THE ULTRASTRUCTURE AND IMMUNOGOLD LABELING OF PANCREATIC POLYPEPTIDE-IMMUNOREACTIVE CELLS ASSOCIATED WITH THE EGG-FORMING APPARATUS OF A MONOGENEAN PARASITE, DICLIDOPHORA-MERLANGI

An electron microscopical examination has been made of the fine structure and disposition of pancreatic polypeptide immunoreactive cells associated with the egg-forming apparatus in Diclidophora merlangi. The cell bodies are positioned in the parenchyma surrounding the ootype and taper to axon-like processes that extend to the ootype wall. The terminal regions of these processes branch and anastomose and, in places, the swollen endings or varicosities form synaptic appositions with the muscle fibres in the ootype wall. The cells are characterized by an extensive GER-Golgi system that is involved in the assembly and packaging of dense-cored vesicles. The vesicles accumulate in the axons and terminal varicosities, and their contents were found to be immunoreactive with antisera raised to the C-terminal hexapeptide amide of pancreatic polypeptide. It is concluded that the cells are neurosecretory in appearance and that, functionally, their secretions may serve to regulate ootype motility and thereby help co-ordinate egg production in the worm.

The POINT-AGAPE survey - I. The variable stars in M31

For the purposes of identifying microlensing events, the POINT-AGAPE collaboration has been monitoring the Andromeda galaxy (M31) for three seasons (1999-2001) with the Wide Field Camera on the Isaac Newton Telescope. In each season, data are taken for one hour per night for roughly 60 nights during the six months that M31 is visible. The two 33 x 33 arcmin(2) fields of view straddle the central bulge, northwards and southwards. We have calculated the locations, periods and brightness of 35 414 variable stars in M31 as a by-product of the microlensing search. The variables are classified according to their period and brightness. Rough correspondences with classical types of variable star (such as Population I and II Cepheids, Miras and semiregular long-period variables) are established. The spatial distribution of Population I Cepheids is clearly associated with the spiral arms, while the central concentration of the Miras and long-period variables varies noticeably, the brighter and the shorter period Miras being much more centrally concentrated.

Flow cytometric analysis of within-strain variation in polysaccharide expression by Bacteroides fragilis by use of murine monoclonal antibodies.

The reactivity of four different monoclonal antibodies (MAbs) with populations of Bacteroides fragilis NCTC 9343, enriched by density gradient centrifugation for a large capsule, small capsule and electron-dense layer (EDL) only visible by electronmicroscopy, was examined. The MAbs reacted strongly with polysaccharides present in both the large capsule- and EDL-enriched populations but not in the small capsule-enriched populations. The pattern of labelling was determined by immunoblotting, immunofluorescence and immuno-electronmicroscopy, and flow cytometry. The MAbs labelled cell membrane-associated epitopes in the large capsule- and EDL-enriched populations and cell-free material in the EDL population. By immunoblotting, ladders of repeating polysaccharide subunits were evident in the EDL population but not in the large capsule population. The proportion of cells labelled within each population was determined by flow cytometry. The reactivity of another MAb with the small capsule population was confirmed by flow cytometry. A qualitative indication of epitope expression was obtained by examination of the flow cytometric profiles. Differential expression of the same saccharide epitope was observed both between and within structurally distinct B. fragilis populations. The MAbs were species-specific and cross-reacted with several recent clinical isolates. These polysaccharides may be relevant to the virulence of B. fragilis.

Plasmid pRTL1 controlling 1-chloroalkane degradation by Rhodococcus rhodochrous NCIMB 13064

