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T Alexopoulos

Publications and source records attributed to T Alexopoulos.

30 records · Page 2Linked to original sources
PubMed2000

Observation of CP violation in K(L)-->pi(+)pi(-)e(+)e(-) decays

We report the first observation of a manifestly CP violating effect in the K(L)-->pi(+)pi(-)e(+)e(-) decay mode. A large asymmetry was observed in the distribution of these decays in the CP-odd and T-odd angle straight phi between the decay planes of the e(+)e(-) and pi(+)pi(-) pairs in the K(L) center of mass system. After acceptance corrections, the overall asymmetry is found to be [13.6+/-2. 5(stat)+/-1.2(syst)]%. This is the largest CP-violating effect yet observed when integrating over the entire phase space of a mode and the first such effect observed in an angular variable.

Journal Article↗
PubMed1991

Scanning electron microscopy of the granular layer of rat cerebellar cortex.

The rat cerebellar cortex has been studied with respect to its cytoarchitectural arrangement using Scanning Electron Microscope. We have distinguished several types of cells in the granular layer and characterized the granules and the Golgi cells. We also characterized the mossy fiber glomeruli which appears round or ovoid. The mossy fibers revealed their "en passant" nature. The climbing fibers formed tendril collaterals and glomeruli. The Golgi cell axon appeared "beaded" and it takes part in the formation of both types of glomeruli.

Animals↗
PubMed1984

[Long-term EEG monitoring in epilepsy diagnosis].

EEG long-term monitorings were carried out in 149 patients using a portable 4-channel miniature recorder system. In most cases EEG was recorded for 48 hours. In addition to preceding routine EEG controls, long-term EEG monitoring disclosed epileptic phenomena in 32.7% of patients suspected for epileptic seizures from their history. This gain of information was based mainly on the detection of abnormal potentials or epileptic seizures appearing during sleep. Using EEG long-term recording numerous EEG routine controls could be replaced which otherwise are often necessary for ensuring the diagnosis of epilepsy. If the patient's history, however, gives only poor reason to believe epileptic seizures, positive findings in EEG long-term monitorings are unlikely. Consequently, careful evaluation of the patient's history is crucial for the indication of this laborious examination. As the limited number of recorder channels may cause false negative results, normal findings should be utilized with caution. Only the sum of all clinical and neurophysiological data should be used for exclusion of suspected epilepsy. The second, even more important application of EEG long-term recordings is the special examination of patients with known epilepsy, such as studies of the circadian profiles of epileptic excitability, documentation of seizure frequency, and electrographic analysis of the course of seizure. Therapy control of epileptic patients can be improved by such informations. In view of the large amount of data which results from long-term recordings, computer assisted methods supporting the visual analysis are necessary. In this regard the continuous spectral analysis of the EEG long-term recordings proved to be highly useful.

Brain Diseases↗
PubMed1982

Three-dimensional structure and cell kinetics at different sites of rat intestinal remnants during the early adaptive response to resection.

In this study the early phase of the morphological adaptation of rat ileum after a proximal resection of 60% has been studied using microdissection and cell labelling techniques. Resected rats and sham-operated controls were killed 2, 4, 6, 10 and 12 days after surgery. Intraperitoneal injections of 3H-thymidine were carried out 24 or 12 h prior to sacrifice. In the latter groups mitotic arrest was achieved by vincristine. A stereo-microscope was used to measure and calculate the following parameters: intestinal diameter; villus: height, width, breadth at base and apex, surface, enterocytes per 100 micrometers length, cell pool, number of villi and absorptive surface per mm2 serosal area; crypt: length, enteroblasts per 100 micrometers length and per column, cell columns and mitoses per crypt, cell pool, crypts, and mitoses per unit serosal area; cell kinetics: migration rate, villus transit time. To test the influence of treatments, postoperative time course and the location of the intestinal segment and their possible interactions, factorial analyses of variance were carried out on the parameters investigated. The main findings, demonstrated for the first time, were: 1. An increase in the villus surface which was achieved by proportional enlargement of villus geometry; 2. This increase in the villus surface led to an enlarged absorptive surface per unit serosal area; 3. A reduction of villus transit time of the individual enterocyte; 4. A most pronounced magnitude of adaptative response in the proximal remnants which was gradually diminished in aboral direction, and 5. A sequential course of adaptative response of the various crypt parameters investigated.

Animals↗
PubMedDate not supplied

Percutaneous insertion of metallic endoprostheses in the biliary tree in 66 patients: relief of the obstruction.

BACKGROUND: We evaluated the efficacy of percutaneous transhepatic insertion of metallic endoprosthesis in 66 patients with biliary obstruction. METHODS: From September 1994 through September 2002, 97 patients with obstructive jaundice attended the radiology department of our hospital; 92 had malignancy and five had benign obstruction (age range, 29-92 years; mean age, 68.3 years). In three patients, findings of percutaneous cholangiography did not indicate further access. Eighty-six metallic stents were implanted in 66 of the 94 remaining patients, and the other 27 patients were treated with percutaneous biliary drainage: external drainage in 21 patients to assist in subsequent operations and combined internal and external drainage in six patients. In one patient we performed percutaneous balloon dilatation of the stenosis of the choledochjejunal anastomosis. Hemobilia occurred in one patient and required embolization of the right hepatic artery. In nine patients (13.6%), a new procedure was used after 40 to 278 days (mean, 129 days) because of occlusion of the endoprosthesis. RESULTS: Clinical improvement and decrease in serum bilirubin level were achieved in 61 of the 66 patients (92.4%). The survival time in patients with malignancy ranged from 6 to 485 days (mean, 139 days). No intervention-related death occurred. Except for the aforementioned hemobilia, one case of biloma occurred and required immediate percutaneous drainage. CONCLUSION: Percutaneous transhepatic insertion of metallic stents was an efficient and secure method to treat biliary obstruction, particularly in malignant inoperable cases.

Adult↗