The effect of age on the response to the pneumococcal polysaccharide vaccine

<p>Abstract</p> <p>Background</p> <p><it>Streptococcus pneumoniae </it>is a leading cause of morbidity and mortality in the elderly. To prevent invasive pneumococcal diseases, the 23-valent pneumococcal polysaccharide vaccine (PPV) is recommended in subjects over 65 years of age. Although it has been reported to provide approximately 50-80% protection against invasive disease in the general elderly population, there is still controversy as to the effectiveness of the PPV in the elderly.</p> <p>Methods</p> <p>To evaluate the immune response to the pneumococcal polysaccharide vaccine in the elderly, samples from young adults and elderly were obtained before and one month after vaccination. The quantitative and qualitative response to the vaccine were measured by the ELISA and opsonophagocytic killing assay for eight vaccine type serotypes (4, 6B, 9V, 14, 18C, 19A, 19F, 23F) and one vaccine-related serotype (6A).</p> <p>Results</p> <p>The response to the pneumococcal polysaccharide vaccine showed a similar response between adults and elderly when evaluated by the ELISA, however the functional activity of the antibodies elicited after vaccination were lower in the elderly group for more than half of the serotypes evaluated. In comparison of the antibody needed for 1:8 opsonic titer, more antibodies were needed in the elderly for serotypes Pn 4, 19F, 23F and 6A, suggesting the functional activity of antibody detected by the ELISA was lower in the elderly compared with the adult group for these serotypes. As for subjects with an opsonic titer <8 after vaccination, only one subject each for serotypes Pn 4, 9V and 6A were found in the adult group. However, up to 10 (30.3%) of the subjects did not show opsonic activity after vaccination in the elderly group for serotypes Pn 4, 9V, 14, 19A and 6A.</p> <p>Conclusions</p> <p>Although the amount of antibodies elicited were similar between the two age groups, distinct differences in function were noted. This report highlights the importance of a quantitative and qualitative evaluation of the immunogenic response to the PPV in the elderly age group.</p> <p>Trial registration</p> <p>This trial is registered with Clinical trials.gov. Registration number NCT00964769</p

A Minimal Threshold of c-di-GMP Is Essential for Fruiting Body Formation and Sporulation in Myxococcus xanthus

Generally, the second messenger bis-(3’-5’)-cyclic dimeric GMP (c-di-GMP) regulates the switch between motile and sessile lifestyles in bacteria. Here, we show that c-di-GMP is an essential regulator of multicellular development in the social bacterium Myxococcus xanthus. In response to starvation, M. xanthus initiates a developmental program that culminates in formation of spore-filled fruiting bodies. We show that c-di-GMP accumulates at elevated levels during development and that this increase is essential for completion of development whereas excess c-di-GMP does not interfere with development. MXAN3735 (renamed DmxB) is identified as a diguanylate cyclase that only functions during development and is responsible for this increased c-di-GMP accumulation. DmxB synthesis is induced in response to starvation, thereby restricting DmxB activity to development. DmxB is essential for development and functions downstream of the Dif chemosensory system to stimulate exopolysaccharide accumulation by inducing transcription of a subset of the genes encoding proteins involved in exopolysaccharide synthesis. The developmental defects in the dmxB mutant are non-cell autonomous and rescued by co-development with a strain proficient in exopolysaccharide synthesis, suggesting reduced exopolysaccharide accumulation as the causative defect in this mutant. The NtrC-like transcriptional regulator EpsI/Nla24, which is required for exopolysaccharide accumulation, is identified as a c-diGMP receptor, and thus a putative target for DmxB generated c-di-GMP. Because DmxB can be—at least partially—functionally replaced by a heterologous diguanylate cyclase, these results altogether suggest a model in which a minimum threshold level of c-di-GMP is essential for the successful completion of multicellular development in M. xanthus

Telomere disruption results in non-random formation of de novo dicentric chromosomes involving acrocentric human chromosomes

