331 research outputs found
A demonstration of nesting in two antarctic icefish (genus Chionodraco) using a fin dimorphism analysis and ex situ videos.
No full textVisual observations and videos of Chionodraco hamatus icefish at the "Acquario di Genova" and histological analyses of congeneric species C. hamatus and C. rastrospinosus adults sampled in the field provided new anatomical and behavioral information on the reproductive biology of these white blooded species that are endemic to the High-Antarctic region. During the reproductive season, mature males of both species, which are different from females and immature males, display fleshy, club-like knob modifications of their anal fin that consisted of a much thicker epithelium. Histology indicated that the knobs were without any specialized glandular or sensorial organization, thus suggesting a mechanical and/or ornamental role of the modified anal fin. In addition, the occurrence of necrotic regions at the base of the thickened epithelium and the detachment of the knobs in post-spawning C. hamatus males indicated the temporary nature of the knobs. The role of these structures was confirmed as mechanical and was clarified using visual observations and videos of the behavior of two C. hamatus during a reproductive event that occurred in an exhibit tank at the "Acquario di Genova". The reproductive process included pre-spawning activity, preparation of the nest, egg guarding and successfully ended with egg hatching. When the spawning event approached, the male prepared the nest. The nest was constructed on an accurately selected bottom surface, which was flattened and maintained free from sand or debris by a combination of radial body movements and continuous anal fin sweeping, thus demonstrating the important mechanical/abrasive function of the anal fin knobs. The present data are the first records of active nesting in icefish and clarify the meaning of dimorphic temporary structures, whose function would have been difficult to obtain in the field
Co-infection of Streptococcus pneumoniae in Respiratory Infections Caused by SARS-CoV-2
No full textAbstract: Viral respiratory infections are often associated with bacterial co-infections that often lead
to increased severity and mortality of the disease. During the recent pandemic caused by severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2), hospitalized patients reported developing
secondary bacterial infections ranging from 0 to 40% of the cases. In the previous influenza pandemics,
Streptococcus pneumoniae was the most isolated bacterial pathogen causing increased mortality in
patients affected by viral pneumonia. Due to the difficulty to detect pneumococcal infection in SARSCoV-2 patients by a rapid clinical test, the real prevalence of S. pneumoniae might be underestimated,
and only a few cases have been documented so far. It has been estimated that 90% of patients admitted
to the Intensive Care Unit are empirically treated with antimicrobial. The application of more rapid and
sensitive diagnostic methods could help with targeted antibiotic therapy. Additionally, pneumococcal
vaccination of high-risk individuals could reduce bacterial pneumonia, hospital admissions, and
comorbidities associated with serious illness
Changes in the oral status and periodontal pathogens in a Sardinian rural community from pre-industrial to modern time
No full textThe oral microbial profile in humans has evolved in response to lifestyle changes over the course of different eras. Here, we investigated tooth lesions and the microbial profile of periodontal bacteria (PB) in dental calculus of a Sardinian pre-industrial rural community. In total, 51 teeth belonging to 12 historical individuals buried in an ossuary in the early 1800s and 26 modern teeth extracted from 26 individuals from the same geographical area were compared to determine the oral health status, bacterial load and amount of most relevant PB. Total caries and bacterial genomes count appeared to be sex-related in historical samples. Historical females presented a higher incidence of caries, PB pathogens and a higher bacterial load than historical males. Furthermore, we compared the PB profile of the historical individuals with the modern ones, revealing a notable increase in modern individuals of PB belonging to “Red complex bacteria” often associated with periodontitis and other chronic diseases of modern life. Our findings could be explained through an analysis of environmental factors such as socioeconomic, hygienic and healthy conditions that can have a great impact on oral health and bacterial composition among individuals of the same and different era
In vitro Interactions between Streptococcus intermedius and Streptococcus salivarius K12 on a Titanium Cylindrical Surface
