Biomedical subjects

Y Koike

Publications and source records attributed to Y Koike.

At least 91 records · Page 5Linked to original sources

PubMed1998

Control of upright standing posture during low-frequency linear oscillation.

We examined the effects of anteroposterior movement of a sled on human upright standing. Each of six healthy men stood on the platform of a sled in the dark. The sinusoidal acceleration was provided, from 0.02 to 0.04 G, followed by 0.06 and 0.08 G, at a stroke length from 6 to 10 m and then to 14 m. Low acceleration (0.02 and 0.04 G) induced body sway, pivoting on the ankle joint. High acceleration (0.06 and 0.08 G) increased body sway, but the head-neck joint remained locked upright. The electromyographic recordings of the lower leg muscles revealed continuous tonic EMG activities of the gastrocnemius and tibialis anterior muscles at acceleration of 0.02 and 0.04 G, while reciprocal activation was observed at 0.06 and 0.08 G. During head movement, the neck muscles were slightly activated tonically at acceleration of 0.02 and 0.04 G, but they were markedly and tonically activated at 0.06 and 0.08 G. We speculate that the sled oscillation caused body sway in proportion to the acceleration, with the ankle joint playing a principal role. Analysis of neck movement also revealed that the head was held in a fixed upright position, indicating that the vestibulocollic reflex might tonically activate the neck muscles.

Acceleration↗

PubMed1998

Enhancing activity of mycobacterial cell-derived adjuvants on immunogenicity of recombinant human hepatitis B virus vaccine.

In a previous study, we demonstrated that a lipophilic derivative of muramyl dipeptide [MDP-Lys(L18)] augmented antibody response to recombinant human hepatitis B surface antigen (rhHBsAg) when it was co-immunized with rhHBsAg solubilized in PBS. Here, we examined adjuvant activity of two bacterial cell-derived adjuvants such as Bacillus Calmette-Guérin cell wall skeleton (BCG-CWS) and trehalose-6,6'-dimycolate (TDM), to enhance immunogenicity of rhHBsAg, comparing their activity with that of MDP-Lys(L18). In an animal model where mice were immunized subcutaneously (s.c.) with rhHBsAg (25 micrograms/mouse) admixed with 100 micrograms/mouse of BCG-CWS (Vac/BCG-CWS) or 50 micrograms/mouse of TDM (Vac/TDM) in o/w emulsion formulation, both mice immunized with Vac/BCG-CWS and Vac/TDM showed higher antibody titres to HB antigen than those of mice immunized with the recombinant vaccine alone. The activity of BCG-CWS and TDM to enhance antibody induction seemed to be almost the same with that of MDP-Lys(L18). Furthermore, the enhanced antibody response raised by these adjuvants was shown to be due to high titres of HB antigen-specific IgG1. In addition, the activity of these three adjuvants to enhance antibody response was shown to be higher than that of the present clinical vaccine, aluminium hydroxide-attached rhHBsAg (rhHBsAg-alum). In an analysis of delayed-type hypersensitivity (DTH) reaction where mice were immunized with rhHBsAg admixed with or without each adjuvant in o/w emulsion and followed by intrafootpad (i.f.) injection of rhHBsAg 4 weeks after immunization, mice immunized with Vac/BCG-CWS and Vac/TDM as well as Vac/MDP-Lys(L18) showed a significant increment of swelling reaction. These results suggest that BCG-CWS, TDM and MDP-Lys(L18) are potential adjuvants to enhance the immunogenicity of rhHBsAg to induce humoral and cellular responses.

Acetylmuramyl-Alanyl-Isoglutamine↗

PubMed1998

Endoscopic papillary balloon dilation for the management of common bile duct stones: experience of 226 cases.

