46 research outputs found
Combined effect of plastic litter and increased atmospheric nitrogen deposition on vegetative propagules of dune plants: a further threat to coastal ecosystems
Large amounts of non-biodegradable plastics are currently deposited on beach-dune systems, and biodegradable plastics could enter these already declining habitats in coming years. Yet, the impacts of plastics on vegetative recruitment, a plant strategy playing a key role in dune stabilization, are unknown. Whether these pollutants interact with increased atmospheric nitrogen (N) deposition, a major global driver of plant biodiversity loss, in affecting plant communities of such nutrient-poor habitats, and how plant-plant interactions mediate their effects need to be explored. In a one-year field experiments, we examined individual and combined effects of plastic (non-biodegradable, biodegradable), N deposition (ambient, elevated) and biotic condition (no interaction, interaction with a conspecific or with a hetero-specific) on the colonization success and growth of vegetative propagules of dune plants. Thinopyrum junceum and Sporobolus pumilus were chosen as models because they co-occur along Mediterranean dunes and differ in ecological role (dune- vs. non dune-building) and photosynthetic pathway (C3 vs. C4). For both species, survival probability was reduced by non-biodegradable plastic and elevated N by up to 100%. Thinopyrum junceum survival was also reduced by S. pumilus presence. Elevated N and biodegradable plastic reduced T. junceum shoot biomass when grown alone and with a conspecific, respectively; these factors in combination mitigated their negative individual effects on root biomass. Biodegradable plastic increased S. pumilus shoot and root biomass, and in combination with elevated N caused a greater biomass investment in belowground (root plus rhizome) than aboveground organs. Non-biodegradable plastic may be a further threat to dune habitats by reducing plant colonization. Biodegradable plastic and increased N deposition could favour the generalist S. pumilus and hinder the dune-building T. junceum. These findings highlight the urgency of implementing measures for preventing plastic deposition on beaches and reducing N input
BTK Inhibitors Impair Platelet-Mediated Antifungal Activity
In recent years, the introduction of new drugs targeting Bruton’s tyrosine kinase (BTK) has allowed dramatic improvement in the prognosis of patients with chronic lymphocytic leukemia (CLL) and other B-cell neoplasms. Although these small molecules were initially considered less immunosuppressive than chemoimmunotherapy, an increasing number of reports have described the occurrence of unexpected opportunistic fungal infections, in particular invasive aspergillosis (IA). BTK represents a crucial molecule in several signaling pathways depending on different immune receptors. Based on a variety of specific off-target effects on innate immunity, namely on neutrophils, monocytes, pulmonary macrophages, and nurse-like cells, ibrutinib has been proposed as a new host factor for the definition of probable invasive pulmonary mold disease. The role of platelets in the control of fungal growth, through granule-dependent mechanisms, was described in vitro almost two decades ago and is, so far, neglected by experts in the field of clinical management of IA. In the present study, we confirm the antifungal role of platelets, and we show, for the first time, that the exposure to BTK inhibitors impairs several immune functions of platelets in response to Aspergillus fumigatus, i.e., the ability to adhere to conidia, activation (as indicated by reduced expression of P-selectin), and direct killing activity. In conclusion, our experimental data suggest that antiplatelet effects of BTK inhibitors may contribute to an increased risk for IA in CLL patients
The Role of T Cell Immunity in Monoclonal Gammopathy and Multiple Myeloma: From Immunopathogenesis to Novel Therapeutic Approaches
Multiple Myeloma (MM) is a malignant growth of clonal plasma cells, typically arising from asymptomatic precursor conditions, namely monoclonal gammopathy of undetermined significance (MGUS) and smoldering MM (SMM). Profound immunological dysfunctions and cyto-kine deregulation are known to characterize the evolution of the disease, allowing immune escape and proliferation of neoplastic plasma cells. In the past decades, several studies have shown that the immune system can recognize MGUS and MM clonal cells, suggesting that anti-myeloma T cell immunity could be harnessed for therapeutic purposes. In line with this notion, chimeric antigen receptor T cell (CAR-T) therapy is emerging as a novel treatment in MM, especially in the re-lapsed/refractory disease setting. In this review, we focus on the pivotal contribution of T cell im-pairment in the immunopathogenesis of plasma cell dyscrasias and, in particular, in the disease progression from MGUS to SMM and MM, highlighting the potentials of T cell-based immunother-apeutic approaches in these settings
Has VZV epidemiology changed in Italy? Results of a seroprevalence study
The aim of the study was to evaluate if and how varicella prevalence has changed in Italy. In particular a seroprevalence study was performed, comparing it to similar surveys conducted in pre-immunization era. During 2013–2014, sera obtained from blood samples taken for diagnostic purposes or routine investigations were collected in collaboration with at least one laboratory/center for each region, following the approval of the Ethics Committee. Data were stratified by sex and age. All samples were processed in a national reference laboratory by an immunoassay with high sensitivity and specificity. Statutory notifications, national hospital discharge database and mortality data related to VZV infection were analyzed as well. A total of 3707 sera were collected and tested. In the studied period both incidence and hospitalization rates decreased and about 5 deaths per year have been registered. The seroprevalence decreased in the first year of life in subjects passively protected by their mother, followed by an increase in the following age classes. The overall antibody prevalence was 84%. The comparison with surveys conducted with the same methodology in 1996–1997 and 2003–2004 showed significant differences in age groups 1–19 y. The study confirms that in Italy VZV infection typically occurs in children. The impact of varicella on Italian population is changing. The comparison between studies performed in different periods shows a significant increase of seropositivity in age class 1–4 years, expression of vaccine interventions already adopted in some regions
