Bacteriophage-encoded 24B_1 molecule resembles herpesviral microRNAs and plays a crucial role in the development of both the virus and its host

by Sylwia Bloch, Natalia Lewandowska, Joanna Zwolenkiewicz, Paulina Mach, Aleksandra Łukasiak, Mikołaj Olejniczak, Logan W. Donaldson, Grzegorz Węgrzyn, Bożena Nejman-Faleńczyk

The 24B_1 small non-coding RNA molecule has been identified in Escherichia coli after induction of Shiga toxin-converting bacteriophage Φ24_B. In this work, we focused on its direct role during phage and bacterial host development. We observed that in many aspects, this phage sRNA resembles herpesviral microRNAs. Similar to microRNAs, the mature 24B_1 is a short molecule, consisting of just 20 nucleotides. It is generated by cleaving the 80-nt long precursor transcript, and likely it undergoes a multi-step maturation process in which the Hfq protein plays an important role, as confirmed by demonstration of its binding to the 24B_1 precursor, but not to the 24B_1 mature form. Moreover, 24B_1 plays a significant role in maintaining the prophage state and reprogramming the host’s energy metabolism. We proved that overproduction of this molecule causes the opposite physiological effects to the mutant devoid of the 24B_1 gene, and thus, favors the lysogenic pathway. Furthermore, the 24B_1 overrepresentation significantly increases the efficiency of expression of phage genes coding for proteins CI, CII, and CIII which are engaged in the maintenance of the prophage. It seems that through binding to mRNA of the sdhB gene, coding for the succinate dehydrogenase subunit, the 24B_1 alters the central carbon metabolism and causes a drop in the ATP intracellular level. Interestingly, a similar effect, called the Warburg switch, is caused by herpesviral microRNAs and it is observed in cancer cells. The advantage of the Warburg effect is still unclear, however, it was proposed that the metabolism of cancer cells, and all rapidly dividing cells, is adopted to convert nutrients such as glucose and glutamine faster and more efficiently into biomass. The availability of essential building blocks, such as nucleotides, amino acids, and lipids, is crucial for effective cell proliferation which in turn is essential for the prophage and its host to stay in the lysogenic state.

History of incarceration and age-related neurodegeneration: Testing models of genetic and environmental risks in a longitudinal panel study of older adults

by Peter T. Tanksley, Matthew W. Logan, J. C. Barnes

History of incarceration is associated with an excess of morbidity and mortality. While the incarceration experience itself comes with substantive health risks (e.g., injury, psychological stress, exposure to infectious disease), most individuals eventually return from prison to the general population where they will be diagnosed with the same age-related conditions that drive mortality in the non-incarcerated population but at exaggerated rates. However, the interplay between history of incarceration as a risk factor and more traditional risk factors for age-related diseases (e.g., genetic risk factors) has not been studied. Here, we focus on cognitive impairment, a hallmark of neurodegenerative conditions like Alzheimer’s disease, as an age-related state that may be uniquely impacted by the confluence of environmental stressors (e.g., incarceration) and genetic risk factors. Using data from the Health and Retirement Study, we found that incarceration and APOE-ε4 genotype (i.e., the chief genetic risk factor for Alzheimer’s disease) both constituted substantive risk factors for cognitive impairment in terms of overall risk and earlier onset. The observed effects were mutually independent, however, suggesting that the risk conveyed by incarceration and APOE-ε4 genotype operate across different risk pathways. Our results have implications for the study of criminal-legal contact as a public health risk factor for age-related, neurodegenerative conditions.

Rates of subsequent surgeries after meniscus repair with and without concurrent anterior cruciate ligament reconstruction

by Joseph B. Kahan, Patrick Burroughs, Logan Petit, Christopher A. Schneble, Peter Joo, Jay Moran, Maxwell Modrak, William Mclaughlin, Adam Nasreddine, Jonathan N. Grauer, Michael J. Medvecky

Objectives

The purpose of this study was to compare the rates of secondary knee surgery for patients undergoing meniscus repair with or without concurrent anterior cruciate ligament reconstruction (ACLr).

Methods

Utilizing a large national database, patients with meniscal repair with or without concurrent arthroscopic ACLr were identified. The two cohorts were then queried for secondary surgical procedures of the knee within the following 2 years. Frequency, age distribution, rates of secondary surgery, and type of secondary procedures performed were compared.

Results

In total, 1,585 patients were identified: meniscus repair with ACLr was performed for 1,006 (63.5%) and isolated meniscal repair was performed for 579 (36.5%). Minimum of two year follow up was present for 487 (30.7% of the overall study population).Secondary surgery rates were not significantly different between meniscus repair with concurrent ACLr and isolated meniscus repairs with an overall mean follow up of 13 years (1.5–24 years) (10.6% vs. 13.6%, p = 0.126). For the 2 year follow up cohort, secondary surgery rates were not significantly different (19.3% vs. 25.6%, p = 0.1098). There were no differences in survivorship patterns between the two procedures, both in the larger cohort (p = 0.2016), and the cohort with minimum 2-year follow-up (p = 0.0586).

Conclusion

The current study assessed secondary surgery rates in patients undergoing meniscus repair with or without concurrent ACLr in a large patient database. Based on this data, no significant difference in rates of secondary knee surgery was identified.

The location of an internal focus of attention differentially affects motor performance

by Andrew J. Strick, Logan T. Markwell, Hubert Makaruk, Jared M. Porter

Prior research has questioned the appropriateness of internal focus instructions or the juxtaposition to external and control conditions. Moreover, there has been a lack of research conducted to test a variety of internal conditions on motor performance. The purpose of the present study was to address those critiques and add to the attentional focus literature by varying the location of an internal focus while performing a standing long jump. Participants performed a standing long jump during five separate conditions (internal focus: toes, knees, hips, arms; and control). The analysis revealed that all internal focus conditions performed worse than the control condition. Furthermore, the only difference between internal conditions was found between arms and knees, where the knee condition resulted in a significantly shorter jump distance relative to the arms. Regardless of the location specified, all internal focus conditions led to detriments in jump performance when compared to the control condition. These findings add to a large body of work demonstrating the importance of instructional content on motor performance.