The cellulose synthase gene of Dictyostelium

Cellulose is a major component of the extracellular matrices formed during development of the social amoeba, Dictyostelium discoideum. We isolated insertional mutants that failed to accumulate cellulose and had no cellulose synthase activity at any stage of development. Development proceeded normally in the null mutants up to the beginning of stalk formation, at which point the culminating structures collapsed onto themselves, then proceeded to attempt culmination again. No spores or stalk cells were ever made in the mutants, with all cells eventually lysing. The predicted product of the disrupted gene (dcsA) showed significant similarity to the catalytic subunit of cellulose synthases found in bacteria. Enzyme activity and normal development were recovered in strains transformed with a construct expressing the intact dcsA gene. Growing amoebae carrying the construct accumulated the protein product of dcsA, but did not make cellulose until they had developed for at least 10 hr. These studies show directly that the product of dcsA is necessary, but not sufficient, for synthesis of cellulose.     

Combining physical performance and Functional Movement Screen testing to identify elite junior Australian Football athletes at risk of injury

The Functional Movement Screen (FMS) and physical performance testing are often suggested to be related to sports injury risk. This study explored if the combination of FMS and physical performance testing improved identification of non-contact injury risk over FMS testing alone in an elite junior Australian football cohort. Over a 3-year period, 573 players completed pre-season injury history questionnaires, FMS, physical performance testing (20-m sprint, vertical jump, planned agility testing, and shuttle run test), and subsequent in-season injury surveillance. Results: Neither previous injury or FMS score <14 were related to an increased risk of subsequent injury in isolation. The combination of FMS composite score ≤14 and previous injury moderately increased the risk of injury (Hazard ratio [HR] = 2.22 [1.09-4.54]). None of the physical performance measures improved the ability to predict injuries based on FMS composite score. FMS asymmetry was only associated with injury when combined with previous injury and vertical jump performance. Players with ≥1 FMS asymmetry and history of previous injury experienced a large increase in injury risk when vertical jump was poor (HR = 4.26 [1.35-13.42]) or good (HR = 3.17 [1.08-9.29]). Players with a combination of a good vertical jump, no previous injury, and no FMS asymmetries were also at moderately increased risk of injury (HR = 3.41 [1.11-10.42]). No physical performance tests improved the ability to identify non-contact injury risk using an FMS composite score threshold. However, a U-shaped relationship between vertical jump and injury risk was identified with both poor and good vertical jump height associated with a moderate-large increase in non-contact injury risk in the presence of ≥1 asymmetrical FMS sub-test.     

The promotion of functional urinary bladder regeneration using anti-inflammatory nanofibers

Current attempts at tissue regeneration utilizing synthetic and decellularized biologic-based materials have typically been met in part by innate immune responses in the form of a robust inflammatory reaction at the site of implantation or grafting. This can ultimately lead to tissue fibrosis with direct negative impact on tissue growth, development, and function. In order to temper the innate inflammatory response, anti-inflammatory signals were incorporated through display on self-assembling peptide nanofibers to promote tissue healing and subsequent graft compliance throughout the regenerative process. Utilizing an established urinary bladder augmentation model, the highly pro-inflammatory biologic scaffold (decellularized small intestinal submucosa) was treated with anti-inflammatory peptide amphiphiles (AIF-PAs) or control peptide amphiphiles and used for augmentation. Significant regenerative advantages of the AIF-PAs were observed including potent angiogenic responses, limited tissue collagen accumulation, and the modulation of macrophage and neutrophil responses in regenerated bladder tissue. Upon further characterization, a reduction in the levels of M2 macrophages was observed, but not in M1 macrophages in control groups, while treatment groups exhibited decreased levels of M1 macrophages and stabilized levels of M2 macrophages. Pro-inflammatory cytokine production was decreased while anti-inflammatory cytokines were up-regulated in treatment groups. This resulted in far fewer incidences of tissue granuloma and bladder stone formation. Finally, functional urinary bladder testing revealed greater bladder compliance and similar capacities in groups treated with AIF-PAs. Data demonstrate that AIF-PAs can alleviate galvanic innate immune responses and provide a highly conducive regenerative milieu that may be applicable in a variety of clinical settings.     

Coincidental diagnosis of tuberculous lymphadenitis: a case report

The aim of this case report was to present a case of multiple calcified tuberculous lymph nodes found on a panoramic radiograph coincidently diagnosed in an endodontic clinic. A detailed discussion on the differential diagnosis of similar such calcification found in the same region is also presented. A 14‐year‐old girl was referred to our department with the complaint of painless swelling in the left side of the lower jaw. Clinical and radiographical examinations were performed, leading to the initial diagnosis of chronic periapical abscess. The patient's medical history was re‐evaluated. Advanced imaging and excisional biopsy were performed in order to confirm the final diagnosis. Regarding the presenting signs and symptoms of bilateral carious mandibular molars, a periapical inflammatory process was considered in the provisional diagnosis. A thorough examination and investigations were suggestive of cervical tuberculous lymphadenitis (scrofula), and the patient underwent excision of the same. The clinician should consider the possibility of chronic granulomatous inflammatory lesions in the differential diagnosis of radiopaque lesions.