Increased membrane and soluble P-selectin in atrial fibrillation.
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Aged↗
Biomedical subjects
S Sanada
Publications and source records attributed to S Sanada.
Relationship between the biodistributions of radioactive metal nuclides in tumor tissue and the physicochemical properties of these metal ions.
This study was undertaken to elucidate the relationship between the biodistribution of radioactive metal nuclides in tumor tissue and its physicochemical properties. Potassium analogs (86Rb, 134Cs, 201Tl) were taken up into viable tumor tissue, although 22Na concentrated in necrotic tumor tissue. 67Ga and 111In were more predominant in inflammatory tissue than in the viable and necrotic tumor tissue. 169Yb and 167Tm accumulated in viable tumor tissue and tissue containing viable and necrotic tumor tissue. 67Ga, 111In, 169Yb and 167Tm were bound to the acid mucopolysaccharide with a mol. wt. of about 10,000 daltons in the tumor tissue. 46Sc, 51Cr, 95Zr, 181Hf, 95Nb, 182Ta, and 103Ru were highly concentrated in inflammatory tissue and were bound to the acid mucopolysaccharides with a mol. wt. exceeding 40,000 daltons. 65Zn and 103Pd concentrated in viable tumor tissue and were bound to the protein in the tissue. The results suggest that the difference in intra-tumor distribution of these elements is caused by a difference in the binding substances (or status) of these elements in the tissues, and the binding substance is determined by physicochemical properties of the elements. We therefore conclude that the biodistribution of radioactive metal ions in tumor tissue is determined by its own physicochemical properties.
Animals↗
Dispersion of signal-averaged P wave duration on precordial body surface in patients with paroxysmal atrial fibrillation.
AIMS: This study sought to investigate whether the spatial dispersion of signal-averaged P wave duration would be increased in patients with paroxysmal atrial fibrillation, by use of precordial mapping of the P wave signal-averaged ECG. METHODS AND RESULTS: The P wave signal-averaged ECG was recorded by the P wave-triggering method from 16 precordial leads in 55 patients with paroxysmal atrial fibrillation and 57 control subjects. As an index of the dispersion of signal-averaged P wave duration, we obtained the difference between the maximum and minimum in 16 recording sites. The dispersion was significantly greater in the patients with paroxysmal atrial fibrillation than the controls (26.6 +/- 9.5 vs 14.8 +/- 6.7 ms, P<0.0001). In 25 patients with symptomatic attacks of paroxysmal atrial fibrillation, the signal-averaged ECG was repeated 1 h after a single dose of orally administered pilsicainide, a new class Ic drug. These patients were prospectively followed-up for 10 +/- 11 months with pilsicainide. The rate of freedom from recurrence of paroxysmal atrial fibrillation attacks was significantly (P<0.0001) higher in patients with whom dispersion was decreased by the single dose (54%[7/13]) than in those in whom dispersion increased (8%[1/12]). CONCLUSION: Increased dispersion of signal-averaged P wave duration would play an important role in generating paroxysmal atrial fibrillation and would be useful in the prediction of drug efficacy to evaluate the change in dispersion by a single administration of pilsicainide.
Administration, Oral↗
New tissue substitutes representing cortical bone and adipose tissue in quantitative radiology.
To employ quantitative radiology more accurately, we examined phantom materials for cortical bone and adipose tissue as calibration standards and as experimental phantoms. New tissue substitutes for cortical bone and adipose tissue composed of liquid phantom were verified by computing their attenuation coefficients and observing their chemical properties. We showed that a potassium pyrophosphate (K4P2O7) solution for cortical bone was comparable to a dipotassium hydrogen phosphate (K2HPO4) solution. Also, the use of methyl alcohol for adipose tissue was more suitable than ethyl alcohol as a phantom material because of its physical and chemical properties.
Adipose Tissue↗
Increased expression of P-selectin on platelets is a risk factor for silent cerebral infarction in patients with atrial fibrillation: role of nitric oxide.
