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Because of the wide use of biodegradable materials in tissue engineering, it is necessary to obtain biocompatible polymers with different mechanical and physical properties as well as degradation ratio. Novel co- and terpolymers of various composition and chain microstructure have been developed and applied for cell culture. The aim of this study was to evaluate the adhesion and proliferation of human chondrocytes to four biodegradable copolymers: lactide-coglycolide, lactide-co-ε-caprolactone, lactide-co-trimethylene carbonate, glycolide-co-ε-caprolactone, and one terpolymer glycolide-colactide-co-ε-caprolactone synthesized with the use of zirconium acetylacetonate as a nontoxic initiator. Chain microstructure of the copolymers was analyzed by means of ¹H and ¹³C NMR spectroscopy and surface properties by AFM technique. Cell adhesion and proliferation were determined by CyQUANT Cell Proliferation Assay Kit. After 4 h the chondrocyte adhesion on the surface of studied materials was comparable to standard TCPS. Cell proliferation occurred on all the substrates; however, among the studied polymers poly(L-lactide-coglycolide) 85 : 15 that characterized the most blocky structure best supported cell growth. Chondrocytes retained the cell membrane integrity evaluated by the LDH release assay. As can be summarized from the results of the study, all the studied polymers are well tolerated by the cells that make them appropriate for human chondrocytes growth.

Slowly degradable copolymers of L-lactide and ε-caprolactone can provide long-term delivery and may be interesting as alternative release systems of cyclosporine A (CyA) and rapamycin (sirolimus), in which available dosage forms cause a lot of side effects. The aim of this study was to obtain slowly degradable matrices containing immunosuppressive drug from PLACL initiated by nontoxic Zr[Acac]₄. Three kinds of poly(L-lactide-co-ε-caprolactone) (PLACL) matrices with different copolymer chain microstructure were used to compare the release process of cyclosporine A and rapamycine. The influence of copolymer chain microstructure on drug release rate and profile was also analyzed. The determined parameters could be used to tailor drug release by synthesis of demanded polymeric drug carrier. The studied copolymers were characterized at the beginning and during the degradation process of the polymeric matrices by NMR spectroscopy, GPC (gel permeation chromatography), and DSC (differential scanning calorimetry). Different drug release profiles have been observed from each kind of copolymer. The correlation between drug release process and changes of copolymer microstructure during degradation process was noticed. It was determined that different copolymer composition (e.g., lower amount of caprolactone units) does not have to influence the drug release, but even small changes in copolymer randomness affect this process.

Background: Nowadays, shift work is a necessity. Unfortunately, according to many studies, it carries serious health implications, e.g. sleep disorders., Objective: To assess the prevalence and determinants of sleep disorders among shift workers compared with daytime workers., Materials and Methods: The study was conducted with use of a questionnaire, containing Sleep Quality Scale (SQS) and Epworth Sleepiness Scale (ESS) to assess sleep quality, as well as a set of open and closed questions concerning the factors that may interfere with sleep., Results: Data have been collected from 286 individuals; 52.8% of shift workers (case group) and 47.2% of regular daytime workers (control group). There was a significant difference in the quality (SQS) of sleep (31.3 +/- 6.50 vs. 27.6 +/- 5.49) and the evaluation (ESS) of sleepiness (8.4 +/- 3.85 vs. 7.6 +/- 4.04) between the two groups. No significant correlations were found between the ESS and SQS values and reported sleep duration, age of respondents, marital status and napping on the job. The more the night shifts a month, the worse the respondents' quality of sleep (SQS). The employees pointed to irritability, depression, fatigue, emotional tension, impaired family and social life as a result of shift work., Conclusions: The prevalence of sleep disorders in the entire study population was high, with its considerably higher rate in the group of shift workers. Shift work causes disorders and emotional problems in family life noticeable by the subjects. It would be advisable to carry out training programs addressed to employees and managers in the field of sleep hygiene and activities that minimize the negative consequences of shift work.