BACKGROUND AND STUDY AIMS: Endoscopic sphincterotomy is a widely accepted technique for the treatment of patients with common bile duct stones. However, it is still associated with occasional complications. The recently developed technique of endoscopic papillary balloon dilation seems to be a safe and effective procedure, and to have great potential for replacing endoscopic sphincterotomy. However, few reports have been published on the use of this technique for bile duct stones. The present study was undertaken to evaluate its safety and efficacy. PATIENTS AND METHODS: Endoscopic papillary balloon dilation was used to remove common bile duct stones in 226 consecutive patients including 41 patients of ASA classification III/IV, 41 elderly patients (> 80 years) 24 with liver cirrhosis, and 86 with periampullary diverticulum. After dilation of the papilla with a balloon diameter of 8 mm, the stones were retrieved. RESULTS: In conjunction with the use of a mechanical or/and electrohydraulic lithotriptor in 79 patients (35%) with large stones (> 10 mm in diameter), clearance of the common bile duct was achieved in 225 of 226 patients (99%) without serious complications, such as hemorrhage or severe pancreatitis; mild (n = 13) or moderate (n = 2) pancreatitis occurred in 7% of cases. CONCLUSIONS: Endoscopic papillary balloon dilation is a safe and effective technique for the treatment of common bile duct stones, even in high-risk patients.

Adult↗

PubMed1998

Digoxin-like immunoreactive substance in the elderly patient and its impact on the TDx digoxin assay.

This study was undertaken to examine the impact of endogenous digoxin-like immunoreactive substance (DLIS) on the therapeutic drug monitoring of digoxin in elderly patients. Serum digoxin concentrations were detected by TDx digoxin assay in 220 patients 65 years of age and older who were not administered cardiac glycosides, spironolactone, or canrenone. The influence of clinical factors and laboratory parameters on the presence of DLIS was also evaluated. The concentration of DLIS averaged .07 ng/ml (range, 0-0.74 ng/ml), and in 25 subjects DLIS was observed over the detection limit of the assay. None of the parameters demonstrated a significant contribution to the presence of DLIS except one: continuous intravenous drip infusion therapy with a sodium-containing solution (DIV). The frequency of DLIS was significantly higher in the elderly subjects than in 121 control subjects younger than 35 years of age (p = 0.01). However, the difference became insignificant when subjects administered DIV were excluded from the analysis (p = 0.15). It was suggested that DIV may be clinically important in indicating the presence of DLIS.

Adult↗

PubMed1998

Evaluation of thrombopoiesis in thrombocytopenic disorders by simultaneous measurement of reticulated platelets of whole blood and serum thrombopoietin concentrations.

To evaluate thrombopoiesis in thrombocytopenic disorders, we simultaneously determined reticulated platelet counts in whole blood by FACScan flow cytometry and serum thrombopoietin (TPO) concentrations by a sensitive sandwich ELISA. The subjects were 40 healthy volunteers and 45 thrombocytopenic patients. In idiopathic thrombocytopenic purpura (ITP), the percentage of reticulated platelets was significantly elevated (5.61 +/- 2.02%: mean +/- SD) relative to normal controls (2.17 +/- 0.90%), but serum TPO concentrations (1.91 +/- 1.27 fmol/l) did not differ significantly from the normal range (1.43 +/- 0.62 fmol/l). The patients with aplastic anemia (AA) had decreased reticulated platelet counts and markedly increased serum TPO concentrations (13.65 +/- 10.64 fmol/l). In thrombocytopenic patients with liver cirrhosis (LC), the absolute number of reticulated platelets (1.65 +/- 1.11 x 10(9)/l) decreased similarly that in AA. However, serum TPO concentrations (1.38 +/- 0.50 fmol/l) did not increase in contrast to AA. Our findings suggested a possible dual mechanism of thrombocytopenia in LC; that is, thrombocytopenia in LC results from the decreased TPO production primarily in the liver adding to an increase in platelet sequestration in the spleen.

Anemia, Aplastic↗

PubMed1998

Pharmacokinetic characteristics of cisapride in elderly patients.

We demonstrated pharmacokinetic characteristics of cisapride in elderly patients (85+/-6 years) who had suffered from constipation based on intestinal motility dysfunction. After a single p.o. dose of 2.5 mg cisapride tablet on the first day, plasma unchanged cisapride concentrations were detected at 9 points within 24 hours, using high-performance liquid chromatography method. Subsequently, the patients were treated with cisapride 3 times daily during next 26 days (from the day 2 to the day 27). On the 28th day, a cisapride tablet was given once in the morning and blood samples were obtained with the same procedure as that on day 1. The obtained elimination half-life averaged 21.8+/-10.6 hours, which seems to be considerably longer than those previously reported. The area under the time-concentration curve (AUC) on the day 28 was 2.7 times larger than AUC on the day 1, suggesting that plasma cisapride concentrations can become higher than expected by physicians when given 3 times daily to extremely elderly patients. Because cisapride sometimes induces fatal ventricular arrhythmias and sudden death in a concentration-dependent manner, this medicine should be administered once or twice per day to such patients.

