The Combination of APRI and ALBI Facilitates Preoperative Risk Stratification for Patients Undergoing Liver Surgery After Neoadjuvant Chemotherapy.

BACKGROUND: Neoadjuvant chemotherapy (NeoCTx) is performed for most patients with colorectal cancer liver metastases (CRCLM). However, chemotherapy-associated liver injury (CALI) has been associated with poor postoperative outcome. To date, however, no clinically applicable and noninvasive tool exists to assess CALI before liver resection. METHODS: Routine blood parameters were assessed in 339 patients before and after completion of NeoCTx and before surgery. The study assessed the prognostic potential of the aspartate aminotransferase (AST)-to-platelet ratio index (APRI), the albumin-bilirubin grade (ALBI), and their combinations. Furthermore, an independent multi-center validation cohort (n = 161) was included to confirm the findings concerning the prediction of postoperative outcome. RESULTS: Higher ALBI, APRI, and APRI + ALBI were found in patients with postoperative morbidity (P = 0.001, P = 0.064, P = 0.001, respectively), liver dysfunction (LD) (P = 0.009, P = 0.012, P < 0.001), or mortality (P = 0.037, P = 0.045, P = 0.016), and APRI + ALBI had the highest predictive potential for LD (area under the curve [AUC], 0.695). An increase in APRI + ALBI was observed during NeoCTx (P < 0.001). Patients with longer periods between NeoCTx and surgery showed a greater decrease in APRI + ALBI (P = 0.006) and a trend for decreased CALI at surgery. A cutoff for APRI + ALBI at - 2.46 before surgery was found to identify patients with CALI (P = 0.002) and patients at risk for a prolonged hospital stay (P = 0.001), intensive care (P < 0.001), morbidity (P < 0.001), LD (P < 0.001), and mortality (P = 0.021). Importantly, the study was able to confirm the predictive potential of APRI + ALBI for postoperative LD and mortality in a multicenter validation cohort. CONCLUSION: Determination of APRI + ALBI before surgery enables identification of high-risk patients for liver resection. The combined score seems to dynamically reflect CALI. Thus, APRI + ALBI could be a clinically relevant tool for optimizing timing of surgery in CRCLM patients after NeoCTx.

Topological constraints strongly affect chromatin reconstitution in silico.

The fundamental building block of chromatin, and of chromosomes, is the nucleosome, a composite material made up from DNA wrapped around a histone octamer. In this study we provide the first computer simulations of chromatin self-assembly, starting from DNA and histone proteins, and use these to understand the constraints which are imposed by the topology of DNA molecules on the creation of a polynucleosome chain. We take inspiration from the in vitro chromatin reconstitution protocols which are used in many experimental studies. Our simulations indicate that during self-assembly, nucleosomes can fall into a number of topological traps (or local folding defects), and this may eventually lead to the formation of disordered structures, characterised by nucleosome clustering. Remarkably though, by introducing the action of topological enzymes such as type I and II topoisomerase, most of these defects can be avoided and the result is an ordered 10-nm chromatin fibre. These findings provide new insight into the biophysics of chromatin formation, both in the context of reconstitution in vitro and in terms of the topological constraints which must be overcome during de novo nucleosome formation in vivo, e.g. following DNA replication or repair.

Shaping the future of liver surgery: Implementation of experimental insights into liver regeneration.

BACKGROUND: While liver surgery has become a safe and feasible operation technique, the incidence of postoperative liver dysfunction still remains a central problem. Approximately 10% of patients undergoing liver resection were shown to develop liver dysfunction, which is associated with an increased risk of morbidity and mortality. Yet, to date there is no effective treatment option for postoperative liver dysfunction available. The development of postoperative liver dysfunction was linked to a disruption in the liver's potential to regenerate. Thus, it is importance to elucidate the underlying mechanisms of liver regeneration and to find potential therapeutic targets for the treatment of patients with postoperative liver dysfunction. METHODS: A review of the literature was carried out. RESULTS: We report on potential future interventions for improvement of liver regeneration after surgical resection. Moreover, we evaluate the benefits and drawbacks of hepatic progenitor cell therapy and hematopoietic stem cell therapy. However, the most significant improvement seems to come from molecular targets. Indeed, von Willebrand factor and its pharmacologic manipulation are among the most promising therapeutic targets to date. Furthermore, using the example of platelet-based therapy, we stress the potentially adverse effects of treatments for postoperative liver dysfunction. CONCLUSION: The present review reports on the newest advances in the field of regenerative science, but also underlines the need for more research in the field of postoperative liver regeneration, especially in regard to translational studies.

