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The principal objective of the present research involved the achievement of high biodegradation degrees of perfluorooctanoic acid (PFOA) and perfluorosulfonic acid (PFOS) using pure individual bacterial strains. The use of such microorganisms can contribute to the improvement of the wastewater treatment process in sewage treatment plants through bioaugmentation or other bioremediation processes. Thus, in this study, we investigated the biodegradation potential of PFOA and PFOS. Bacterial strains tested in this study were from the Pseudomonas genus, namely: Pseudomonas aeruginosa and Pseudomonas putida, due to their known capacity to degrade xenobiotic compounds. The results indicated that Pseudomonas aeruginosa was able to transform 27.9% of PFOA and 47.3% of PFOS in 96 h, while Pseudomonas putida managed to transform 19.0% of PFOA and 46.9% of PFOS in the same time frame. During the biodegradation tests, PFHxA was recognized as the principal biotransformation product of PFOA in the presence of Pseudomonas aeruginosa, and PFPeA, PFPxA and PFHpA were recognized as the biotransformation products in the presence of Pseudomonas putida. For PFOS, only two biotransformation products (PHHxA and PFHpA) were observed as a consequence of biodegradation by both bacterial strains. [ABSTRACT FROM AUTHOR]

Human replication protein A binds to the 5' side of its ssDNA substrate and then extends in the 3' direction. Binding and unwinding of the DNA is most efficient when both strands of the DNA bubble region contain polypyrimidine rather than purine.

Low back pain is a major public health issue associated with degeneration of the intervertebral disc (IVD). The early stages of degeneration are characterized by the dehydration of the central, gelatinous portion of the IVD, the nucleus pulposus (NP). One possible treatment approach is to replace the NP in the early stages of IVD degeneration with a hydrogel that restores healthy biomechanics while supporting tissue regeneration. The present study evaluates a novel thermosensitive hydrogel based on poly(N‐isopropylacrylamide‐graft‐chondroitin sulfate) (PNIPAAM‐g‐CS) for NP replacement. The hypothesis was tested that the addition of freeze‐dried, calcium crosslinked alginate microparticles (MPs) to aqueous solutions of PNIPAAm‐g‐CS would enable tuning of the rheological properties of the injectable solution, as well as the bioadhesive and mechanical properties of the thermally precipitated composite gel. Further, we hypothesized that the composite would support encapsulated cell viability and differentiation. Structure‐material property relationships were evaluated by varying MP concentration and diameter. The addition of high concentrations (50 mg/mL) of small MPs (20 ± 6 μm) resulted in the greatest improvement in injectability, compressive mechanical properties, and bioadhesive strength of PNIPAAm‐g‐CS. This combination of PNIPAAM‐g‐CS and alginate MPs supported the survival, proliferation, and differentiation of adipose derived mesenchymal stem cells toward an NP‐like phenotype in the presence of soluble GDF‐6. When implanted ex vivo into the intradiscal cavity of degenerated porcine IVDs, the formulation restored the compressive and neutral zone stiffnesses to intact values and resisted expulsion under lateral bending. Overall, results indicate the potential of the hydrogel composite to serve as a scaffold for supporting NP regeneration. This work uniquely demonstrates that encapsulation of re‐hydrating polysaccharide‐based MPs may be an effective method for improving key functional properties of in situ forming hydrogels for orthopedic tissue engineering applications. [ABSTRACT FROM AUTHOR]

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The goal of this work is to develop an injectable nucleus pulposus (NP) tissue engineering scaffold with the ability to form an adhesive interface with surrounding disc tissue. A family of in situ forming hydrogels based on poly( N-isopropylacrylamide)-graft-chondroitin sulfate (PNIPAAm- g-CS) were evaluated for their mechanical properties, bioadhesive strength, and cytocompatibility. It was shown experimentally and computationally with the Neo-hookean hyperelastic model that increasing the crosslink density and decreasing the CS concentration increased mechanical properties at 37 °C, generating several hydrogel formulations with unconfined compressive modulus values similar to what has been reported for the native NP. The adhesive tensile strength of PNIPAAm increased significantly with CS incorporation ( p < 0.05), ranging from 0.4 to 1 kPa. Live/Dead and XTT assay results indicate that the copolymer is not cytotoxic to human embryonic kidney (HEK) 293 cells. Taken together, these data indicate the potential of PNIPAAm- g-CS to function as a scaffold for NP regeneration. [ABSTRACT FROM AUTHOR]

Focuses on molecular polarity of human replication protein A (hRPA) binding to pseudo-origin DNA substrates. Details on hRPA binding of a 48 bp simian virus 40 pseudo-origin substrate; Effects of single-stranded DNA bubble region with polypyrimidine on hRPA binding affinity; Implication of hRPA binding molecular polarity for DNA replication initiation.

Aims Stereotactic body radiotherapy (SBRT) represents an interesting opportunity in the treatment of ovarian cancer (OC) isolated recurrences or residual lesions after systemic treatment, as well as a valid tool to lengthen the free time of re-challenge with platinum. However, studies on this topic are sporadic and with few cases. The aim of this multicentric retrospective pooled analysis was to collect the largest unselected real-life dataset of OC patients treated with SBRT in the attempt to define the safety and efficacy. Secondary objectives were to identify the best dose/fractionation regimen in terms of local control as well as to describe acute and late toxicities. Methods Eight Italian cancer Centers were firstly started the project giving their adhesion to this retrospective pooled analysis. A specific data-set for standardized data collection for ovarian cancer SBRT treatment was developed. Participants were required to fill a data sets including: age, histotype, site of irradiation, previous treatments, best response, toxicity as well as technical/dosimetric data about SBRT treatment. Patients' data were obtained from the historical database of radiation oncologists who joined the study. Results Data on 73 OC patients (median age: 63.5, range 40-83) carrying a total of 120 lesions were considered suitable for analysis. Between 2005 and 2018 all patients underwent SBRT in single or multiple fractions with a median biological equivalent dose (BEDα/β 10) of 76.8 Gy (range 7.5-262.5). Patient and treatment characteristics as well as acute toxicity are detailed in Table 1. Safety. 52 patients (71.3%) did not experience acute toxicity, the others 21 (28.7%) experienced low grade acute toxicity with no patient showing > grade 2 toxicity. With a median follow-up of 18 months (range: 1 - 120), 68 patients (93.1%) did not experienced late toxicity, the others 5 (6.9%) experienced low grade late toxicity with no patient showing > grade 2 toxicity. Efficacy. On a per-lesion basis, the 12-and 24-months actuarial local control inside SBRT field were 88.3% and 86.2%, respectively. BED10 > 50Gy was correlated with a better 12-months local control (91.7% versus 72.9%, p=0.034). Conclusions Preliminary results on a population-level confirm that SBRT delivered in 1-10 consecutive fractions is safe and well tolerated notwithstanding several previous surgical and systemic treatments. Therefore, this treatment can be considered as a further resource in order to lengthen the free time of re-challenge with platinum. [ABSTRACT FROM AUTHOR]