Molecular genetics of Alzheimer's disease: presenilin 1 gene analysis in a cohort of patients from the Poznań region

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by memory loss and personality changes. Pathological hallmarks of AD are: deposition of amyloid plaques and neurofibrillary tangles in the brain, accompanied by neuronal and synaptic loss. The genetic background of AD is heterogeneous and strongly depends on the form of the disease. In most of the families with early-onset AD (EOAD) (10% of the total population of patients), the disease segregates as an autosomal dominant fully penetrant trait. To date, some missense mutations in three genes encoding the amyloid precursor protein, presenilin 1 (PS1) and 2 (PS2) have been found to cause familial EOAD. We screened for mutations in the presenilin genes in a sample of 55 patients with familial or sporadic form of EOAD from the Poznan region. We found 4 missense mutations in the PS1 gene: A246E in exon 7, P267L in exon 8, E318G in exon 9, and L424R in exon 12 among 5 unrelated patients. The frequency of PS1 mutations was 11% (5 of 55) in the whole sample of the patients with EOAD or 50% (3 of 6) if the analysis was restricted to familial cases with a positive history of dementia in the patient's family.     

Trends in atmospheric concentrations of weed pollen in the context of recent climate warming in Poznań (Western Poland)

A significant increase in summer temperatures has been observed for the period 1996–2011 in Poznań, Poland. The phenological response of four weed taxa, widely represented by anemophilous species (Artemisia spp., Rumex spp. and Poaceae and Urticaceae species) to this recent climate warming has been analysed in Poznań by examining the variations in the course of airborne pollen seasons. Pollen data were collected by 7-day Hirst-type volumetric trap. Trends in pollen seasons were determined using Mann–Kendall test and Sen’s slope estimator, whereas the relationships between meteorological and aerobiological data were established by Spearman’s rank correlation coefficient. Significant trends in pollen data were detected. The duration of pollen seasons of all analysed taxa increased (from +2.0 days/year for Urticaceae to +3.8 days/year for Rumex), which can be attributed to a delay in pollen season end dates rather than earlier start dates. In addition, the intensity of Artemisia pollen seasons significantly decreased and correlates with mean July–September daily minimum temperatures (r?=??0.644, p?Rumex pollen seasons. The results of this study show that observed shifts in weed pollen seasons in Poznań, i.e. longer duration and later end dates, might be caused by the recorded increase in summer temperature. This influence was the strongest in relation to Artemisia, which is the taxon that flowers latest in the year. The general lack of significant correlations between Rumex and Urticaceae pollen seasons and spring and/or summer temperature suggests that other factors, e.g. land use practices, could also be partially responsible for the observed shifts in pollen seasons.     

Variation in pollen concentration of the mostallergenic taxa in Poznań (Poland), 1995–1996

The airborne pollen concentration of the four mostfrequent and most allergenic taxa in Poland; Alnus, Betula, Poaceae, and Artemisia atPozna in the years 1995–1996 has been analyzed,using a Hirst-type volumetric spore trap. Theappearance of the earliest pollen producing taxa wasobserved as early as January and February, which isrelevant information for people subject to allergiesin the Pozna region, where Spring usually beginsin March. The periods of high and very high pollenconcentration of individual taxa have been comparedfor the two years.     

Variability of Mercury Concentrations in Soil and Leaves of Acer plantanoides and Tilia platyphyllos in Poznań City,Poland

The paper presents the results of research on mercury in the soil and leaves of maple (Acer plantanoides) and linden (Tilia platyphyllos) collected in the four districts of the city of Poznań (Poland), which differ in terms of anthropogenic pressure. The average concentration of mercury in soil was 132 μg kg^?1. The highest concentration of mercury was determined in Tilia platyphyllos (233 μg kg^?1), whereas in Acer plantanoides it amounted to 207 μg kg^?1. Based on the study, it was found that the highest concentration of mercury in the investigated leaf species was observed in the samples collected in the districts of Grunwald, Je?yce, and Old Town. The lowest concentration was observed in the samples collected in the district of New Town. The comparison of the obtained results of mercury concentration in soil and leaf samples was made in terms of anthropogenic pressure in the investigated areas and depending on the studied leaf species. Based on the statistical analysis, it was found that there is no statistically significant relationship between mercury concentration in both studied species of trees. There was, however, a relationship between the mercury concentration in leaves and soil.     

