Search PubMed⌕ Search

Biomedical subjects

P Krajewski

Publications and source records attributed to P Krajewski.

16 recordsLinked to original sources
PubMed2006

Molecular background of polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome in a Polish population: novel AIRE mutations and an estimate of disease prevalence.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is an autosomal-recessive autoimmune disease caused by autoimmune regulator gene mutations. The aim of this study was to examine the mutation profile of Polish APECED patients, determine the carrier rate of the most frequent mutation(s) and estimate disease prevalence. While studying 14 unrelated patients, we identified three novel mutations (c.1A>T, affecting the start codon; [IVS1 + 1G>C; IVS1 + 5delG], a complex mutation affecting splice site; c. 908G>C, p.R303P, a missense mutation in plant homeodomain (PHD) and three previously reported mutations (c.769C>T, p.R257X; c.967_979del13bp, C322fsX372; c.931delT, p.C311fsX376). Eleven patients had mutations on both chromosomes, whereas in three patients only a single alteration with proven or likely pathogenic effect was detected. The most frequent was the p.R257X mutation (71% of chromosomes); its carriage rate was assessed in the background population. Analysis of 2008 samples showed eight heterozygotes, indicating the frequency of 0.40% (1:250) and the disease prevalence - 1:129,000 (95% confidence interval: 1:555,000 to 1:30,000). Comparison with an epidemiological estimate (1:619,000, derived for women) suggested that in Poland, APECED is underdiagnosed. Among the patients, no genotype/phenotype correlations were found, but we noted that women had earlier onset of hypoparathyroidism (p < 0.02) and were younger at diagnosis (p < 0.05) than men.

Adolescent↗
PubMed2005

Model testing using data on 137Cs from Chernobyl fallout in the Iput River catchment area of Russia.

Data collected for 10 years following the Chernobyl accident in 1986 have provided a unique opportunity to test the reliability of computer models for contamination of terrestrial and aquatic environments. The Iput River scenario was used by the Dose Reconstruction Working Group of the BIOMASS (Biosphere Modelling and Assessment Methods) programme. The test area was one of the most highly contaminated areas in Russia following the accident, with an average contamination density of 137Cs of 800,000 Bq m-2 and localized contamination up to 1,500,000 Bq m-2, and a variety of countermeasures that were implemented in the test area had to be considered in the modelling exercise. Difficulties encountered during the exercise included averaging of data to account for uneven contamination of the test area, simulating the downward migration and changes in bioavailability of 137Cs in soil, and modelling the effectiveness of countermeasures. The accuracy of model predictions is dependent at least in part on the experience and judgment of the participant in interpretation of input information, selection of parameter values, and treatment of uncertainties.

Cesium Radioisotopes↗
PubMed2005

Model testing using data on 131I released from Hanford.

The Hanford test scenario described an accidental release of 131I to the environment from the Hanford Purex Chemical Separations Plant in September 1963. Based on monitoring data collected after the release, this scenario was used by the Dose Reconstruction Working Group of BIOMASS to test models typically used in dose reconstructions. The primary exposure pathway in terms of contribution to human doses was ingestion of contaminated milk and vegetables. Predicted mean doses to the thyroid of reference individuals from ingestion of 131I ranged from 0.0001 to 0.8 mSv. For one location, predicted doses to the thyroids of two children with high milk consumption ranged from 0.006 to 2 mSv. The predicted deposition at any given location varied among participants by a factor of 5-80. The exercise provided an opportunity for comparison of assessment methods and conceptual approaches, testing model predictions against measurements, and identifying the most important contributors to uncertainty in the assessment result. Key factors affecting predictions included the approach to handling incomplete data, interpretation of input information, selection of parameter values, adjustment of models for site-specific conditions, and treatment of uncertainties.

Iodine Radioisotopes↗
PubMed2005

Analyzing multi-environment variety trials using randomization-derived mixed models.

Of interest is the analysis of results of a series of experiments repeated at several environments with the same set of plant varieties. Suppose that the experiments, multi-environment variety trials, are all conducted in resolvable incomplete block (IB) designs. Following the randomization approach adopted in Caliński and Kageyama (2000, Lecture Notes in Statistics, 150), two models for analyzing such trial data can be considered. One is derived under a complete additivity assumption, the other takes into account possible different responses of the varieties to variable environmental conditions. The analysis under the first, the standard model, does not provide answers to questions related to the performance of the individual varieties at different environments. These can be considered when using the more general second model. The purpose of this article is to devise interesting parameter estimation and hypothesis testing procedures under that more realistic model. Its application is illustrated by a thorough analysis of a set of data from a winter wheat series of trials.