Oxidative stress is one of several factors which contribute to the development of colorectal carcinogenesis. The aim of the study was an assessment of the activity of antioxidant enzymes in tumour and corresponding normal distal mucosa in a group of patients with colorectal adenocarcinoma. Samples of tumour and corresponding normal mucosa were obtained during a resection of colorectal cancer from 47 patients aged between 26 and 82 years. The average distance of corresponding normal distal mucosa from the tumour was 4.49 cm. Activities of antioxidant enzymes: superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione S-transferase (GST), and catalase (CAT) were measured in tissue homogenates. The patients were grouped according to the tumour stage (Duke's staging), grading, localization, and size of tumour, as well as age and sex. Statistical analysis was performed. The activity of SOD and GPx was considerably increased, while the activity of GST decreased significantly in tumour as compared with normal mucosa. GR activity in colorectal cancer was evidently higher in tumours of proximal location compared with the distal ones. The distance of corresponding normal distal mucosa from the tumour was analyzed and related to all assayed parameters. A decreased GST activity was observed in corresponding normal mucosa more than 5 cm distant from the tumour in patients with CD Duke's stage. The higher activity of superoxide dismutase and glutathione peroxidase in tumour compared to corresponding normal mucosa could indicate higher oxidative stress in colorectal adenocarcinoma cells.

Enzyme-catalyzed degradation of poly(trimethylene carbonate) homo-polymer (PTMC) and poly(trimethylene carbonate-co-glycolide) co-polymer (PTGA) was investigated in the presence of lipases from Candida antarctica and Hog pancreas. Degradation was monitored by gravimetry, size-exclusion chromatography (SEC), nuclear magnetic resonance (NMR), tensiometry and environmental scanning electron microscopy (ESEM). PTMC can be rapidly degraded by Candida antarctica lipase with 98% mass loss after 9 days, while degradation by Hog pancreas lipase leads to 27% mass loss. Introduction of 16% glycolide units in PTMC chains strongly affects the enzymatic degradation. Hog pancreas lipase becomes more effective to PTGA co-polymer with a mass loss of 58% after 9 days, while Candida antarctica lipase seems not able to degrade PTGA. Bimodal molecular weight distributions are observed during enzymatic degradation of both PTMC and PTGA, which can be assigned to the fact that the surface is largely degraded while the internal part remains intact. The composition of the PTGA co-polymer remains constant, and ESEM shows that the polymers are homogeneously eroded during enzymatic degradation. Contact angle measurements confirm the enzymatic degradation mechanism, i.e., enzyme adsorption on the polymer surface followed by enzyme-catalyzed chain cleavage.

The effect of poly(L-lactide-co-TMC) chain microstructure (and its changes during degradation) on immunosuppressive drugs' release process was analyzed. Three kinds of poly(L-lactide-co-TMC) (PLATMC)--two semiblock and one random were used to prepare matrices containing cyclosporine A or rapamycine and drug free matrices. All of them degraded slowly enough to provide long term delivery of immunosuppressive agents. Moreover, copolymer chain microstructure determined the effect of drug loading on the degradation process. It was observed that matrices without drug obtained from semiblock copolymer degraded differently than matrices containing cyclosporine A or rapamycine, whereas all kinds of matrices obtained from random PLATMC degraded in similar way. This is the evidence that the only in case of semiblock copolymer factors concerning the presence of drug and the kind of drug influenced degradation process. Based on the obtained results, correlations between copolymer degradation and drug release process are proposed. According to our outcomes, regular drug release process may be obtained from highly randomized copolymers (R ≈ 1) that remain amorphous during degradation process. Determination of this factor may help in development of biodegradable systems, in which drug release rate and profile can be tailored by synthesis of polymer with appropriate chain microstructure., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Objective: Heat shock proteins (HSPs) play a very important role in eukaryotic and prokaryotic cells. They are produced in cells constitutively or induced under stress conditions. During carcinogenesis, HSPs have been reported to show alteration of their expression levels., Aim of the Study: The aim of the study was assessment of the concentration of HSP 27 in tumour and adjacent distal normal mucosa in colorectal adenocarcinomas., Material and Methods: Samples of tumour tissues and adjacent distal normal colon tissues were obtained during resection operations from 47 patients aged between 26-82. Average distance of adjacent distal normal mucosa from the tumour was 4.49 cm. In tissues homogenate total protein level and concentration of HSP 27 were assayed. The patients were grouped according to clinical classification (Duke's staging), grade of differentiation, localization, and size of tumour, as well as age and sex. Relation between adjacent distal normal mucosa collected in different distances from the tumour and compared to concentration of HSP 27 was analyzed. Statistical analysis was performed., Results: The concentration of HSP 27 was significantly increased in adjacent distal normal tissues compared with tumour tissues. Moreover, the concentration of HSP 27 was increased in adjacent normal tissues in patients with CD Duke's staging compared to patients with AB Duke's staging. No differences in concentration of HSP 27 between tumour and normal tissues compared with grade of differentiation, localization, and size oftumour, as well as age and sex were observed. No relation between adjacent distal normal mucosa collected in different distances from the tumour and compared to concentration of HSP 27 was observed., Conclusions: The higher concentration of HSP 27 in adjacent distal normal mucosa can be a response to stress factors related with metabolic changes of cancer tissues or can be a protective function to stress factors of the tumour.

