Device and method for nonlinear ultrasonic measurements on highly irradiated 304 stainless steel specimens in a hot cell environment.

This paper reports on the first successful nonlinear ultrasonic measurement on highly irradiated specimens in a hot cell environment. The specimens are ANSI 304 stainless steel specimens for which the microstructure characterization and ultrasonic velocity measurement have been previously conducted. The critical part of this research is the development of an automatic fixture device that can facilitate repeatable loading and unloading to place the contact ultrasonic transducers on and off of the specimen. The key step to achieve high measurement repeatability is a careful adjustment of the support-spring constants such that the contact force at the interface between the transducer face and specimen surface is as uniform and constant as possible. The longitudinal ultrasonic velocities, which are obtained as a by-product of the nonlinear ultrasonic measurements, show a level of random variation in terms of (max-min)/average (%) below 0.2%, and the velocity distributions and magnitudes are in good agreement with those from the previous work. The ultrasonic nonlinearity parameters show the level of random variation below 4.7%, which is extremely low, considering that the measurements are conducted in a hot cell environment. The nonlinearity parameters also show a strong dependence on the measurement location in a particular specimen with respect to the radiation source, demonstrating a possible inhomogeneous microstructure evolution in these 12.7 mm thick specimens. This research demonstrates the feasibility of making nonlinear ultrasonic measurement on highly radioactive materials and/or in a highly radioactive environment using the device and procedure developed.

Effect of Intracranial Atherosclerotic Disease on Endovascular Treatment for Patients with Acute Vertebrobasilar Occlusion.

BACKGROUND AND PURPOSE: Although intracranial atherosclerotic disease is often encountered during endovascular treatment for acute vertebrobasilar occlusions, its clinical implication is not well-known. We aimed to evaluate whether intracranial atherosclerotic disease influences the clinical outcomes following endovascular treatment of acute vertebrobasilar occlusive stroke. MATERIALS AND METHODS: Fifty-one patients with acute vertebrobasilar occlusive stroke were included. The onset-to-groin puncture time was ≤12 hours, and aspiration- or stent-based thrombectomy was used as the primary treatment method. Following primary endovascular treatment, intracranial atherosclerotic disease (IAD group) was angiographically diagnosed when a fixed focal stenosis was observed at the occlusion site, whereas embolism (embolic group) was diagnosed if no stenosis was observed. Clinical and treatment variables were compared in both groups, and IAD was evaluated as a prognostic factor for clinical outcomes. RESULTS: The baseline NIHSS score tended to be lower (14 versus 22, P = .097) in the IAD group (n = 19) than in the embolic group (n = 32). The procedural time was longer in the IAD group (96 versus 61 minutes, P = .002), despite similar rates of TICI 2b-3 (89.5% versus 87.5%, P = 1.000). The NIHSS score at 7 days was higher (21 versus 8, P = .060) and poor outcomes (mRS 4-6 at 3 months) were more frequent in the IAD group (73.7% versus 43.8%, P = .038). IAD (odds ratio, 5.469; 95% CI, 1.09-27.58; P = .040) was independently associated with poor outcomes. CONCLUSIONS: An arterial occlusion related to IAD was associated with a longer procedural time and poorer clinical outcome. Further studies are warranted to elucidate the appropriate endovascular strategy.

The cyclin-dependent kinase 5 activator, p39, is expressed in stripes in the mouse cerebellum.

Cyclin-dependent kinase 5 (Cdk5) activity is required for CNS development. The Cdk5 activator, p35, is well characterized but its isoform, p39, has been less studied. Previously, p39 mRNA expression in rat brain was shown to peak at 3 weeks postnatal, and the level remains high in the adult cerebellum [Neurosci Res 28 (1997) 355]. However, p39 protein expression and specific localization in the cerebellum, where p39 mRNA level significantly exceeds that of p35, have not been examined. Here, we explored the specific cerebellar localization of the p39 protein in the developing and adult mice. Adult cerebellar Purkinje cell somata and dendritic arbors were strongly positive for p39 but only rare and barely detectable p39 was observed in Purkinje cell axons. Cdk5 also localized in Purkinje cell somata and dendrites of the adult cerebellum, but p35 localized only in Purkinje cell somata, further suggesting a functional difference between p35 and p39. During development, cerebellar p39 was first noted at P10. Primary cultures of a developing cerebellum also showed strong p39 immunoreactivity in Purkinje cell somata and dendrites, but weak p39 immunoreactivity in Purkinje cell axons. Starting from P10, p39 was observed in a subset of Purkinje cells that form parasagittal bands throughout the vermis and hemispheres. These bands were bilaterally symmetrical and continuous from one lobule to another. Conversely, Cdk5 and p35 showed a uniform staining pattern. The pattern of p39 closely resembled that of zebrin II/aldolase C, suggesting that p39 may play a role in the adult cerebellum rather than in pattern development. This premise is consistent with the normal pattern of zebrin II/aldolase C zones and stripes in mutant p39-/- mice. The alternating p39 parasagittal band pattern may reflect a role for p39 or Cdk5/p39 in the functional compartmentation of the cerebellum.

Comparison of catecholamine release in the isolated adrenal glands of SHR and WKY rats.