Gene essentiality in Aspergillus fumigatus.

Products of essential genes of Aspergillus fumigatus are seen as potential targets for antifungal drugs, and both functional screens and bioinformatics approaches have been used to help identify such genes. The random screening approach makes use of the deletion of one copy of a gene in a diploid, and failure to recover the deletant during haploidization. In order to investigate the function of putative essential genes identified by both screening and bioinformatics approaches, the conditional promoter of the alcA gene of Aspergillus nidulans has been used. In some cases, the genes identified are not absolutely essential, but their deletion leads to slow growth. Such deletants can be recovered and cultivated for phenotypic characterization following transformation of haploid strains.

Repair of UV-damaged incoming plasmid DNA in Saccharomyces cerevisiae.

A whole-cell transformation assay was used for the repair of UV-damaged plasmid DNA in highly transformable haploid strains of Saccharomyces cerevisiae having different repair capabilities. Six rad alleles were selected from the three epistasis groups: rad 1-1 and rad2-1 from the RAD3 group, rad6-1 and rad18-2 from the RAD6 group, and rad52-1 and rad54-1 from the RAD52 group. Cells carrying single, double and triple rad alleles were transformed to uracil prototrophy by centromeric plasmid DNA (YCp19) modified in vitro with UV (254 nm). Surviving fractions were calculated as the number of transformants at each fluence relative to the number of transformants with unirradiated plasmid DNA. The sensitivity of incoming DNA in single rad mutants shows that most repair is carried out by excision repair and a RAD18-dependent process. In the rad52-1 host, the sensitivity of incoming DNA was intermediate between those found in RAD+ and rad2-1 hosts, suggesting the involvement of a recombinational repair process. Non-epistatic interactions were observed between rad alleles belonging to different epistasis groups. This provides validation for the classification of the three epistasis groups concerning the repair of chromosomal DNA for UV-incoming DNA. In both rad1-1 rad6-1 and rad1-1 rad18-2 rad54-1 hosts, the mean fluence for one lethal event corresponds approximately to one pyrimidine dimer per plasmid molecule, indicating that they are absolute repairless hosts for incoming DNA. A comparison between cell and plasmid survival reveals that there are differences in the repairability of both chromosomal and incoming DNA. The large effect of rad6-1 mutation on cell survival and the small effect on incoming DNA suggest that, in the RAD+ strain, the RAD6 product may be essential for the repair processes which act on chromosomal DNA, but not for those which act on incoming DNA. It is proposed that in yeasts postreplication repair of incoming DNA is limited to supercoiled molecules with 1-2 pyrimidine dimers that can initiate replication.

Experience with moderate intensity anticoagulation and aspirin after mechanical valve replacement. A retrospective, non-randomized study.

A selected group of patients who underwent valve replacement were analyzed to evaluate the feasibility, effectiveness and safety of combined treatment with moderate intensity anticoagulation plus aspirin. One hundred ninety-six patients who received a total of 204 mechanical valve prostheses between 1985 and 1991 were selected according to rigid criteria. The prostheses included 124 valves of caged ball design, 62 St. Jude valves and 18 others. The follow up of the whole population was 581.8 patient years, with an average of 2.97 patient years, and was complete by the definition criteria. All patients received moderate intensity anticoagulation with acenocoumarol (target International Normalized Ratio 2.5 to 3.5) and daily aspirin (100 mg or 325 mg). The incidence of thromboembolic events for the whole group was 3.26% per patient year, but only 1.6% in patients "compliant" with treatment. Preoperative embolism and non-compliance with treatment had a strong correlation with postoperative thromboembolism. The INR values had a strong correlation with both thromboembolic and hemorrhagic events. The incidence of serious hemorrhagic events was 4.12% patient years although only two cases (0.34%/pty) were fatal (cerebral hemorrhages). There was no difference in hemorrhagic incidence between patients receiving either 325 mg or 100 mg daily. A low incidence of thromboembolic complications was attained with the use of combined antithrombotic and antiplatelet therapy, even in the first generation caged ball type prostheses. However, the combination of moderate intensity anticoagulation with either 325 mg or 100 mg aspirin was associated with a risk of bleeding similar to high intensity anticoagulation alone. The risk of bleeding appeared to be greater in the presence of gastric pathology, and the combination of anticoagulants and aspirin should be avoided in patients with these conditions.