Human parvovirus 4 'PARV4' remains elusive despite a decade of study
Human parvovirus 4 ('PARV4') is a small DNA tetraparvovirus, first reported in 2005. In some populations, PARV4 infection is uncommon, and evidence of exposure is found only in individuals with risk factors for parenteral infection who are infected with other blood-borne viruses. In other settings, seroprevalence studies suggest an endemic, age-associated transmission pattern, independent of any specific risk factors. The clinical impact of PARV4 infection remains uncertain, but reported disease associations include an influenza-like syndrome, encephalitis, acceleration of HIV disease, and foetal hydrops. In this review, we set out to report progress updates from the recent literature, focusing on the investigation of cohorts in different geographical settings, now including insights from Asia, the Middle East, and South America, and discussing whether attributes of viral or host populations underpin the striking differences in epidemiology. We review progress in understanding viral phylogeny and biology, approaches to diagnostics, and insights that might be gained from studies of closely related animal pathogens. Crucial questions about pathogenicity remain unanswered, but we highlight new evidence supporting a possible link between PARV4 and an encephalitis syndrome. The unequivocal evidence that PARV4 is endemic in certain populations should drive ongoing research efforts to understand risk factors and routes of transmission and to gain new insights into the impact of this virus on human health
On the unusual flowering of plagiotropic shoots in the seagrass Posidonia oceanica
The seagrass Posidonia oceanica (L.) Delile can produce plagiotropic (horizontally oriented) and orthotropic (vertically oriented) axes. These axes differ in various morphological and growth characteristics and ecological functions. Only orthotropic shoots are likely to support flowering and seed production. To asses whether flowering may occur on plagiotropic shoots, we examined plagiotropic axes that grew at the edge of a meadow during the flowering of 2003. We identified and analysed 10 rhizome fragments that bore at least one reproductive plagiotropic shoot. We then investigated whether reproductive plagiotropic shoots differed from orthotropic ones in morphological characteristics and investment in flowering (i.e., number of hermaphroditic flowers per inflorescence). Multivariate analysis did not show any significant difference between plagiotropic and orthotropic shoots with regard to the characteristics examined and investment in flowering. Further studies are necessary to ascertain if the observed pattern of flowering is a common or an exceptional event in P oceanic
Effect of seed density and sediment nutrient heterogeneity on recruitment and early patch growth in the seagrass Cymodocea nodosa
Two mesocosm experiments were performed to examine the effects of seed density and
small-scale nutrient heterogeneity on seedling recruitment and early development of patches of
Cymodocea nodosa. In the first experiment, seeds were sown at 4 densities selected after determining
mean natural density of seeds in the field, and the emergence and survival rates of seedlings were
monitored for 1 yr. In the second experiment, seedlings were grown individually for 2 yr, either on
substrate made heterogeneous or homogeneous with the addition of a fertiliser or on unfertilised substrate.
The emergence rate and proportional survival of seedlings decreased significantly with
increasing seed density. Seedlings grown on fertilised substrates were able to form patches, while
those grown on unfertilised substrate failed to branch, providing experimental evidence of the role of
nutrient limitation as a constraint for patch initiation. The size of seed-generated patches was significantly
larger (in terms of total length of the rhizome network and number of shoots) on heterogeneous
substrate than on homogeneous substrate at the same overall level of nutrient supply.
Apparently, no preferential proliferation of shoots and branches occurred in the nutrient-rich half of
the heterogeneous substrate. The results support our hypothesis that negative density dependence at
the seed-seedling stage plays an important role in regulating population size. They also reveal that
seedlings experiencing nutrient heterogeneity are capable of exploiting resources more efficiently
than those in homogeneous environments, but are probably unable to escape from unfavourable
patches or to select favourable ones, at least at the scale examined here
Qualitative and quantitative assessment of the reproductive litter from Posidonia oceanica accumulated on a sand beach following a storm
The biomass of reproductive litter from Posidonia oceanica deposited on a 3.5 km stretch of beach in the north-western Mediterranean, as a consequence of a storm in May 2004, was quantified. The damage caused by this storm to the meadow from which fruits originated was evaluated in terms of loss of seed production. Intermediate fruits (i.e., developing fruits) were the most important reproductive component, followed by immature and damaged fruits. No fully mature fruits were found. No significant differences in the average number of fruits and biomass accumulated were detected among beach sections hundreds of metres apart. Extrapolation of the results at four beach sections indicated that about I million fruits were deposited on the entire (3.5 km) beach. This was equivalent to the seed production potential of about 313,217 inflorescences, or a flowered area of 1500 m(2). The organic input to the beach was 224 kg ash-free dry weight (AFDM). These results suggest that storms may provide an unpredictable source of seed mortality in P. oceanica. The reproductive material produced by storms, however, may constitute an important source of allochthonous organic matter to the beach