Images in cardiovascular medicine. Acute coronary syndrome due to intramural hematoma.
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Acute Disease↗
Biomedical subjects
Keiko Oikawa
Publications and source records attributed to Keiko Oikawa.
Basaloid squamous cell carcinoma of the maxillary sinus: a report of two cases.
Basaloid squamous cell carcinoma (BSCC) is a highly aggressive neoplasm and a histologically distinctive variant of squamous cell carcinoma. Since the first description by Wain et al. in 1986, only 18 cases with BSCC in the nasal cavity or in the paranasal cavity have been reported in the English literature. We report herein two cases of BSCC of the maxillary sinus. Case 1 was 78-year-old man, who received preoperative radiotherapy and operation. He was alive without disease for 25 months after the operation. Case 2 was a 60-year-old man who received radiotherapy without operation. He died of lung metastasis 6 months after the initial diagnosis. We reviewed the clinical features of BSCC from the literature.
Aged↗
The effects of the glucocorticoid receptor antagonist RU486 and phospholipase A2 inhibitor quinacrine on acoustic injury of the mouse cochlea.
Glucocorticoids are used clinically for the treatment of acoustic injury. However, the protective mechanism of glucocorticoid in acoustic injury has not been completely clarified. Also, the effects of phospholipase A2 (PLA2) on acoustic injury have not been examined to the best of our knowledge. The purpose of the present study was to examine the effects of methylprednisolone, a glucocorticoid receptor inhibitor (RU486) and a phospholipase A2 inhibitor (quinacrine) on cochlear injury induced by acoustic overexposure. Seventy-eight mice were exposed to a 4kHz pure tone at 128dB SPL for 4h. The auditory brainstem response (ABR) was used to examine the hearing thresholds. Cochlear morphology was examined to estimate the outer hair cell loss induced by acoustic overexposure. Methylprednisolone and quinacrine significantly alleviated the hearing threshold shift and hair cell loss induced by acoustic overexposure. RU486 antagonized the protective effect of methylprednisolone. The present findings suggest firstly that glucocorticoids exert protective effects against acoustic injury; secondly, that the protective effect of methylprednisolone was exerted by binding glucocorticoid receptors, and finally that activation of PLA2 may be involved in acoustic injury.
Acoustic Stimulation↗
Synchronous unilateral parotid gland neoplasms of three different histological types.
A 67-year-old male with three synchronous tumors in the unilateral parotid gland is reported. Postoperative histological examinations confirmed the presence of three synchronous primary tumors, specifically pleomorphic adenoma, Warthin's tumor and salivary duct carcinoma, in the right parotid gland. To our knowledge, this is the first case report describing three different histological types in the unilateral parotid gland.
Adenolymphoma↗
Protective effects of glucocorticoids on ischemia-reperfusion injury of outer hair cells.
OBJECTIVE: This animal study aimed to investigate effects of glucocorticoids on the functional recovery of outer hair cells (OHCs) after transient ischemia. METHODS: Distortion-product otoacoustic emission (DPOAE) was examined before, during, and after transient cochlear ischemia of 30 minutes using albino guinea pigs. RESULTS: DPOAE decreased to noise level during ischemia. On recirculation, DPOAE initially recovered with time until 20 minutes after the onset of reperfusion, but thereafter, the DPOAE level gradually decreased toward the noise level in the control animals. Prednisolone and methylprednisolone significantly improved the DPOAE level 60 minutes after the onset of reperfusion. CONCLUSIONS: The present findings suggest that glucocorticoids possess protective effects against ischemia-reperfusion injury of OHCs.
Animals↗
Relationship between baroreflex sensitivity and oxygen uptake in patients with chronic heart failure.
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Baroreflex↗
Dehydroepiandrosterone sulfate reduces acoustic injury of the guinea-pig cochlea.
The present study was performed to determine effects of dehydroepiandrosterone sulfate (DHEAS), a neurosteroid, on acoustic injury. Albino guinea pigs were exposed to a 2 kHz pure tone of 120 or 125 dB sound pressure level for 10 min immediately after intravenous administration of DHEAS. Statistically significant improvement in the compound action potential threshold shifts and in amplitude reduction of distortion-product otoacoustic emissions was observed 1 week after the acoustic overexposure in the animals treated with DHEAS. The present results suggest that DHEAS has a protective effect against acoustic injury of the cochlea.
Acoustic Stimulation↗
Preload-adjusted 2 wave-intensity peaks reflect simultaneous assessment of left ventricular contractility and relaxation.