Administration, Oral↗

PubMed1998

[The relationship between subjective sleepiness and polysomnographic findings in sleep apnea syndrome].

We investigated factors of daytime sleepiness in 22 middle-aged male patients with sleep apnea syndrome (SAS) using the Epworth sleepiness scale (ESS) and polysomnography. The subjects were classified into two groups according to ESS score as follows; low ESS group: ESS score < 10, and high ESS group; ESS score > or = 10. ESS score was significantly correlated with duration in which nocturnal oxygen saturation decreased below 90% (Time of SpO2 < 90%) (r = 0.54, p < 0.05). Time of SpO2 < 90% and percent of movement arousals at the termination of apnea/hypopnea (number of movement arousal/total number of apnea/hypopneas x 100) were significantly higher in high ESS group than in low ESS group. Our findings suggest that the severity of oxygen desaturation and sleep fragmentation caused by arousal response at the termination of apnea/hypopnea may be important factors of daytime sleepiness in patients with SAS.

Aged↗

PubMed1997

Apoptosis in human leukemic cells induced by lactoferricin, a bovine milk protein-derived peptide: involvement of reactive oxygen species.

We examined the activity of bovine lactoferricin (Lfcin-B), a peptide derived from a bovine milk protein lactoferrin (LF-B), to induce apoptosis in THP-1 human monocytic leukemic cells. Treatment with Lfcin-B at up to 50 micrograms/ml induced cell death in THP-1 cells in dose- and time-dependent manner, showing apparent morphological changes, hypodiploid forms of genomic DNA and apoptotic DNA fragmentation, whereas LF-B was inactive even at a high dose (500 micrograms/ml). The apoptosis-inducing effect of Lfcin-B increased with reduction of serum concentration, but was inhibited by addition of Zn2+, a inhibitor of Ca2+/Mg(2+)-dependent endonucleases in a dose-dependent manner. Furthermore, Lfcin-B-induced apoptosis in THP-1 cells was completely abolished by addition of antioxidants such as N-acetyl-L-cysteine (NAC) and glutathione (GSH), but not by various cytokines and mitogen which can activate monocytic cells. In addition, THP-1 cells treated with Lfcin-B, but not LF-B, showed high levels of intracellular reactive oxygen species (ROS) from the early period (20 min) of Lfcin-B treatment. And the production of ROS by Lfcin-B was dependent upon the dose of Lfcin-B added. These results suggested that Lfcin-B, a LF-B-derived peptide, but not LF-B itself, is able to induce apoptosis in THP-1 human monocytic tumor cells, and that its apoptosis-inducing activity is related to the pathway mediated by production of the intracellular ROS and activation of Ca2+/Mg(2+)-dependent endonucleases.

Acetylcysteine↗

PubMed1997

Relationship between respiratory failure and plasma noradrenaline levels in amyotrophic lateral sclerosis.

We evaluated plasma noradrenaline (NA) levels at test and during head-up tilt test in 20 patients with sporadic amyotrophic lateral sclerosis (ALS). Their fasting plasma NA levels ranged from 195 to 4227 pg/ml. The average plasma NA level was 483 pg/ml in five ambulatory patients, 341 in two wheelchair-bound patients, 1264 in 11 bedridden patients, and 208 in two respirator-dependent patients whose disability grading was the worst among the four groups. Arterial carbon dioxide (PCO2) was evaluated as a measure of respiratory function. The coefficient of correlation between PCO2 and plasma NA was r = 0.654 (p < 0.01). Either respiratory failure or lower motor neuron dysfunction may relate to the elevation of plasma NA levels. In the two bedridden patients, plasma NA levels and heart rate at rest increased significantly as the disease progressed. Cardiovascular responses to head-up tilting were normal. These data suggest that the elevation of plasma NA levels may be related to progression of respiratory failure and lower motor neuron dysfunction. In conclusion, sympathetic hyperactivity in ALS is considered to be not primary, but secondary to somatic motor disabilities and respiratory failure.

