11,888 research outputs found
Application of algal bioassays in the determination of eutrophic power of waste water (”Conclusions” only) [Translation from: 1g.Sanita pubbl. 31 257-267, 1975]
The best evidence for establishing the level of eutrophy of a water-body is its algal production which makes it possible to identify the type and the intensity of the eutrophication according to the kind and number of algal species present: when the number of algae exceeds half a million per litre then one speaks o an ”algal bloom”. The scope of the present research aims to verify if the alga Selenastrum capricornutum can be used as a test alga under our culture conditions and to determine the eutrophic level of the secondary effluent of a modern plant for the treatment of domestic discharge and to investigate the eventual ”limiting factors”. Finally this paper aims to study the effect on the secondary effluent of tertiary treatment carried out artificially in the laboratory
Extensive tracheal injuries: a reasoned multi-step approach to guarantee mechanical ventilatory support developed during COVID-19 pandemic.
COVID-19 pandemic has notably increased the need for prolonged mechanical ventilation (MV) in patients with respiratory failure. This has increased the risk of extensive tracheal injuries (ETI) associated with life-threatening complications in very complex patients. Furthermore, tracheal injury treatment in COVID-19 patients has not
been described yet. Three COVID-19 patients with ETI who required MV treated between April and November 2020 were included. A multi-step approach was performed in order to restore tracheal integrity with a custom remodeled stent and tracheostomy tube placement to allow ventilatory support. Efficient MV with no residual air leaks was obtained in all cases. One patient died six weeks after the procedure due to COVID-19 lung damage. Two patients have completely been weaned from MV. This multi-step procedure could be used in order to maintain ventilatory support in case of ETI, working as a bridge to subsequent surgery when clinical conditions improve
Awaiting a cure for COVID-19: therapeutic approach in patients with different severity levels of COVID-19
COVID-19 is an unpredictable infectious disease caused by SARS-CoV-2. The development of effective anti-COVID-19 vaccines has enormously minimized the risk of severe illness in most immunocompetent patients. However, unvaccinated patients and non-re-sponders to the COVID-19 vaccine are at risk of short-and long-term consequences. In these patients, the outcome of COVID-19 relies on an interplay of multiple factors including age, immunocompetence, comorbid-ities, inflammatory response triggered by the virus as well as the virulence of SARS-CoV-2 variants. General-ly, COVID-19 is asymptomatic or mildly symptomatic in young people, but it may manifest with respiratory insufficiency requiring mechanical ventilation in cer-tain susceptible groups of patients. Furthermore, severe SARS-CoV-2 infection induces multiorgan failure syndrome by affecting liver, kidney heart and nervous system. Since December 2019, multiple drugs have been test-ed to treat COVID-19, but only a few have been prov-en effective to mitigate the course of the disease that continues to cause death and comorbidity worldwide. Current treatment of COVID-19 patients is essential-ly based on the administration of supportive oxygen therapy and the use of specific drugs such as steroids, anticoagulants, antivirals, anti-SARS-CoV-2 antibodies and immunomodulators. However, the rapid spread of new variants and the release of new data coming from the numerous ongoing clinical trials have cre-ated the conditions for maintaining a continuous up-dating of the therapeutic management of COVID-19 patients. Furthermore, we believe that a well-estab-lished therapeutic strategy along with the continu-um of medical care for all patients with COVID-19 is pivotal to improving disease outcomes and restoring healthcare care fragmentation caused by the pandem-ic. This narrative review, focusing on the therapeutic management of COVID-19 patients, aimed to provide an overview of current therapies for (i) asymptomatic or mildly/moderate symptomatic patients, (ii) hospitalized patients requiring low-flow oxygen, (iii) high-flow oxygen and (iv) mechanical ventilation
Adult Neural Stem Cell Regulation by Small Non-coding RNAs: Physiological Significance and Pathological Implications
The adult neurogenic niches are complex multicellular systems, receiving regulatory input from a multitude of intracellular, juxtacrine, and paracrine signals and biological pathways. Within the niches, adult neural stem cells (aNSCs) generate astrocytic and neuronal progeny, with the latter predominating in physiological conditions. The new neurons generated from this neurogenic process are functionally linked to memory, cognition, and mood regulation, while much less is known about the functional contribution of aNSC-derived newborn astrocytes and adult-born oligodendrocytes. Accumulating evidence suggests that the deregulation of aNSCs and their progeny can impact, or can be impacted by, aging and several brain pathologies, including neurodevelopmental and mood disorders, neurodegenerative diseases, and also by insults, such as epileptic seizures, stroke, or traumatic brain injury. Hence, understanding the regulatory underpinnings of aNSC activation, differentiation, and fate commitment could help identify novel therapeutic avenues for a series of pathological conditions. Over the last two decades, small non-coding RNAs (sncRNAs) have emerged as key regulators of NSC fate determination in the adult neurogenic niches. In this review, we synthesize prior knowledge on how sncRNAs, such as microRNAs (miRNAs) and piwi-interacting RNAs (piRNAs), may impact NSC fate determination in the adult brain and we critically assess the functional significance of these events. We discuss the concepts that emerge from these examples and how they could be used to provide a framework for considering aNSC (de)regulation in the pathogenesis and treatment of neurological diseases