The theoretical analysis of the thermal and magnetic properties of iron-sulfur superclusters has been studied by taking into account Heisenberg interactions and resonance delocalizations (double exchange interactions). The numerical calculations are based on the determination of the lowest energy states for different values of spins (from S = 0.5 to S = 12.5) and Heisenberg exchange integrals. It is shown that the spin magnetic susceptibility of the iron-sulfur superclusters decreases with increasing temperature and increases with increasing the double exchange parameter. In contrast to the susceptibility, the heat capacity decreases with the increasing values of the double exchange parameter. It was theoretically found that spin of ground state for the iron-sulfur supercluster is equal to 0.5. Based on our results, we can state that the Heisenberg model of spin interactions describes the thermodynamic properties of the iron-sulfur superclusters which are the important constituents of proteins and enzymes.

Biodegradable polymers have become common materials used in pharmacy and medicine due to their properties such as mechanical strength, biocompatibility and non-toxic degradation products. Different compositions of copolymers and also their chain microstructure may have an effect on matrices degradation and thus on the drug release profile. In our study, we aimed at the influence of paclitaxel content on hydrolytic degradation process of terpolymeric matrices. Hydrolytic degradation of three kinds of matrices (with 5 or 10% of paclitaxel and drug free matrices) prepared from three types of terpolymers was performed in vitro at 37 degrees C in phosphate buffer solution (PBS, pH 7,4). The 1H and 13C NMR spectra of terpolymers were recorded. Thermal properties were monitored by differential scanning calorimetry (DSC). Molecular weight dispersity (D) and molecular weight were determined using gel permeation chromatography (GPC). The surface morphology was studied by means of the scanning electron microscopy (SEM). The most significant degradation was observed in case of poly(L-lactide-co-glycolide-co-epsilon-caprolactone) 44:32:24. Weight loss and water uptake were similar in the event of the same type of matrices obtained from the two poly(L-lactide-co-glycolide-co-TMC). Decelerated paclitaxel release in case of matrices with 51:26:23 molar ratio was noticed and it can be connected with higher content of carbonate units. Knowledge of paclitaxel influence on hydrolytic degradation process may contribute to receive valuable information about its release mechanisms from biodegradable terpolymers.

In the process of evolution a number of complicated mechanisms have developed to protect the gastric mucous membrane, e.g., angiogenesis and stimulation of mucosal growth. The aim of this study was to determine the role of vascular endothelial growth factor (VEGF) administered intraperitoneally in the gastroprotective response to stress-induced acute gastric ulcers in rats. A dramatic increase in the number of blood vessels was observed when VEGF was injected 24 h before stress exposure. Gastric secretion, depth of ulceration and ulceration index decreased significantly after VEGF application. The results demonstrate the gastroprotective effect of VEGF on stress-induced ulceration., (Copyright 2009 Prous Science, S.A.U. or its licensors. All rights reserved.)