No full textPeri-implantitis is a steadily rising disease and is caused by oral bacterial pathogens able to form biofilm on implant surfaces and peri-implant tissues, making antibiotics treatment less effective. The use of commercial probiotics against oral pathogens could serve as an alternative to prevent biofilm formation. Streptococcus intermedius is one of the early colonizers of biofilm formation in dental implants. The aim of this study was to model the interaction between S. intermedius and Streptococcus salivarius strain K12, a probiotic bacterium producing bacteriocins. S. intermedius was co-cultured with S. salivarius K12 in an in vitro model simulating the biofilm formation in a dental implant composed by a titanium cylinder system. Biofilm formation rate was assessed by Real-Time PCR quantification of bacterial count and expression levels of luxS gene, used in response to cell density in the biofilm. Biofilm formation, bacteriocin production, luxS expression patterns were found to be already expressed within the first 12 h. More importantly, S. salivarius K12 was able to counter the biofilm formation in a titanium cylinder under the tested condition. In conclusion, our dental implant model may be useful for exploring probiotic-pathogen interaction to find an alternative to antibiotics for peri-implantitis treatment
Thermochronological Record of a Jurassic Heating-Cooling Cycle Within a Distal Rifted Margin (Calizzano Massif, Ligurian Alps)
No full textThe aim of the present study is to analyse, through thermochronological investigations, the thermal evolution of a fossil distal margin owing to the Alpine Tethys rifting system. The studied distal margin section consists of a polymetamorphic basement (Calizzano basement) and of a well-developed Mesozoic sedimentary cover (Case Tuberto unit) of the Ligurian Alps (NW Italy). The incomplete reset of zircon (U-Th)/He ages and the non-reset of the zircon fission track ages during the Alpine metamorphism indicate that during the subduction and the orogenic stages these rocks were subjected to temperatures lower than ~200 oC. Thus, the Alpine metamorphic overprint occurred during a short-lived, low temperature pulse. The lack of a pervasive orogenic reset, allowed the preservation of an older heating-cooling event that occurred during Alpine Tethys rifting. Zircon fission-track data indicate, in fact, that the Calizzano basement records a cooling under ~240 °C, at ~156 Ma (early Upper Jurassic). This cooling followed a Middle Jurassic syn-rift heating at temperatures of about 300-350°C, typical of greenschist facies conditions occurred at few kilometres depth, as indicated by stratigraphic and petrologic constraints. Thus, in our interpretation, major crustal thinning likely promoted high geothermal gradients (~60-90°C/km) triggering the circulation of hot, deep-seated fluids along brittle faults, causing the observed thermal anomaly at shallow crustal level
ApuA, a multifunctional x-glucan-degrading enzyme of Streptococcus suis, mediates adhesion to porcine epithelium and mucus
No full textWe have identified apuA in Streptococcus suis, which encodes a bifunctional amylopullulanase with conserved -amylase and pullulanase substrate-binding domains and catalytic motifs. ApuA exhibited properties typical of a Gram-positive surface protein, with a putative signal sequence and LPKTGE cell-wall-anchoring motif. A recombinant protein containing the predicted N-terminal -amylase domain of ApuA was shown to have -(1,4) glycosidic activity. Additionally, an apuA mutant of S. suis lacked the pullulanase -(1,6) glycosidic activity detected in a cell-surface protein extract of wild-type S. suis. ApuA was required for normal growth in complex medium containing pullulan as the major carbon source, suggesting that this enzyme plays a role in nutrient acquisition in vivo via the degradation of glycogen and food-derived starch in the nasopharyngeal and oral cavities. ApuA was shown to promote adhesion to porcine epithelium and mucus in vitro, highlighting a link between carbohydrate utilization and the ability of S. suis to colonize and infect the host
Evaluation of “Caterina assay”: An Alternative Tool to the Commercialized Kits Used for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Identification
No full textHere we describe the first molecular test developed in the early stage of the pandemic to diagnose the first cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Sardinian patients in February–March 2020, when diagnostic certified methodology had not yet been adopted by clinical microbiology laboratories. The “Caterina assay” is a SYBR®Green real-time reverse-transcription polymerase chain reaction (rRT-PCR), designed to detect the nucleocapsid phosphoprotein (N) gene that exhibits high discriminative variation RNA sequence among bat and human coronaviruses. The molecular method was applied to detect SARS-CoV-2 in nasal swabs collected from 2110 suspected cases. The study article describes the first molecular test developed in the early stage of the declared pandemic to identify the coronavirus disease 2019 (COVID-19) in Sardinian patients in February–March 2020, when a diagnostic certified methodology had not yet been adopted by clinical microbiology laboratories. The assay presented high specificity and sensitivity (with a detection limit ≥50 viral genomes/μL). No false-positives were detected, as confirmed by the comparison with two certified commercial kits. Although other validated molecular methods are currently in use, the Caterina assay still represents a valid and low-cost detection procedure that could be applied in countries with limited economic resources
New aspects of the relationship between acetylcholinesterase activity and cancer. I: Poly-Aps experiments.
