Ecosystem engineering by seagrasses interacts with grazing to shape an intertidal landscape

Self-facilitation through ecosystem engineering (i.e., organism modification of the abiotic environment) and consumer-resource interactions are both major determinants of spatial patchiness in ecosystems. However, interactive effects of these two mechanisms on spatial complexity have not been extensively studied. We investigated the mechanisms underlying a spatial mosaic of low-tide exposed hummocks and waterlogged hollows on an intertidal mudflat in the Wadden Sea dominated by the seagrass Zostera noltii. A combination of field measurements, an experiment and a spatially explicit model indicated that the mosaic resulted from localized sediment accretion by seagrass followed by selective waterfowl grazing. Hollows were bare in winter, but were rapidly colonized by seagrass during the growth season. Colonized hollows were heavily grazed by brent geese and widgeon in autumn, converting these patches to a bare state again and disrupting sediment accretion by seagrass. In contrast, hummocks were covered by seagrass throughout the year and were rarely grazed, most likely because the waterfowl were not able to employ their preferred but water requiring feeding strategy ('dabbling') here. Our study exemplifies that interactions between ecosystem engineering by a foundation species (seagrass) and consumption (waterfowl grazing) can increase spatial complexity at the landscape level.     

Novel metabolic aspects related to adenosine deaminase inhibition in a human astrocytoma cell line

Adenosine deaminase, which catalyzes the deamination of adenosine and deoxyadenosine, plays a central role in purine metabolism. Indeed, its deficiency is associated with severe immunodeficiency and abnormalities in the functioning of many organs, including nervous system. We have mimicked an adenosine deaminase-deficient situation by incubating a human astrocytoma cell line in the presence of deoxycoformycin, a strong adenosine deaminase inhibitor, and deoxyadenosine, which accumulates in vivo when the enzyme is deficient, and have monitored the effect of the combination on cell viability, mitochondrial functions, and other metabolic features. Astrocytomas are the most common neoplastic transformations occurring in glial cell types, often characterized by a poor prognosis. Our experimental approach may provide evidence both for the response to a treatment affecting purine metabolism of a tumor reported to be particularly resistant to chemotherapeutic approaches and for the understanding of the molecular basis of neurological manifestations related to errors in purine metabolism. Cells incubated in the presence of the combination, but not those incubated with deoxyadenosine or deoxycoformycin alone, underwent apoptotic death, which appears to proceed through a mitochondrial pathway, since release of cytochrome c has been observed. The inhibition of adenosine deaminase increases both mitochondrial reactive oxygen species level and mitochondrial mass. A surprising effect of the combination is the significant reduction in lactate production, suggestive of a reduced glycolytic capacity, not ascribable to alterations in NAD⁺/NADH ratio, nor to a consumption of inorganic phosphate. This is a hitherto unknown effect presenting early during the incubation with deoxyadenosine and deoxycoformycin, which precedes their effect on cell viability.     

Disseminated pulmonary adiaspiromycosis in a crested porcupine (Hystrix cristata Linnaeus, 1758)

Adiaspiromycosis is primarily a necrotizing granulomatous pneumonia caused by a dimorphic fungus of the genus Emmonsia. A young crested porcupine (Hystrix cristata) found dead showed multiple fractures, chronic pleuritis, and granulomatous pneumonia. Microscopically, cystic structures were consistent with adiaspiromycosis by Emmonsia crescens. The diagnosis was confirmed using molecular methods.     

The life history of 21 breast cancers

Cancer evolves dynamically as clonal expansions supersede one another driven by shifting selective pressures, mutational processes, and disrupted cancer genes. These processes mark the genome, such that a cancer's life history is encrypted in the somatic mutations present. We developed algorithms to decipher this narrative and applied them to 21 breast cancers. Mutational processes evolve across a cancer's lifespan, with many emerging late but contributing extensive genetic variation. Subclonal diversification is prominent, and most mutations are found in just a fraction of tumor cells. Every tumor has a dominant subclonal lineage, representing more than 50% of tumor cells. Minimal expansion of these subclones occurs until many hundreds to thousands of mutations have accumulated, implying the existence of long-lived, quiescent cell lineages capable of substantial proliferation upon acquisition of enabling genomic changes. Expansion of the dominant subclone to an appreciable mass may therefore represent the final rate-limiting step in a breast cancer's development, triggering diagnosis.     

Sphingosine 1-phosphate stimulates proliferation and migration of satellite cells: role of S1P receptors

Satellite cells are resident stem cells of skeletal muscle; they are normally quiescent but upon post-trauma activation start to proliferate and fuse with damaged fibers contributing to muscle regeneration. In this study the effect of the bioactive sphingolipid sphingosine 1-phosphate (S1P) on the proliferative and migratory response of murine satellite cells has been examined. S1P was found to stimulate labeled thymidine incorporation in a phosphatidylinositol 3-kinase-dependent manner. Moreover, by employing selective S1P receptor agonists and antagonists and silencing individual S1P receptors, the mitogenic action of S1P in satellite cells was shown to depend on S1P2 and S1P3. Notably, by using different experimental approaches S1P was found to positively influence satellite cell migration, necessary for their recruitment at the site of muscle damage. Interestingly, the specific silencing of individual S1P receptor subtypes demonstrated the pivotal role of S1P1 and S1P4 in mediating the S1P migratory effect. This latter result demonstrates for the first time that S1P4 receptor has a role in skeletal muscle cells, supporting the notion that this receptor subtype plays a biological action broader than that so far identified in lymphoid tissue. On the contrary, S1P2 was found to negatively regulate cell migration. Collectively, these results are in favour of an important function of S1P in satellite cell biology that could in principle be exploited as novel pharmacological target for improving skeletal muscle regeneration.     

