p53 and DNA damage checkpoint responses in the human prostate

Prostate cancer is the most common noncutaneous malignancy and the second leading cause of cancer mortality in men. In 2004, 5237 new cases were diagnosed and altogether 25 664 men suffered from prostate cancer in Finland (Suomen Syöpärekisteri). Although extensively investigated, we still have a very rudimentary understanding of the molecular mechanisms leading to the frequent transformation of the prostate epithelium. Prostate cancer is characterized by several unique features including the multifocal origin of tumors and extreme resistance to chemotherapy, and new treatment options are therefore urgently needed. The integrity of genomic DNA is constantly challenged by genotoxic insults. Cellular responses to DNA damage involve elegant checkpoint cascades enforcing cell cycle arrest, thus facilitating damage repair, apoptosis or cellular senescence. Cellular DNA damage triggers the activation of tumor suppressor protein p53 and Wee1 kinase which act as executors of the cellular checkpoint responses. These are essential for genomic integrity, and are activated in early stages of tumorigenesis in order to function as barriers against tumor formation. Our work establishes that the primary human prostatic epithelial cells and prostatic epithelium have unexpectedly indulgent checkpoint surveillance. This is evidenced by the absence of inhibitory Tyr15 phosphorylation on Cdk2, lack of p53 response, radioresistant DNA synthesis, lack of G1/S and G2/M phase arrest, and presence of persistent gammaH2AX damage foci. We ascribe the absence of inhibitory Tyr15 phosphorylation to low levels of Wee1A, a tyrosine kinase and negative regulator of cell cycle progression. Ectopic Wee1A kinase restored Cdk2-Tyr15 phosphorylation and efficiently rescued the ionizing radiation-induced checkpoints in the human prostatic epithelial cells. As variability in the DNA damage responses has been shown to underlie susceptibility to cancer, our results imply that a suboptimal checkpoint arrest may greatly increase the accumulation of genetic lesions in the prostate epithelia. We also show that small molecules can restore p53 function in prostatic epithelial cells and may serve as a paradigm for the development of future therapeutic agents for the treatment of prostate cancer We hypothesize that the prostate has evolved to activate the damage surveillance pathways and molecules involved in these pathways only to certain stresses in extreme circumstances. In doing so, this organ inadvertently made itself vulnerable to genotoxic stress, which may have implications in malignant transformation. Recognition of the limited activity of p53 and Wee1 in the prostate could drive mechanism-based discovery of preventative and therapeutic agents.

A detailed study of Li-DNA fibres at various salt concentrations reveals a non-helical B-DNA and a possible similarity of solution and solid state structures

A thorough investigation of salt concentration dependence of lithium DNA fibres is made using X-ray diffraction. While for low salt the C-form pattern is obtained, crystalline B-type diffraction patterns result on increasing the salt concentration. The salt content in the gel (from which fibres are drawn) is estimated by equilibrium dialysis using the Donnan equilibrium principle. The salt range giving the best crystalline B pattern is determined. It is found that in this range meridional reflections occur on the fourth and sixth layer lines. In addition, the tenth layer meridian is absent at a particular salt concentration. These results strongly suggest the presence of non-helical features in the DNA molecule. Preliminary analysis of the diffraction patterns indicates a structural variability within the B-form itself. Further, the possibility of the structural parameters of DNA being similar in solid state and in solution is discussed.

Sex Determination - A Hypothesis Based On Noncoding Dna

Certain recent models of sex determination in mammals, Drosophila melanogaster, Caenorhabditis elegans, and snakes are examined in the light of the hypothesis that the relevant genetic regulatory mechanisms are similar and interrelated. The proposed key element in each of these instances is a noncoding DNA sequence, which serves as a high-affinity binding site for a repressor-like molecule regulating the activity of a major "sex-determining" gene. On this basis it is argued that, in several eukaryotes, (i) certain DNA sequences that are sex-determining are noncoding, in the sense that they are not the structural genes of a sex-determining protein; (ii) in some species these noncoding sequences are present in one sex and absent in the other, while in others their copy number or accessibility to regulatory molecules is significantly unequal between the two sexes; and (iii) this inequality determines whether the embryo develops into a male or a female.

Develop added value uses of high anti-bacterial honey

Honey is valued for its medicinal properties. There interest from industry to develop a rapid method to detect the bioactivity of honey and also to develop value added products from high antibacterial honey.

N-[2-naphthyl]-glycine hydrazide, a potent inhibitor of dna-dependent rna-polymerase of mycobacterium-tuberculosis h37rv

N-[2-Naphthyl]-glycine hydrazide has been shown for the first time as a potent inhibitor of the DNA-dependent RNA polymerase (EC 2.7.7.6) of Mycobacterium tuberculosis H37Rv. At a concentration of 10 to the power -9 M, the compound shows maximum inhibition of the enzyme, the inhibition being less at higher concentrations. It is suggested that the novel type of inhibition pattern may be due to hydrophobic interactions occurring between the molecules of the compound at higher concentrations. The finding that there is a shift in the max of the compound could also account for this phenomenon. The effect of this compound was also tested on DNA-dependent RNA polymerases from an eukaryotic fungus, Microsporum canis. At a concentration of 10 to the power-9 M it inhibits RNA polymerase II (32 percent) but not RNA polymerases I and III.