Unlabelled: The study population included employees of metal works, with significant exposure to lead (Pb) for about 20 years (mean blood lead level PbB = 43 microg/dl), divided into four groups: normotensive (Pb-normotensive), high-normotensive, first (HT-1), and second degree (HT-2) of hypertension. The control group comprised of 30 office workers with normal blood pressure and no history of occupational exposure to lead. In erythrocytes, the activity of antioxidant enzymes and lipid peroxidation (measured as concentration of malondialdehyde (MDA)) was estimated. MDA concentration, glutathione peroxide (GPx), and superoxide dimutase (SOD) activities were significantly higher in Pb-normotensive group when compared to the normotensive control. Body mass index, age, duration of exposure to lead, and PbB were higher in both hypertensive groups than in Pb-normotensive or high-normotensive groups. MDA increased in HT-1 group by 48% and in HT-2 by 72%, and the activity of GPx decreased significantly in HT-1 group, by 30% and in HT-2 by 43%. No significant differences were observed in their activity of SOD, catalase, and glutathione reductase in erythrocytes. Arterial blood pressure (both systolic and diastolic) positively correlated with body mass index (BMI), age, lead exposure duration, PbB, MDA, and negatively correlated with GPx. There was no significant correlation between BMI and MDA, BMI and GPx, age and MDA, AND age and GPx., In Conclusion: (1) lead increases erythrocyte MDA concentration and the activity of GPx as well as SOD in normotensive subjects. (2) Among individuals exposed to lead, with arterial hypertension diagnosed, higher body mass index, age, values of blood lead level, and prolonged exposure to lead have been noticed, accompanied by intensified oxidative stress and the decrease in the activity of glutathione peroxidase in erythrocytes. The reasons for increase of blood pressure in lead exposure remain unrecognized.

New photoluminescence oligoazomethines possessing both hole and electron-transporting units in the main chain were synthesized. Triphenylamine (TPA) was used as the electron-donating group, while 4,4'-diaminooctafluorobiphenyl, 4,4'-(hexafluoro-isopropylidene)dianiline, 4-aminophenylsulfone, 4,4'-(4,4'-isopropylidenediphenyl-1,1'diyldioxy)dianiline and 2,5-bis(4-aminophenyl)-1,3,5-oxadiazole were used as the electron-acceptor or as the electron-donating group. The bifunctional oligomers (D-pi-A and D-pi-D) were soluble in some organic solvents such as chloroform, DMA, HMPA, NMP and formed transparent films on glass support. All oligomers exhibit high glass transition temperature in the range of 188-227 degrees C as determined by differential scanning calorimetry (DSC). The photoluminescence (PL) emission maximum peaks of the oligomers in solution are in the range of 459-552 nm (2.70-2.25 eV) corresponding to blue, blue-green or green light. The solvatochromic and protonation behavior of the oligomers in two solvents (DMA, chloroform) were detected. Oligomers protonated with methanesulfonic acid (MSA) are hypsochromically shifted with respect to the PL spectra of the pristine oligomers measured in solution. Relative PL intensity of the oligomers investigated in chloroform solution was found in the range of 0.10-0.50%, while for protonated ones it was detected in the range of 33-50% in relation to 9,10-diphenylanthracene. Blends of the oligoazomethines with poly(methylmethacrylate) (PMMA) (0.1%, w/w) emitted blue light. Thin films were also doped with iodine. Calculated energy gap for the undoped films following the Tauc relation was in the range of 2.46-2.69 eV while for the iodine doped oligomers in the range of 1.76-2.38 eV was found.

Bioresorbable new terpolymers of L-lactide, glycolide, and trimethylene carbonate with different compositions were synthesized via ring-opening polymerization reaction of the cyclic monomers using low-toxicity zirconium(IV) acetylacetonate as initiator. The thermal and mechanical properties were investigated by means of thermogravimetry, differential scanning calorimetry, stress-strain measurements, and dynamical mechanical analysis. The glass transition temperature of the terpolymers changes with composition from 12 to 42 degrees C in a predictable manner. All terpolymers display shape memory properties and, after undergoing 100% deformation, they recover the permanent shape in a time frame of seconds. Terpolymers with high L-lactide content show a glass transition in the range of 38-42 degrees C, recovery temperature close to body temperature, and good recovery ratio (>0.89). Low-toxicity bioresorbable terpolymers with shape memory properties are promising new materials for biomedical applications.