Copyright: © 2010 Stimpson et al.Genome rearrangement often produces chromosomes with two centromeres (dicentrics) that are inherently unstable because of bridge formation and breakage during cell division. However, mammalian dicentrics, and particularly those in humans, can be quite stable, usually because one centromere is functionally silenced. Molecular mechanisms of centromere inactivation are poorly understood since there are few systems to experimentally create dicentric human chromosomes. Here, we describe a human cell culture model that enriches for de novo dicentrics. We demonstrate that transient disruption of human telomere structure non-randomly produces dicentric fusions involving acrocentric chromosomes. The induced dicentrics vary in structure near fusion breakpoints and like naturally-occurring dicentrics, exhibit various inter-centromeric distances. Many functional dicentrics persist for months after formation. Even those with distantly spaced centromeres remain functionally dicentric for 20 cell generations. Other dicentrics within the population reflect centromere inactivation. In some cases, centromere inactivation occurs by an apparently epigenetic mechanism. In other dicentrics, the size of the alpha-satellite DNA array associated with CENP-A is reduced compared to the same array before dicentric formation. Extrachromosomal fragments that contained CENP-A often appear in the same cells as dicentrics. Some of these fragments are derived from the same alpha-satellite DNA array as inactivated centromeres. Our results indicate that dicentric human chromosomes undergo alternative fates after formation. Many retain two active centromeres and are stable through multiple cell divisions. Others undergo centromere inactivation. This event occurs within a broad temporal window and can involve deletion of chromatin that marks the locus as a site for CENP-A maintenance/replenishment.This work was supported by the Tumorzentrum Heidelberg/Mannheim grant (D.10026941)and by March of Dimes Research Foundation grant #1-FY06-377 and NIH R01 GM069514

The immunogenicity and safety of a reduced PRP-content DTPw-HBV/Hib vaccine when administered according to the accelerated EPI schedule

<p>Abstract</p> <p>Background</p> <p>Combination vaccines improve coverage, compliance and effectively introduce new antigens to mass vaccination programmes. This was a phase III, observer-blind, randomized study of GSK Biologicals diphtheria-tetanus-whole cell pertussis vaccine combined with hepatitis B and <it>Haemophilus influenzae </it>type b vaccines, containing a reduced amount of polyribosyl-ribitol-phosphate (PRP) and a DTPw component manufactured at a different site (DTPw-HBV/Hib_2.5[Kft]). The primary aim of this study was to demonstrate that DTPw-HBV/Hib_2.5[Kft] was not inferior to the licensed DTPw-HBV/Hib (<it>Tritanrix</it>(tm)-HepB/<it>Hiberix</it>(tm)) vaccine or the DTPw-HBV/Hib_2.5vaccine, also containing a reduced amount of PRP, with respect to the immune response to the PRP antigen, when administered to healthy infants, according to the Expanded Programme for Immunization (EPI) schedule at 6, 10 and 14 weeks of age.</p> <p>Methods</p> <p>299 healthy infants were randomised to receive either DTPw-HBV/Hib_2.5[Kft] DTPw-HBV/Hib_2.5or DTPw-HBV/Hib according to the 6-10-14 week EPI schedule. Blood samples were analysed prior to the first dose of study vaccine and one month after the third vaccine dose for the analysis of immune responses. Solicited local and general symptoms such as pain, redness and swelling at the injection site and drowsiness and fever, unsolicited symptoms (defined as any additional adverse event) and serious adverse events (SAEs) were recorded up to 20 weeks of age.</p> <p>Results</p> <p>One month after the third vaccine dose, 100% of subjects receiving DTPw-HBV/Hib_2.5[Kft] or DTPw-HBV/Hib and 98.8% of subjects receiving DTPw-HBV/Hib_2.5vaccine had seroprotective levels of anti-PRP antibodies (defined as anti-PRP antibody concentration ≥0.15 μg/ml). Seroprotective antibody concentrations were attained in over 98.9% of subjects for diphtheria, tetanus and hepatitis B. The vaccine response rate to pertussis antigen was at least 97.8% in each group. Overall, the DTPw-HBV/Hib_2.5[Kft] vaccine was well tolerated in healthy infants; no SAEs were reported in any group.</p> <p>Conclusions</p> <p>The DTPw-HBV/Hib_2.5[Kft] vaccine was immunogenic and well-tolerated when administered according to the EPI schedule to Indian infants.</p> <p>Trial registration</p> <p><url>http://www.clinicaltrials.gov</url> NCT00473668</p

