Infectivity decline of an RNA plant virus by increased mutagenesis supports the lethal defection model in vivo

Lethal mutagenesis is a new antiviral therapy based on increasing the mutation rate by using mutagenic base and nucleoside analogues whose molecular mechanisms are not fully understood. Most of the research has been conducted on animal RNA viruses in cell culture and, to a lesser extent, in vivo. There is experimental evidence supporting the model of lethal defection for lethal mutagenesis of RNA viruses. In this model, viral genomes with a low degree of mutation and low specific infectivity, termed "defectors", exert an interfering activity leading to virus loss. Lethal mutagenesis of plant viruses has not been addressed yet despite being excellent in vivo model systems that develop systemic infections, undergo rapid bottlenecks and pose no ethical issues. Here, we address lethal mutagenesis in vivo of Tobacco mosaic virus (TMV), a single-stranded positive RNA virus of 6.4 Kb. Nicotiana tabacum plants cultured in vitro were treated with 25, 50 and 100 µg/ml of the base analogue 5-fluorouracil (FU) and 24 h later were inoculated with 50 lesion forming units (lfu) of TMV. We analyzed the infectivity, viral load and mutant spectra of viral populations after 5 and 10 days of treatment, as well as of populations that went 10 days of treatment followed by 21 days of ex vitro growth in the absence of FU. The results show that TMV infectivity decreases when treated with 50 and 100 µg/ml FU for 10 days. TMV mutagenized populations grown without FU reach infectivity values higher than untreated populations. Predominant mutations in FU-treated populations with decreased infectivity at 10 dpi are U→C, A→G and G→A transitions, which are expected due to the action of FU. TMV replication is not affected by FU at any dose and there are no imbalances of ribonucleotide triphosphate pools measured by HPLC. No differences in mutation frequencies and Shannon Entropies between control and FU-treated populations with declined infectivity were found. However, we did found a dose-dependent decrease of specific infectivity in FU-treated populations, but not in untreated samples, as well as dominance of molecules with a low degree of mutation. Specific infectivity recovered to control levels after 21 days of growth without the analogue. Altogether, our results suggest that TMV defector molecules mediate the decrease in TMV infectivity. This is the first report that addresses the molecular basis of lethal defection in vivo using an RNA plant virus.Junta de Andalucía (P09-CVI-5428 y P10-CVI-6561), Plan Nacional I+D+i (BFU2007-65080 BMC) y Universidad de Málaga (Plan propio

Effect of a Pre-Treatment Educational Video in Improving Patient Satisfaction with 5-Fluorouracil Treatment for Actinic Keratoses: A Randomized Controlled Trial.

IntroductionPatient treatment satisfaction and adherence may be affected by the initial understanding of outcomes in the treatment of actinic keratoses with 5-fluorouracil 5% cream (5-FU). Pre-treatment educational videos may optimize this understanding. The objective of this study was to determine whether prospective patient viewing of an educational video delineating treatment effects and expectations improves patient satisfaction and treatment completion rates for the treatment of actinic keratoses with 5-FU.MethodsForty-four participants were recruited to the UC Davis Dermatology outpatient clinic. Each participant was randomized to the video (group A) or control group (group B), and topical 5-FU cream treatment was conducted for 2 weeks in both groups.ResultsA follow-up questionnaire was performed to assess patient satisfaction and adherence to the treatment regimen. The results of these questions were analyzed using the Mann-Whitney test. One item on the questionnaire asked the patient to rate their overall level of satisfaction on a score of 0-100. The results of this question were analyzed using the unpaired t test. The results of the statistical analysis show no significant difference between the patient group that viewed the video and the patient group that did not view the video.ConclusionsWe speculate that this study may establish a foundation for subsequent studies that may affect the broader medical community and promote development of educational videos

Randomized trial of calcipotriol combined with 5-fluorouracil for skin cancer precursor immunotherapy