Environmental factors are a significant cause of many civilization-related diseases, including diseases of the circulatory system which have been the main causes of death in Poland for years. The aim of the research was evaluation of the intensity and changes in premature deaths due to diseases of the circulatory system in the population of the Upper Silesia Region at the beginning of the XXI century within particular districts. For the needs of the analysis, the premature deaths are represented by deaths before the age of 65 years. The premature death date was calculated as a quotient of the number of total deaths, which occurred before the age of 65 years and the number of inhabitants at the ages from 0-64 years in given districts. The research was planned as an analysis of secondary epidemiological data obtained from the State Office of Statistics. The results were prepared using the Statistics v.6.0i program and have been placed in tables and graphs separately for general and premature deaths. Deaths due to diseases of the circulatory system are still the main causes of death both for the crude and the premature ones in districts selected for research. The worst health situation can be noted in Katowice where both the rate of crude and premature deaths has considerably risen. The diseases of the circulatory system are the most frequent causes of death among women who begin suffering from heart diseases on average several years later then men. Such an alarming health situation in the population of Silesia requires organized preventive actions such as introduction of prevention and promotion health programs on a mass scale.

The subject of this work is new method of the synthesis of biodegradable copolymers compatible with brain tissue. Copolymerization of glycolide with lactide was conducted in solution or in bulk in the presence of LiBu, LiAcac, MgBu(2), Mg(acac)(2) as initiators. In all cases, copolymers with molecular weight of 20000-40000 were obtained, which enables to use them as drug carriers. During the reactions of copolymer chain growth, the intermolecular transesterification occurs, changing the distribution of comonomeric units in copolymer chain. Magnesium initiators showed a lower contribution to transesterification in comparison with lithium and calcium compounds. The copolymerization of glycolide with epsilon-caprolactone using magnesium compounds as initiators was also described. The random glycolide/epsilon-caprolactone copolymer (10/90) obtained with MgBu(2) was used in in vivo study in the forms of microspheres and foils. Complete degradation of microspheres during 6 weeks was observed after the implantation to brain tissue. All implanted copolymers are compatible with brain tissue.

Borrelia burgdorferi sensu lato is an aethiological factor of borreliosis. Borrelia spirochete is transmitted to humans by ticks. The aim of the study was to estimate the spirochetes B. burgdorferi s.1. infection in Ixodes ricinus ticks by using PCR analysis of the flagellin gene fragment. The study was carried out in 2001-2003 in recreational areas of the Silesian Region in Poland (Tarnowskie G6ry and Zabrze administrative districts). In the 233 ticks analysed the DNA of B. burgdorferi s.l. was detected in 33 (14,2%) cases. Further comparison of spirochetes infection percentages in ticks during the three consecutive vegetation seasons was made. The investigation of B. burgdorferi s.l. detection in tick populations of recreational and endemic areas is important for the evaluation of the risk of infection.

It has been shown that hydroxyurea (HU) induces free radicals which exert cytotoxic effects on cells. However, the molecular mechanism of this effect is still obscure. A possible mechanism for HU-mediated cell death induced by unbalanced growth could be the overproduction, altered accumulation, and progressive leakage of many hydrolytic enzymes through the cell membrane, leading to "lytic" cell death. Protection by antioxidants and radicals scavengers does not change the inhibition of DNA synthesis dependent on ribonucleotide reductase, the main mechanism of the antineoplastic activity of HU. These observations support the hypothesis that membranes are targets for the side effects of HU toxicity. Damage of erythrocytes and granulocytes seems to be an important clinical feature of the HU side toxicity generating free radicals.