SAVVY Vaginal Gel (C31G) for Prevention of HIV Infection: A Randomized Controlled Trial in Nigeria

The objective of this trial was to determine the effectiveness of 1.0% C31G (SAVVY) in preventing male-to-female vaginal transmission of HIV infection among women at high risk.This was a Phase 3, double-blind, randomized, placebo-controlled trial. Participants made up to 12 monthly follow-up visits for HIV testing, adverse event reporting, and study product supply. The study was conducted between September 2004 and December 2006 in Lagos and Ibadan, Nigeria, where we enrolled 2153 HIV-negative women at high risk of HIV infection. Participants were randomized 1 ratio 1 to SAVVY or placebo. The effectiveness endpoint was incidence of HIV infection as indicated by detection of HIV antibodies in oral mucosal transudate (rapid test) or blood (ELISA), and confirmed by Western blot or PCR testing. We observed 33 seroconversions (21 in the SAVVY group, 12 in the placebo group). The Kaplan-Meier estimates of the cumulative probability of HIV infection at 12 months were 0.028 in the SAVVY group and 0.015 in the placebo group (2-sided p-value for the log-rank test of treatment effect 0.121). The point estimate of the hazard ratio was 1.7 for SAVVY versus placebo (95% confidence interval 0.9, 3.5). Because of lower-than-expected HIV incidence, we did not observe the required number of HIV infections (66) for adequate power to detect an effect of SAVVY. Follow-up frequencies of adverse events, reproductive tract adverse events, abnormal pelvic examination findings, chlamydial infections and vaginal infections were similar in the study arms. No serious adverse event was attributable to SAVVY use.SAVVY did not reduce the incidence of HIV infection. Although the hazard ratio was higher in the SAVVY than the placebo group, we cannot conclude that there was a harmful treatment effect of SAVVY

Genetic Interactions between the Drosophila Tumor Suppressor Gene ept and the stat92E Transcription Factor

Tumor Susceptibility Gene-101 (TSG101) promotes the endocytic degradation of transmembrane proteins and is implicated as a mutational target in cancer, yet the effect of TSG101 loss on cell proliferation in vertebrates is uncertain. By contrast, Drosophila epithelial tissues lacking the TSG101 ortholog erupted (ept) develop as enlarged undifferentiated tumors, indicating that the gene can have anti-growth properties in a simple metazoan. A full understanding of pathways deregulated by loss of Drosophila ept will aid in understanding potential links between mammalian TSG101 and growth control.We have taken a genetic approach to the identification of pathways required for excess growth of Drosophila eye-antennal imaginal discs lacking ept. We find that this phenotype is very sensitive to the genetic dose of stat92E, the transcriptional effector of the Jak-Stat signaling pathway, and that this pathway undergoes strong activation in ept mutant cells. Genetic evidence indicates that stat92E contributes to cell cycle deregulation and excess cell size phenotypes that are observed among ept mutant cells. In addition, autonomous Stat92E hyper-activation is associated with altered tissue architecture in ept tumors and an effect on expression of the apical polarity determinant crumbs.These findings identify ept as a cell-autonomous inhibitor of the Jak-Stat pathway and suggest that excess Jak-Stat signaling makes a significant contribution to proliferative and tissue architectural phenotypes that occur in ept mutant tissues

A prospective study of decline in fat free mass and skeletal muscle strength in chronic obstructive pulmonary disease

