Evaluation of the efficacy of Alpron disinfectant for dental unit water lines

AIMS: To assess the efficacy of a disinfectant, Alpron, for controlling microbial contamination within dental unit water lines. METHODS: The microbiological quality of water emerging from the triple syringe, high speed handpiece, cup filler and surgery hand wash basin from six dental units was assessed for microbiological total viable counts at 22 degrees C and 37 degrees C before and after treatment with Alpron solutions. RESULTS: The study found that the use of Alpron disinfectant solutions could reduce microbial counts in dental unit water lines to similar levels for drinking water. This effect was maintained in all units for up to six weeks following one course of treatment. In four out of six units the low microbial counts were maintained for 13 weeks. CONCLUSIONS: Disinfectants may have a short term role to play in controlling microbial contamination of dental unit water lines to drinking water quality. However, in the longer term attention must be paid to redesigning dental units to discourage the build up of microbial biofilms

Ferritins: furnishing proteins with iron

Ferritins are a superfamily of iron oxidation, storage and mineralization proteins found throughout the animal, plant, and microbial kingdoms. The majority of ferritins consist of 24 subunits that individually fold into 4-α-helix bundles and assemble in a highly symmetric manner to form an approximately spherical protein coat around a central cavity into which an iron-containing mineral can be formed. Channels through the coat at inter-subunit contact points facilitate passage of iron ions to and from the central cavity, and intrasubunit catalytic sites, called ferroxidase centers, drive Fe2+ oxidation and O2 reduction. Though the different members of the superfamily share a common structure, there is often little amino acid sequence identity between them. Even where there is a high degree of sequence identity between two ferritins there can be major differences in how the proteins handle iron. In this review we describe some of the important structural features of ferritins and their mineralized iron cores and examine in detail how three selected ferritins oxidise Fe2+ in order to explore the mechanistic variations that exist amongst ferritins. We suggest that the mechanistic differences reflect differing evolutionary pressures on amino acid sequences, and that these differing pressures are a consequence of different primary functions for different ferritins

Genome wide association mapping of grain arsenic, copper, molybdenum and zinc in rice (Oryza sativa L.) grown at four international field sites

Peer reviewedPublisher PD

Women’s experiences of receiving care for pelvic organ prolapse: a qualitative study

Background Pelvic organ prolapse is a common urogenital condition affecting 41–50% of women over the age of 40. To achieve early diagnosis and appropriate treatment, it is important that care is sensitive to and meets women’s needs, throughout their patient journey. This study explored women’s experiences of seeking diagnosis and treatment for prolapse and their needs and priorities for improving person-centred care. Methods Twenty-two women receiving prolapse care through urogynaecology services across three purposefully selected NHS UK sites took part in three focus groups and four telephone interviews. A topic guide facilitated discussions about women’s experiences of prolapse, diagnosis, treatment, follow-up, interactions with healthcare professionals, overall service delivery, and ideals for future services to meet their needs. Data were analysed thematically. Results Three themes emerged relating to women’s experiences of a) Evaluating what is normal b) Hobson’s choice of treatment decisions, and c) The trial and error of treatment and technique. Women often delayed seeking help for their symptoms due to lack of awareness, embarrassment and stigma. When presented to GPs, their symptoms were often dismissed and unaddressed until they became more severe. Women reported receiving little or no choice in treatment decisions. Choices were often influenced by health professionals’ preferences which were subtly reflected through the framing of the offer. Women’s embodied knowledge of their condition and treatment was largely unheeded, resulting in decisions that were inconsistent with women’s preferences and needs. Physiotherapy based interventions were reported as helping women regain control over their symptoms and life. A need for greater awareness of prolapse and physiotherapy interventions among women, GPs and consultants was identified alongside greater focus on prevention, early diagnosis and regular follow-up. Greater choice and involvement in treatment decision making was desired. Conclusions As prolapse treatment options expand to include more conservative choices, greater awareness and education is needed among women and professionals about these as a first line treatment and preventive measure, alongside a multi-professional team approach to treatment decision making. Women presenting with prolapse symptoms need to be listened to by the health care team, offered better information about treatment choices, and supported to make a decision that is right for them

