorophotometric method with DCFH-DA may be useful in quantitatively evaluating oxidative stress in the retina in vivo.

Animals↗