Meta-analyses identify 13 loci associated with age at menopause and highlight DNA repair and immune pathways

To newly identify loci for age at natural menopause, we carried out a meta-analysis of 22 genome-wide association studies (GWAS) in 38,968 women of European descent, with replication in up to 14,435 women. In addition to four known loci, we identified 13 loci newly associated with age at natural menopause (at P < 5 x 10(-8)). Candidate genes located at these newly associated loci include genes implicated in DNA repair (EXO1, HELQ, UIMC1, FAM175A, FANCI, TLK1, POLG and PRIM1) and immune function (IL11, NLRP11 and PRRC2A (also known as BAT2)). Gene-set enrichment pathway analyses using the full GWAS data set identified exoDNase, NF-kappaB signaling and mitochondrial dysfunction as biological processes related to timing of menopause.

Variety quality management in strawberry, using DNA genotyping as a tool

Quality management strawberry, DNA genotyping.

Molecular and epidemiological aspects of Streptococcus pyogenes disease in Finland: Severe infections and bacterial, non-necrotizing cellulitis

Streptococcus pyogenes (group A streptococcus) is an important human pathogen, causing a wide array of infections ranging in severity. The majority of S. pyogenes infections are mild upper respiratory tract or skin infections. Severe, invasive infections, such as bacteraemia, are relatively rare, but constitute a major global burden with a high mortality. Certain streptococcal types are associated with a more severe disease and higher mortality. Bacterial, non-necrotizing cellulitis and erysipelas are localised infections of the skin, and although they are usually not life-threatening, they have a tendency to recur and therefore cause substantial morbidity. Despite several efforts aimed at developing an effective and safe vaccine against S. pyogenes infections, no vaccine is yet available. In this study, the epidemiology of invasive S. pyogenes infections in Finland was described over a decade of national, population-based surveillance. Recent trends in incidence, outcome and bacterial types were investigated. The beta-haemolytic streptococci causing cellulitis and erysipelas infections in Finland were studied in a case-control study. Bacterial isolates were characterised using both conventional and molecular typing methods, such as the emm typing, which is the most widely used typing method for beta-haemolytic streptococci. The incidence of invasive S. pyogenes disease has had an increasing trend during the past ten years in Finland, especially from 2006 onwards. Age- and sex-specific differences in the incidence rate were identified, with men having a higher incidence than women, especially among persons aged 45-64 years. In contrast, more infections occurred in women aged 25-34 years than men. Seasonal patterns with occasional peaks during the midsummer and midwinter were observed. Differences in the predisposing factors and underlying conditions of patients may contribute to these distinctions. Case fatality associated with invasive S. pyogenes infections peaked in 2005 (12%) but remained at a reasonably low level (8% overall during 2004-2007) compared to that of other developed countries (mostly exceeding 10%). Changes in the prevalent emm types were associated with the observed increases in incidence and case fatality. In the case-control study, acute bacterial non-necrotizing cellulitis was caused predominantly by Streptococcus dysgalactiae subsp. equisimilis, instead of S. pyogenes. The recurrent nature of cellulitis became evident. This study adds to our understanding of S. pyogenes infections in Finland and provides a basis for comparison to other countries and future trends. emm type surveillance and outcome analyses remain important for detecting such changes in type distribution that might lead to increases in incidence and case fatality. Bacterial characterisation serves as a basis for disease pathogenesis studies and vaccine development.

Recent developments in DNA evidence

DNA evidence has made a significant contribution to criminal investigations in Australia and around the world since it was widely adopted in the 1990s (Gans & Urbas 2002). The direct matching of DNA profiles, such as comparing one obtained from a crime scene with one obtained from a suspect or database, remains a widely used technique in criminal investigations. A range of new DNA profiling techniques continues to be developed and applied in criminal investigations around the world (Smith & Urbas 2012). This paper is the third in a series by the Australian Institute of Criminology (AIC) on DNA evidence. The first, published in 1990 when the technology was in its relative infancy, outlined the scientific background for DNA evidence, considered early issues such as scientific reliability and privacy and described its application in early criminal cases (Easteal & Easteal 1990). The second, published in 2002, expanded on the scientific background and discussed a significant number of Australian cases in a 12-year period, illustrating issues that had arisen in investigations, at trial and in the use of DNA in the review of convictions and acquittals (Gans & Urbas 2002). There have been some significant developments in the science and technology behind DNA evidence in the 13 years since 2002 that have important implications for law enforcement and the legal system. These are discussed through a review of relevant legal cases and the latest empirical evidence. This paper is structured in three sections. The first examines the scientific techniques and how they have been applied in police investigations, drawing on a number of recent cases to illustrate them. The second considers empirical research evaluating DNA evidence and databases and the impact DNA has on investigative and court outcomes. The final section discusses significant cases that establish legal precedent relating to DNA evidence in criminal trials where significant issues have arisen or new techniques have been applied that have not yet been widely discussed in the literature. The paper concludes by reflecting on implications for policy and practice.