Prime movers : mechanochemistry of mitotic kinesins

Mitotic spindles are self-organizing protein machines that harness teams of multiple force generators to drive chromosome segregation. Kinesins are key members of these force-generating teams. Different kinesins walk directionally along dynamic microtubules, anchor, crosslink, align and sort microtubules into polarized bundles, and influence microtubule dynamics by interacting with microtubule tips. The mechanochemical mechanisms of these kinesins are specialized to enable each type to make a specific contribution to spindle self-organization and chromosome segregation

Estimation of the specificity of an antibody ELISA for paratuberculosis generated from a sector of the UK cattle population using results from a paratuberculosis control programme

In the United Kingdom (UK) a voluntary programme to control paratuberculosis in cattle based on herd management and serological screening has been operating since 1998. The programme assigns a risk level to each participating herd according to the within herd seroprevalence and the confirmation of the presence of infection with Mycobacterium avium subspecies paratuberculosis (MAP) by faecal culture or polymerase chain reaction (PCR). From the outset a general concern over the specificity of the paratuberculosis antibody enzyme-linked immunosorbent assay (ELISA) resulted in the use of a faecal screen for the causal organism to negate or confirm infection in individual seropositive animals. Progress in improving the diagnostic tests has been gradual throughout the life of the programme and the under-pinning approach to using tests to determine the risk of paratuberculosis for a herd required to be re-examined. This study used a large data set of more than 143,000 test results over five years from the lowest paratuberculosis risk level category of herds to estimate the specificity of a commercially available paratuberculosis antibody ELISA for cattle. In each year of the study the estimated specificity reached or exceeded 0.998. We also examined the apparent impact that annual or more frequent application of the single intradermal comparative cervical tuberculin (SICCT) test for tuberculosis (TB), using purified protein derivatives of Mycobacterium bovis and Mycobacterium avium subspecies avium, had on specificity of the antibody ELISA for paratuberculosis. We found a statistically significant difference in three of the five years with herds that were officially tuberculosis free and not subject to frequent SICCT testing. This difference was small and considered to be of little practical importance for the paratuberculosis assurance programme. We concluded that, in the UK the mandatory TB surveillance programme of cattle herds is not a limiting factor in the use of serological testing to support herd-level assurance schemes for paratuberculosis. Furthermore, in paratuberculosis, where shedding of MAP is intermittent and the sensitivity of the commercially available PCR tests for detection MAP is highly variable, faecal screening of seropositive animals is an unreliable method for negating infection in seropositive cattle

Culex pipiens development is greatly influenced by native bacteria and exogenous yeast

Culex pipiens is the most cosmopolitan mosquito of the Pipiens Assemblage. By studying the nature of interactions between this species and microorganisms common to its breeding environment we can unravel important pitfalls encountered during development. We tested the survival rate of larval stages, pupae and adults of a Cx. pipiens colony exposed to a variety of microorganisms in laboratory conditions and assessed the transmission to offspring (F1) by those organisms that secured development up to adulthood. Three complementary experiments were designed to: 1) explore the nutritional value of yeasts and other microorganisms during Cx. pipiens development; 2) elucidate the transstadial transmission of yeast to the host offspring; and 3) to examine the relevance of all these microorganisms in female choice for oviposition-substratum. The yeast Saccharomyces cerevisiae proved to be the most nutritional diet, but despite showing the highest survival rates, vertical transmission to F1 was never confirmed. In addition, during the oviposition trials, none of the gravid females was attracted to the yeast substratum. Notably, the two native bacterial strains, Klebsiella sp. and Aeromonas sp., were the preferred oviposition media, the same two bacteria that managed to feed neonates until molting into 2nd instar larvae. Our results not only suggest that Klebsiella sp. or Aeromonas sp. serve as attractants for oviposition habitat selection, but also nurture the most fragile instar, L1, to assure molting into a more resilient stage, L2, while yeast proves to be the most supportive diet for completing development. These experiments unearthed survival traits that might be considered in the future development of strategies of Cx. pipiens control. These studies can be extended to other members of the Pipiens Assemblag

Peptidases compartmentalized to the Ascaris suum intestinal lumen and apical intestinal membrane