Monoterapia biológica en pacientes con artritis reumatoidea en Argentina / Biological monotherapy in patients with rheumatoid arthritis in Argentina

Introducción: La utilización de agentes biológicos para el tratamiento de la Artritis Reumatoidea (AR) es habitualmente usada en aquellos pacientes con enfermedad activa que no hayan respondido al tratamiento con drogas modificadoras de la Artritis Reumatoidea convencionales (DMARD, por sus siglas en inglés) o que hayan presentado intolerancia a las mismas. Al estado actual de la evidencia, la terapia combinada de agentes biológicos más un DMARD convencional (principalmente metotrexato) constituye el estándar de tratamiento. Sin embargo existen algunos escenarios como la intolerancia, la falta de adherencia y la aparición de eventos adversos a las DMARDs convencionales donde la monoterapia biológica emerge como una opción terapéutica válida. Según los distintos registros a nivel internacional, la frecuencia de utilización de agentes biológicos en monoterapia oscila entre 12 a 39%. Debido a la ausencia de estos datos a nivel local decidimos realizar este estudio para conocer el porcentaje de pacientes que se encuentran en monoterapia biológica y analizar las causas que llevaron a este tipo de tratamiento. Materiales y métodos: Estudio de tipo corte transversal donde se invitó a participar a diferentes centros reumatológicos distribuidos a lo largo de Argentina. Cada centro revisó las historias clínicas de los últimos 30 a 50 pacientes consecutivos vistos con AR, mayores de 18 años, que habían presentado inadecuada respuesta al tratamiento con DMARDs y que estaban bajo tratamiento biológico. Se completaba una ficha por cada paciente incluido, registrando datos demográficos, de la enfermedad y tratamientos previos. Resultados: Se incluyeron 32 centros y se evaluaron 1148 historias clínicas de pacientes con AR durante el mes de octubre y noviembre del 2012. Un 21,4% (246) de los pacientes al momento del estudio se encontraba bajo tratamiento biológico en monoterapia...

Introduction: The use of biological agents for the treatment of rheumatoid arthritis (RA) is commonly used in patients with active disease who have not responded to treatment with conventional rheumatoid arthritis-modifying drugs (DMARDs) or Who have presented intolerance to them. At the present state of evidence, combined therapy of biological agents plus conventional DMARD (mainly methotrexate) is the standard of treatment. However, there are some scenarios such as intolerance, lack of adherence and the appearance of adverse events to conventional DMARDs where biological monotherapy emerges as a valid therapeutic option. According to different international registries, the frequency of use of biological agents in monotherapy ranges from 12 to 39%. Due to the absence of these data at the local level we decided to carry out this study to know the percentage of patients who are in biological monotherapy and to analyze the causes that led to this type of treatment. Materials and methods: A cross-sectional study where different rheumatologic centers throughout Argentina were invited to participate. Each center reviewed the medical records of the last 30 to 50 consecutive patients seen with RA, older than 18 years, who had inadequate response to treatment with DMARDs and who were under biological treatment. One card was completed for each patient included, recording demographic, disease and previous treatment data. Results: Thirty-two centers were included and 1148 clinical records of patients with RA were evaluated during October and November 2012. A total of 244 patients (246) at the time of the study were under monotherapy...

A colony procedure for transformation of Saccharomyces cerevisiae.

A rapid and simple yeast transformation procedure has been developed using colonies on agar plates. Saccharomyces cerevisiae SHY3 cells were picked up from colonies on YPD plates grown freshly or stored at 4 degrees C and incubated with M13RK9-T DNA at 30 degrees C for 1-2 h in a solution of Li+, Ca2+, Mg2+, triacetin and polyethylene glycol. About 3,500 transformants were obtained per microgram of double stranded M13RK9-T DNA. Unlike the existing spheroplast techniques, single stranded M13RK9-T DNA transformed intact cells below one-hundredth frequency of the duplex form.

Repair of ultraviolet light damage in Saccharomyces cerevisiae as studied with double- and single-stranded incoming DNAs.