BACKGROUND. Actinic keratosis is a precursor to cutaneous squamous cell carcinoma. Long treatment durations and severe side effects have limited the efficacy of current actinic keratosis treatments. Thymic stromal lymphopoietin (TSLP) is an epithelium-derived cytokine that induces a robust antitumor immunity in barrier-defective skin. Here, we investigated the efficacy of calcipotriol, a topical TSLP inducer, in combination with 5-fluorouracil (5-FU) as an immunotherapy for actinic keratosis. METHODS. The mechanism of calcipotriol action against skin carcinogenesis was examined in genetically engineered mouse models. The efficacy and safety of 0.005% calcipotriol ointment combined with 5% 5-FU cream were compared with Vaseline plus 5-FU for the field treatment of actinic keratosis in a randomized, double-blind clinical trial involving 131 participants. The assigned treatment was self-applied to the entirety of the qualified anatomical sites (face, scalp, and upper extremities) twice daily for 4 consecutive days. The percentage of reduction in the number of actinic keratoses (primary outcome), local skin reactions, and immune activation parameters were assessed. RESULTS. Calcipotriol suppressed skin cancer development in mice in a TSLP-dependent manner. Four-day application of calcipotriol plus 5-FU versus Vaseline plus 5-FU led to an 87.8% versus 26.3% mean reduction in the number of actinic keratoses in participants (P < 0.0001). Importantly, calcipotriol plus 5-FU treatment induced TSLP, HLA class II, and natural killer cell group 2D (NKG2D) ligand expression in the lesional keratinocytes associated with a marked CD4(+) T cell infiltration, which peaked on days 10–11 after treatment, without pain, crusting, or ulceration. CONCLUSION. Our findings demonstrate the synergistic effects of calcipotriol and 5-FU treatment in optimally activating a CD4(+) T cell–mediated immunity against actinic keratoses and, potentially, cancers of the skin and other organs. TRIAL REGISTRATION. ClinicalTrials.gov NCT02019355. FUNDING. Not applicable (investigator-initiated clinical trial)

PAF and Haematopoiesis. I. 5-Fluoro-Uracil Induces PAF Production in Haematopoietic Organs of Rats

Haematopoietic organs of rats were examined for the presence of platelet-activating factor (PAF) and acetylhydrolase before and after treatment with 5-fluoro-uracil (5-FU) (200 mg/kg) a chemotherapeutic compound with apoptotic effects. PAF was reported in thymus, spleen and femoral bone marrow of rats with or without 5-FU. Although acetylhydrolase activity in organs was not affected by 5-FU treatment, elevated levels of PAF were observed in thymus and spleen. For the first time PAF is reported in haematopoietic organs of rats, strengthening in vitro data suggesting its role in the apoptotic processes in thymus, in the modulation of the immune response, and in the regulation of haematopoiesis

Energy teacher: Camilo José Cela in Francisco Umbral

La amistad entre Francisco Umbral (FU) y Camilo José Cela (CJC) se fraguó en torno a 1975 y se mantuvo inquebrantable hasta la muerte de este último en 2002. CJC fue primero un nombre mítico para FU, quien descubrió sus novelas en la adolescencia y valoró siempre su estilo y producción literaria. Más tarde el escritor gallego se convertiría en amigo, confidente y valedor del madrileño ante editoriales, premios y academias. Quizá por ello FU lo convirtió en un habitual de sus textos, como hizo con otros personajes famosos. A través de las innumerables citas del escritor gallego rastreables en las entrevistas y los libros de memorias de FU, es posible trazar una figura doble del Premio Nobel: el retrato personal, mundano, del escritor de fama mundial y el análisis biográfico de las claves de la prosa y la novela del premio Nobel, con un quiebro final que desdice parte importante de lo dicho anteriormenteFrancisco Umbral (FU) and Camilo José Cela (CJC) became friends around 1975, and their friendship remained unbreakable until the demise of the latter in 2002. CJC was at first a mythical name for FU, who discovered his novels during his adolescence and always valued his style and literary production. Later, CJC would become a friend, confidant and defender of FU facing publishing houses, awards and academies. Maybe that is the reason why Umbral made him a regular character in his texts, as he did with other celebrities/ well-known people. Through CJC’s countless quotes, traceable in FU's interviews and memoirs, a double figure of the Noble Prize winner can be outlined: a mundane, personal portrait of the worldwide known writer and a biographical analysis of the essential components of his prose and novels, with a substantial change at the end of his writings, which is out of keeping of the honesty of FU’s former Works sincerit