Algorithms↗
PubMed2001

A nicked duplex decamer DNA with a PEG(6) tether.

A dumbbell double-stranded DNA decamer tethered with a hexaethylene glycol linker moiety (DDSDPEG), with a nick in the centre of one strand, has been synthesised. The standard NMR methods, E.COSY, TOCSY, NOESY and HMQC, were used to measure (1)H, (31)P and T:(1) spectral parameters. Molecular modelling using rMD-simulated annealing was used to compute the structure. Scalar couplings and dipolar contacts show that the molecule adopts a right-handed B-DNA helix in 38 mM phosphate buffer at pH 7. Its high melting temperature confirms the good base stacking and stability of the duplex. This is partly attributed to the presence of the PEG(6) linker at both ends of the duplex that restricts the dynamics of the stem pentamers and thus stabilises the oligonucleotide. The inspection of the global parameters shows that the linker does not distort the B-DNA geometry. The computed structure suggests that the presence of the nick is not disturbing the overall tertiary structure, base pair geometry or duplex base pairing to a substantial extent. The nick has, however, a noticeable impact on the local geometry at the nick site, indicated clearly by NMR analysis and reflected in the conformational parameters of the computed structure. The (1)H spectra also show much sharper resonances in the presence of K(+) indicating that conformational heterogeneity of DDSDPEG is reduced in the presence of potassium as compared to sodium or caesium ions. At the same time the (1)H resonances have longer T:(1) times. This parameter is suggested as a sensitive gauge of stabilisation.

Cations↗
PubMed2001

Relationship between CMV infection and coronary heart disease.

Conflicting evidence implicating CMV infection in coronary heart disease (CHD) exists. In this work using serological methods (IgM-CMV by Western blot and IgG-CMV by ELISA) correlation between CMV infection and CHD was not found. On the other hand presence of CMV DNA in atherosclerotic plaques with absence in unchanged vessel indicates possible role of CMV infection in progression of this process.

Antibodies, Viral↗
PubMed2001

Electrophoretic seed globulin patterns and species relationships in the genus Lens Miller.

SDS-PAGE analysis of seed globulins covered 200 accessions of the following Lens taxa: L. culinaris subsp. culinaris, L. culinaris subsp. orientalis, L. odemensis, L. ervoides, L. nigricans, L. lamottei and L. tomentosus. The number of polypeptide bands detected in particular taxa varied from 22 in L. lamottei to 35 in L. ervoides. All the taxa under study showed variation due to differences among accessions and individual variation. Electrophoretic data were subjected to statistical analysis by the UPGMA method based on Euclidean distances. In the case of L. culinaris subsp. culinaris, some distinctness of the microsperma accessions from southern and central Asia was found. As to relationships among the studied taxa, the obtained results showed that L. culinaris subsp. culinaris appeared to be most closely allied to L. odemensis, while L. culinaris subsp. orientalis was found to be the closest relative of L. tomentosus. The four taxa formed one cluster separated from L. lamottei and L. ervoides. L. nigricans was shown to be the most divergent taxon.

Journal Article↗
PubMed2000

A multivariate approach to the problem of QTL localization.

QTL mapping with statistical likelihood-based procedures or asymptotically equivalent regression methods is usually carried out in a univariate way, even if many traits were observed in the experiment. Some proposals for multivariate QTL mapping by an extension of the maximum likelihood method for mixture models or by an application of the canonical transformation have been given in the literature. This paper describes a method of analysis of multitrait data sets, aimed at localization of QTLs contributing to many traits simultaneously, which is based on the linear model of multivariate multiple regression. A special form of the canonical analysis is employed to decompose the test statistic for the general no-QTL hypothesis into components pertaining to individual traits and individual, putative QTLs. Extended linear hypotheses are used to formulate conjectures concerning pleiotropy. A practical mapping algorithm is described. The theory is illustrated with the analysis of data from a study of maize drought resistance.

Genes, Plant↗
PubMed2000

The quality of heart valve tissue for homograft transplantation.

