Biomedical subjects

M Lyra

Publications and source records attributed to M Lyra.

5 recordsLinked to original sources

PubMed2000

Damage-spreading dynamic scaling for the ising model on the sierpinski gasket fractal

We study the relaxation towards equilibrium of the ferromagnetic Ising model on the Sierpinski gasket, which is a fractal lattice. We do this by performing Monte Carlo simulations, based on the heat-bath dynamics, and investigating the time evolution of the Hamming distance between two different configurations of the model. Starting with an initial damage created in all lattice sites, we calculate the average values of two quantities that characterize the relaxation process: the nonlinear damage relaxation time (tau), and the time for all sites to be undamaged at least once (tau(c)). We find that tau diverges, at low temperatures, with a dynamical exponent z which depends linearly on the inverse of temperature, as predicted by a generalized scaling theory developed by Henley. There is a complete breakdown of scaling for tau(c).

Journal Article↗

PubMed2000

New hepatitis viruses.

Three new hepatitis viruses are reviewed; Hepatitis E Virus (HEV), Hepatitis G Virus (HGV), and Transfusion Transmitted Virus (TTV). Only HEV has been clearly associated with liver damage. It is transmitted by the fecal-oral route and tends to occur in poor socio-economic conditions. Acute disease is diagnosed by the presence of anti-HEV IgM antibodies in the serum. Hepatitis G virus and TTV are transmitted parenterally. HGV is the same agent as GBV-C. Although it is hepatotropic, and high levels of viremia may occur, pathogenicity to the liver has not been proven. TTV may also be transmitted by the fecal-oral route. It is abundant in liver tissue but, like HGV, pathogenicity has not been proven.

DNA Virus Infections↗

PubMed1999

Examination frequencies and patient doses from computed tomography examinations in the area of Athens, Greece.

A survey was conducted in the Athens region between the years 1996-1997, in which 33 CT scanner facilities from the 67 operating in this area participated. Examination frequencies from the 33 scanners were 187,875 per year for all types of examinations. Using published estimations for the mean effective dose for each type of examination, it was estimated that the collective dose from the above examinations was about 1,100 person-Sv, which, if projected to the total number of 152 CT scanners operating in Greece at the time of the survey, results in about 0.5 mSv per caput dose each year for the Greek population, which is probably the highest in Europe.

Greece↗

PubMed1996

Cancer consequences of the Chernobyl accident in Europe outside the former USSR: a review.

The accident which occurred during the night of April 25-26, 1986 in reactor 4 of the Chernobyl nuclear power plant in the Ukraine released considerable amounts of radioactive substances into the environment. Outside the former USSR, the highest levels of contamination were recorded in Bulgaria, Austria, Greece and Romania, followed by other countries of Central, Southeast and Northern Europe. Studies of the health consequences of the accident have been carried out in these countries, as well as in other countries in Europe. This report presents the results of a critical review of cancer studies of the exposed population in Europe, carried out on the occasion of the 10th anniversary of the Chernobyl accident. Overall, three is no evidence to date of a major public health impact of the Chernobyl accident in the field of cancer in countries of Europe outside the former USSR.

Adolescent↗

PubMedDate not supplied

Continuous subcutaneous octreotide in gastrointestinal cancer patients: pain control and beta-endorphin levels.

BACKGROUND: Somatostatin is a naturally occurring hormone widely identified in a number of human tissues, with a broad spectrum of physiological actions. Octreotide is a synthetic analogue of somatostatin, which seems to be promising in clinical use. AIMS: a. to evaluate the efficacy of octreotide in pain control of patients with advanced gastrointestinal cancer, as well as octreotide's outcome in the hepatic function; b. to investigate the relationship between pain intensity and beta-endorphin blood levels in the patients. PATIENTS: The study group consisted of 25 patients (age range: 48-89 years, 14 males, 11 females) with far advanced gastrointestinal cancer. METHODS: All the patients were under s.c. morphine administration using a continuous infusion pump. When pain intensity increased, 0.6 mg/day of octreotide was added to the therapeutic regimen in the same syringe of the continuous infusion pump. Pain intensity and beta-endorphin blood levels were measured five times: Once before octreotide administration and the other four 12, 24, 48 hours and 7 days after. A complete blood count and a biochemical screening profile were taken before the administration of octreotide as well as on the 7th and the 14th day. RESULTS: 24 out of 25 cases showed a reduction in pain intensity (pretreatment x = 5.3, post-treatment x = 0.6). beta-endorphin blood levels increased significantly during the study (an increase of 184.78% was observed on the 7th treatment day). In one patient pain control was achieved by increasing morphine dosage. Statistically significant changes were observed in hepatic function indices (p < 0.02). Significant side-effects were not observed. CONCLUSION: Octreotide can be used as an adjuvant analgesic in the management of gastrointestinal cancer pain which is managed by continuous s.c. administration. Although fuither research needs to be done, octreotide's administration seemed to improve hepatic function of these patients, therefore, it could potentially have a positive effect in the patient's quality of life.

Aged↗