Role of plasma phosphorylated neurofilament heavy chain (pNfH) in amyotrophic lateral sclerosis

The phosphorylated neurofilament heavy chain (pNfH) is a promising biomarker in amyotrophic lateral sclerosis (ALS). We examined plasma pNfH concentrations in order to corroborate its role as a diagnostic and prognostic biomarker in ALS. Incident ALS cases enrolled in a population‐based registry were retrospectively selected and matched by sex and age with a cohort of healthy volunteers. Plasma pNfH levels were measured by an ELISA kit and correlated with clinical parameters. Discrimination ability of pNfH was tested using receiving operating characteristic (ROC) curves. Kaplan–Meier (KM) analysis and Cox proportional hazard models were used for survival analysis. Plasma pNfH was significantly higher in patients compared to controls. An optimal cut‐off of 39.74 pg/ml discriminated cases from controls with an elevated sensitivity and specificity. Bulbar‐onset cases had higher plasma pNfH compared to spinal onset (p = 0.0033). Furthermore, plasma pNfH positively correlated with disease progression rate (r = 0.19, p = 0.031). Baseline plasma pNfH did not influence survival in our cohort. Our findings confirmed the potential utility of plasma pNfH as a diagnostic biomarker in ALS. However, further studies with longitudinal data are needed to corroborate its prognostic value.     

Resveratrol Inhibits Sodium/Iodide Symporter Gene Expression and Function in Rat Thyroid Cells

Resveratrol is a polyphenol found in grapes and berries that has antioxidant, antiproliferative and anti-inflammatory properties. For these reasons, it is available as a dietary supplement, and it is under investigation in several clinical trials. Few data are available regarding the effects of resveratrol on thyroid function. A previous study showed that resveratrol transiently increases iodide influx in FRTL-5 rat thyroid cells. Indeed, this increase arises after short treatment times (6–12 h), and no further effects are seen after 24 h. The aim of the present study was to investigate the effects of resveratrol on iodide uptake and sodium/iodide symporter expression in thyroid cells after longer times of treatment. For this purpose, the effects of resveratrol were evaluated both in vitro and in vivo using the rat thyroid FRTL-5 cell line and Sprague-Dawley rats, respectively. In FRTL-5 cells, resveratrol decreased the sodium/iodide symporter RNA and protein expression as a function of time. Furthermore, resveratrol decreased cellular iodide uptake after 48 h of treatment. The inhibitory effect of resveratrol on iodide uptake was confirmed in vivo in Sprague-Dawley rats. This study demonstrates that with longer-term treatment, resveratrol is an inhibitor of sodium/iodide symporter gene expression and function in the thyroid. These data suggest that resveratrol can act as a thyroid disruptor, which indicates the need for caution as a supplement and in therapeutic use.     

Telemedicine for Hip Preservation Patients: Access,Ability and Preference

BackgroundRecent events have resulted in rapid rises in the use of telemedicine in orthopaedic surgery, despite limited evidence regarding patient preferences or concerns. The purpose of this study is to determine access to and, ability to use telemedicine technology in an adult hip preservation patient population, as well as determine associations with patient characteristics. Additionally, we seek to understand patients’ perceived benefits, risks and preferences of telemedicine.MethodsWe performed a cross-sectional survey administered on patients scheduled to undergo joint preservation surgery by one of three surgeons at a single academic institution. Both preoperative and postoperative established patients were included and called for a telephone administered survey if a date of surgery was scheduled between October 1, 2019 and March 30, 2020 and were 18 years or older. The survey had seven sections with 45 questions relating to demographics, technology access, videoconferencing capability, confidence using technology, telehealth experiences, perceptions.Results101 patients completed the survey (48% response rate, 101/212). Overall, 99% of participants reported using the internet, 94% reporting owning a device capable of videoconferencing, and 86% of patients had participated in a video call in the past year. When asked for their preferred method for a physician visit: 79% ranked in-person as their first choice and 16% ranked a videoconference visit as their first choice. Perceived benefits of telemedicine visits included reduced travel to appointments (97% agree) and reduced cost of attending appointments (69% agree). However, patients were concerned that they would not establish the same patient-physician connection (51% agree) and would not receive the same level of care (38% agree) through telemedicine visits versus in person visits.ConclusionThe majority of hip preservation patients have access to and are capable of using the technology required for telemedicine visits. However, patients still prefer to have in person visits over concerns that they will not establish the same patient-physician connection and will not receive the same level of care. Telemedicine visits in hip preservation patients may be most attractive to return patients with an established doctor-patient relationship, particularly those with concerns for long distances of travel and associated costs.Level of Evidence: III