BACKGROUND: Platelet activation and decreased levels of nitrite and nitrate (NOx), stable end products of nitric oxide (NO), are reported in patients with atrial fibrillation (AF). We examined the time-course changes in plasma NOx levels and the expression of P-selectin on platelets after the onset of AF in a canine model and determined whether these parameters could be risk factors for silent cerebral infarction in patients with AF. METHODS AND RESULTS: AF was induced by rapid atrial pacing in the canine model of AF. Plasma NOx levels were significantly decreased and the levels of P-selectin on platelets and of neutrophil/platelet conjugates were significantly increased after the onset of AF in this model. The in vitro experiments demonstrated that the inhibition of NO synthesis increased the expression of P-selectin on platelets. Plasma NOx levels (19.7+/-2.4 versus 27.5+/-2.8 micromol/L) were significantly lower in 25 patients with AF compared with age- (+/-2 years) and sex-matched control subjects. Conversely, the levels of P-selectin on platelets (7.6+/-0.8% versus 4.8+/-0.7%) and of neutrophil/platelet conjugates (14.8+/-0.9% versus 8.1+/-0.6%) were significantly higher in patients with AF. Multiple regression analysis revealed that increased P-selectin on platelets and advanced age were associated with the number of foci of silent cerebral infarction. CONCLUSIONS: An irregular heart rate that is characteristic of AF appeared to blunt NO synthesis. The increased expression of P-selectin on platelets associated with the reduced NO levels was a risk factor for silent cerebral infarction in patients with AF.
Adult↗
Prediction of the effectiveness of long-term beta blocker treatment for dilated cardiomyopathy by signal averaged electrocardiography.
OBJECTIVE: To determine whether the effectiveness of long-term beta blocker treatment for idiopathic dilated cardiomyopathy can be predicted by signal averaged electrocardiography (ECG). PATIENTS: 31 patients with dilated cardiomyopathy and without bundle branch block were included in a retrospective study and 16 in a prospective study. METHODS: A signal averaged ECG was recorded before beta blocker treatment, and three variables were measured from the vector magnitude: QRS duration, root mean square voltage for the last 40 ms (RMS40), and duration of the terminal low amplitude signals (< 40 microV) (LAS40). In the retrospective study, these variables were compared among good responders (showing > or = 0.10 increase in ejection fraction 12 months after start of beta blocker treatment) and poor responders without such improvement. The validity of the signal averaged ECG criteria for prediction of the response to beta blocker treatment was examined in the prospective study. RESULTS: In the retrospective study, good responders (n = 16) had a shorter QRS duration (mean (SD): 122.9 (11) v 138 (14.4) ms, p < 0.005) and LAS40 (33.1 (8.9) v 42.5 (7.8) ms, p < 0.005), and a higher RMS40 (31.6 (16.3) v 19.0 (10.3) microV, p < 0.02) than poor responders (n = 15). Signal averaged ECG criteria for good response were defined as two or more of the following: QRS duration < 130 ms, RMS40 > 20 microV, LAS40 < 40 ms (sensitivity 81%, specificity 73%). In the prospective study, six of seven patients who met these criteria showed a good response to the beta blocker treatment, while eight of nine who did not showed a poor response (chi 2 = 6.1, p < 0.02). The signal averaged ECG criteria gave a sensitivity of 86% and a specificity of 89% for predicting the effectiveness of beta blocker treatment. CONCLUSIONS: A signal averaged ECG might be useful in predicting the effectiveness of beta blocker treatment for dilated cardiomyopathy.
Adrenergic beta-Antagonists↗
[Computer-aided diagnosis in the detection of temporal changes in sequential chest radiographs].
To aid radiologists in the diagnosis of screening chest radiographs, a temporal subtraction technique using digital image processing was developed. The accurate image registration of two sequential images enables us to detect even subtle changes in the "difference image" between them. In this report, a new method based on matching "lung markings" is introduced. Twenty-nine pairs of sequential posteroanterior chest radiographs with and without temporal changes were selected from cases examined with the computed radiography system. Image registration was employed, with the local matching of "lung markings" in previous and current radiographs. Observer performance tests were carried out by eight radiologists, with and without the "difference image." Observer performance tests with the temporal subtraction image showed that six of eight observers diagnosed them with higher sensitivity (mean, 43.9% vs. 55.3%) and a comparable false positive response. Mean area under the AFROC (alternative free-response receiver operating characteristics) curve also improved from 0.596 to 0.647, a statistically significant difference. The subtraction image using this registration technique improved diagnostic accuracy for subtle temporal changes.
Adolescent↗
Prediction of transition to chronic atrial fibrillation in patients with paroxysmal atrial fibrillation by signal-averaged electrocardiography: a prospective study.
