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Biomedical subjects

A Ikeda

Publications and source records attributed to A Ikeda.

At least 217 records · Page 12Linked to original sources
PubMed1996

Influence of baseline airway calibre and pulmonary emphysema on bronchial responsiveness in patients with chronic obstructive pulmonary disease.

STUDY OBJECTIVE: Bronchial hyper-responsiveness (BHR) is widely observed in patients with chronic obstructive pulmonary disease (COPD). However, its clinical significance in COPD has not yet been established. To determine the factors that influence BHR in COPD, multiple linear regression analysis was used to analyse the relationship between BHR to methacholine and baseline forced expiratory volume in 1 s (FEV1), vital capacity (VC), residual volume (RV)/total lung capacity (TLC), static compliance (Cst), transfer coefficient of the lung (Kco), and the percentage of low attenuation area (%LAA) determined by computed tomographic (CT) scan. METHODS: Bronchial responsiveness to methacholine was determined in 63 patients with COPD by the dosimeter method and expressed as PD20FEV1. Residual volume and TLC were determined by body plethysmography. The percentage of low attenuation area was defined as the percentage of area less than -960 Hounsfield unit on a CT scan of the thorax. RESULTS: Forced expiratory volume in 1s (%predicted) and %LAA correlated with BHR (P = 0.023 and 0.020, respectively), while VC (%pred), RV/TLC, Cst and Kco did not. The coefficient of determination was 0.43. The regression analysis showed that a 10% increase in FEV1 (%pred) and a 10% decrease in %LAA would increase log(PD20FEV1) by 0.145 and 0.117, respectively. CONCLUSIONS: A considerable proportion of the BHR in COPD is related to functional abnormalities and morphologic changes of emphysema, such as decreased baseline airway calibre and destruction of the lung parenchyma.

Aged↗
PubMed1996

Supplementary motor area seizure resembling sleep disorder.

Two patients presented with a complaint of frequent sudden arousals during sleep followed by tachypnea and palpitation associated with stiffness in the upper extremities in one case and by elevation of the left lower limb in the other. All night video-electroencephalogram (EEG) polysomnography (VPSG) confirmed the diagnosis of seizure arising from the supplementary motor area (SMA seizure) in both cases. Carbamazepine (CBZ) produced remarkable improvement both in clinical seizures and in their subjective sleep quality. Repeated polysomnography after treatment showed a clear improvement in sleep architecture with higher percentages of slow wave sleep. SMA seizure could disturb nocturnal sleep and is one of the important differential diagnoses for a patient complaining of frequent arousals associated with motor disturbance during sleep.

Adult↗
PubMed1996

Occurrence of deoxyribonucleic acid fragmentation during prolactin-induced structural luteolysis in cycling rats.

We determined whether fragmentation of genomic DNA, one of the hallmarks of apoptosis, occurs during structural luteolysis in cycling rats. Corpora lutea (CL) were collected from rats at each estrous cycle stage (1800 h), and fragmented DNA was extracted. Only CL from rats at the proestrous stage showed distinct DNA fragmentation. To determine the period of occurrence of DNA fragmentation, CL were collected at several points between 1200 h on the day of proestrus and 0600 h on the day of estrus. Distinct DNA fragmentation was observed from 1800 h (proestrus) to 2400 h (proestrus), and the extent was significantly lower at 0600 h (estrus). It is known that prolactin (PRL) induces structural luteolysis in rats. To examine the role of PRL in luteal DNA fragmentation, 2-bromo-alpha-ergocryptine (BE) was used to suppress the PRL surge on the day of proestrus. CL collected at 1800 h from BE-treated rats did not show distinct DNA fragmentation, and PRL injection offset the effect of BE. Histochemical analysis with a 3'-end labeling technique confirmed the occurrence of DNA fragmentation in luteal tissue. These results suggest that apoptotic cell death occurs during PRL-induced structural luteolysis.

Animals↗
PubMed1996

Subdural recording of ictal DC shifts in neocortical seizures in humans.