The nematode intestine is a tissue of interest for developing new methods of therapy and control of parasitic nematodes. However, biological details of intestinal cell functions remain obscure, as do the proteins and molecular functions located on the apical intestinal membrane (AIM), and within the intestinal lumen (IL) of nematodes. Accordingly, methods were developed to gain a comprehensive identification of peptidases that function in the intestinal tract of adult female Ascaris suum. Peptidase activity was detected in multiple fractions of the A. suum intestine under pH conditions ranging from 5.0 to 8.0. Peptidase class inhibitors were used to characterize these activities. The fractions included whole lysates, membrane enriched fractions, and physiological- and 4 molar urea-perfusates of the intestinal lumen. Concanavalin A (ConA) was confirmed to bind to the AIM, and intestinal proteins affinity isolated on ConA-beads were compared to proteins from membrane and perfusate fractions by mass spectrometry. Twenty-nine predicted peptidases were identified including aspartic, cysteine, and serine peptidases, and an unexpectedly high number (16) of metallopeptidases. Many of these proteins co-localized to multiple fractions, providing independent support for localization to specific intestinal compartments, including the IL and AIM. This unique perfusion model produced the most comprehensive view of likely digestive peptidases that function in these intestinal compartments of A. suum, or any nematode. This model offers a means to directly determine functions of these proteins in the A. suum intestine and, more generally, deduce the wide array functions that exist in these cellular compartments of the nematode intestine

A systematic analysis of host factors reveals a Med23-interferon-λ regulatory axis against herpes simplex virus type 1 replication

Herpes simplex virus type 1 (HSV-1) is a neurotropic virus causing vesicular oral or genital skin lesions, meningitis and other diseases particularly harmful in immunocompromised individuals. To comprehensively investigate the complex interaction between HSV-1 and its host we combined two genome-scale screens for host factors (HFs) involved in virus replication. A yeast two-hybrid screen for protein interactions and a RNA interference (RNAi) screen with a druggable genome small interfering RNA (siRNA) library confirmed existing and identified novel HFs which functionally influence HSV-1 infection. Bioinformatic analyses found the 358 HFs were enriched for several pathways and multi-protein complexes. Of particular interest was the identification of Med23 as a strongly anti-viral component of the largely pro-viral Mediator complex, which links specific transcription factors to RNA polymerase II. The anti-viral effect of Med23 on HSV-1 replication was confirmed in gain-of-function gene overexpression experiments, and this inhibitory effect was specific to HSV-1, as a range of other viruses including Vaccinia virus and Semliki Forest virus were unaffected by Med23 depletion. We found Med23 significantly upregulated expression of the type III interferon family (IFN-λ) at the mRNA and protein level by directly interacting with the transcription factor IRF7. The synergistic effect of Med23 and IRF7 on IFN-λ induction suggests this is the major transcription factor for IFN-λ expression. Genotypic analysis of patients suffering recurrent orofacial HSV-1 outbreaks, previously shown to be deficient in IFN-λ secretion, found a significant correlation with a single nucleotide polymorphism in the IFN-λ3 (IL28b) promoter strongly linked to Hepatitis C disease and treatment outcome. This paper describes a link between Med23 and IFN-λ, provides evidence for the crucial role of IFN-λ in HSV-1 immune control, and highlights the power of integrative genome-scale approaches to identify HFs critical for disease progression and outcome

Responses of zostera marina and cymodocea nodosa to light-limitation stress

The effects of light-limitation stress were investigated in natural stands of the seagrasses Zostera marina and Cymodocea nodosa in Ria Formosa coastal lagoon, southern Portugal. Three levels of light attenuation were imposed for 3 weeks in two adjacent meadows (2–3 m depth), each dominated by one species. The response of photosynthesis to light was determined with oxygen electrodes. Chlorophylls and carotenoids were determined by high-pressure liquid chromatography (HPLC). Soluble protein, carbohydrates, malondialdehyde and phenol contents were also analysed. Both species showed evident signs of photoacclimation. Their maximum photosynthetic rates were significantly reduced with shading. Ratios between specific light harvesting carotenoids and the epoxidation state of xanthophyll cycle carotenoids revealed significantly higher light harvesting efficiency of C. nodosa, a competitive advantage in a low light environment. The contents of both soluble sugars and starch were considerably lower in Z. marina plants, particularly in the rhizomes, decreasing even further with shading. The different carbohydrate energy storage strategies found between the two species clearly favour C. nodosa's resilience to light deprivation, a condition enhanced by its intrinsic arrangement of the pigment pool. On the other hand, Z. marina revealed a lower tolerance to light reduction, mostly due to a less plastic arrangement of the pigment pool and lower carbohydrate storage. Our findings indicate that Z. marina is close to a light-mediated ecophysiological threshold in Ria Formosa