Purified double- and single-stranded DNAs of the autonomously replicating vector M13RK9-T were irradiated with ultraviolet light (UV) in vitro and introduced into competent whole cells of Saccharomyces cerevisiae. Incoming double-stranded DNA was more sensitive to UV in excision repair-deficient rad2-1 cells than in proficient repair RAD+ cells, while single-stranded DNA exhibited high sensitivity in both host cells. The results indicate that in yeast there is no effective rescue of UV-incoming single-stranded DNA by excision repair or other constitutive dark repair processes.

Anterolateral dislocation of the lumbosacral junction.

An unusual case of anterolateral fracture-dislocation of the lumbosacral junction is reported, and seven additional cases from the literature are discussed. The mechanism of injury is forced hyperflexion and shear. The prevalence of neurologic involvement is high, as is the number of fractures of the adjacent spinal elements and the occurrence of disk fragments in the spinal canal. The value of plain radiography and computed tomography in diagnosis and planning treatment is illustrated.

[Report of a new case of Cobb syndrome. Meningo-spinal cutaneous angiomatosis]. / Aporte de un nuevo caso de síndrome de Cobb. Angiomatosis cutáneo meningoespinal.

The authors present a 47 years old female patient with cutaneomeningospinal angiomatosis or Cobb's syndrome of thoracic location. This entity, included in the primarily mesodermic phacomatose, is extremely rare, and only 17 cases have been sufficiently documented in the literature on the subject. The rare association with vertebral haemangioma of the same metameric level was present in this patient. The diagnostic criteria, possible associations, pathophysiology and nosological situation are discussed. The telangiectasic type of angioma and the principally extradural location are stressed. The authors concluded on the importance of clinical suspicion of this diagnosis based on a spinal cord syndrome in the presence of a cutaneous angioma of the same metameric level. The necessity of a complete paraclinical studies which includes selective spinal angiography and linear tomography of the spine are also stressed. With this methodology the real incidence of this syndrome will be revealed, permitting a planned surgical treatment which will diminish the high mortality and morbidity of the cases published up to the present.

Endo.SK1: an inducible site-specific endonuclease from yeast mitochondria.

Site-specific endonucleases have been found in various eukaryotic organelles such as mitochondria, chloroplasts and nuclei. These endonucleases initiate site-specific or homologous gene conversion in mitochondrial and nuclear DNA. Here, we report a new site-specific endonuclease activity, Endo.SK1, identified in mitochondria of strain SK1, a homothallic diploid strain of Saccharomyces cerevisiae. Nucleotide sequences around the Endo.SK1-cleavage sites are different from those of known yeast site-specific endonucleases. The Endo.SK1 activity is, at least partly, specified by a gene in the SK1-derived mitochondria. A novel feature of the Endo.SK1 activity is its inducibility: the endonuclease activity was induced by ca. 40-fold by transfer of cells from a glucose medium into an acetate medium, and was then repressed. This transient induction was independent of the ploidy level of the cells, and coincided with induction of fumarase, a mitochondrial enzyme involved in the TCA cycle. Co-induction and co-repression of the mitochondrial site-specific endonuclease activity and a respiration-related enzyme indicate that the endonuclease activity in regulated in response to physiological conditions, and suggest a possible role for the endonuclease in mitochondrial DNA metabolism.

Gene PSO5 of Saccharomyces cerevisiae, involved in repair of oxidative DNA damage, is allelic to RAD16.

The pos5-1 mutation renders Saccharomyces cerevisiae cells sensitive to DNA-damaging agents. We have isolated plasmids from a S. cerevisiae genomic library capable of restoring wild-type levels of 254-nm ultraviolet light sensitivity of the pso5-1 mutant. DNA sequence analysis revealed that the complementing activity resides in RAD16, a gene involved in excision repair. Tetrad analysis showed that PSO5, like RAD16, is tightly linked to LYS2 on chromosome II. Moreover, allelism between the pso5-1 and rad16 mutants was demonstrated by the comparison of mutagen sensitivity phenotypes, complementation tests, and by meiotic analysis. The cloned RAD16 gene was capable of restoring wild-type resistance of the pso5-1 mutant to H2O2 and photoactivated 3-carbethoxypsoralen, both treatments generating oxidative stress-related DNA damage. This indicates that RAD16/PSO5 might also participate in the repair of oxidative base damage.