The flavodoxin FldA activates the class Ia ribonucleotide reductase of Campylobacter jejuni.

Campylobacter jejuni is a microaerophilic zoonotic pathogen with an atypical respiratory Complex I that oxidizes a flavodoxin (FldA) instead of NADH. FldA is essential for viability and is reduced via pyruvate and 2-oxoglutarate oxidoreductases (POR/OOR). Here, we show that FldA can also be reduced by FqrB (Cj0559), an NADPH:FldA reductase. An fqrB deletion mutant was viable but displayed a significant growth defect. FqrB is related to flavoprotein reductases from Gram-positive bacteria that can reduce NrdI, a specialized flavodoxin that is needed for tyrosyl radical formation in NrdF, the beta subunit of class 1b-type (Mn) ribonucleotide reductase (RNR). However, C. jejuni possesses a single class Ia-type (Fe) RNR (NrdAB) that would be expected to be ferredoxin dependent. We show that CjFldA is an unusually high potential flavodoxin unrelated to NrdI, yet growth of the fqrB mutant, but not the wild-type or a complemented strain, was stimulated by low deoxyribonucleoside (dRNS) concentrations, suggesting FldA links FqrB and RNR activity. Using purified proteins, we confirmed the NrdB tyrosyl radical could be regenerated in an NADPH, FqrB, and FldA dependent manner, as evidenced by both optical and electron paramagnetic resonance (EPR) spectroscopy. Thus, FldA activates RNR in C. jejuni, partly explaining its essentiality.

Advances in the Optimization of Fe Nanoparticles: Unlocking Antifungal Properties for Biomedical Applications.

In recent years, nanotechnology has achieved a remarkable status in shaping the future of biological applications, especially in combating fungal diseases. Owing to excellence in nanotechnology, iron nanoparticles (Fe NPs) have gained enormous attention in recent years. In this review, we have provided a comprehensive overview of Fe NPs covering key synthesis approaches and underlying working principles, the factors that influence their properties, essential characterization techniques, and the optimization of their antifungal potential. In addition, the diverse kinds of Fe NP delivery platforms that command highly effective release, with fewer toxic effects on patients, are of great significance in the medical field. The issues of biocompatibility, toxicity profiles, and applications of optimized Fe NPs in the field of biomedicine have also been described because these are the most significant factors determining their inclusion in clinical use. Besides this, the difficulties and regulations that exist in the transition from laboratory to experimental clinical studies (toxicity, specific standards, and safety concerns) of Fe NPs-based antifungal agents have been also summarized.

Effectiveness of Photobiomodulation Therapy in the Treatment of Myofascial Pain Syndrome of the Upper Trapezius Muscle: A Systematic Review and Meta-Analysis.

Objective: This systematic review aimed to investigate the efficacy of photobiomodulation therapy (PBMT) on pain and pressure pain threshold (PPT) in patients with myofascial pain syndrome (MPS) of the upper trapezius muscle. Materials and methods: A total of 17 studies (944 patients) were included; data regarding participants, intervention parameters, outcome measures, time of measurement, and follow-up were extracted. Evaluation of the methodological quality was performed by Physiotherapy Evidence Database (PEDro) scale. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used to assess the quality of evidence. A meta-analysis was performed on 16 studies, and standardized mean difference (SMD), corresponding 95% confidence interval (CI), and overall effect size (ES) were calculated. Results: Meta-analysis using a random-effect model was performed to evaluate the effects of PBMT alone or PBMT plus exercise (EX) compared with placebo, medical treatment, physical therapy (PT) modality, manual therapy, or complementary PT. Assessment according to the PEDro scale revealed 12 high-quality, 3 fair-quality, and 2 low-quality studies. According to the GRADE system, studies exhibited low to medium quality of evidence, with medium ES [SMD -0.54 (95% CI -1.05 to -0.02)] for studies using PBMT alone and large ES [SMD -0.80 (95% CI -1.35 to -0.26)] for PBMT+EX. Conclusions: The present systemic review revealed that PBMT is an effective PT modality for reducing pain and increasing PPT in patients with MPS of the upper trapezius. PBMT, when combined with EX, had more significant effects in reducing pain and increasing PPT compared with controls. The low-quality studies with low to moderate quality of evidence limit the confidence in the effect estimate and recommend further high-quality studies for standardization of treatment protocols and irradiation parameters. PROSPERO registration number: CRD42021241155.