PURPOSE: Invasive ictal EEG recording is often necessary to delineate epileptogenic areas in patients with intractable partial epilepsy, but even intracranial ictal recordings often reveal ill-defined onset zones in neocortical epilepsy. We studied the physiologic significance of ictal direct current (DC) potentials recorded intracranially in human epilepsy. METHODS: We made intracranial ictal EEG recordings in three patients with intractable partial seizures arising from frontal, lateral temporal, and parietal neocortical areas by using closely spaced subdural electrodes (platinum in two patients and stainless steel in one patient) with both standard (1.5 Hz) and open (0.016 Hz) low-frequency filter (LFF) settings. RESULTS: The initial ictal pattern was localized to two to nine subdural electrodes and characterized by very low voltage and high-frequency rhythmic activity ("electrodecremental pattern"). A slow-rising negative potential (DC potential) was seen in a slightly more restricted area (two to six electrodes) and occurred 1-10 s before the initial ictal EEG discharges in two patients. CONCLUSIONS: These results agree with those of previous studies of ictal DC shifts in animals and suggest that ictal DC shifts may be helpful in delineating the epileptogenic area more precisely in human epilepsy.

Adolescent↗
PubMed1996

Pain-related somatosensory evoked potentials can quantitatively evaluate hypalgesia in Wallenberg's syndrome.

In 6 patients with Wallenberg's syndrome who showed a dissociated loss of pain sense, we recorded pain-related somatosensory evoked potentials following CO2 laser stimulation of the hand dorsum (pain SEPs). Two components, N2 and P2, were recorded by stimulation of the unaffected hand, whereas on the affected side they were absent or decreased in proportion to the severity of hypalgesia which was evaluated by both needle test and CO2 laser stimulation. Latency of either component, if appeared, was longer in the affected hand stimulation than that in the unaffected one. In contrast, N20 of the conventional electrically-stimulated SEPs (electric SEPs) showed no difference between the two sides. It is concluded that, unlike other electrophysiological methods, pain SEPs following CO2 laser stimulation can quantitatively evaluate functional impairment of the spinothalamic tract in Wallenberg's syndrome.

Adult↗
PubMed1996

Dose response study of ipratropium bromide aerosol on maximum exercise performance in stable patients with chronic obstructive pulmonary disease.

BACKGROUND: Although the bronchodilating effect of inhaled anticholinergics has been established in patients with chronic obstructive pulmonary disease (COPD), their effects on exercise capacity are still controversial. Previous studies have suggested that the standard dosage hardly affects exercise tolerance, whereas higher doses might elicit an improvement. The aim of the present study was to determine the dose of ipratropium bromide aerosol that improves exercise performance using progressive cycle ergometry in patients with stable COPD. METHODS: Twenty men with stable COPD of mean (SD) age 69.2 (4.6) years and forced expiratory volume in one second (FEV1) 1.00 (0.37) 1 were studied in a randomised double blind manner. Each patient received ipratropium bromide in doses of 240 micrograms, 160 micrograms, 80 micrograms, 40 micrograms, and placebo from a metered dose inhaler (MDI) with an InspirEase spacer on five separate days. Spirometric parameters were assessed before and at 30, 60, 90, and 120 minutes after each inhalation, and pulse rate and blood pressure were also measured immediately before each spirometric measurement. Symptom limited progressive (20 watts/min) cycle ergometer exercise tests were performed 90 minutes after each inhalation. RESULTS: Ipratropium bromide in doses of 160 micrograms and 240 micrograms produced a greater increase in FEV1 than 40 micrograms or 80 micrograms ipratropium bromide at all time points. Doses of 160 micrograms and 240 micrograms ipratropium bromide also produced greater increases in maximal work load and maximal oxygen consumption than placebo, whereas 40 micrograms and 80 micrograms ipratropium bromide did not. There was a weak correlation between the change in FEV1 and the change in maximal work load (r = 0.45). No differences were found in pulse rate or blood pressure between the treatment and placebo groups, and no side effects were noted throughout the study. CONCLUSIONS: A dose of at least four times the standard dose of ipratropium bromide from an MDI with a spacer device was necessary to improve maximal cycle exercise capacity in patients with stable COPD. Although the data from cycle ergometry cannot be directly applied to exercise performed during day to day activities, it is conceivable that the recommended doses of ipratropium bromide do not elicit the optimal clinical benefits.

