The influence of split doses of gamma-radiation on human erythrocytes

Human erythrocyte suspensions in an isotonic Na-phosphate buffer, pH 7.4, of hematocrit of 2% were exposed under air to gamma radiation at a dose rate of 2.2 kGy. Erythrocytes were irradiated with single doses, and identical doses split into two fractions with an interval time of 3.5 h between following exposures. The obtained results indicated that the irradiation of enucleated human erythrocytes with split doses caused a reduction of hemolysis (2.4 times), a decrease in the level of damage to membrane lipids and the contents of MetHb, compared with identical single doses. However, the splitting of radiation doses did not change the level of damage to the membrane proteins, as was estimated with a maleimide spin label. The obtained results suggest that a decrease in the level of damage to lipids was related to a decrease in hemolysis.     

Use of chitosan in medicine and biomedical engineering

Applicability of different forms of chitosan in medicine and biomedical engineering has been discussed on the basis of a literature survey. Attention was paid to the use of chitosan as a drug carrier and as a pharmacological agent in the treatment of hypercholesterolemia. Suitability of the polymer was proved in the process of blood purification (LDL-apheresis, haemoperfusion, dialysis) and wound healing (dressings). A possibility of using it in biohybrid artificial organs and as athrombogenic surfaces was also mentioned.     

Preliminary results of objective audiological assessment of children with hearing impairment selected in neonatal hearing screening

The aim of the paper was to present the results of the objective audiological assessment of 48 babies and infants at the age of 1-16 months, referred the Department of Phoniatrics and Audiology in Poznań (Poland) from January 2001 to July 2002. The children were selected in neonatal hearing screening, based on the OAE, questionnaire of hearing loss with high risk factors. We discuss high percentage of false positive results of OAE, late referrals for hearing screening, difficulties of follow-up.     

Cardiogenic shock in myocardial infarction-results of in-hospital follow-up

The purpose of this study was to present the outcomes of treatment of cardiogenic shock (CS) complicating acute myocardial infarction (AMI) among patients hospitalized from 1999 through 2006. The study enrolled 1003 patients. Group 1 comprised 87 patients presenting with AMI complicated with CS, whereas Group 2 comprised 916 patients presenting with AMI without CS symptoms. Determination of invasive treatment was according to standard guidelines. The endpoint comprised death, stroke, and reocclusion/reinfarction. Follow-up was confined to the intra-hospital period. CS was observed more frequently in cases of ST-elevation MI (STEMI) and right ventricular MI. The transportation and door-to-needle time were shorter in Group 1. CS patients were characterized by a more severe coronary artery disease, higher maximal creatinine kinase levels, lower global ejection fractions, and increased incidence of atrioventricular conduction disorders. The efficacy of percutaneous coronary intervention (PCI) was 82.26% in Group 1 and 95.03% in Group 2. Death occurred in 33.3% of CS patients and in 3.6% of AMI patients (p<0.0001). Our study proved that in a short-term follow-up, PCI is a procedure of high efficacy in CS patients. The short-term follow-up precluded a conclusion of statistically significant benefits from the shortening of the transportation and door-to-needle time.     

Possible effects of environmental nitrates and toxic organochlorines on human thyroid in highly polluted areas in Slovakia.

Heavy environmental pollution resulting from uncontrolled industrial and agricultural activities has occurred in several areas of Slovakia. So far, field surveys focused mainly on the thyroid have been conducted in one area polluted by nitrates and in a large area polluted mainly by organochlorinated toxicants. In children from the high nitrate area (HNA, n = 324) significantly higher thyroid volume (ThV) by ultrasound was found compared with age-matched children from surrounding areas with low nitrate (LNA, n = 764). In blood samples of 324 children from the HNA and of 100 children from the LNA no difference between areas was found in the level of total thyroxine (T4) and free triiodothyronine (T3). However, positive thyroid peroxidase antibodies (TPOAb) were found in 7/324 (2.2%) and thyrotropin (TSH) levels > 4.0 mIU/L in 13/324 (4.0%) of children from the HNA area, while no positive values were obtained in the LNA. In the area heavily polluted by an organochlorine (OC) cocktail consisting of polychlorinated biphenyls (PCBs), 2,2'-bis(4-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE), hexachlorobenzene (HCB), and dioxins and furans (polluted area) and in the background pollution area (background area) a total of 2046 adults were examined. In polluted area very high blood levels of OCs were found as well as increased ThV and prevalence of thyroid hypoechogenicity by ultrasound. For the evaluation of data the level of PCBs was used as a marker of all OCs. Increasing PCB levels were significantly associated with the increase of free T4 (p < 0.001) and total T3 (p < 0.05) in blood, while slight but not significant negative association of PCBs was observed with the level of TSH. In both women and men the prevalence of TPOAb was significantly higher in polluted area. Although the absolute TPOAb prevalence in both areas was higher in women than that in men, the increase in polluted vs. background area was more striking in men. From these data it appears that the effects of environmental pollution on the thyroid cannot be neglected.     

Natural mediators of physiological interferon synthesis

Resident peritoneal cells of BALB/c mice were found to release two types of mediators influencing physiological interferon synthesis, a nondialysable stimulator and a dialysable low molecular inhibitor. The influence of macrophage secreted, biologically active substances on interferon production is discussed. Their participation in the induction of physiological interferons is considered.