BACKGROUND AND AIM OF THE STUDY: The results of heart valve replacement surgery may be improved by refining surgical techniques and/or developing new heart valve transplants. The aim of this study was to examine the effect of age on the presence of cholesterol clefts and lipid deposits in the cusp base and sinus wall of aortic homografts. METHODS: Seventy-one valves were obtained at autopsy from donors (aged 15- 40 years) with no history of illness or evidence of serious illness. Trauma was the predominant cause of death among patients. The valves were examined using an osmium-vaporization technique. RESULTS: Osmiophilic deposits were detected in the cusp base in 28 cases (42%), and in the sinus wall in 49 cases (69%). Cholesterol crystals in the cusp base were found in 16 cases (24%), and sinus wall cholesterol clefts in 26 cases (38%). The model-predicted probability of cusp base lipid deposits existing was 76% in 40-year-old donors, 36% in 30-years-olds, and 11% in 20-year-olds; the probability of cusp base cholesterol clefts existing was 45%, 21% and 8% in these age groups, respectively. The influences of immunological reactions, biochemical changes (centers of calcification) and acceleration of atherosclerotic processes are discussed. CONCLUSION: The microscopic study of heart valves demonstrated the presence of lipid deposits in subjects of an unexpectedly young age. Among our study material, 58% of valves obtained from donors aged 11-40 years were unsuitable for transplantation. Our results confirmed the need for macroscopic inspection of heart valves before their being transplanted.

Adolescent↗
PubMed1997

[Analysis of factors affecting HBV and HCV infections in premature children].

Premature children with the very low birth weight, who need a long hospital treatment after the birth, belong to the group of the highest risk of HBV and HCV infections. The study includes 32 premature children, 14 girls and 18 boys, who were born between 26 and 35 week of pregnancy with the birth weight from 800 to 2400 g. Chronic hepatitis were found in these children; 11 children had HBV infection, 10 children had HCV infection, and both HBV and HBC infections were found in 11 children. Blood transfusions, parenteral nutrition, parenteral antibiotics, surgical treatment and other medical interventions were considered as the most important factors affecting HBV/HBC infections. All these factors should be taken into consideration in efforts to reduce the frequency of HBV and HBC infections in premature children.

Adult↗
PubMed1994

Radiocesium in diet and humans in northeastern Poland after the Chernobyl accident.

137Cs and 134Cs concentrations were determined in the daily diet and foodstuffs in northeastern Poland in the fourth through sixth years after the Chernobyl accident. Intakes, body burdens, and dose equivalents were evaluated in the consecutive years. The data from this and previous work were used for the calculation of the effective half-time of radiocesium in humans. The effective half-time for 137Cs (1.94 y) was similar to that observed after nuclear weapons tests. The effective half-time for 134Cs was 0.98 y. Taking these half-times into account, the whole-body committed dose equivalent for the adult population was estimated to be 256 microSv; it was about 50% higher than that after the nuclear weapons tests.

Accidents↗
PubMed1991

[Evaluation of equivalent body burden in the thyroid for the people of Poland on results of 131I absorption after the disaster in Czernobyl. Determination of thyroid blockade with potassium iodide].

An assessment of effectiveness of the administering of single dose of stable iodine in Poland on the reduction of 131I doses in thyroid has been performed. 5-compartment model of metabolism of iodine developed by Johnson has been used to evaluate predicted levels of stable iodine and 131I content in thyroid and commitment dose equivalent H50 for different doses of stable iodine and various age and sex group population. The measured values of 131I concentration in air and in milk and standard values for milk and food consumption and inhalation rate as well as metabolic parameters were used. Theoretical calculations showed that administering of stable iodine on 1986-04-28, 1986-04-29, 1986-04-30 and 1986-05-01 could have reduced committed dose equivalent H50 form ingestion with inhalation pathway by about 44%, 40%, 26%, 12% respectively. On the basis of measured 131I activity in the thyroid for inhabitants from different districts in Poland (1400 measurement) committed dose equivalents were determined and analysis of radiation hazard from 131I were performed. In the most contaminated regions of Poland average H50 doses for children 1-5 and 5-10 years old are close to 50 mSv (permissible level for population) and maximal doses exceed this limit four times. These maximal doses occurred for about from 5% inhabitants from these area. In the moderate and low contaminated regions of Poland the average doses are fivefold and tenfold less respectively.

Air Pollutants, Radioactive↗
PubMed1991

[Effect of student knowledge in gastronomy schools and origin of residence on their nutritional habits and nutritional status].

Nutritional habits and nutritional status of 142 pupils of a Gastronomic School Complex were examined from the standpoint of the year of school, school marks and place of residence. It was found that the year of school and place of residence exerted an effect on the nutritional habits of pupils. These young people failed to prefer dishes and food products recommended in the prophylaxis of civilization diseases. In all subjects the levels of total lipids and beta-lipoproteins exceeded the upper range of the norm. Hemoglobin concentration fluctuated within the lower range of the norm, and that of glucose--within the upper range of the norm. When completing school, the pupils displayed a lowered protein level and elevated glucose level. Pupils inhabiting the school boarding house ought to take part in the decisions on the menu and on food purchases. Recommendations concerning nutrition in the prophylaxis of civilization diseases ought to be as soon as possible introduced into the teaching program of the Gastronomic School Complex.

Feeding Behavior↗