Aerosols↗
PubMed1996

The effect of alpha-linolenic acid-rich emulsion on fatty acid metabolism and leukotriene generation of the colon in a rat model with inflammatory bowel disease.

The purpose of this study was to investigate the efficacy of alpha-linolenic acid-rich perilla oil emulsion (POE) in a rat model with trinitrobenzenesulfonic acid (TNB)-induced inflammatory bowel disease. Three different isocaloric solutions, which are glucose solution (FF), soybean oil emulsion (SOE) and POE, were infused for 14 days after instillation of TNB. After infusion, total cholesterol and phospholipid concentration in the plasma in the POE group were significantly decreased compared with the FF and SOE groups. Arachidonic acid level in the colonic phospholipids was significantly decreased and eicosapentaenoic acid level was significantly increased in the POE group compared with the FF and SOE groups. Thickness, damage score and leukotriene B4 content in the colon in the POE group were the lowest among the infusion groups. These results suggest that alpha-linolenic acid suppresses the synthesis of leukotriene B4 in the colon by changing the fatty acid composition in the colonic phospholipids and that POE may be effective in the improvement of inflammation in the colon.

Animals↗
PubMed1996

The nutritional effect of a-linolenic acid-rich emulsion with total parenteral nutrition in a rat model with inflammatory bowel disease.

The purpose of this study was to investigate the nutritional effect of perilla oil emulsion (POE) in a rat model with inflammatory bowel disease (IBD) induced by 2,4,6-trinitrobenzenesulfonic acid. POE and soybean oil emulsion (SOE) were infused at 20% of nonprotein energy during 7 days' total parenteral nutrition (TPN). After infusion of test solutions, body weight gain and cumulative nitrogen balance in the POE group were significantly higher than those in the fat-free TPN (FF) group after infusion of test solutions. Moreover, those in the POE group were higher than those in the SOE group, but no significant difference was observed between the POE and SOE groups. In the POE group, total cholesterol and phospholipid concentration in the plasma was significantly decreased compared with the FF and SOE groups. Triglyceride concentration in the plasma did not significantly differ between the POE, SOE and FF groups. Plasma lipid peroxide concentration in the POE group was significantly lower than that in the SOE group, but it was not different from the FF group. In fatty acid composition in the plasma total lipids, linoleic acid in the POE and SOE groups and alpha-linolenic acid in the POE group were significantly increased compared with those in the FF group. Arachidonic acid (AA) in the POE and FF groups were significantly decreased compared with that in the SOE group. Otherwise, eicosapentaenoic acid (EPA) in the POE group was significantly increased compared with that in the SOE and FF groups. EPA/AA ratio in the POE group was significantly increased compared with the SOE group. The thickness and damage score of the colon were significantly depressed in the POE group compared with the SOE group. These results suggest that POE has a superior nutritional effect and improves inflammation in the IBD.

Animal Nutritional Physiological Phenomena↗
PubMed1996

Effects of insufficient sleep on blood pressure monitored by a new multibiomedical recorder.

