Characterization of Neochloris oleoabundans under Different Cultivation Modes and First Results on Bioactivity of Its Extracts against HCoV-229E Virus

Microalgae are proposed in several biotechnological fields because of their ability to produce biomass enriched in high-value compounds according to cultivation conditions. Regarding the health sector, an emerging area focuses on natural products exploitable against viruses. This work deals with the characterization of the green microalga Neochloris oleoabundans cultivated under autotrophic and mixotrophic conditions as a source of whole aqueous extracts, tested as antivirals against HCoV-229E (Coronaviridae family). Glucose was employed for mixotrophic cultures. Growth and maximum quantum yield of photosystem II were monitored for both cultivations. Algae extracts for antiviral tests were prepared using cultures harvested at the early stationary phase of growth. Biochemical and morphological analyses of algae indicated a different content of the most important classes of bioactive compounds with antiviral properties (lipids, exo-polysaccharides, and total phenolics, proteins and pigments). To clarify which phase of HCoV-229E infection on MRC-5 fibroblast cells was affected by N. oleoabundans extracts, four conditions were tested. Extracts gave excellent results, mainly against the first steps of virus infection. Notwithstanding the biochemical profile of algae/extracts deserves further investigation, the antiviral effect may have been mainly promoted by the combination of proteins/pigments/phenolics for the extract derived from autotrophic cultures and of proteins/acidic exo-polysaccharides/lipids in the case of mixotrophic ones.

Cell cycle block by p53 activation reduces SARS-CoV-2 release in infected alveolar basal epithelial A549-hACE2 cells

SARS-CoV viruses have been shown to downregulate cellular events that control antiviral defenses. They adopt several strategies to silence p53, key molecule for cell homeostasis and immune control, indicating that p53 has a central role in controlling their proliferation in the host. Specific actions are the stabilization of its inhibitor, MDM2, and the interference with its transcriptional activity. The aim of our work was to evaluate a new approach against SARS-CoV-2 by using MDM2 inhibitors to raise p53 levels and activate p53-dependent pathways, therefore leading to cell cycle inhibition. Experimental setting was performed in the alveolar basal epithelial cell line A549-hACE2, expressing high level of ACE2 receptor, to allow virus entry, as well as p53 wild-type. Cells were treated with several concentrations of Nutlin-3 or RG-7112, two known MDM2 inhibitors, for the instauration of a cell cycle block steady-state condition before and during SARS-CoV-2 infection, and for the evaluation of p53 activation and impact on virus release and related innate immune events. The results indicated an efficient cell cycle block with inhibition of the virion release and a significant inhibition of IL-6, NF-kB and IFN-λ expression. These data suggest that p53 is an efficient target for new therapies against the virus and that MDM2 inhibitors deserve to be further investigated in this field.

Increased nuchal translucency can be ascertained using transverse planes

BACKGROUND

The detection of increased nuchal translucency is crucial for the assessment risk of aneuploidies and other fetal anomalies.

OBJECTIVE

This study aimed to investigate the ability of a transverse view of the fetal head to detect increased fetal nuchal translucency at 11 to 13 weeks of gestation.

STUDY DESIGN

This was a prospective study enrolling a nonconsecutive series of women who attended our outpatient clinic from January 2020 to April 2021 for combined screening and were examined by operators certified by the Fetal Medicine Foundation. In each patient, nuchal translucency measurements were obtained both from a median sagittal view and from a transverse view. A second sonologist blinded to the results of the first examination obtained another measurement to assess intermethod and interobsever reproducibility.

RESULTS

A total of 1023 women were enrolled. An excellent correlation was found between sagittal and transverse nuchal translucency measurements, with a mean difference of 0.01 mm (95% confidence interval, -0.01 to 0.02). No systematic difference was found between the 2 techniques. The inter-rater reliability (intraclass correlation coefficient, 0.957; 95% confidence interval, 0.892-0.983) and intrarater reliability (intraclass correlation coefficient, 0.976; 95% confidence interval, 0.941-0.990) of axial measurements were almost perfect. Transverse measurements of 3.0 mm identified all cases with sagittal measurements of ≥3.0 with a specificity of 99.7%; transverse measurements of >3.2 mm identified all cases with sagittal measurements of 3.5 mm with a specificity of 99.7%. The time required to obtain transverse nuchal translucency measurements was considerably shorter than for sagittal measurements, particularly when the fetus had an unfavorable position.