Rhodococcus rhodochrous NCIMB13064 can dehalogenate and use a wide range of 1-haloalkanes as sole carbon and energy source. The 1-chloroalkane degradation phenotype may be lost by cells spontaneously or after treatment with Mitomycin C. Two laboratory derivatives of the original strain exhibited differing degrees of stability of the chloroalkane degradation marker. Plasmids of approximately 100 kbp (pRTL1) and 80 kbp (pRTL2) have been found in R. rhodochrous NCIMB13064. pRTL1 was shown to be carrying at least some genes for the dehalogenation of 1-chloroalkanes with short chain lengths (C-3 to C-9). However, no connection was found between the utilization of 1-chloroalkanes with longer chain lengths (C-12 to C-18) and the presence of pRTL1. Three separate events were observed to lead to the inability of NCIMB13064 to dehalogenate the short-chain 1-chloroalkanes; the complete loss of pRTL1, the integration of pRTL1 into the chromosome, or the deletion of a 20-kbp fragment in pRTL1. High-frequency transfer of the 1-chloroalkane degradation marker associated with pRTL1 has been demonstrated in bacterial crosses between different derivatives of R. rhodochrous NCIMB13064, (C) 1995 Academic Press, Inc.

Akt-Mediated Proinflammatory Response of Mononuclear Phagocytes Infected with Burkholderia cenocepacia Occurs by a Novel GSK3 beta-Dependent, I kappa B Kinase-Independent Mechanism

The environmental bacterium Burkholderia cenocepacia causes opportunistic lung infections in immunocompromised individuals, particularly in patients with cystic fibrosis. Infections in these patients are associated with exacerbated inflammation leading to rapid decay of lung function, and in some cases resulting in cepacia syndrome, which is characterized by a fatal acute necrotizing pneumonia and sepsis. B. cenocepacia can survive intracellularly in macrophages by altering the maturation of the phagosome, but very little is known on macrophage responses to the intracellular infection. In this study, we have examined the role of the PI3K/Akt signaling pathway in B. cenocepacia-infected monocytes and macrophages. We show that PI3K/Akt activity was required for NF-kappa B activity and the secretion of proinflammatory cytokines during infection with B. cenocepacia. In contrast to previous observations in epithelial cells infected with other Gram-negative bacteria, Akt did not enhance I kappa B kinase or NF-kappa B p65 phosphorylation, but rather inhibited GSK3 beta, a negative regulator of NF-kappa B transcriptional activity. This novel mechanism of modulation of NF-kappa B activity may provide a unique therapeutic target for controlling excessive inflammation upon B. cenocepacia infection. The Journal of Immunology, 2011, 187: 635-643.

Mitochondrial J haplogroup is associated with lower blood pressure and anti-oxidant status: findings in octo/nonagenarians from the BELFAST Study

Mitochondria produce cellular energy but also free-radicals, which damage cells despite an array of endogenous anti-oxidants. In Northern Europe, the mitochondrial haplogroup J has been related to longevity in nonagenarians and centenarians but also with age-related disease. Hypertension is an important contributor to atherosclerotic-related diseases and its pathogenesis is associated with increased oxidative stress. In this study, we questioned whether J haplogroup octo/nonagenarians from the Belfast Elderly Longitudinal Free-living Elderly STudy (BELFAST) study showed evidence of protective blood pressure or anti-oxidant profile which might explain their longevity advantage. Briefly, in a cross-sectional study, community-living, mentally alert (Folstein >25/30), octo/nonagenarian subjects, recruited for good health, were enlisted and consented as part of the BELFAST study, for blood pressure, anthropometric measurements and blood sampling. DNA typing for mitochondrial haplotypes was carried out with measurements for enzymatic and non-enzymatic antioxidants. J haplogroup carriers showed lower systolic blood pressure and glutathione peroxidase activity (Gpx) with higher folate measurements. There was no change in urate, bilirubin, albumin or nutrition-related antioxidants-selenium or vitamins A, C and a and ß carotene. BELFAST study mtDNA J haplogroup octo/nonagenarians showed lower blood pressure and reduced glutathione peroxidase activity and higher folate, but no change for other antioxidants. These findings are of interest in view of mtDNA J haplogroup's association with increased age in some previous studies.

Elevated soluble cellular adhesion molecules are associated with increased mortality in a prospective cohort of renal transplant recipients

Increased plasma levels of cellular adhesion molecules (CAMs) have been shown to be predictors of all cause mortality in individuals with chronic renal failure 12 and patients with end-stage renal disease receiving haemodialysis 3. In renal transplant recipients the predictive value of CAMs has not been well characterised. The aim of this study was to assess the relationship between CAMs and all-cause mortality during prospective follow-up of a renal transplant cohort.

