Age-dependent NK cell dysfunctions in severe COVID-19 patients.

Natural Killer (NK) cells are key innate effectors of antiviral immune response, and their activity changes in ageing and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, we investigated the age-related changes of NK cell phenotype and function during SARS-CoV-2 infection, by comparing adult and elderly patients both requiring mechanical ventilation. Adult patients had a reduced number of total NK cells, while elderly showed a peculiar skewing of NK cell subsets towards the CD56lowCD16high and CD56neg phenotypes, expressing activation markers and check-point inhibitory receptors. Although NK cell degranulation ability is significantly compromised in both cohorts, IFN-γ production is impaired only in adult patients in a TGF-ß-dependent manner. This inhibitory effect was associated with a shorter hospitalization time of adult patients suggesting a role for TGF-ß in preventing an excessive NK cell activation and systemic inflammation. Our data highlight an age-dependent role of NK cells in shaping SARS-CoV-2 infection toward a pathophysiological evolution.

Cereblon regulates NK cell cytotoxicity and migration via Rac1 activation.

Rearrangement of the actin cytoskeleton is critical for cytotoxic and immunoregulatory functions as well as migration of natural killer (NK) cells. However, dynamic reorganization of actin is a complex process, which remains largely unknown. Here, we investigated the role of the protein Cereblon (CRBN), an E3 ubiquitin ligase complex co-receptor and the primary target of the immunomodulatory drugs, in NK cells. We observed that CRBN partially colocalizes with F-actin in chemokine-treated NK cells and is recruited to the immunological synapse, thus suggesting a role for this protein in cytoskeleton reorganization. Accordingly, silencing of CRBN in NK cells results in a reduced cytotoxicity that correlates with a defect in conjugate and lytic synapse formation. Moreover, CRBN depletion significantly impairs the ability of NK cells to migrate and reduces the enhancing effect of lenalidomide on NK cell migration. Finally, we provided evidence that CRBN is required for activation of the small GTPase Rac1, a critical mediator of cytoskeleton dynamics. Indeed, in CRBN-depleted NK cells, chemokine-mediated or target cell-mediated Rac1 activation is significantly reduced. Altogether our data identify a critical role for CRBN in regulating NK cell functions and suggest that this protein may mediate the stimulatory effect of lenalidomide on NK cells.

Artificial intelligence predicts delirium following cardiac surgery: A case study.

Delirium is a highly relevant complication of surgical interventions. Current research indicates that despite increased awareness for delirium, it is often overlooked. We implemented an AI-based tool to monitor delirium in cardiac surgery patients in our specialist clinic. This appears to be a promising approach to improve detection of delirium, especially for underrecognized forms and in peripheral wards without intensive screening. We present a case in which the AI identified delirium, confirmed by our routine screening and specialist evaluation.

Long-term effects of silver nanoparticles on reproductive activity of rabbit buck.

Using the rabbit as an animal model, this study evaluated the long-term effect of silver nanoparticles (NPs) administered intravenously (0.6 mg/kg bw) on reproductive activity and sperm quality. Semen analysis was performed by optical microscopy and sperm motility evaluation by computer assisted sperm analyzer (CASA). Mitochondria oxygen consumption, light and transmission electron microscopy of rabbit testis and ejaculated sperm were also carried out. Throughout the experiment NP-treated rabbits showed higher seminal reactive oxygen species (ROS), less motile sperm, and lower curvilinear velocity and oxygen consumption than control animals. In contrast, libido, serum testosterone, sperm concentration, and semen volume were hardly affected by NPs. Transmission electron microscopy analysis did not show any evident morphological damage in testes; however, Ag NPs are visible in spermatids and ejaculated sperm. These preliminary results show that Ag NPs can reach the testes, compromising sperm motility, sperm speed, and acrosome and mitochondria shape and function.

The effects of husbandry system on the grass intake and egg nutritive characteristics of laying hens.

BACKGROUND: The aim of this study was to determine the effect of husbandry system and season on the grass intake and egg quality in laying hens considering that characteristics of organic eggs obtained in a system with no grass in the external area are similar conventional ones. RESULTS: Three hundred and sixty Ancona hens were randomly assigned to three groups: a control group (C), with the hens kept in cages under standard housing conditions; the organic group (O), with the hens kept under an organic production system (4 m² per hen) and the organic-plus group (OP), with the hens maintained under organic conditions but with a larger grass paddock availability (10 m² per hen). The estimated intake of forage, carotenoids and flavonoids of the OP hens was very high as the amounts deposited in eggs, mainly in the spring season. The fatty acid composition of the yolk was significantly affected by pasture. The OP eggs showed lower concentrations of polyunsaturated fatty acids (PUFA) n-6 and a higher percentage of PUFA n-3. CONCLUSIONS: The results showed that the grass intake was largely affected by the husbandry system and highlighted the seasonal effect of grass availability on the nutritional quality of eggs produced in organic systems.