BACKGROUND: Skeletal muscle depletion is an important complication of chronic obstructive pulmonary disease (COPD) but little prospective data exists about the rate at which it occurs and the factors that promote its development. We therefore prospectively investigated the impact of disease severity, exacerbation frequency and treatment with corticosteroids on change in body composition and maximum isometric quadriceps strength (QMVC) over one year. METHODS: 64 patients with stable COPD (FEV(1 )mean (SD) 35.8(18.4) %predicted) were recruited from clinic and studied on two occasions one year apart. Fat free mass was determined using bioelectrical impedance analysis and a disease specific regression equation. RESULTS: QMVC fell from 34.8(1.5) kg to 33.3(1.5) kg (p = 0.04). The decline in quadriceps strength was greatest in those with the highest strength at baseline (R -0.28 p = 0.02) and was not correlated with lung function, exacerbation frequency or steroid treatment. Decline in fat free mass was similarly higher in those with largest FFM at baseline (R = -0.31 p = 0.01) but was more strongly correlated with greater gas trapping (R = -0.4 p = 0.001). Patients with frequent exacerbations (>1 per year) (n = 36) experienced a greater decline in fat free mass compared to infrequent exacerbators (n = 28) -1.3(3.7)kg vs. +1.2(3.1)kg (p = 0.005), as did patients on maintenance oral steroids (n = 8) -2.8(3.3) kg vs. +0.2(3.5) kg (p = 0.024) whereas in those who stopped smoking (n = 7) fat free mass increased; +2.7(3.1) kg vs. -0.51(3.5) kg (p = 0.026). CONCLUSION: Decline in fat free mass in COPD is associated with worse lung function, continued cigarette consumption and frequent exacerbations. Factors predicting progression of quadriceps weakness could not be identified from the present cohort

Flagellin-Induced Corneal Antimicrobial Peptide Production and Wound Repair Involve a Novel NF-κB–Independent and EGFR-Dependent Pathway

The bacterial protein flagellin plays a major role in stimulating mucosal surface innate immune response to bacterial infection and uniquely induces profound cytoprotection against pathogens, chemicals, and radiation. This study sought to determine signaling pathways responsible for the flagellin-induced inflammatory and cytoprotective effects on human corneal epithelial cells (HCECs).Flagellin purified from Pseudomonas aeruginosa (strain PAK) or live bacteria were used to challenge cultured HCECs. The activation of signaling pathways was assessed with Western blot, and the secretion of cytokine/chemokine and production of antimicrobial peptides (AMPs) were measured with ELISA and dot blot, respectively. Effects of flagellin on wound healing were assessed in cultured porcine corneas. L94A (a site mutation in TLR5 binding region) flagellin and PAK expressing L94A flagellin were unable to stimulate NF-kappaB activation, but were potent in eliciting EGFR signaling in a TGF-alpha-related pathway in HCECs. Concomitant with the lack of NF-kappaB activation, L94A flagellin was ineffective in inducing IL-6 and IL-8 production in HCECs. Surprisingly, the secretion of two inducible AMPs, LL-37 and hBD2, was not affected by L94A mutation. Similar to wild-type flagellin, L94A induced epithelial wound closure in cultured porcine cornea through maintaining EGFR-mediated signaling.Our data suggest that inflammatory response mediated by NF-kappaB can be uncoupled from epithelial innate defense machinery (i.e., AMP expression) and major epithelial proliferation/repair pathways mediated by EGFR, and that flagellin and its derivatives may have broad therapeutic applications in cytoprotection and in controlling infection in the cornea and other mucosal tissues

Neuroprotection or Increased Brain Damage Mediated by Temperature in Stroke Is Time Dependent

The control of temperature during the acute phase of stroke may be a new therapeutic target that can be applied in all stroke patients, however therapeutic window or timecourse of the temperature effect is not well established. Our aim is to study the association between changes in body temperature in the first 72 hours and outcome in patients with ischemic (IS) and hemorrhagic (ICH) stroke. We prospectively studied 2931 consecutive patients (2468 with IS and 463 with ICH). Temperature was obtained at admission, and at 24, 48 and 72 hours after admission. Temperature was categorized as low (<36°C), normal (36–37°C) and high (>37°C). As the main variable, we studied functional outcome at 3 months determined by modified Rankin Scale