BACKGROUND: It is well known that paroxysmal atrial fibrillation (PAF) often precedes the establishment of chronic atrial fibrillation (CAF). However, there have been no definite methods to predict the transition from PAF to CAF. The purpose of this report was to determine prospectively whether P-wave-triggered signal-averaged ECG (P-SAE) is useful for the prediction of the transition to CAF in patients with PAF. METHODS AND RESULTS: One hundred twenty-two consecutive patients with PAF were prospectively followed after P-SAE, echocardiography, and 24-hour Holter monitoring at study entry. The duration (Ad) and root-mean-square voltage for the last 30 ms (LP30) of the filtered P wave were measured in P-SAE. The abnormality of P-SAE for the prediction of transition to CAF was defined as Ad > or = 145 ms and LP30 < 3.0 microV. Twenty-three (19%; group 1) of the patients had the abnormality of P-SAE, whereas the others (group 2) did not. During the follow-up period (mean, 26+/-12 months), 10 patients (43%) in group 1 acquired CAF, whereas the transition to CAF was observed in only 4 patients (4%) in group 2. Kaplan-Meier analysis revealed that the transition to CAF was significantly observed more often in group 1 than in group 2 (log-rank test, P<.0001). The Cox proportional hazards regression model identified that the variables most significantly associated with the transition to CAF were Ad (chi2=8.6, P=.003) and LP30 (chi2=5.1, P=.02), although significant differences in the left atrial dimension (40.8+/-5.3 versus 37.3+/-5.5 mm, P<.01) and the number of atrial premature contractions (3641+/-4524 versus 1489+/-2895 beats/d, P<.05) were observed between groups 1 and 2. CONCLUSIONS: These results indicate that P-SAE could be useful to identify patients at risk for the transition from PAF to CAF.
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Mental deterioration in childhood epilepsy.
Mental retardation is detected in 20-30% of children with epilepsy at hospitals specializing in treatment of childhood epilepsy. However, the incidence of mental deterioration in childhood epilepsy is not high. In this study, mental deterioration was found in 52 (1.8%) of the 2,880 children with epilepsy at Okayama University Hospital. The patients showing mental deterioration mostly suffered from specific epileptic syndromes, such as West syndrome, Lennox-Gastaut syndrome, severe myoclonic epilepsy in infancy and epilepsy with continuous spike-waves during slow wave sleep. These types of epilepsy show generalized electroencephalographic (EEG) abnormalities. It is presumed that mental deterioration is caused by the total effects of prolonged diffuse EEG abnormalities and the age of the patients. Antiepileptic drugs exert a relatively minor effect on mental deterioration.
Adolescent↗
Cerebral blood flow velocity in handicapped children.
Using a transcranial Doppler blood flowmeter, the blood flow velocity (BFV) ratio of the middle cerebral artery (MCA) to the basilar artery (BA) was investigated in 12 patients with severe motor and intellectual disability syndrome. The BFV of the MCA was also investigated in 58 handicapped children, classified according to the severity of their motor and intellectual disability. The ratio of the MCA to the BA was lower by 2 SD from the mean of our previously reported standard value in 8 out of the 12 cases with severe motor and intellectual disability syndrome, suggesting a more profound decrease in the level of brain activity in the MCA area than that of the BA area. The BFV of the MCA mainly decreased in cases belonging to the category of the most severe motor disability (bed-ridden). Hence, it is suggested that motor disability is the main factor related to the decrease in the BFV of the MCA.
Blood Flow Velocity↗
[Development of a regimen comprehension scale].
Whether elderly patients can take prescription drugs as directed by a physician is often unclear. So elderly patients could receive adequate instruction regarding their medications, we developed a regimen comprehension scale (RCS) with simple questions regarding information on dosage and administration. This information was written on the outside of the paper bags in which the medications are usually dispensed. The subjects were 21 healthy volunteers (11 men and 10 women, averaged age 38.3 +/- 11.2 years) and 17 inpatients (9 men and 8 women, averaged age 73.4 +/- 6.8 years). Five kinds of drugs, which differed with respect to dosage and administration were used. The subjects were questioned in an interview about taking the five drugs and their regimen comprehension was assessed with the RCS (maximum score: 10 points, lowest score: 10 points. Then regimen comprehension was classified into 4 grades: normal (10), caution needed (9 or 8), training needed (7 or 6), and assistance needed (5 or less). In addition, intelligence was tested with the revised version of Hasegawa's dementia scale (HDS-R). Eight of the 21 healthy volunteers (38%) and 13 of the 17 elderly patients (76%) misunderstood some aspects of the regimens written on the paper bags. The regimen comprehension was classified as "normal", "caution needed", and "training needed" in 13, 7, and 1 of the healthy volunteers, respectively, it was classified as "normal", "caution needed", "training needed", and "assistance needed" in 4, 4, 4, and 5 elderly patients, respectively. The five elderly patients classified as "assistance needed" were suspected to have dementia because they had scores on the HDS-R of 21 or less. A significant positive correlation (r = 0.797) was noted between scores on the HDS-R and on the RCS. When treating elderly patients with chronic disease (for example, hypertension) it is important to evaluate their regimen comprehension with an index such as the RCS to determine the need for medication counseling before the start of a medication regimen.