BACKGROUND: The magnitudes of the first (WI1) and the second wave-intensity peak (WI2) during the ejection period can be used as indices of left ventricular (LV) contractility and relaxation, respectively. However, use of WI to characterize LV dp/dt and the end-diastolic volume (V ed) relationship may be more problematic, as WI may be affected by changes in preload. METHODS AND RESULTS: The LV pressure-volume data sets, consisting of 23 recordings obtained by the conductance method from 12 heart disease patients, were studied. End-systolic elastance (E es) and volume-axis-intercept (V0) were calculated with varying preload. Time constant of LV relaxation (tau), V ed, and WI were calculated from steady-state averaged data. The E es showed a weak correlation with WI1 (r = 0.46, p < 0.05) but a better correlation with preload-adjusted WI1 [WI1/V ed; r=0.86, WI1/V(ed)2; r = 0.92, WI1/(V ed - V0)2; r = 0.89, all p < 0.01]. Similarly, tau did not correlate with WI2 but did correlate with preload-adjusted WI2 [WI2/V ed; r = -0.73, WI2/V(ed) 2; r = -0.63, WI2/(V ed - V0)2; r = -0.78, all p < 0.01]. CONCLUSIONS: These data demonstrate the importance of preload-adjustment when using the WI index for simultaneous assessment of LV contractility and relaxation.
Diastole↗
Cerebral oxygenation during exercise and exercise recovery in patients with idiopathic dilated cardiomyopathy.
We compared cerebral oxygenation during exercise and during exercise recovery between 22 healthy subjects and 35 patients with idiopathic dilated cardiomyopathy (IDC). Although cerebral oxyhemoglobin increased during exercise in most of the healthy subjects, oxyhemoglobin decreased during exercise in 15 of 35 patients with IDC. Cerebral oxygenation during exercise and exercise recovery was related to left ventricular function in the patients with IDC.
Cardiomyopathy, Dilated↗
Impaired baroreflex as a cause of chronotropic incompetence during exercise via autonomic mechanism in patients with heart disease.
PURPOSE: It is thought that the mechanisms responsible for impaired chronotropic response to exercise are related to disturbance of cardiovascular autonomic regulation such as the baroreflex. However, it is still unclear whether the baroreflex mechanisms modulate heart rate (HR) responses to exercise via vagal and/or sympathetic alteration. We therefore investigated the effects of baroreflex sensitivity (BRS) on the exercise HR response in the early phase of vagal deactivation and in the later phase of sympathetic excitation via metabolic stimulation. METHODS: Twenty-four patients (18 males and 6 females, age 59+/-9 years) with heart disease underwent symptom-limited treadmill exercise testing according to the Bruce protocol, and BRS was measured utilizing the phenylephrine method. Subjects were grouped by their resting BRS value: 12 with normal BRS (> or =6 ms/mmHg) and 12 with depressed BRS (<6 ms/mmHg). The HR response to exercise was assessed using two parameters: the increment in HR during exercise and the ratio of HR response to the metabolic reserve (chronotropic index). RESULTS: (1) In the patients with depressed BRS, the HR responses within 1 min after the start of exercise and from 1 min to peak exercise were attenuated compared with those having a normal BRS (15+/-8 vs. 24+/-8 bpm and 36+/-9 vs. 47+/-15 bpm, respectively). (2) The chronotropic index in the patients with depressed BRS was lower than in those with normal BRS (0.50+/-0.14 vs. 0.64+/-0.08). CONCLUSION: These findings suggest that impaired BRS modulates both the parasympathetic influence in early exercise and sympathetic effects in the later phase on HR response to exercise.
Aged↗
Relationship between double product break point, lactate threshold, and ventilatory threshold in cardiac patients.
A double product break point (DPBP) occurs simultaneously with both ventilatory threshold (VT) and lactate threshold (LT) in normal subjects. We sought to determine whether a DPBP also occurs in cardiac patients and to investigate correlations between DPBP, VT and LT (study 1). We also evaluated a non-invasive DPBP measurement system that determined blood pressure automatically by the cuff method (study 2). Study 1 comprised 15 patients [8 men and 7 women, mean (SD) age 47.7 (11.1) years] who performed cardiopulmonary exercise tests on a cycle ergometer. The double product was defined as the product of heart rate and direct systolic blood pressure. Arterial blood samples were obtained for measurement of lactate, pyruvate, pH, and norepinephrine levels. VT was determined by gas analysis, and LT was determined as the lactate/pyruvate ratio. DPBPs were detected in all 15 patients. Double product slopes above the DPBP were significantly greater than those below the DPBP (286.2 vs 98.5/W, P<0.001). The lactate/pyruvate ratio increased, arterial pH decreased, and plasma norepinephrine concentration increased above the DPBP. DPBP had strong positive correlations with VT ( r=0.93) and LT ( r=0.95). Study 2 comprised 65 cardiac patients. The DPBP was detected in 89.2% of patients and correlated closely with VT. We conclude that DPBP occurs near VT and LT in cardiac patients during incremental exercise, that the noninvasive DPBP measurement method is comparable to the invasive method, and that DPBP may be as useful an index of exercise intensity in patients with cardiac disease as VT or LT.
Adult↗
Glucocorticoids and dehydroepiandrosterone sulfate ameliorate ischemia-induced injury of the cochlea.
This study aimed to evaluate the effects of steroidal drugs on the functional recovery of the cochlea after transient ischemia. Albino guinea pigs were subjected to transient cochlear ischemia of 30 min duration, and the threshold shifts of the compound action potential (CAP) from the pre-ischemic values were evaluated 4 h after ischemia. Pre-ischemic administration of a glucocorticoid, prednisolone or methylprednisolone, significantly ameliorated the post-ischemic CAP threshold shifts as compared with control animals at a relatively wide range of doses. Post-ischemic administration of these glucocorticoids also exhibited protective effects. Pre-ischemic administration of dehydroepiandrosterone sulfate significantly decreased the post-ischemic CAP threshold shifts 4 h after ischemia. The present results indicate that glucocorticoids and dehydroepiandrosterone sulfate possess therapeutic effects against ischemic injury of the cochlea, such as idiopathic sudden sensorineural hearing loss.