Evidence for an FU Orionis-like Outburst from a Classical T Tauri Star

We present pre- and post-outburst observations of the new FU Orionis-like young stellar object PTF 10qpf (also known as LkHα 188-G4 and HBC 722). Prior to this outburst, LkHα 188-G4 was classified as a classical T Tauri star (CTTS) on the basis of its optical emission-line spectrum superposed on a K8-type photosphere and its photometric variability. The mid-infrared spectral index of LkHα 188-G4 indicates a Class II-type object. LkHα 188-G4 exhibited a steady rise by ~1 mag over ~11 months starting in August 2009, before a subsequent more abrupt rise of >3 mag on a timescale of ~2 months. Observations taken during the eruption exhibit the defining characteristics of FU Orionis variables: (1) an increase in brightness by ≳ 4 mag, (2) a bright optical/near-infrared reflection nebula appeared, (3) optical spectra are consistent with a G supergiant and dominated by absorption lines, the only exception being Hα which is characterized by a P Cygni profile, (4) near-infrared spectra resemble those of late K-M giants/supergiants with enhanced absorption seen in the molecular bands of CO and H_(2)O, and (5) outflow signatures in H and He are seen in the form of blueshifted absorption profiles. LkHα 188-G4 is the first member of the FU Orionis-like class with a well-sampled optical to mid-infrared spectral energy distribution in the pre-outburst phase. The association of the PTF 10qpf outburst with the previously identified CTTS LkHα 188-G4 (HBC 722) provides strong evidence that FU Orionis-like eruptions represent periods of enhanced disk accretion and outflow, likely triggered by instabilities in the disk. The early identification of PTF 10qpf as an FU Orionis-like variable will enable detailed photometric and spectroscopic observations during its post-outburst evolution for comparison with other known outbursting objects

Treatment of keloid scars with intralesional triamcinolone and 5-fluorouracil injections - a randomized controlled trial

Keloids have high recurrence rates. Current first-line therapy is triamcinolone (TAC) injection, but it has been suggested that approximately 50% of keloids are steroid resistant. We compared the efficacy of intralesional 5-fluorouracil (5-FU) and triamcinalone injections in a double-blind randomized controlled trial. Forty-three patients with 50 keloid scars were treated with either intralesional TAC or 5-FU-injections over 6 months. There was no statistically significant difference in the remission rate at 6 months between the 5-FU and TAC groups (46% vs 60%, respectively). Local adverse effects were higher in the TAC group compared to the 5-FU group. Occurrence of skin atrophy in TAC group was 44% and in the 5-FU group 8% (p <0.05). Also the occurrence of telangiectasia in the TAC group was 50% and in the 5-FU 21% (p <0.05). Vascularity of the keloids, assessed by spectral imaging and immunohistochemical staining for blood vessels, after treatment decreased in the TAC group, but not in the 5-FU group (p <0.05). Fibroblast proliferation evaluated by Ki-67 staining significantly decreased in the TAC group (p <0.05) but increased in the 5-FU group (p <0.05). TAC and 5-FU injections did not differ in their clinical effectivity in this randomized study, but 5-FU injections lead to increased proliferation rate and did not affect vascular density in histological assessment. Due to the greater number of adverse effects observed after TAC treatment, 5-FU injections may be preferable for cosmetically sensitive skin areas. (C) 2018 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.Peer reviewe

Estudio del gen RHBDD2 como marcador pronóstico/predictivo frente al tratamiento neoadyuvante en el cáncer colorrectal

El cáncer colorrectal (CCR) es una enfermedad heterogénea a nivel molecular. El 5-Fluorouracilo (5-Fu) constituye la principal droga empleada como primera línea de tratamiento. En estudios previos, determinamos que el gen RHBDD2 se sobreexpresa en estadios avanzados del CCR, que se induce frente al tratamiento con 5-Fu y que se asocia al proceso de Respuesta a Estrés del Retículo Endoplasmático, fundamentalmente a la vía del UPR. El aumento de expresión de RHBDD2 en estadios avanzados del CCR y su inducción frente al 5Fu hacen del gen/proteína un target interesante a evaluar como marcador del seguimiento al tratamiento. Objetivos: evaluar en pacientes con cáncer de recto la expresión de RHBDD2 antes y después del tratamiento neoadjuvante. Establecer el efecto fenotípico de la expresión diferencial (sobreexpresión y silenciamiento) de RHBDD2 en líneas celulares de cáncer colorrectal y su comportamiento ante el tratamiento con 5-Fu