Creating contacts between replication and movement at plasmodesmata – a role for membrane contact sites in plant virus infections?

Parts of this work were funded by the University of Florida, Institute of Food and Agricultural Sciences, Early Career Seed Grant No. 00127818 to AL and by the UK Biotechnology and Biomedical Sciences Research Council (BBSRC) grant BB/M007200/1 to JT.To infect their hosts and cause disease, plant viruses must replicate within cells and move throughout the plant both locally and systemically. RNA virus replication occurs on the surface of various cellular membranes, whose shape and composition become extensively modified in the process. Membrane contact sites (MCS) can mediate non-vesicular lipid-shuttling between different membranes and viruses co-opt components of these structures to make their membrane environment suitable for replication. Whereas animal viruses exit and enter cells when moving throughout their host, the rigid wall of plant cells obstructs this pathway and plant viruses therefore move between cells symplastically through plasmodesmata (PD). PD are membranous channels connecting nearly all plant cells and are now viewed to constitute a specialized type of endoplasmic reticulum (ER)-plasma membrane (PM) MCS themselves. Thus, both replication and movement of plant viruses rely on MCS. However, recent work also suggests that for some viruses, replication and movement are closely coupled at ER-PM MCS at the entrances of PD. Movement-coupled replication at PD may be distinct from the main bulk of replication and virus accumulation, which produces progeny virions for plant-to-plant transmission. Thus, MCS play a central role in plant virus infections, and may provide a link between two essential steps in the viral life cycle, replication and movement. Here, we provide an overview of plant virus-MCS interactions identified to date, and place these in the context of the connection between viral replication and cell-to-cell movement.Publisher PDFPeer reviewe

Effects of air pollution on liver metabolism with relevance for cardiovascular disease: a multilevel analysis

The liver is a possible target organ for exposure to particulate air pollution, which has been associated with acute and chronic cardiovascular effects. The studies contained within this dissertation evaluate the effects of ambient measures of PM10, NO2 and SO2 in relation to individual cholesterol parameters, LDL and HDL, in manuscript one, and alanine aminotransferase (ALT) levels in manuscript two. I employed multilevel analysis on individuals nested in counties in a nationally representative sample survey data merged with ambient air pollution monitoring data. I explored the contribution of the mean county and deviation from the mean county pollution levels to evaluate the independent contribution of aggregate and individual exposures on individual outcome parameters. In random intercepts models of LDL, a mean county average increase of 10[microgram]/dL of PM10 and 10 ppb of NO2 was associated with an increase of 4.26 mg/dL (95% CI: -1.57, 10.06) and 3.61 mg/dL (95% CI: 0.98,6.30). To the extent that individual level variation exists, the individual level pollutant estimates support the positive effect of PM10 and NO2 at the county level. Some evidence exists that the individual level effects of PM10 and SO2 are higher at higher county mean levels of air pollution. Log ALT levels are inversely related to PM10 exposure at both the county (-0.011; 95% CI: -0.040, 0.017 ) and individual level ( -0.019 95% CI: -0.032, -0.005). The data suggest that log ALT is positively associated with county-level NO2 and though negative at mean county levels, the individual-level effect is more positive at higher county levels of NO2. Though the direction of these results is not consistent with hepatotoxicity, these results suggest alterations in liver metabolism that are shared with current cigarette smoking and may signify pathological changes in the liver. These data from around the country provide exposure contrasts that are evaluated against the alterations in the outcome measures at the appropriate level in the mixed models analysis. The cholesterol study provides evidence for a link between PM and atherosclerosis. The ALT study suggests a paradoxical relationship that may point to a meaningful alteration in metabolism with relevance to atherosclerosis

Increased hand washing reduces influenza virus surface contamination in Bangkok households, 2009–2010

Within a hand-washing clinical trial, we evaluated factors associated with fomite contamination in households with an influenza-infected child. Influenza virus RNA contamination was higher in households with low absolute humidity and in control households, suggesting that hand washing reduces surface contamination

Trends in all-cause mortality during the scale-up of an antiretroviral therapy programme: a cross-sectional study in Lusaka, Zambia.