The time-dependent effects of prostate granules and seminal plasma on the capacitation, acrosome reaction, and motility of rabbit sperm.

The present study investigated the role of rabbit seminal plasma and prostate granules on capacitation, the acrosomal reaction (AR), and sperm motility. Semen ejaculates obtained from five mature New Zealand White rabbit bucks in three collection series were used in the study. Raw semen, Percoll-selected sperm alone and in presence of either seminal plasma or prostate granules were incubated for 120min in capacitation medium. Chlortetracycline fluorescence (reflecting capacitation and the acrosome reaction) and sperm kinetic traits were analysed in each sample. All traits were observed from 0 to 120min of incubation at 37°C in 5% CO2. Both seminal plasma and prostatic granules markedly improved the sperm motility but seminal plasma mainly inhibited the capacitation progress whereas prostatic granules inhibited the AR. In conclusion, prostatic granules and seminal plasma have specific roles in synchronising sperm capacitation and the AR with egg availability.

Role of rabbit prostate granules on sperm viability and acrosome reaction evaluated with different methods.

In the present study, the role of rabbit seminal granules was observed. Their influence on motility, capacitation and acrosome reaction, as well as the presence of apoptosis and the morphology of rabbit sperm, were compared in different conditions. Ejaculated sperm from five mature New Zealand White rabbit bucks during three series of collections were studied, comparing raw semen, Percoll-selected sperm and Percoll-selected sperm plus prostate granules. We observed sperm motility kinetic traits by computer-assisted sperm analyzer (CASA) analysis in each sample. Acrosome status was evaluated by FITC-labeled Pisum sativum Agglutinin staining and chlortetracycline fluorescence assay, phosphatidylserine translocation was determined by AnnexinV/Propidium iodide assay and sperm morphology was studied using transmission electron microscopy (TEM). All traits were observed after 30 min incubation at 37 °C in 5% CO(2). Data showed that sperm motility and viability markedly improved in the presence of prostate granules, whereas capacitation, acrosome reaction and phosphatidylserine translocation were lowered. TEM confirmed these results. In conclusion, the role of granules was confirmed in synchronizing sperm capacitation and acrosome reaction with egg availability; indeed, rabbit ovulation occurs only 6 to 10 h after mating.

What is the best frame rate for evaluation of sperm motility in different species by computer-assisted sperm analysis?

OBJECTIVE: To evaluate the effect of acquisition rate in the computer-assisted sperm analysis (CASA) of sperm motility with different kinetic characteristics (linearity and track speed) belonging to different species. DESIGN: Prospective research study. SETTING: Andrology laboratory of department of applied biology. PATIENT(S): Semen samples from human fertile donors, rabbit, bull, and ram. INTERVENTION(S): Semen analysis by optical microscopy and sperm motility evaluation with the use of CASA. MAIN OUTCOME MEASURE(S): Analysis of sperm tracks with a CASA system acquired at different frame rates (FRs) (12-200 Hz). RESULT(S): The FR had no effect on the motility rate or on the sperm track reconstruction, whereas all the other kinetic values were affected by sampling frequency. Sperm with low speed (category b) and/or linear trajectories (category a) are less affected by sampling frequency and do not require particularly high FR to be correctly evaluated. On the contrary, fast nonlinear sperm (category c) would require a very high frequency to fully describe the path. CONCLUSION(S): Because all the commercial CASA systems acquire at an FR of 30-60 Hz, an increase in FR is required to render the estimation results closer to the "real path" mainly for fast nonlinear sperm.

Effects of sports training in adolescence on growth, puberty and bone health.

Athletic training in adolescent females is important for their well-being; indeed, it may have both positive and negative effects on some physiological processes, as growth, reproductive axis and bone health. Adequate physical activity likely exerts neither a positive nor a negative effect on growth. By contrast, intensive training and insufficient diet may have a negative influence on growth, probably due to energy deficiency and impairment of the growth hormone-insulin-like growth factor-I axis; net long term-effects of such alterations remain to be established. Adolescents who perform regular athletic training present with normal or slightly advanced sexual maturation, because increased strength and power associated with earlier maturation advantage them. However, intensive training and inadequate energy intake may induce delayed menarche and menstrual dysfunctions. The consequent hypoestrogenism, in association with the nutritional deficiencies, may affect bone health. On the contrary, regular physical activity increases the amount of bone mass gained during childhood and adolescence mainly at the bone sites which are trained. Since the number of adolescent females involved in strenuous sports from an early age is increasing, physicians must be aware of such effects, explain to girls and their parents the 'right' sports training and appropriate dietary regimens, and recognize problems due to excessive training as soon as possible. These issues should not be a cause of lesser involvement in athletic participation of young people.