Recovery of protein synthesis to assay DNA repair activity in transcribed genes in living cells and tissues

Transcription-coupled nucleotide excision repair (TC-NER) is an important DNA repair mechanism that protects against the negative effects of transcription-blocking DNA lesions. Hereditary TC-NER deficiencies cause pleiotropic and often severe neurodegenerative and progeroid symptoms. While multiple assays have been developed to determine TC-NER activity for clinical and research purposes, monitoring TC-NER is hampered by the low frequency of repair events occurring in transcribed DNA. ’Recovery of RNA Synthesis’ is widely used as indirect TC-NER assay based on the notion that lesion-blocked transcription only resumes after successful TC-NER. Here, we show that measuring novel synthesis of a protein after its compound-induced degradation prior to DNA damage induction is an equally effective but more versatile manner to indirectly monitor DNA repair activity in transcribed genes. This ‘Recovery of Protein Synthesis’ (RPS) assay can be adapted to various degradable proteins and readouts, including imaging and immunoblotting. Moreover, RPS allows real-time monitoring of TC-NER activity in various living cells types and even in differentiated tissues of living organisms. To illustrate its utility, we show that DNA repair in transcribed genes declines in aging muscle tissue of C. elegans. Therefore, the RPS assay constitutes an important novel clinical and research tool to investigate transcription-coupled DNA repair

El genoma y sus metáforas: ¿Detectives, héroes o profetas?

La «nueva genética», es decir, el impulso que esta disciplina toma a partir del denominado Proyecto Genoma, aspira a un cambio de paradigma en ciencias de la salud. Este cambio se postula desde una aproximación fenotípica de los problemas de salud hacia una aproximación genotípica, y por tanto excluyendo básicamente la influencia del medioambiente, lo que podría comprometer gravemente los fundamentos para el desarrollo y el ejercicio de la salud pública. Desde que empezó a desarrollarse el Proyecto Genoma, los nuevos descubrimientos genéticos se convirtieron en temas frecuentes de noticias en los medios de comunicación de masas. En este sentido, tanto genetistas como periodistas suelen utilizar metáforas para dar a conocer los conceptos complejos de la investigación genética para los que no existen bases en el lenguaje profano. Cabe señalar que los medios de comunicación no sólo modelan el establecimiento de la agenda social, sino que son también el espacio donde se conforma la cultura de salud de la población. Se presentan los resultados de un estudio preliminar en el que se exploran las metáforas utilizadas en los tres diarios de mayor difusión nacional (ABC, El País y El Mundo) en relación con las noticias sobre la «nueva genética» y se plantean las posibles consecuencias para la cultura de salud que puede tener la historia natural o el proceso catacrético de estas metáforas, mediante el cual se traslada el sentido figurativo de un término al sentido literal. En el proceso de revisión se ha desarrollado una taxonomía preliminar de las metáforas encontradas. Un 14,8% de los titulares identificados (51 de 342) contenía metáforas. Las metáforas estratégicas, como «programa», «control», «código», «mapa» o «puzle» son las más utilizadas, seguidas de las teleológicas, con términos como «misterio» o «lenguaje de Dios», y por último las bélicas, como «ataque», «derrota» o «captura». Los tres tipos de metáforas se caracterizan por su intento de dotar de intencionalidad a los genes. Según estas observaciones, el punto de vista tecnocrático es el que parece estar prevaleciendo frente al religioso o el bélico, y es el que puede ejercer una mayor influencia en la construcción futura de la cultura de salu

IMMEDIATELY LOADED ZYGOMATIC IMPLANTS VERSUS CONVENTIONAL DENTAL IMPLANTS IN AUGMENTED ATROPHIC MAXILLAE: THREE-YEAR POST-LOADING RESULTS FROM A MULTICENTRE RANDOMISED CONTROLLED TRIAL

PURPOSE. To compare the clinical outcomes of immediately loaded cross-arch maxillary prostheses supported by zygomatic implants versus conventional implants placed in augmented bone. MATERIALS AND METHODS. Seventy-one edentulous patients with severely atrophic maxillae not having sufficient bone volumes for placing dental implants, or when it was possible to place only two implants of minimal diameter 3.5 mm and length of 8 mm in the frontal area and there was less than 4 mm of bone height subantrally were randomi-sed according to a parallel-group design to receive either zygomatic implants (35 patien-ts) to be loaded immediately or xenograft followed, after 6 months of graft consolidation, by placement of six to eight conventional dental implants submerged for 4 months (36 patients). Outcome measures were: prosthesis, implant and augmentation failures, any complica-tions, quality of life (OHIP-14), number of days with totally or partially impaired activity, time to function, and number of dental visits, as assessed by independent assessors. Patients were followed up to 3 years after loading. RESULTS. Eight patients from the augmentation group dropped out versus three from the zygomatic group. One augmentation procedure failed. Eight prostheses could not be fitted or failed in the augmentation group versus two prostheses in the zygomatic group, the difference being not statistically significant (difference in proportions = 18.18%; 95% CI: 1.44 to 34.91; P = 0.082). Nine patients in the augmentation group lost 42 implants versus three patients who lost six zygomatic implants, the difference being not statistically significant (difference in proportions = 21.65%; 95% CI: 2.02 to 41.20; P = 0.052). Sixteen augmented patients were affected by 30 complications versus 29 zygomatic patients (55 complications), the difference being statistically significant (difference in proportions =-30.87 %; 95% CI:-51.88 to-9.86; P = 0.007). The 3-year OHIP-14 score was 4.11±7.27 in augmented patients and 4.51±6.23 in zygomatic patients, with no statistically significant differences between groups (mean difference = 0.40; 95% CI:-2.80 to 3.61; P = 0.624). Both groups had significantly improved OHIP-14 scores from before rehabilitation (P < 0.01 for both augmentation and zygomatic patients). Days of total infirmity were, on average, 7.42±3.17 in the augmentation group and 7.17±1.96 in the zygomatic group, the difference not being statistically significant (mean difference =-0.25; 95% CI:-1.52 to 1.02; P = 0.692). Days of partial infirmity were on average, 14.24±4.64 in the augmented group and 12.17±3.82 in the zygomatic group, the difference being statistically significant (mean difference =-2.07; 95% CI:-4.12 to-0.02; P = 0.048). The mean number of days to functional prosthesis fitting were 444.32±207.86 in augmentation patients and 1.34±2.27 in zygomatic patients, the difference being statistically significant (mean difference =-442.98; 95% CI:-513.10 to-372.86; P < 0.001). The average number of dental appointments was 23.00±11.80 for augmentation patients and 20.05±6.23 for zygomatic patients, the difference not being statistically significant (mean difference =-2.94; 95% CI:-7.62 to 1.74; P = 0.213)