Blood pressure varies in relation to factors such as physical activity, body position, ambient temperature, and autonomic nervous system activity. Therefore, we have developed a portable multibiomedical (PMB) recorder that monitors five parameters: indirect blood pressure, physical activity, body position, ambient temperature, and RR interval of the electrocardiogram. In the present study, we applied the PMB recorder over a 24-hour period to study the effect of insufficient sleep on blood pressure in subjects doing extensive overtime work. The parameters listed above were measured by the PMB recorder throughout a normal workday (mean period of sleep, 8 hours) and throughout a day with insufficient sleep (mean period of sleep, 3.6 hours) in 18 male technical workers aged 23 to 48 years old. Blood pressure (mean systolic/diastolic pressure +/- SD) significantly increased the day after a sleep-insufficient night (129 +/- 8/79 +/- 6 mm Hg) compared with the day after a normal night (123 +/- 8/76 +/- 7 mm Hg, P<.05). However, ambient temperature, mean number of steps per minute, and percentage of time spent in a standing position showed no significant difference between these days. Spectral analysis of RR intervals showed that the ratio of the low-frequency component on the RR power spectrum (0.05 to 0.15 Hz) to the high-frequency component (0.15 to 0.40 Hz) was higher on the sleep-insufficient day (2.17 +/- 0.37 versus 1.81 +/- 0.37), as was the urinary excretion of norepinephrine (P<.05). Heart rate was significantly higher on the sleep-insufficient day (81 +/- ll versus 76 +/- 8 beats per minute), after the data of two subjects with abnormal levels of physical activity were excluded (P<.Ol). These data suggest that lack of sleep may increase sympathetic nervous system activity on the following day, leading to increased blood pressure. The PMB recorder was useful for precisely evaluating the relationship between blood pressure and environmental factors.

Adult↗
PubMed1996

Physiologic factors that determine the health-related quality of life in patients with COPD.

STUDY OBJECTIVE: To determine the physiologic factors that influence the health-related quality of life (HRQL) in patients with stable COPD and to identify the factors that most influence HRQL. METHODS: The Nottingham Health Profile (NHP) was used as a general HRQL measure and the Chronic Respiratory Disease Questionnaire (CRQ) was used as a disease-specific HRQL measure to investigate 132 patients with stable COPD, and measurements of HRQL were compared with physiologic measures. RESULTS: Vital capacity, FEV1, the ratio of the FEV1 to the FVC, diffusion capacity for carbon monoxide, diffusion capacity corrected for alveolar volume, lifetime cigarette consumption expressed as pack-years, and age were weakly correlated with several dimensions of both the NHP and the CRQ. Factor analysis reduced these variables to three factors. Two factors mainly referring to airflow limitation and diffusing capacity were weakly correlated with several dimensions of both the NHP and the CRQ. Logistic regression analysis identified 4 independent predictors of HRQL: airflow limitation (odds ratio [OR] = 0.59 to 0.69), diffusing capacity (OR = 0.75 to 0.82), pack-years (OR = 1.20 to 1.23), and age (OR = 2.13). The CRQ was more sensitive to impairment of HRQL than the NHP. CONCLUSIONS: The HRQL of patients with stable COPD is partly determined by airflow limitation, diffusing capacity, pack-years, and age. However, these factors could not predict the whole spectrum of HRQL, and the contribution of these factors to HRQL was limited. Therefore, HRQL should be measured directly in addition to physiologic measures.

Aged↗
PubMed1996

[Volumetric measurement of the maxillary sinus by coronal CT scan].