Aged↗

PubMed1997

The demonstration of serum interleukin-8 and superoxide dismutase in Adamantiades-Behçet's disease.

Serum interleukin-8 (IL-8) production was measured in 43 Adamantiades-Behçet's disease (A-BD) patients and in 46 healthy volunteers using a sandwich enzyme-linked immunosorbent assay (ELISA). The mean serum IL-8 level of the patients (14.6 +/- 3 pg/ml) was significantly higher than that of controls (10.8 +/- 3 pg/ml, P < 0.05). Since IL-8 is known to have proinflammatory properties, it may play some role in the pathogenesis of A-BD. We also investigated the activity of serum superoxide dismutase (SOD) in the 43 patients with A-BD and in the 46 healthy volunteers. Serum SOD activity was markedly increased in the patients with A-BD (13.1 +/- 3%), especially in active A-BD, compared with that in the healthy volunteers (6.7 +/- 3%, P < 0.01). Our results suggest the involvement of IL-8 and SOD in the pathogenesis of A-BD as seen in other inflammatory diseases.

Adult↗

PubMed1997

Possible explanations for trajectory curvature in multijoint arm movements.

Although the straightness of hand paths is a widely accepted feature of human multijoint reaching movement, detailed examinations have revealed slight curvatures in some regions of the workspace. This observation raises the question of whether planned trajectories are straight or curved. If they are straight, 3 possible factors can explain the observed curvatures: (a) imperfect control, (b) visual distortion, or (c) interaction between straight virtual trajectories and the dynamics of the arm. Participants instructed to generate straight movement paths produced movements much straighter than those generated spontaneously. Participants generated spontaneously curved trajectories in the frontoparallel plane, where visual distortion is not expected. Electromyograms suggested that participants generated straighter paths without an increase in arm stiffness. These findings argue against the 3 factors. It follows that planned trajectories are likely to be curved.

Adult↗

PubMed1997

Circulating soluble selectins in Kawasaki disease.

To investigate the significance of circulating adhesion molecules associated with leucocyte-endothelial cell interaction in Kawasaki disease (KD), serum levels of soluble E-, P-, L-selectin (sE-, sP-, sL-selectin), and vascular cell adhesion molecule-1 (VCAM-1) were measured in 16 patients with KD, eight with other febrile diseases, six with Henoch-Schonlein purpura (HSP), and 10 healthy children using an ELISA. Serum sE-selectin levels from patients in the acute phase of KD were significantly higher than from those in other groups (P < 0.01). The levels of sP-selectin in the subacute phase of KD were significantly higher than in other groups (P < 0.01). Serum sL-selectin levels tended to rise in the convalescent phase of KD. There were also significant correlations between sE-selectin levels and C-reactive protein (r = 0.80, P < 0.0001), and between sP-selectin levels and platelet counts (r = 0.57, P < 0.0001) in KD patients. These data indicate that circulating soluble forms of three selectins may have different kinetics during the clinical course of KD, suggesting that they may reflect its inflammatory process.

Child↗

PubMed1997

Characteristics of juvenile dermatomyositis in Japan.

Questionnaires were sent to 1290 hospitals in Japan asking for data on patients with juvenile dermatomyositis (JDM) diagnosed between June 1984 and May 1994. Of the 204 patients identified by these questionnaires, 102 met the criteria for JDM. JDM is categorized into three subtypes: Banker-type JDM, Brunsting-type and fulminant-type; patients with the latter exhibit markedly elevated serum levels of creatinine phosphokinase (> 10,000 U/mL) and appear to be at risk of renal failure. Cutaneous manifestations were present in 98% of patients and preceded the appearance of other symptoms. This tendency is one of the reasons for the difficulty in some cases in diagnosing the onset of JDM. Better criteria for early treatment of JDM are needed. The results of the present study suggest that itching and calcinosis are factors that indicate a poor prognosis in patients with JDM. Muscle enzyme levels do not always reflect disease activity, suggesting that methods other than measurement of muscle enzymes, such as measurement of the levels of neoprerin and von Willebrand factor antigen, as well as magnetic resonance imaging should be used to be evaluate disease severity. Patients with Brunsting-type JDM who exhibit dysphagia and antinuclear antibody positivity and patients with Banker-type JDM should be treated aggressively. Pulse therapy should be selected as the initial therapy in patients with fulminant-type JDM.