CONCLUSION

When the sonogram is performed by an expert sonologist, the difference in nuchal translucency measurement obtained with a transverse or sagittal plane is minimal. Increased nuchal translucency can be reliably identified by using transverse views, and in some cases, this may technically be advantageous.

Humoral and adaptive immune responses to the SARS-CoV-2 vaccine

Vaccines against SARS-CoV-2 ameliorate infection and adverse outcomes from SARS-CoV-2. Elicitation of high affinity and durable protective antibody responses is a hallmark of a successful humoral immune response to vaccination. To assess the relevance of serum levels of SARS-CoV-2 specific antibodies and to further characterize the immune response to SARS-CoV-2 vaccines, we report i) the levels of spike-binding and neutralizing antibodies to SARS-COV-2 in the sera of 30 healthy volunteers at nine months after the second vaccination dose of mRNA vaccine and one month after the booster dose; ii) the levels of IFN-γ production by blood T cells exposed to SARS-CoV-2 spike antigen (Wuhan, Alpha B.1.1.7, Delta B.1.617.2, and Omicron B1.1.529 variants); and iii) the specific phenotype of T cells related with exposure to SARS-CoV-2 spike antigen. We observed that the booster dose induced increased humoral and adaptive immune responses and led to early activation of the memory CD8+ T subset.

3'UTR-HLA-G polymorphisms and circulating sHLA-G are associated with breast cancer: Evidence from a meta-analysis

BACKGROUND

Human leukocyte antigen-G (HLA-G) gene polymorphisms and circulating sHLA-G have often been linked to the risk of breast cancer (BC). However, the results remain controversial. To resolve this issue, we performed a meta-analysis of HLA-G gene polymorphisms and sHLA-G levels in BC.

METHODS

We performed a meta-analysis on the association of HLA-G 14-bp Insertion/Deletion (Ins/Del) and HLA-G +3142 C/G polymorphisms with BC as well as the relationship between sHLA-G and the disease outcome.

RESULTS

Pooled analysis showed a statistically significant association between the HLA-G 14-bp Ins/Del polymorphism and BC susceptibility for the overall population and for Caucasians. The Del allele and genotypes with at least one copy of the Del allele presented significant risks for BC. For HLA-G +3142 C/G polymorphism, the G allele significantly decreased the risk of BC for the overall population and for Caucasians, indicating that the G allele was a protective factor against BC and that the C allele was a significant risk factor for BC. The meta-analysis revealed a significantly increased level of sHLA-G patients with BC compared to the control group for the overall population, Caucasians and Asians.

CONCLUSION

The present meta-analysis showed a major association of both HLA-G 14-bp Ins/Del and +3142 C/G polymorphisms with BC susceptibility, suggesting Del and C variants as highly significant risk factors for BC. The present study also showed significantly higher sHLA-G levels in patients with BC compared to healthy controls. Our pooled results suggested a critical role of HLA-G in BC, thereby providing evidence to use HLA-G as a biomarker and a therapeutic tool.

Investigating Serum sHLA-G Cooperation With MRI Activity and Disease-Modifying Treatment Outcome in Relapsing-Remitting Multiple Sclerosis

Relapsing-remitting multiple sclerosis (RRMS) is a demyelinating disease in which pathogenesis T cells have a major role. Despite the unknown etiology, several risk factors have been described, including a strong association with human leukocyte antigen (HLA) genes. Recent findings showed that HLA class I-G (HLA-G) may be tolerogenic in MS, but further insights are required. To deepen the HLA-G role in MS inflammation, we measured soluble HLA-G (sHLA-G) and cytokines serum level in 27 patients with RRMS at baseline and after 12 and 24 months of natalizumab (NTZ) treatment. Patients were divided into high (sHLA-G>20 ng/ml), medium (sHLA-G between 10 and 20 ng/ml), and low (sHLA-G <10 ng/ml) producers. Results showed a heterogeneous distribution of genotypes among producers, with no significant differences between groups. A significant decrease of sHLA-G was found after 24 months of NTZ in low producers carrying the +3142 C/G genotype. Finally, 83.3% of high and 100% of medium producers were MRI-activity free after 24 months of treatment, compared to 63.5% of low producers. Of note, we did not find any correlation of sHLA-G with peripheral cell counts or cytokines level. These findings suggest that serum sHLA-G level may partly depend on genotype rather than peripheral inflammation, and that may have impacted on MRI activity of patients over treatment.