Action Potentials↗
Involvement of poly(ADP-ribose) synthetase in acoustic trauma of the cochlea.
We investigated effects of poly(ADP-ribose) synthetase (PARS) inhibitors on acoustic trauma. Albino guinea pigs were intravenously given 3-aminobenzamide, nicotinamide or 3-aminobenzoic acid (an inactive analog of 3-aminobenzamide) just prior to exposure to a 2 kHz pure tone of 120 dB sound pressure level (SPL) for 10 minutes. The threshold of the compound action potential (CAP) and the amplitude of distortion-product otoacoustic emissions (DPOAEs) were measured before and 4 hours after the acoustic overexposure. Statistically significant decreases in the CAP threshold shifts and significant increases in the DPOAE amplitudes were observed 4 hours after the acoustic overexposure in the animals treated with 3-aminobenzamide or nicotinamide, whereas 3-aminobenzoic acid did not exert any protective effect. These results strongly suggest that excessive activation of PARS is involved in generation of the acoustic trauma.
Acoustic Stimulation↗
[Clinical application of exercise testing in heart failure].
Patients with heart failure frequently complain of fatigue and/or dyspnea during daily life. These exertional symptoms can be evaluated by the cardiopulmonary exercise testing. Peak oxygen uptake, anaerobic threshold(AT), the ratio of the increase in minute ventilation to the increase in carbon dioxide output(VE-VCO2 slope), the slope of the increase in oxygen uptake relative to the increase in work rate (delta VO2/delta WR), and the time constant of oxygen uptake (tau on) are reported to be useful to assess the severity and prognosis of heart failure patient. The information obtained from cardiopulmonary exercise testing can be used to select therapeutic option to improve both functional capacity and prognosis, and to identify patients with the greatest need for cardiac transplantation.
Anaerobic Threshold↗
[Relationship between exercise capacity and brain natriuretic peptide in patients after cardiac surgery].
OBJECTIVES: Physical training in cardiac patients can increase exercise capacity and reduce plasma brain natriuretic peptide(BNP) concentration, but these effects may depend on the etiology of cardiac disease. The change in exercise capacity and BNP during the training period were investigated in patients with different cardiac diseases. METHODS: Ninety-one patients after coronary artery bypass grafting(CABG) and 78 patients after valve replacement (VR) underwent a symptom-limited incremental cardiopulmonary exercise test before (1 month) and 6 months after physical training. Anaerobic threshold and peak oxygen uptake(peak-Vo2) were measured during the cardiopulmonary exercise test. Before each cardiopulmonary exercise test, a blood sample was obtained in the resting condition for measuring BNP. RESULTS: Anaerobic threshold and peak-Vo2 were increased significantly from 1 month to 6 months in both groups. BNP in the CABG group indicated a tendency to decrease (194.6 +/- 155.3-->144.2 +/- 232.2 pg/ml, p < 0.1) from 1 month to 6 months. BNP in VR group was significantly decreased (159. 9 +/- 115.5-->112.8 +/- 131.7 pg/ml, p < 0.05) during the training period. The CABG group showed a significant negative correlation between peak-Vo2 and BNP at 1 month(r = -0.28, p < 0.01) and at 6 months(r = -0.39, p = 0.001). The VR group showed a significant negative correlation between peak-Vo2 and BNP at 6 months(r = -0.32, p < 0.01), but not at 1 month. CONCLUSIONS: Six months of physical training in patients after cardiac surgery may improve exercise capacity and reduce BNP. BNP concentration in the VR group before physical training did not reflect functional capacity.
Aged↗
Outer hair cells functionally and structurally deteriorate during reperfusion.
Transient ischemia of the cochlea was induced in 65 albino guinea pigs by pressing the labyrinthine artery, and the effects of cochlear reperfusion on cochlear potentials (endocochlear potential, compound action potential and cochlear microphonics (CM)) and structural changes in hair cells were examined. Although 15 min ischemia did not elevate the post-ischemic CM pseudo-threshold as compared with the pre-ischemic value, ischemia of 30 min or longer significantly elevated the CM pseudo-threshold. CM amplitude tended to progressively decrease during the reperfusion period in the animals subjected to 45 or 60 min ischemia. After transient ischemia, outer hair cells (OHCs) were swollen and exhibited alterations of the nucleus. Severer structural deterioration of OHCs was induced by 4 h reperfusion than ischemia itself when the ischemic period was 45 or 60 min. Perilymphatic perfusion of dimethylthiourea, a hydroxyl radical scavenger, partially ameliorated the elevation of the CM pseudo-thresholds and the structural changes of OHCs. These results indicate that cochlear reperfusion induces functional and structural deterioration of OHC probably by hydroxyl radical generation.
Action Potentials↗