1 The present study was designed to investigate the secretion of catecholamines (CA) evoked by stimulation of cholinergic receptors and membrane depolarization from the isolated perfused adrenal gland of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKYR) at adult age. 2 The wet weight of adrenal gland in SHR was greater than that in WKYR. The CA releasing responses evoked by acetylcholine (5.32 x 10-3 m), and high potassium (5.6 x 10-2 m), a membrane depolarizer, were significantly lower in WKYR than in SHR. 3 The secretory responses of CA evoked by DMPP (10-4 m for 2 min), a selective agonist of neuronal nicotinic receptors, and McN-A-343 (10-4 m for 2 min), a selective agonist of neuronal muscarinic receptors, were also significantly lower in WKYR than in SHR. 4 The CA release evoked by Bay-K-8644 (10-5 m), a dihydropyridine-sensitive Ca2+ channel activator, and cyclopiazonic acid (10-5 m), a selective inhibitor of Ca2+-ATPase in the endoplasmic reticulum, were also significantly greater in SHR than WKYR. 5 Taken together, these experimental results demonstrate that the CA secretion evoked by stimulation of cholinergic (nicotinic and muscarinic) receptors as well as membrane depolarization is enhanced more greatly in the perfused adrenal glands of SHR than in those of WKYR. It is suggested that the augmented CA release in SHR compared with WKYR was involved in essential hypertensive pathogenesis.

Development of reusable and expandable communication for wearable medical sensor network.

To meet the various communication requirements of the wearable medical sensor network, the reusable and expandable wireless communications platform has been developed. The connection between the central monitoring unit and the sensors around the body is implemented using the Bluetooth technology. And the data can be uploaded and downloaded to an external Internet server by the CDMA modem or Bluetooth LAN access point (LAP). The system used PDA as a central monitoring unit which records and displays the data received.

Realization of an e-health system to perceive emergency situations.

Emergency situations can occur anywhere and anytime in daily life. In the paper, we present an e-health system to perceive emergency situations of a patient. Using a wearable shirt (BioShirt) and a personal monitoring system (PBM), we obtain the body signals of a user. The monitoring system collects and transmits the vital signs to a personal digital assistant (PDA) via a BlueTooth communication module. To detect emergency from the received data, a simple detection algorithm is performed in the PDA. And the PDA forwards the data to an e-health central monitoring room (ECMR), if necessary. In the ECMR, several operators supervise the registered users based on incoming body signals from each user's device. If an automatic decision-making algorithm generates an emergency alarm, the operators try to contact the corresponding patient and recognize his status. Ultimately if they decide that the patient is an urgent situation, they give phone calls and messages to the emergency center and the patient's medical attendant immediately.

Restoration of atrial mechanical function after maze operation in patients with structural heart disease.

BACKGROUND: The maze operation is effective for the restoration of sinus rhythm; however, restoration of atrial mechanical function has not been demonstrated in all patients. METHODS: Maze operations were performed in 32 patients (13 men, 19 women; mean age 47.1 +/- 9.0 years) combined with valvular surgery (n = 25), coronary artery bypass graft (CABG) (n = 3), and others (n = 4). At 1 week, 3 months, 6 months, and 1 year after the operation, prospective serial Doppler echocardiographic examination was carried out to determine the presence of atrial mechanical function. RESULTS: Sinus rhythm was restored and maintained during the follow-up period in 26 (81%) patients; in 22 patients this was due solely to the operation, whereas in four patients an antiarrhythmic agent was needed to maintain sinus rhythm. Another four patients showed paroxysmal atrial fibrillation (AF) despite treatment with an antiarrhythmic agent. Right atrial mechanical function was restored in all 30 patients with sinus rhythm or paroxysmal AF; in 19 (63%) of these, left atrial mechanical function was restored. In patients with restored left atrial mechanical function, peak A velocity (A) and A/E ratio (A/E) of mitral inflow were significantly lower than in the 16 postoperative control patients (A: 0.46 +/- 0.14 m/sec vs 0. 75 +/- 0.29 m/sec, p < 0.01; A/E: 0.40 vs 0.80, p < 0.01). In patients with left atrial mechanical function, the duration of AF was significantly shorter than in patients without left atrial mechanical function (1.9 +/- 2.9 years vs 7.1 +/- 3.0 years, p < 0. 01), but there were no significant differences in left atrial size and volume. CONCLUSIONS: The maze operation could be safely added to standard open heart surgery for the correction of underlying structural heart disease. The rate of conversion to sinus rhythm resulting solely from the operation might be lower than the rates previously reported with only the duration of AF adversely affecting the restoration of left atrial mechanical function. Considering the fact that not all patients converted to sinus rhythm show atrial mechanical function, the role of the maze operation in the prevention of systemic embolism, with subsequent improvement in survival, requires further study.

Successful management of mechanical complications following acute myocardial infarction--a case report.

Rupture of the heart as a complication of myocardial infarction is one of the most common causes of in-hospital mortality. Rupture of the free wall of the ventricle or interventricular septum has a poor prognosis when treated conservatively. So, rupture of the heart after infarction requires prompt diagnosis and early surgical repair despite the high overall incidence of early operative mortality before hemodynamic deterioration and multiorgan failures develop. Rupture of the left ventricle results in pseudoaneurysm if the overlying pericardium adhers to the surface of the heart. Pseudoaneurysms which rarely develop after infarction, tend to rupture. Their presence alone is an indicator for operation because of the very poor prognosis following rupture. We experienced successful management of 2 rare complications after acute myocardial infarction: ventricular septal defect and pseudoaneurysm. The first patient was a 49-year-old man who had an apical septal defect. His electrocardiogram showed Q wave in leads V2-V6, II, III, and aVF but a coronary angiogram showed normal findings. He was successfully treated by patch closure of the septal defect. The second patient was a 65-year-old female who had false aneurysm of the left ventricle. She had neither chest pain nor abnormality on the electrocardiogram. A coronary angiogram showed complete occlusion of the distal circumflex artery. Under cardiopulmonary bypass, the neck of the aneurysmal sac was successfully closed with a prolene suture.