Forestry workers are a group of a high risk of occupational exposure to tick-borne diseases. The group of 51 healthy persons with a history of more than 3 years forestry working was tested for antibodies against B. burgdorferi and tick-borne encephalitis (TBE) and reviewed on tick-bites preventive methods usage. Two-steps serological examination revealed the anti-B. burgdorferi antibodies in 14 (27.5%) persons. Anti-TBE antibodies were present in 6 (11.8%) persons. Despite of multiple tick bites in anamnesis, methods of ticks bites prevention (clothes, repellents) were used by less than 30% of workers. Similarly, anti-TBE vaccination was conducted only in 11 persons. Concluding, the elaboration of educational, prophylactic and efficacy monitoring standards for this occupational group is needed.

The study population included healthy men and hypertensive employees of zinc and lead steelworks in the south of Poland. Workers exposed to lead (n=137) were divided into two groups: the first included employees with low exposure to lead (LL) with mean blood lead (PbB) 25-40 microg/dL and the second one with PbB over 40 microg/dL (HL group). The administration workers (n=35) were the control group. Evaluation of lipids and oxidative changes of cholesterol and lipids were estimated in blood samples. No significant changes in concentration of 7-ketocholesterol and blood lipids (cholesterol, HDL, LDL, triglycerides) were found. Lipid peroxidation (LP) was significantly higher in both exposed groups in plasma and in the HL group in erythrocytes when compared with control. There can be two independent sources of LP increase: the first is connected with the direct effect of lead's ions on erythrocytes, the second is the prooxidative effect of delta-aminolevulinic acid. Hypertension in the HL group when compared with people with PbB below 40 microg/dL (OR 4.4, 95%CI 1.4-14.5) was found more often. LP significantly increased by about 71% and concentration of 7-ketocholesterol by about 122% in hypertensives when compared with normotensives in the HL group.

The adduction of the aldehydic end-products of lipid peroxidation to DNA induces bulky adducts, leading to genome instability. The bulky-DNA adducts are miscoding and thus play a fundamental role in mutagenesis and cancerogenesis. Special attention is given to the etheno- and propanoadducts, recognized as DNA modifiers. Such DNA lesions are repaired by different DNA repair mechanisms, mainly base excision repair (BER) and nucleotide excision repair (NER), as well as nucleotide incision repair (NIR) and transcription-coupled repair (TCR).

A series of copolymers with various compositions were synthesized by bulk ring-opening polymerization of glycolide and epsilon-caprolactone, using stannous (II) octoate or zirconium (IV) acetylacetonate as initiator. Reaction time and temperature were varied so as to induce different chain microstructures. The resulting copolymers were characterized by (1)H NMR, SEC, DSC, and X-ray diffraction. The average lengths of glycolyl (L(G)) and caproyl sequences (L(C)) and the degree of randomness (R) were calculated and compared to the values of completely random chains. The concentration of CGC sequences was also obtained which resulted from transesterification reactions. Data showed that stannous (II) octoate leads to less transesterification than zirconium (IV) acetylacetonate, and lower temperatures lead to less transesterification than higher ones. The copolymers exhibited a more or less blocky chain structure because of the reactivity difference between glycolide and epsilon-caprolactone. The crystalline structure and thermal properties depend on both the composition and the chain microstructure. PGA- and PCL-type crystallites were obtained for copolymers with intermediate compositions.

A series of glycolide/epsilon-caprolactone copolymers were compression molded and allowed to degrade in a pH 7.4 phosphate buffer at 37 degrees C. Degradation was monitored by various analytical techniques such as (1)H NMR, X-ray diffraction, DSC, CZE, ESI-MS, and inherent viscosity measurements. The results show that the degradation rate depends not only on the copolymer composition but also on its chain microstructure. Generally, copolymers with a higher C-G bond content or a higher degree of randomness exhibit higher degradation rates. Sequences with odd numbers of glycolyl units such as -CGC- and -CGGGC-, which result from the second mode transesterification, appear more resistant to hydrolysis. As a consequence, degradation residues obtained at the later stages of degradation are mainly composed of long glycolyl and caproyl sequences linked by -CGC- and -CGGGC- ones. The degradation rate of the copolymers depends also on the degree of crystallinity of each component which is related to the block length. The caproyl component can be preferentially degraded if it is in the amorphous state and the glycolyl component is semicrystalline.