OBJECTIVE: To follow the trends in all-cause mortality in Lusaka, Zambia, during the scale-up of a national programme of antiretroviral therapy (ART). METHODS: Between November 2004 and September 2011, we conducted 12 survey rounds as part of a cross-sectional study in Lusaka, with independent sampling in each round. In each survey, we asked the heads of 3600 households to state the number of deaths in their households in the previous 12 months and the number of orphans aged less than 16 years in their households and investigated the heads' knowledge, attitudes and practices related to human immunodeficiency virus (HIV). FINDINGS: The number of deaths we recorded - per 100 person-years - in each survey ranged from 0.92 (95% confidence interval, CI: 0.78-1.09) in September 2011, to 1.94 (95% CI: 1.60-2.35) in March 2007. We found that mortality decreased only modestly each year (mortality rate ratio: 0.98; 95% CI: 0.95-1.00; P = 0.093). The proportion of households with orphans under the age of 16 years decreased from 17% in 2004 to 7% in 2011. The proportions of respondents who had ever been tested for HIV, had a comprehensive knowledge of HIV, knew where to obtain free ART and reported that a non-pregnant household member was receiving ART gradually increased. CONCLUSION: The expansion of ART services in Lusaka was not associated with a reduction in all-cause mortality. Coverage, patient adherence and retention may all have to be increased if ART is to have a robust and lasting impact at population level in Lusaka

Links between Main Frequencies of Established Rotating Stall and Rotational Frequencies and/or Blade Passing Frequencies

The ratios between the main frequency of rotating stall and rotational frequency may be considered in the form of exact ratios of small natural numbers if the pressure signals in compressors during rotating stall include the rotor rotation frequency component. During rotating stall in compressors with good rotor balancing (with absence of the rotational frequency component in the frequency characteristics of pressure signals), these ratios between the main frequency of rotating stall and rotational frequency are or are not in the form of ratios of small natural numbers. The experimentally received characteristics of power spectral density of pressure signals also show the presence of components with combinations of blade passing frequency and different harmonics of main rotating stall frequency

TB STIGMA – MEASUREMENT GUIDANCE

TB is the most deadly infectious disease in the world, and stigma continues to play a significant role in worsening the epidemic. Stigma and discrimination not only stop people from seeking care but also make it more difficult for those on treatment to continue, both of which make the disease more difficult to treat in the long-term and mean those infected are more likely to transmit the disease to those around them. TB Stigma – Measurement Guidance is a manual to help generate enough information about stigma issues to design and monitor and evaluate efforts to reduce TB stigma. It can help in planning TB stigma baseline measurements and monitoring trends to capture the outcomes of TB stigma reduction efforts. This manual is designed for health workers, professional or management staff, people who advocate for those with TB, and all who need to understand and respond to TB stigma

Elevated transmission of upper respiratory illness among new recruits in military barracks in Thailand.

BACKGROUND: New recruits within military barracks present conditions favorable for the spread of respiratory pathogens. However, respiratory pathogen transmission in such confined settings in the tropics has not been well studied. METHODS: Recruits in four successive Royal Thai Army basic training classes living in military barracks were monitored for the symptoms of influenza-like illness (ILI) or upper respiratory illness (URI). Classes 1 and 2 were also monitored after basic training. Nasal/throat swabs from acute illnesses were collected and tested by influenza RT-PCR (all four classes). In addition, class 1 had multiplex PCR performed along with the analysis of bed locations within the barracks. RESULTS: Influenza-like illness/upper respiratory illness rates ranged from 4·7 to 6·9 per 100 recruit-weeks in the four classes and generally decreased during the course of basic training (P < 0·05 in three of four classes). Rates during basic training were 1·7 (95% CI: 1·29, 2·29) and 2·5 (95% CI: 1·5, 4·1) times higher than after basic training (classes 1 and 2, respectively). In class 1, coronavirus, parainfluenza virus, and rhinovirus were the most commonly identified respiratory pathogens; only one influenza PCR-positive infection was detected in all four classes. Bed locations of URI/ILI cases in class 1 tended to be in closer proximity to each other. CONCLUSION: Basic training recruits in military barracks in the tropics had high rates of acute respiratory illnesses with illness patterns consistent with external seeding followed by substantial internal transmission. Our findings may contribute to control measures in similar confined settings both within and outside the military