Adult↗
Detection of patients with sick sinus syndrome by use of low amplitude potentials early in filtered P wave.
OBJECTIVES: This study sought to determine whether patients with sick sinus syndrome could be detected by analyzing the initial portion of the signal-averaged P wave corresponding to the electrical activity of the perinodal atrial myocardial cells. BACKGROUND: In sick sinus syndrome, pathophysiologic abnormalities have been shown not only in the sinus node, but also in the atrial muscle, especially the perinodal portion. METHODS: The study included 41 patients with sick sinus syndrome and 140 age-matched control subjects. Eighteen of 41 patients with sick sinus syndrome had paroxysmal atrial fibrillation. Signal-averaged P wave electrocardiograms (ECGs) were recorded through a bandpass filter of 40 to 300 Hz with a P wave-triggering technique. Signals of the orthogonal bipolar leads were combined into a spatial magnitude. The root mean square voltage for the initial 30 ms (EP30) and the duration of initial low amplitude signals < 4 microV (ED4) of the filtered P wave were measured. The root mean square voltage for the last 20 ms (LP20) and the duration of the filtered P wave were also measured. RESULTS: EP30 was significantly lower and ED4 was significantly longer in patients with sick sinus syndrome than in the control subjects (EP30 [mean +/- SD]: 2.18 +/- 0.90 vs. 3.94 +/- 1.45 microV, p < 0.0001; ED4: 31.7 +/- 14.5 vs. 14.0 +/- 7.4 ms, p < 0.0001), although there was no significant difference in LP20 between patients with sick sinus syndrome without paroxysmal atrial fibrillation and the control subjects. The duration of the filtered P wave was significantly but minimally longer in patients with sick sinus syndrome than in the control subjects (139.8 +/- 18.8 vs. 127.3 +/- 13.6 ms, p < 0.0001). The criteria of EP30 < 3.0 microV and ED4 > 22 ms as atrial early potential gave a sensitivity of 76%, a specificity of 91%, a positive predictive value of 74% and a negative predictive value of 93% for identification of patients with sick sinus syndrome. CONCLUSIONS: These results suggest that the long, low amplitude signals early in the filtered P wave on the signal-averaged ECGs are characteristic of sick sinus syndrome. Thus, the atrial early potential could be a useful marker to identify patients with sick sinus syndrome.
Adult↗
Effects of high-dose antiepileptic drugs on event-related potentials in epileptic children.
N200 and P300 of event-related potentials (ERPs) were recorded from 22 epileptic children receiving high-dose antiepileptic drugs. The patients were undergoing monotherapy with supratherapeutic serum level and were not mentally retarded. P300 latency was prolonged in 5 of 8 patients (62.5%) of the carbamazepine (CBZ) group and in 4 of 7 patients (57.1%) of the phenytoin (PHT) group. Only one child of the PHT group showed abnormality in brain-stem auditory evoked potentials (BAEPs). Abnormality of P300 was more frequent than that of BAEP. In patients of the PHT group who underwent examinations consecutively before and after changing the dose, P300 latency was prolonged rapidly when the PHT level exceeded 30 micrograms/ml. This suggested that the prolongation was dose dependent. In all patients of the valproic acid (VPA) group, P300 latency was normal. Only 2 patients of the PHT group had P300 prolongation simultaneously with clinical signs of intoxication. Others demonstrated changes in P300 without symptoms of side effects.
Adolescent↗
[Two cases of cavity formation in prostatic urethra after transurethral microwave thermotherapy (TUMT) with Prostatron].
The Prostatron device, developed by Dr. Devonec, provides microwave heating of the prostate and simultaneous conductive cooling of the urethra. Treatment with Prostatron (transurethral microwave thermotherapy: TUMT) of BPH can be performed in a single session, and the urethra, the rectum and the surrounding tissue are protected with the temperature monitoring system. TUMT with Prostatron may be more suitable for a small adenoma with mild symptoms than a large adenoma with severe symptoms, because objective improvement is rarely observed compared with subjective improvement. We have treated 40 cases of BPH with Prostatron (Prostasoft 2, max. energy: 50 watt, max. urethral temperature: 44.5 degrees C, max. rectal temperature: 42.5 degrees C) since March 1993. Among them, there were 2 cases of large cavity formation involving the prostatic urethra. With cavity formation, TUMT may have its place in the treatment of a large adenoma with severe urinary symptoms, but loses its advantage in the prevention of persistent urinary infection and retrograde ejaculation, especially in the treatment of a small adenoma in a younger patient with mild urinary symptoms. It is unknown why such cavity formation occurred only in 2 patients among 40 equally treated cases, but the causes of cavity formation and safety of TUMT should be evaluated again, even though no injury to the rectum and the external urethral sphincter were detected. We report these 2 cases, and causes of cavity formation and discuss the prospects of TUMT.