The aims of this study were to assess the effects of sterilization with gamma-irradiation on (i). bulk cladribine and (ii). cladribine-containing biodegradable copolymers. The stability of cladribine upon irradiation was confirmed by TLC, HPLC, UV, IR, DSC, rentgenography and electron microscopy. The stability of copolymers containing cladribine upon irradiation was assessed by IR, DSC and EPR. In vitro kinetics of nucleoside release from the copolymers before and after irradiation were compared, and only slight changes were found. Results of our study indicate that gamma-irradiation can be safely applied for the sterilization of cladribine or cladribine-containing copolymers for medical purposes.

Bronchial asthma belongs to the group of illnesses of allergic and inflammatory origin. Despite numerous research divergent results are described in literature, that is the reason why a decision was made to conduct a careful study of the influence of various factors on induction and clinical course of bronchial asthma among children. The research included 5945 children of 10-11 from 86 primary schools of the Katowice province (presently Silesian province). The factor evaluated was the influence of the exposure to tobacco smoke on asthma induction and its clinical course. The data concerning the exposure were obtained from the children's parents. The dependence analyses were conducted with the use of statistical packets Statistica and BUGS. Smoking was declared in 3594 cases (68.5%), and non-smoking were 1637 people (31.2%). The probability of developing asthma is constant within the range of 0-40 cigarettes smoked daily; then it grows quite rapidly (R-0.794, p-0.011). The clinical course of asthma was evaluated on the basis of appearing wheezing respiration, pressure in chest, dyspnoea and cough. In the investigated population/group only the probability of pressure in chest incidence correlated with the number of cigarettes smoked (R-0.86, p = 0.014), in case of the remaining symptoms the correlation was statistically insignificant. The obtained results have proved a substantial influence of tobacco smoke on the development of asthma. This indicates the necessity of taking sanitary measures in the habitats, and especially elimination of tobacco smoke. The results of the research concerning the influence of tobacco smoke on clinical course of asthma were less unequivocal. This might be caused by the evaluation method of the exposure (purposeful underrating, smoking away from home, or in another room). This points to the necessity to employ a more unbiased method of evaluation of the exposure to tobacco smoke.

Because of spreading increase of the percentage of obese people in our society, there exists a need to draw attention of young people to this problem. In the investigation the positive measures of somatic growth (weight and height) in the assessment of the intensity of overweight, or obesity were used. In the research 518 women and 323 males were involved, first year students of Medical University of Silesia, admitted in Student's Ambulatory of Medical University of Silesia in years 1989-1993. The level of overweight was estimated by use of Body Mass Index BMI, and by calculation of amount of fat tissue. The overweight estimated by BMI was found in 9.6% of surveyed population, the percentage of males with overweight over two times outnumbered the percentage of women--15.2% and 5.8% respectively. Level of obesity estimated by mathematical calculation by use of a formula for amount of fat tissue is not convergent with BMI results because of very broad range of dispersion of the overweight. The continuation of started research may draw the attention of medical students to problems of obesity, one of the most important risk factors of their future diseases.

Bronchial asthma belongs to a large group of illnesses of allergic and inflammatory origin. Despite long-term studies still not much is known about the factors inducing children's bronchial asthma. This fact influenced the line of the research. The research included 5945 children of 10-11 from 86 primary schools of the Katowice province (presently Silesian province). The factor evaluated was the influence of the exposure to air pollution on asthma induction. The data concerning the exposure was obtained from questionnaires, reports of the Institute of Meteorology and Water Management and medical examinations. The dependence analyses were conducted with the use of statistical packets Statistica and BUGS. The analysis proved that long-term exposure to SO2 caused an increased number of cases of children's asthma (correlation R = 0.95 with p < 0.05), whereas the current concentration of Sos did not correlate with the number of asthmatic children (p > 0.05). The concentration of dust did not correlate with occurrence of asthma (p > 0.05). The exposure to NO2 caused a significant increase in incidence of asthma (R = 0.98 with p < 0.05). Previous exposure to CO did not influence the occurrence of asthma (p < 0.05) whereas its present concentration correlated with the number of cases of children's bronchial asthma (R = 0.918 with p = 0.001). The results obtained point to significant influence of long-term exposure to nitrogen and sulphur oxides on later development of asthma (a comparison between the concentration of these gases in the past and the present state of health). As far as evaluation of the influence of the present pollution concentrations is concerned the results were not so unequivocal (perhaps the duration of exposure has been too short to allow for the development of the illness). The fact that the results of the research are unequivocal points to the necessity to change the evaluation method of the children's exposure to environmental factors. This concerns especially the estimation of gas pollution in the air by measuring the blocmarkers in the organic liquids, and not only by evaluation of the exposure to the factors in the air.