Paraoxonase polymorphisms are not associated with cardiovascular risk in renal transplant recipients

Paraoxonase (PON1) gene variants have been identified as risk factors for cardiovascular disease (CVD). There are two common PON1 polymorphisms at position 55 (Leu-Met change) and 192 (Gln-Arg change) of the amino acid chain. Leucine at position 55 and arginine at position 192 have been associated with increased cardiovascular risk. The increased prevalence of CVD in renal transplant recipients can be only partly explained by the increased prevalence of conventional risk factors.

Decreased serum retinol is associated with increased mortality in renal transplant recipients

Vitamin A plays a central role in epithelial integrity and immune function. Given the risk of infection after transplantation, adequate vitamin A concentrations may be important in patients with a transplant. We assessed whether there was an association between retinol concentration and all-cause mortality in renal transplant recipients.

Genome-wide association study identifies a common variant in RAD51B associated with male breast cancer risk

We conducted a genome-wide association study of male breast cancer comprising 823 cases and 2,795 controls of European ancestry, with validation in independent sample sets totaling 438 cases and 474 controls. A SNP in RAD51B at 14q24.1 was significantly associated with male breast cancer risk (P = 3.02 × 10(-13); odds ratio (OR) = 1.57). We also refine association at 16q12.1 to a SNP within TOX3 (P = 3.87 × 10(-15); OR = 1.50).

Kruppel-associated Box (KRAB)-associated co-repressor (KAP-1) Ser-473 phosphorylation regulates heterochromatin protein 1β (HP1-β) mobilization and DNA repair in heterochromatin

The DNA damage response encompasses a complex series of signaling pathways that function to regulate and facilitate the repair of damaged DNA. Recent studies have shown that the repair of transcriptionally inactive chromatin, named heterochromatin, is dependent upon the phosphorylation of the co-repressor, Krüppel-associated box (KRAB) domain-associated protein (KAP-1), by the ataxia telangiectasia-mutated (ATM) kinase. Co-repressors, such as KAP-1, function to regulate the rigid structure of heterochromatin by recruiting histone-modifying enzymes, such HDAC1/2, SETDB1, and nucleosome-remodeling complexes such as CHD3. Here, we have characterized a phosphorylation site in the HP1-binding domain of KAP-1, Ser-473, which is phosphorylated by the cell cycle checkpoint kinase Chk2. Expression of a nonphosphorylatable S473A mutant conferred cellular sensitivity to DNA-damaging agents and led to defective repair of DNA double-strand breaks in heterochromatin. In addition, cells expressing S473A also displayed defective mobilization of the HP1-ß chromodomain protein. The DNA repair defect observed in cells expressing S473A was alleviated by depletion of HP1-ß, suggesting that phosphorylation of KAP-1 on Ser-473 promotes the mobilization of HP1-ß from heterochromatin and subsequent DNA repair. These results suggest a novel mechanism of KAP-1-mediated chromatin restructuring via Chk2-regulated HP1-ß exchange from heterochromatin, promoting DNA repair.

Frequency and distribution of group I intron genotypes of Candida albicans colonising critically ill patients

A study is performed to examine the distribution and frequency of 25S rRNA intron genotypes of Candida albicans isolated from different anatomical sites of patients in an intensive care unit (ICU) setting. Germ-tube positive Candida isolates (n=65) from 65 patients are included and isolates are characterised by 25S intron genotyping, whereby all can be subdivided into four genotypes (A-D). Results demonstrated that there were no significant differences between the frequency and genotype distribution of the Candida isolates and the anatomical site of colonisation. Furthermore, analysis of the transposable intron region in the 25S rRNA gene demonstrated equal distribution, regardless of age and anatomical site of isolation (groin, throat, etc.). Therefore, there does not appear to be any selective pressure associated with any anatomical site, resulting in an ecological shift in the frequency of genotypes present. This suggests that C. albicans intron genotypes equally colonise those sites of the body examined in this study. Although such an ecological finding as this is interesting, it perpetuates the continued need to find a genotypic typing scheme that helps to identify the source (nosocomial or endogenous) and mode of entry of C. albicans into patients in the ICU setting, resulting in C. albicans bloodstream infection.