Urban rotifers: structure and densities of rotifer communities in water bodies of the Poznań agglomeration area (western Poland)

The rotifer fauna of 19 mostly small water bodies (natural and artificial ponds, clay-pits and pools) in Pozna was studied on four occasions during 1996–98 to determine the suitability of urban areas for rotifer habitats. Rotifers were present in all the water bodies studied, with 114 species in 39 genera found, representing ca. 25% of all rotifers recorded from Poland. Mean diversity was 10 spp (range 1–36). Most common were: Brachionus angularis and Keratella cochlearis (spring), Colurella uncinata, Lecane closterocercaand Lepadella patella (summer) and L. closterocerca and K. cochlearis (autumn). Rotifer densities (1-1503 ind l^–1), Shannon's diversity (H 0.00-3.71) and dominant species differed in different water-bodies. The index of percentage similarity of community showed strong differences in qualitative structure of rotifer assemblages. The different types of water habitats, both the existing or the newly created in towns, may explain the relatively high diversity of rotifer communities observed in the urban areas studied.     

Extensive sequence variation in the 3′ untranslated region of the KRAS gene in lung and ovarian cancer cases

While cancer is a serious health issue, there are very few genetic biomarkers that predict predisposition, prognosis, diagnosis, and treatment response. Recently, sequence variations that disrupt microRNA (miRNA)-mediated regulation of genes have been shown to be associated with many human diseases, including cancer. In an early example, a variant at one particular single nucleotide polymorphism (SNP) in a let-7 miRNA complementary site in the 3′ untranslated region (3′ UTR) of the KRAS gene was associated with risk and outcome of various cancers. The KRAS oncogene is an important regulator of cellular proliferation, and is frequently mutated in cancers. To discover additional sequence variants in the 3′ UTR of KRAS with the potential as genetic biomarkers, we resequenced the complete region of the 3′ UTR of KRAS in multiple non-small cell lung cancer and epithelial ovarian cancer cases either by Sanger sequencing or capture enrichment followed by high-throughput sequencing. Here we report a comprehensive list of sequence variations identified in cases, with some potentially dysregulating expression of KRAS by altering putative miRNA complementary sites. Notably, rs712, rs9266, and one novel variant may have a functional role in regulation of KRAS by disrupting complementary sites of various miRNAs, including let-7 and miR-181.     

Variations and trends of birch pollen seasons during 15 years (1996–2010) in relation to weather conditions in Poznań (western Poland)

Birch (Betula) pollen seasons were examined in relation to meteorological conditions in Poznań (1996–2010). Birch pollen grains were collected using a volumetric spore trap. An alternate biennial cycle of birch pollen season intensity was noticed in Poznań. The main factors influencing birch pollen season intensity were average daily minimum temperatures during the second fortnight of May and the month of June one year before pollination as well as the intensity of the pollen season of the previous year. Most of the pollen grains are recorded during the first week of the season; the number of pollen grains recorded at this time is positively correlated with mean maximum temperature and negatively correlated with daily rainfall. The significant effect of rainfall in reducing the season pollen index was noticed only during weak pollen seasons (season pollen index <?mean). In addition, mean daily maximum temperature during the first two weeks of the birch pollen season markedly influences its duration. No significant trends in duration and intensity of the pollen season were recorded, however, a slight tendency towards early pollination was observed (?0.4 days/year, p?=?0.310).     

Soil microflora of the rhizosphere of plants from several habitats in the botanical garden in Poznań.

The abundance and activity of certain groups of soil microorganisms were estimated in the rhizosphere of 13 plants from four different habitats at several dates. An additional study was made of the rhizosphere microflora of Ledum palustre from a peat-bog. Numbers of proteolytic, nitrate assimilating, denitrifying, and cellulolytic bacteria were estimated. The intensity of ammonification, nitrification and Clostridium growth was estimated. The studies have revealed that the abundance and the activity of all the groups of bacteria studied depended on the habitat. Within one habitat, however, the influence of the plant was sometimes more pronounced than that of the habitat itself, particularly on the abundance of proteolytic bacteria (Fig. 1). The date of sampling had very little effect on the abundance of all the bacterial groups studied except the cellulolytic bacteria.     