No full textSince the first ‘80s, we found that some tumor types, and in particular lung tumors present increase, or
generally change in acetylcholinesterase activity. Acetylcholinesterase is an enzyme associated to the cholinergic signal
system, whose classic role is to remove acetylcholine from the receptors. Nevertheless, it is also involved in cell-to-cell
communication driving embryonic development and in the regulation of several cellular features, such as apoptosis and
cell movements. The presence of molecules related to the cholinergic signal system in the healthy and carcinogenic lung
tissues, raised the hypothesis that substances inhibiting or affecting the cholinergic signaling system could exert an anticancer
action at least in these tissues. Cytotoxicity tests on immortalized and primary cell lines derived from lung tumor
(NSCLC) showed an AChE inhibition-dependent selective reduction of cell viability, statistically significant. The same
cells, exposed to non toxic AChE inhibitors exhibited a loss in the mitochondrial potential, characteristic of the early
apoptotic events and showed positive response to the annexin V assay, and to the T-terminal assay, that are specific
features of the apoptotic event. Moreover, three-dimensional cell cultures (spheroids) of tumor cells, on exposure to
AChE inhibitors show a decrease in the membrane-linked oligosaccharides, that are responsible for the adhesivity of the
metastatic cells. In this promising picture, the need emerges of further studies aimed at understanding the effects of
AChE inhibition on the regulation of acetylcholine release and the effects of AChE inhibitors on the functioning of
acetylcholine receptors
A bibliometrics-enhanced, PAGER-Compliant scoping review of the literature on paralympic powerlifting. Insights for practices and future research
No full textParalympic powerlifting (PP), formerly known as “International Paralympic Committee”
(IPC) powerlifting, is the format of powerlifting adapted for athletes with disabilities, and it differs
from the version for able-bodied athletes in that it consists of bench press only. According to the
mandate of the IPC, PP athletes should be enabled to achieve sporting excellence. As such, rigorous
evidence is needed. However, to the best of our knowledge, there exists no systematic assessment
of the body of scholarly evidence in the field of PP. Therefore, the present study was conducted to
fill in this gap of knowledge, by conducting a scoping review of the literature enhanced by a
bibliometrics analysis and by mining two major scholarly databases (MEDLINE via PubMed and
Scopus). The aim was to provide a review/summary of the findings to date to help practitioners and
athletes. Thirty-seven studies were retained in the present study. These covered the following
thematic areas: (i) warm-up strategies (n = 2); (ii) aspects of training (n = 2); (iii) physiological aspects
and responses (n = 2); (iv) psychological aspects and responses (n = 2); (v) biomechanics of bench
press (n = 8); (vi) recovery strategy (n = 5); (vii) impact of the disability and type of disability (n = 4);
(viii) epidemiology of PP (n = 6); and (ix) new analytical/statistical approaches for kinematics
assessments, internal load monitoring, and predictions of mechanical outputs in strength exercises
and in PP (n = 6). Bibliometrics analysis of the PP-related scientific output revealed that, despite
having already become a paralympic sports discipline in 1984, only in the last few years, PP has
been attracting a lot of interest from the community of researchers, with the first scholarly
contribution dating back to 2012, and with more than one-third of the scientific output being
published this year (2022). As such, this scholarly discipline is quite recent and young. Moreover,
the community dealing with this topic is poorly interconnected, with most authors contributing to
just one article, and with one single author being a hub node of the author network. Distributions
of the number of articles and the authors/co-authors were found to be highly asymmetrical,
indicating that this research is still in its infancy and has great room as well as great potential to
grow. Reflecting this, many research topics are also overlooked and underdeveloped, with the
currently available evidence being based on a few studies
Multiple functions of the cholinesterase inhibiting polyalkylpyridinium salts extracted from the marine sponge, Haliclona sarai.
No full textThe interest on the Mediterranean sponge Haliclona sarai was raised some years ago by the fact that this
sponge appears free from parasites and fouling organisms present in its environment. The study of such a
feature was at the beginning due to the interest in finding new and efficient anti-fouling substances for
applicative purposes. The characteristic was related to the expression of poly-alkylpyridinium salts (poly-
APs), a mixture of two of 3-octylpyridinium polymers, including 29 and 99 monomeric units. The main
effect of this compound was represented by the strong specific and non-toxic acetylcholinesterase inhibition
in vitro. The substance was first tested for its effect on larval development and settling of incrusting
organisms, such as Amphibalanus amphitrite. The experiments confirmed the ability of Poly-APs to prevent
settlement of sessile organism, by impinging on the AChE activity. Acetylcholinesterase is an enzyme
associated to the cholinergic signal system, but is also involved in cell-to-cell communication driving
embryonic development and in the regulation of several cellular features, such as apoptosis and cell
movements, and is present in some tumour cells and biopsies. Cytotoxicity tests on immortalized and
primary cell lines derived from lung tumour (NSCLC) showed a poly-APS dose-dependent selective
reduction of cell viability, statistically significant. The same cells, exposed to the poly-APS salts exhibited a
loss in the mitochondrial potential, and positive response to apoptosis assays. What makes the poly-APS salts
interesting as anticancer therapy adjuvant is that they, at the concentrations inducing apoptosis in tumour
cells, seem to scarcely affect the viability of lymphocytes isolated from healthy patients. In this promising
frame, the need emerges for the isolation of synthetic homologs of poly-APS molecules, in order to start a
study for the therapeutical application of the drug.
Key words: Lung Cancer, Acetylcholinesterase; Apoptosis; Cell Proliferation; Poly-APS
1 Introduction
Nature has supplied several active anticancer
agents (vinca alkaloids, anthracyclines, epipodophyllotoxin,
and taxanes), which have significantly
improved th
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