Una enfermedad lejana: la información sobre poliomielitis y síndrome post-polio en la prensa hispanolusa, 1995-2009

Se explora el cambio en la percepción social de la polio en la Península Ibérica a través del análisis de contenidos, entre 1995 y 2009, de dos periódicos de gran tirada. La desaparición en la agenda periodística de la polio y de las personas que viven con sus secuelas influyó en el olvido de la misma en la agenda pública. La poliomielitis se vinculó a la pobreza y la ignorancia en países lejanos, susceptibles de acciones de cooperación, siendo objeto de atención solo cuando es percibida como amenaza para Occidente, vinculada a crisis sanitarias o en un sentido metafórico. Así, el síndrome post-polio fue invisibilizado en el caso portugués y débilmente representado en España por el movimiento asociativo

Mutation of a Single Conserved Nucleotide between the Cloverleaf and Internal Ribosome Entry Site Attenuates Poliovirus Neurovirulence

The chemical synthesis of poliovirus (PV) cDNA combined with the cell-free synthesis of infectious particles yielded virus whose mouse neurovirulence was highly attenuated (J. Cello, A. V. Paul, and E. Wimmer, Science 297:1016-1018, 2002). Compared to the wild-type PV1 (Mahoney) [PV1(M)] sequence, the synthetic virus genome harbored 27 nucleotide (nt) changes deliberately introduced as genetic markers. Of the 27 nucleotide substitutions, the UA-to-GG exchanges at nucleotides 102/103, mapping to a region between the cloverleaf and the internal ribosome entry site (IRES) in the 5′-nontranslated region, were found to be involved in the observed attenuation phenotype in mice. The UA/GG mutation at nt 102/103 in the synthetic PV1(M) [sPV1(M)] background conferred also a ts phenotype of replication to the virus in human neuroblastoma cells. Conversely, the exchange of GG to wild-type (wt) UA at 102/103 in an sPV1(M) background restored wt neurovirulence in CD155 transgenic (tg) mice and suppressed the ts phenotype in SK-N-MC cells. All poliovirus variants replicated well in HeLa cells at the two temperatures, regardless of the sequence at the 102/103 locus. Analyses of variants isolated from sPV(M)-infected CD155 tg mice revealed that the G(102)G(103)-to-G(102)A(103) reversion alone reestablished the neurovirulent phenotype. This suggests that a single mutation is responsible for the observed change of the neurovirulence phenotype. sPV1(M) RNA is translated in cell extracts of SK-N-MC cells with significantly lower efficiency than PV1(M) RNA or sPV1(M) RNA with a G(102)-to-A(102) reversion. These studies suggest a function for the conserved nucleotide (A(103)) located between the cloverleaf and the IRES which is important for replication of PV in the central nervous system of CD155 tg mice and in human cells of neuronal origin

Mac-1(+) Cells Are the Predominant Subset in the Early Hepatic Lesions of Mice Infected with Francisella tularensis

The cell composition of early hepatic lesions of experimental murine tularemia has not been characterized with specific markers. The appearance of multiple granulomatous-necrotic lesions in the liver correlates with a marked increase in the levels of serum alanine transferase and lactate dehydrogenase. Francisella tularensis, detected by specific antibodies, can be first noted by day 1 and becomes associated with the lesions by 5 days postinoculation. These lesions become necrotic, with some evidence of in situ apoptosis. The lesions do not contain B, T, or NK cells. Rather, the lesions are largely composed of two subpopulations of Mac-1(+) cells that are associated with the bacteria. Gr-1(+) Mac-1(+) immature myeloid cells and major histocompatibility complex class II-positive (MHC-II(+)) Mac-1(+) macrophages were the most abundant cell phenotypes found in the granuloma and are likely major contributors in controlling the infection in its early stages. Our findings have shown that there is an early development of hepatic lesions where F. tularensis colocalizes with both Gr-1(+) Mac-1(+) and MHC-II(+) Mac-1(+) cells

Dry heat sterilization as a method to recycle N95 respirator masks: The importance of fit.