The volume of the maxillary sinus was estimated by coronal CT scan. The purpose of this study was to compare the estimated volume of the normal maxillary sinus with that of the inflamed maxillary sinus. Patients were classified following evaluation by CT scan of the paranasal sinuses into 3 categories. Group A: Patients suffered from headache, facial pain and epistaxis, but CT scans of their nasal cavity and paranasal sinus were within normal limits without inflammatory change; 102 patients (40 males and 62 females, aged 15-80 years, mean 49.1). Group B: Patients with bilateral chronic maxillary sinusitis, CT scans of whom showed inflammatory changes in both maxillary sinuses. All of the patients in this group underwent sinus surgery after coronal CT scans; 69 patients (38 males and 31 females, aged 15-68 years, mean 44.7) Group C: Patients with unilateral chronic maxillary sinusitis, CT scans of whom showed inflammatory change in unilateral maxillary sinuses; 14 patients (6 males and 8 females, aged 16-71 years, mean 43.2) CT scans of these patients were measured by Plannimeter to take the area of each image of the maxillary sinus. Consecutively imaged areas were summated by integral calculus to obtain an estimate of the sinus volume. Group A normal cases had a mean maxillary sinus volume of 20.5 +/- 9.2 ml (M +/- SD), and Group B bilateral maxillary sinusitis patients had a volume of 17.3 +/- 7.6 ml. The mean maxillary sinus volume in the bilateral chronic maxillary sinusitis patients (group B) was significantly smaller than that in the normal cases (group A) (p < 0.01, t-test). In both groups A and B, the mean of the maxillary sinus volume in males was significantly greater than in females (p < 0.01, t-test), and patients aged from 20 to 29 years old had the largest volume of all the age group. Group C patients with unilateral maxillary sinusitis had a mean maxillary affected sinus volume of 24.2 +/- 7.7 ml, and contralateral normal sinuses with a mean volume of 26.9 +/- 9.3ml. The mean maxillary sinus volume in the affected sinuses was significantly smaller than those in the contralateral normal sinuses (p < 0.05, Wilcoxon-test). The various volumes of the maxillary sinuses and the developmental cause were discussed. Comparison of groups A with B suggested three distinct patterns; 1. the maxillary sinus volume has decreased due to inflammatory changes in the bone; 2. the small sinuses have a tendency to develop chronic inflammatory change; 3. the aeration in the maxillary sinus may be decreased when anatomic variations that may obstruct the ethmoid infundibulum exist.

Adolescent↗
PubMed1996

[Symptoms, FEV1/FVC, and peak flow as indices of the control of asthma].

In a cross-sectional study, we evaluated success in the control of asthma as defined by criteria for symptoms, for FEV1/FVC, and for peak flow rates. One hundred and three patients with chronic asthma who had been treated with inhaled steroids were studied. Chest tightness, dyspnea, wheezing, sputum production, and coughing were each scored from 1 (worst) to 5 (best). Symptoms were said to have been controlled if the symptoms scores for the preceding 4 weeks were greater than or equal to 20; FEV1/FVC was said to be under control if it was greater than or equal to 70% when measured in the clinic; peak flow was said to have been controlled if the lowest peak flow in the preceding 4 weeks was greater than or equal to 80% of the highest measured value. Symptoms were controlled in 72% of the patients, FEV/FVC was under control in 83%, and peak flow was controlled in 66%. The patients were grouped by severity of disease into four classes, and these percentages did not differ significantly among the classes. In 22 out of 74 (30%) patients in whom symptoms were controlled, peak flow was not controlled. Furthermore, in 18 out of 64 (28%) patients in whom symptoms and FEV/FVC were controlled, peak flow was not controlled. We concluded that in treating asthma, not should symptoms be controlled, but peak flow should also be measured each day to avoid undertreatment.

Adult↗
PubMed1996

Event-related potentials during paired associate memory paradigm.

We have studied event-related potentials (ERPs) during a visual paired association task with delayed discrimination in 10 normal right-handed subjects. After subjects completely memorized 4 pairs of figures during a learning period, they were presented with each cue (S1) and asked to judge whether the following figure (S2) formed one of the memorized pairs or not. A choice reaction task with delay was used for control in an attempt to identify brain activity specifically related to memory function. ERPs were recorded from 21 scalp electrodes and those occurring between the S1 and S2 presentation were analyzed. Two ERP components associated with memory function were identified in the difference waveform between the responses in the paired association task and those in the choice reaction task. One was a posterior positive component which appeared between 390 ms and 1100 ms after the S1 presentation and the other was a sustained frontal negative component which began at about 1100 ms after S1 and ended just before the S2 presentation. Both potentials were distributed predominantly on the scalp overlying the left hemisphere. It is postulated that the early posterior positive component may reflect retrieval of information from association memory, whereas the late frontal negativity may reflect retention of information in working memory.

Adult↗