Chronic venous insufficiency is a major social problem. The nature of this illness lies in disturbances of the dynamic pressure balance in venous vessels, which leads to difficulties in venous reflux. As a consequence teleangiectasia and varices are formed, and they are the basis for the development of trophic skin changes. The causes of the illness have not been fully recognised. It is suggested that genetic factors, body mass, past pregnancies, mode of life, or sex hormones may play an important role in the pathogenesis. The occurrence of this illness has been estimated to reach between 9 and 58% of the developed countries of North America and Europe's population; and women are suffer from it more often than men do. We decided to check the frequency of occurrence of the chronic venous insufficiency in the population of women inhabiting Zabrze-Rokitnica. In addition to this we tried to evaluate the influence of various factors on the occurrence and intensity of the illness. The research included women between 18 and 60 years of age, patients of the NZOZ "Therapeutica" in Zabrze. The occurrence of teleangiectasia and varices according to CEAP was appreciated. The height and body mass were measured as well as a short history was made concentrating on the chronic venous insufficiency risk factors. In the so-far surveyed population of women 49.7% had symptoms of chronic venous insufficiency, and 27.0% of the whole group had teleangiectasia and 22.7%--varices. The frequency of occurrence of chronic venous insufficiency correlated with BMI, age and the number of pregnancies.

The aims of our study were to assess the release of cytotoxic nucleoside analogs 5-fluorouracil and 2-chloro-2'-deoxyadenosine from different lactide-glycolide or lactide-caprolactone biodegradable copolymers and the effects of sterilization on this release. The polymers were sterilized either with ethylene oxide at 37 degrees C, or with gamma radiation (15 kGy, 20 kGy, or 25 kGy). The kinetics of nucleoside release from the copolymers were measured over 50 days. Four copolymers exhibited relatively constant release of nucleosides in micromolar concentrations during the entire observation period. Sterilization with either ethylene oxide or gamma radiation only slightly influenced nucleoside release. Further development of these copolymers as an intracerebral nucleoside delivery system for local treatment of brain tumors is indicated.

Low birth weight is still important health problem in many countries. Children's low birth weight increases mortality, injures central nervous system, somatic, interferes with intellectual and emotional development. Low birth weight is frequently occurring in Poland--between 7-9% of live births. There are many risk factors, among them behavioural and environmental. In Poland an attention was put on chemical and physical environmental factors. Behavioural factors (stress) are disregarded. In the present paper it was decided to check the relationship between stress during pregnancy (estimated by pregnant), child birth weight and frequency of low birth weight. The research was carried out by use of a questionnaire using the "case-control study". In the research were involved 450 mothers of new-born children (the group of cases: untimely, premature delivery or child birth weight below 2500 g) and 450 mothers of new-born children (control group-physiologically delivered). Mothers were asked about their relations to the pregnancy; professional and personal stress during pregnancy was estimated. The results were analysed by counting risk ratio coefficient (RR) and correlation coefficient. The research showed, that there is no relation between acceptation of pregnancy, stress and frequency of low birth weight or the average child birth weight. The researches didn't prove unfavourable influence of stress reaction caused by professional and personal stressors on intrauterine foetus development.

NMR investigations of model protein of elastic fibre is presented. Detailed conformation of alpha-elastin polypeptide chain is discussed by comparison with the conformation of synthetic repeat peptides of elastin. Amino acid composition of alpha-elastin obtained from C-13 NMR spectra correlates with the results of sequencing of tropoelastin.