Detection and differentiation of bovine herpesvirus 1 and 5 using a multiplex real-time polymerase chain reaction.

A multiplex real-time PCR was developed for the detection and differentiation of two closely related bovine herpesviruses 1 (BoHV-1) and 5 (BoHV-5). The multiplex real-time PCR combines a duplex real-time PCR that targets the DNA polymerase gene of BoHV-1 and BoHV-5 and a real-time PCR targeting mitochondrial DNA, as a house-keeping gene, described previously by Cawthraw et al. (2009). The assay correctly identified 22 BoHV-1 and six BoHV-5 isolates from the Biosecurity Sciences Laboratory virus collection. BoHV-1 and BoHV-5 were also correctly identified when incorporated in spiked semen and brain tissue samples. The detection limits of the duplex assay were 10 copies of BoHV-1 and 45 copies of BoHV-5. The multiplex real-time PCR had reaction efficiencies of 1.04 for BoHV-1 and 1.08 for BoHV-5. Standard curves relating Ct value to template copy number had correlation coefficients of 0.989 for BoHV-1 and 0.978 for BoHV-5. The assay specificity was demonstrated by testing bacterial and viral DNA from pathogens commonly isolated from bovine respiratory and reproductive tracts. The validated multiplex real-time PCR was used to detect and differentiate BoHV-1 and BoHV-5 in bovine clinical samples with known histories.

DNA markers linked to the R(2) rust resistance gene in sunflower (Helianthus annuus L.) facilitate anticipatory breeding for this disease variant.

Pre-emptive breeding for host disease resistance is an effective strategy for combating and managing devastating incursions of plant pathogens. Comprehensive, long-term studies have revealed that virulence to the R (2) sunflower (Helianthus annuus L.) rust resistance gene in the line MC29 does not exist in the Australian rust (Puccinia helianthi) population. We report in this study the identification of molecular markers linked to this gene. The three simple sequence repeat (SSR) markers ORS795, ORS882, and ORS938 were linked in coupling to the gene, while the SSR marker ORS333 was linked in repulsion. Reliable selection for homozygous-resistant individuals was efficient when the three markers, ORS795, ORS882, and ORS333, were used in combination. Phenotyping for this resistance gene is not possible in Australia without introducing a quarantinable race of the pathogen. Therefore, the availability of reliable and heritable DNA-based markers will enable the efficient deployment of this gene, permitting a more effective strategy for generating sustainable commercial cultivars containing this rust resistance gene.

Anti-bacterial surfaces: Natural agents, mechanisms of action, and plasma surface modification

Strategies that confine antibacterial and/or antifouling property to the surface of the implant, by modifying the surface chemistry and morphology or by encapsulating the material in an antibiotic-loaded coating, are most promising as they do not alter bulk integrity of the material. Among them, plasma-assisted modification and catechol chemistry stand out for their ability to modify a wide range of substrates. By controlling processing parameters, plasma environment can be used for surface nano structuring, chemical activation, and deposition of biologically active and passive coatings. Catechol chemistry can be used for material-independent, highly-controlled surface immobilisation of active molecules and fabrication of biodegradable drug-loaded hydrogel coatings. In this article, we comprehensively review the role plasma-assisted processing and catechol chemistry can play in combating bacterial colonisation on medically relevant coatings, and how these strategies can be coupled with the use of natural antimicrobial agents to produce synthetic antibiotic-free antibacterial surfaces.

Plasma assisted surface modification of organic biopolymers to prevent bacterial attachment

Despite many synthetic biomaterials having physical properties that are comparable or even superior to those of natural body tissues, they frequently fail due to the adverse physiological reactions they cause within the human body, such as infection and inflammation. The surface modification of biomaterials is an economical and effective method by which biocompatibility and biofunctionality can be achieved while preserving the favorable bulk characteristics of the biomaterial, such as strength and inertness. Amongst the numerous surface modification techniques available, plasma surface modification affords device manufacturers a flexible and environmentally friendly process that enables tailoring of the surface morphology, structure, composition, and properties of the material to a specific need. There are a vast range of possible applications of plasma modification in biomaterial applications, however, the focus of this review paper is on processes that can be used to develop surface morphologies and chemical structures for the prevention of adhesion and proliferation of pathogenic bacteria on the surfaces of in-dwelling medical devices. As such, the fundamental principles of bacterial cell attachment and biofilm formation are also discussed. Functional organic plasma polymerised coatings are also discussed for their potential as biosensitive interfaces, connecting inorganic/metallic electronic devices with their physiological environments.