Two cases of mother–infant cannibalism in orangutans

Observations of ape cannibalism have to this point been limited to chimpanzees (Pan troglodytes) where it is associated with infanticide and consumption by unrelated individuals (Watts and Mitani, Primates 41(4):357–365, 2000). Here we report for the first time observations of two unrelated female Sumatran orangutans (Pongo abelii) cannibalizing the remains of their infants on different occasion, a behavior never before reported in any ape species. The two orangutans were wild-born rehabilitated individuals, and had been reintroduced to an area hosting a largely unregulated primate tourism industry and experienced restricted ranging conditions. Though it is possible that this is a strategy to regain energy and nutrients or a result of individual history, comparative data suggest that this is an aberrant behavior which may be linked to environmental stressors within the area. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Flowering phenology and potential pollen emission of three <Emphasis Type="Italic">Artemisia</Emphasis> species in relation to airborne pollen data in Poznań (Western Poland)

Artemisia pollen is an important allergen in Europe. In Poznań (Western Poland), three Artemisia species, A. vulgaris, A. campestris and A. absinthium, are widely distributed. However, the contributions of these species to the total airborne pollen are unknown. The aim of the study was to determine the flowering phenology and pollen production of the three abovementioned species and to construct a model of potential Artemisia pollen emission in the study area. Phenological observations were conducted in 2012 at six sites in Poznań using a BBCH phenological scale. Pollen production was estimated by counting the pollen grains per flower and recalculating the totals per inflorescence, plant and population in the study area. Airborne pollen concentrations were obtained using a Hirst-type volumetric trap located in the study area. Artemisia vulgaris began to flower the earliest, followed by A. absinthium and then A. campestris. The flowering of A. vulgaris corresponded to the first peak in the airborne pollen level, and the flowering of A. campestris coincided with the second pollen peak. The highest amounts of pollen per single plant were produced by A. vulgaris and A. absinthium. A. campestris produced considerably less pollen, however, due to its common occurrence, it contributed markedly (30 %) to the summation of total of recorded pollen. A. vulgaris is the most important pollen source in Poznań, but the roles of two other Artemisia species cannot be ignored. In particular, A. campestris should be considered as an important pollen contributor and likely might be one of the main causes of allergic reactions during late summer.     

Influence of lead nitrate oń dimethylnitrosamine intoxication

The effect of lead nitrate, an inhibitor of the hepatic drug-metabolizing enzyme system upon the acute hepatotoxicity of dimethylnitrosamine (DMN) was studied.Lead pretreatment significantly prevented polysomal disaggregation induced by the nitrosamine. Cell necrosis, evaluated morphologically and by the release of serum glutamic-pyruvic transaminase (GPT), was also diminised.The metabolism of DMN in rats pretreated with lead nitrate was investigated by following its clearance from blood and by determining, in vitro the demethylation of the nitrosamine. Lead increased, although not significantly, the clearance of DMN from blood, but it lowered the activity of DMN-demethylase 24 h after its administration.Finally, lead lowered the lethal effects of DMN. The mechanism by which lead influenced DMN toxicity is discussed.     

Association of polymorphisms and haplotypes in the 5′ region of COLIA1 gene with the risk of osteoporotic fractures in Russian women from Volga-Ural region

The analysis of ?1997G/T, ?1663indelT, and +1245G/T polymorphic loci of the 5′-region of COLIA1 gene in 124 females aged from 50 to 70 years old with low numbers of traumatic fractures as well as 150 healthy individuals from Volga-Ural region has been conducted. The association of ?1663indelT and +1245G/T loci with the risk of osteoporotic fractures has been discovered. It has been shown that ?1997*G*G/?1663*I*D/+1245*G*T genotype combination and ?1997*G/?1663*D/+1245*T haplotype can be considered as markers for fracture development.     

Strand symmetry of mutation rates in theβ-globin region

Summary It has been suggested that there may be inequalities in the types of substitution on the two DNA strands (in particular, in the frequencies of transversions from R to Y and from Y to R) due to a higher error rate on the lagging than the leading strand during replication. Reexamination of 11 kb of the -globin region sequenced in six primates fails to confirm this suggestion. Examination of the 73-kb -globin region sequenced in humans shows that the frequency of pyrimidines in different parts of this region is more variable than expected in a random sequence, but the pattern is more consistent with nonrandomness generated by DNA turnover mechanisms than with strand asymmetry due to a higher error rate on the lagging strand.