Aged↗
Tumour affinity of 203Pb-chloride: comparison with 67Ga-citrate and 201Tl-chloride.
The radionuclide 203Pb decays completely by electron capture to stable 203Tl with a half-life of 52 h. The primary radiation from the decay is gamma-ray radiation 280 keV (80%). 203Pb is produced easily from the natural metal thallium by the method described below. 203Pb-chloride is a promising imaging agent for tumour scanning because of the large retention value for tumour tissue and the small value for normal organs, but the large value for the kidney and bone is a shortcoming when considering it as an imaging agent. The retention value of 203Pb in tumour tissue is larger than that of 201Tl and smaller than that of 67Ga. The tumour/inflammatory lesion retention ratio for 203Pb is very large in comparison with those for 67Ga and 201Tl. 203Pb accumulates to a large extent in viable tumour tissue, and less in necrotic tumour tissue and in inflammatory lesion. Therefore, 203Pb-chloride is far better for visualization of viable tumour tissue than 67Ga and 201Tl if the large retention values for the kidney and bone were reduced.
Animals↗
The effects of age on the N200 component of the auditory event-related potentials.
This study was undertaken to determine the effects of development and aging on N200 of event-related potentials from childhood to adulthood. Event-related potentials were recorded from 164 normal subjects ranging in age from 4 to 77 years. A total of 127 of the 164 subjects demonstrated N200 peaks. N200 showed marked developmental changes. During childhood, the N200 latency decreased rapidly with age to the minimum (217 +/- 17.3 ms) at 16 years of age, while it was prolonged gradually with age during adulthood. The latency/age slope in the subjects from 5 to 15 years of age was -9.03 ms/year, while +0.97 ms/year in those from 16 to 77. The N200-P300 interpeak latency remained constant in all age groups and showed no age-related changes. The N200 amplitude decreased as age increased. Nineteen young cases showed N200 peaks to the frequent stimuli. Their ages ranged from 5 to 17 years. Our study suggests that N200 is valuable in evaluating the developmental and aging processes in the central nervous system. The results of this study could be used as normative data in clinical practices.
Acoustic Stimulation↗
Developmental and physiologic changes in cerebral blood flow velocity.
Developmental change of mean blood flow velocity (MBFV) and resistance index of the basilar artery (BA), as well as the changes in MBFV of the BA and the middle cerebral artery (MCA) during sleep and hyperventilation, were studied using transcranial Doppler sonography in healthy Japanese subjects. The MBFV of the BA increased with age from infancy through early childhood, reaching the maximum (64.4 +/- 2.6 cm/s) at the age of 5 y, and then gradually decreased. MBFV ratio of MCA to BA was almost stable between 1.57 to 1.64 in all age groups. The resistance index of the BA showed a maximum value in infants, decreased in 1- to 2-y-olds, and remained constant thereafter. The MBFV of both the MCA and BA were lower during non-rapid eye movement sleep than during wakefulness, whereas during rapid eye movement sleep they showed almost the same value as during wakefulness. They were also decreased during hyperventilation. At an expiratory CO2 level of 25 mm Hg (33.33 kPa), the average decrease in MBFV in children (n = 10) was -50.1 +/- 3.9% in the BA, and -46.2 +/- 7.4% in the MCA, significantly (p < 0.05) more marked than that in adults (n = 10) (-41.5 +/- 5.9% and -37.9 +/- 4.2%, respectively). Transcranial Doppler sonography is a noninvasive method that has a potentially wide range of applications in pediatric neurology.
Adolescent↗
Computer-aided diagnosis: development of automated schemes for quantitative analysis of radiographic images.
Preliminary results obtained with computer-aided diagnosis (CAD) from various radiographic examinations are very encouraging. However, CAD is still at an early stage of its development. It will be necessary to increase further the understanding of image features of normal and abnormal patterns, to establish databases, and to devise specific approaches for particular types of pathology. Although the existing schemes are designed to be applied to digital radiographs, similar techniques can be applied in the future to cross-sectional images such as CT, MRI, and ultrasound. We believe that CAD will become clinically practical in the near future.
Angiography↗