miRNAs are essential for survival and differentiation of newborn neurons but not for expansion of neural progenitors during early neurogenesis in the mouse embryonic neocortex
Neurogenesis during the development of the mammalian cerebral cortex involves a switch of neural stem and progenitor cells from proliferation to differentiation. To explore the possible role of microRNAs (miRNAs) in this process, we conditionally ablated Dicer in the developing mouse neocortex using Emx1-Cre, which is specifically expressed in the dorsal telencephalon as early as embryonic day (E) 9.5. Dicer ablation in neuroepithelial cells, which are the primary neural stem and progenitor cells, and in the neurons derived from them, was evident from E10.5 onwards, as ascertained by the depletion of the normally abundant miRNAs miR-9 and miR-124. Dicer ablation resulted in massive hypotrophy of the postnatal cortex and death of the mice shortly after weaning. Analysis of the cytoarchitecture of the Dicer-ablated cortex revealed a marked reduction in radial thickness starting at E13.5, and defective cortical layering postnatally. Whereas the former was due to neuronal apoptosis starting at E12.5, which was the earliest detectable phenotype, the latter reflected dramatic impairment of neuronal differentiation. Remarkably, the primary target cells of Dicer ablation, the neuroepithelial cells, and the neurogenic progenitors derived from them, were unaffected by miRNA depletion with regard to cell cycle progression, cell division, differentiation and viability during the early stage of neurogenesis, and only underwent apoptosis starting at E14.5. Our results support the emerging concept that progenitors are less dependent on miRNAs than their differentiated progeny, and raise interesting perspectives as to the expansion of somatic stem cells
Solar UV-B Radiation Influences Carotenoid Accumulation of Tomato Fruit through Both Ethylene-Dependent and -independent Mechanisms
The effect of UV-B shielding on ethylene production in ripening tomato fruits and the contribution of
ethylene and UV-B radiation on carotenoid accumulation and profile during ripening were assessed
to get more insight about the interplay between these two regulatory factors. To this aim, rin and nor
tomato mutants, unable to produce ripening ethylene, and cv Ailsa Craig were cultivated under
control or UV-B depleted conditions until full fruit ripening. The significantly decreased ethylene
evolution following UV-B depletion, evident only in Ailsa Craig, suggested the requirement of
functional rin and nor genes for UVB-mediated ethylene production. Carotenoid content and profile
were found to be controlled by both ethylene and UV-B radiation. This latter influenced carotenoid
metabolism either in an ethylene-dependent or -independent way, as indicated by UVB-induced
changes also in nor and rin carotenoid content and confirmed by correlation plots between ethylene
evolution and carotenoid accumulation performed separately for control and UV-B shielded fruits. In
conclusion, natural UV-B radiation influences carotenoid metabolism in a rather complex way,
involving ethylene-dependent and -independent mechanisms, which seem to act in an antagonistic
way
Over-expression of the Arabidopsis AtMYB41 gene alters cell expansion and leaf surface permeability
The Arabidopsis AtMYB41 gene encodes an R2R3-MYB transcription factor whose expression is not detectable under normal growth conditions in any organ or at any developmental stage analysed. It is expressed at high levels in response to drought, ABA and salt treatments, suggesting a possible role in stress responses. Transgenic lines over-expressing this transcription factor showed a pleiotropic phenotype similar to that exhibited by some mutants that affect cuticle biosynthesis. This includes a dwarf appearance, dependent on smaller cells with abnormal morphology, enhanced sensitivity to desiccation, and enhanced permeability of leaf surfaces, suggesting discontinuity in the cuticle. The expression of genes involved in lipid metabolism and transport, in cell-wall modifications and cell expansion, genes coding for membrane-associated proteins and genes specifically involved in cuticle metabolism was differentially modulated between wild-type and transgenic plants, suggesting a direct or indirect role of AtMYB41 in the regulation of their transcription. Taken together, our results suggest that AtMYB41 is part of a complex network of transcription factors controlling cell expansion and cuticle deposition in response to abiotic stress
Clinical characterization and whole genome sequence-based typing of two cases of endophthalmitis due to Listeria monocytogenes
Endophthalmitis due to Listeria monocytogenes is a rare form of listeriosis. Here, we report two cases that occurred in patients with different medical history, a 46-years-old woman with no comorbidities and an elderly man with several comorbidities. There was no history of trauma or surgery in either patient suggesting an endogenous origin. Despite antibiotic treatment, both patients showed poor visual acuity outcomes. Subtyping clinical isolates using whole genome sequencing could allow to characterise Listeria monocytogenes strains involved in rare clinical manifestation, such as in unusual anatomical sites, even in immunocompetent patients
- …