Child↗

PubMed1997

Effects of oren-gedoku-to and unsei-in, Chinese traditional medicines, on interleukin-8 and superoxide dismutase in rats.

This study was conducted to elucidate the mechanisms of action of two Chinese traditional drugs, Oren-gedoku-to and Unsei-in, which have been used for many years in the treatment of inflammatory disorders. In rats with acetic acid-induced inflammation, both drugs reduced interleukin-8 concentrations in the serum. Neither drug significantly affected superoxide dismutase activity in the serum, although Unsei-in increased superoxide dismutase activity in liver after 1 month of administration. Oren-gedoku-to showed no significant effect on liver superoxide dismutase activity. It was considered that these medicines exert their anti-inflammatory effects mainly on the early stages of inflammation, wherein increased capillary permeability and migration of leucocytes occur.

Animals↗

PubMed1997

Autonomic dysfunction in Parkinson's disease.

This article is a review of autonomic dysfunction in idiopathic Parkinson's disease (iPD), as well as the clinical features of a specific form of PD, i.e. autonomic failure (AF) with PD, and is based mainly on the results obtained from our recent studies. Since James Parkinson's original discription, the definition of autonomic dysfunctions in iPD and their clinical characteristics have undergone changes. Autonomic dysfunction is considered to be uncommon and rarely severe on one hand, while not infrequent but not as severe as in Shy-Drager syndrome on the other hand. AF with PD is characterized by severe orthostatic hypotension, postprandial hypotension, supersensitivity to noradrenaline, low or absent uptake of m-[123I]iodobenzylguanidine scintigraphy of the limbs, and preserved arginine vasopressin response to head-up tilt, suggesting a postganglionic sympathetic lesion resembling pure AF (PAF). On the other hand, reduced cortical glucose metabolism in positron emission tomography study may indicate that AF with PD has diffuse nervous system lesions resembling diffuse Lewy body disease.

Autonomic Nervous System↗

PubMed1997

Angiotensin II-induced pulmonary edema in a rabbit model.

We conducted the present study to propose a rabbit model of pulmonary edema (PE) induced by angiotensin II (AII) and to test the preventive effect of losartan on this form of PE. AII was administered to rabbits intravenously at 50, 100, 150 or 300 microg/kg, either by continuous infusion (10 min) or by bolus injection (30 sec). Continuously administered AII (150 microg/kg) induced PE in most cases, while a bolus injection of the same dosage did not. Additionally, the incidence of PE increased with higher dosages of AII when it was infused continuously. A newly established parameter, the area under the systolic blood pressure-time curve corrected by baseline (cAUC), was prone to rise as the incidence of PE increased. Moreover, cAUC signficantly correlated with the wet-dry lung weight ratio (r=0.66, P<0.05). Subsequently, 0.5 or 3.0 mg/kg of losartan was given before continuous infusion of 150 microg/kg of AII. The higher dosage of losartan prevented PE completely, while the lower one did so moderately. We concluded that intravenous administration of AII induces PE, probably as a result of increasing afterload. Furthermore, an adequate dosage of losartan can prevent PE because it reduces the pressor effect of AII.

Angiotensin II↗

PubMed1997

[Impaired associated movement in Parkinson's disease].

We analyzed the intended voluntary movement and simultaneously occurring automatic associated movement in Parkinson's disease(PD). We studied wrist dorsiflexion as a movement associated with grip and Bell's phenomenon(upward rolling of the eyeballs on forcible closure of the eyelids) in patients with PD and normal controls. The patients showed significantly smaller wrist dorsiflexion and upward rolling of the eyeballs. Patients with PD have a greater reduction of automatic associated movement than intended voluntary movement. This discrepancy between the associated movement and voluntary movement may be one of the bases of clinical symptoms of PD patients in early stage.

Basal Ganglia↗

PubMed1997

[Physiological test].

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Autonomic Nervous System↗