In times of crisis, including the current COVID-19 pandemic, the supply chain of filtering facepiece respirators, such as N95 respirators, are disrupted. To combat shortages of N95 respirators, many institutions were forced to decontaminate and reuse respirators. While several reports have evaluated the impact on filtration as a measurement of preservation of respirator function after decontamination, the equally important fact of maintaining proper fit to the users' face has been understudied. In the current study, we demonstrate the complete inactivation of SARS-CoV-2 and preservation of fit test performance of N95 respirators following treatment with dry heat. We apply scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction (XRD) measurements, Raman spectroscopy, and contact angle measurements to analyze filter material changes as a consequence of different decontamination treatments. We further compared the integrity of the respirator after autoclaving versus dry heat treatment via quantitative fit testing and found that autoclaving, but not dry heat, causes the fit of the respirator onto the users face to fail, thereby rendering the decontaminated respirator unusable. Our findings highlight the importance to account for both efficacy of disinfection and mask fit when reprocessing respirators to for clinical redeployment

Cold-Adapted Viral Attenuation (CAVA): Highly Temperature Sensitive Polioviruses as Novel Vaccine Strains for a Next Generation Inactivated Poliovirus Vaccine.

The poliovirus vaccine field is moving towards novel vaccination strategies. Withdrawal of the Oral Poliovirus Vaccine and implementation of the conventional Inactivated Poliovirus Vaccine (cIPV) is imminent. Moreover, replacement of the virulent poliovirus strains currently used for cIPV with attenuated strains is preferred. We generated Cold-Adapted Viral Attenuation (CAVA) poliovirus strains by serial passage at low temperature and subsequent genetic engineering, which contain the capsid sequences of cIPV strains combined with a set of mutations identified during cold-adaptation. These viruses displayed a highly temperature sensitive phenotype with no signs of productive infection at 37°C as visualized by electron microscopy. Furthermore, decreases in infectious titers, viral RNA, and protein levels were measured during infection at 37°C, suggesting a block in the viral replication cycle at RNA replication, protein translation, or earlier. However, at 30°C, they could be propagated to high titers (9.4-9.9 Log10TCID50/ml) on the PER.C6 cell culture platform. We identified 14 mutations in the IRES and non-structural regions, which in combination induced the temperature sensitive phenotype, also when transferred to the genomes of other wild-type and attenuated polioviruses. The temperature sensitivity translated to complete absence of neurovirulence in CD155 transgenic mice. Attenuation was also confirmed after extended in vitro passage at small scale using conditions (MOI, cell density, temperature) anticipated for vaccine production. The inability of CAVA strains to replicate at 37°C makes reversion to a neurovirulent phenotype in vivo highly unlikely, therefore, these strains can be considered safe for the manufacture of IPV. The CAVA strains were immunogenic in the Wistar rat potency model for cIPV, inducing high neutralizing antibody titers in a dose-dependent manner in response to D-antigen doses used for cIPV. In combination with the highly productive PER.C6 cell culture platform, the stably attenuated CAVA strains may serve as an attractive low-cost and (bio)safe option for the production of a novel next generation IPV

Secondary RNA structure prediction of Domain II and Domain VI of the IRES in Brunenders and CAVA using the MFOLD program developed by M. Zuker.

<p>Circled nucleotides (at positions 133, 142, 146, and 163 in domain II and at positions 597, 609 in domain VI) represent nucleotide changes between CAVA and Brunenders. The last remaining CAVA IRES mutation (nt579) lies outside of any IRES domains and in the spacer region between Domains V and VI. After serial passage at increasing temperature (<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1005483#ppat.1005483.g006" target="_blank">Fig 6</a>) nucleotide 127 (indicated by square box) mutated in both passaging experiments (n = 2) from U to C, forming a C–G base pair with CAVA mutation nt 163. The CAVA mutations induce a change in predicted secondary structure and increased free energy (ΔG) for domain II, whilst for domain VI only the free energy is affected.</p

<i>In vivo</i> immunogenicity of the CAVA vaccine strains as compared to cIPV.

<p>Groups of ten (n = 10) rats were immunized with a full dose (FD: 100% 40:8:32 DU/dose or 150% 60:12:48 DU/dose) or a 1:2, 1:4 or 1:16 dilution of the full dose. Poliovirus type 1, 2 and 3-specific neutralizing antibody titers were determined by Sabin Virus Neutralizing Assay at day 21 post immunization. Each dot represents one individual animal; the connected line represents the geometric mean at each dose. Relative potency estimates and 95% confidence intervals of the difference between the CAVA vaccine strain and cIPV reference based on the number of seroconverting animals are depicted in the table, horizontal dotted line represents the seroconversion limit for each assay.</p