Competition for Dominance Within Replicating Quasispecies During Prolonged SARS-CoV-2 Infection in an Immunocompromised Host

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) emerge for their capability to better adapt to the human host aimed and enhance human-to-human transmission. Mutations in spike largely contributed to adaptation. Viral persistence is a prerequisite for intra-host virus evolution, and this likely occurred in immunocompromised patients who allow intra-host long-term viral replication. The underlying mechanism leading to the emergence of variants during viral persistence in the immunocompromised host is still unknown. Here, we show the existence of an ensemble of minor mutants in the early biological samples obtained from an immunocompromised patient and their dynamic interplay with the master mutant during a persistent and productive long-term infection. In particular, after 222 days of active viral replication, the original master mutant, named MB61⁰, was replaced by a minor quasispecies (MB61²²²) expressing two critical mutations in spike, namely Q493K and N501T. Isolation of the two viruses allowed us to show that MB61²²² entry into target cells occurred mainly by the fusion at the plasma membrane (PM), whereas endocytosis characterized the entry mechanism used by MB61⁰. Interestingly, coinfection of two human cell lines of different origin with the SARS-CoV-2 isolates highlighted the early and dramatic predominance of MB61²²² over MB61⁰ replication. This finding may be explained by a faster replicative activity of MB61²²² as compared to MB61⁰ as well as by the capability of MB61²²² to induce peculiar viral RNA-sensing mechanisms leading to an increased production of interferons (IFNs) and, in particular, of IFN-induced transmembrane protein 1 (IFITM1) and IFITM2. Indeed, it has been recently shown that IFITM2 is able to restrict SARS-CoV-2 entry occurring by endocytosis. In this regard, MB61²²² may escape the antiviral activity of IFITMs by using the PM fusion pathway for entry into the target cell, whereas MB61⁰ cannot escape this host antiviral response during MB61²²² coinfection, since it has endocytosis as the main pathway of entry. Altogether, our data support the evidence of quasispecies fighting for host dominance by taking benefit from the cell machinery to restrict the productive infection of competitors in the viral ensemble. This finding may explain, at least in part, the extraordinary rapid worldwide turnover of VOCs that use the PM fusion pathway to enter into target cells over the original pandemic strain.

Identification of the most common BRCA alterations through analysis of germline mutation databases: Is droplet digital PCR an additional strategy for the assessment of such alterations in breast and ovarian cancer families?

Breast and ovarian cancer represent two of the most common tumor types in females worldwide. Over the years, several non‑modifiable and modifiable risk factors have been associated with the onset and progression of these tumors, including age, reproductive factors, ethnicity, socioeconomic status and lifestyle factors, as well as family history and genetic factors. Of note, BRCA1 and BRCA2 are two tumor suppressor genes with a key role in DNA repair processes, whose mutations may induce genomic instability and increase the risk of cancer development. Specifically, females with a family history of breast or ovarian cancer harboring BRCA1/2 germline mutations have a 60‑70% increased risk of developing breast cancer and a 15‑40% increased risk for ovarian cancer. Different databases have collected the most frequent germline mutations affecting BRCA1/2. Through the analysis of such databases, it is possible to identify frequent hotspot mutations that may be analyzed with next‑generation sequencing (NGS) and novel innovative strategies. In this context, NGS remains the gold standard method for the assessment of BRCA1/2 mutations, while novel techniques, including droplet digital PCR (ddPCR), may improve the sensitivity to identify such mutations in the hereditary forms of breast and ovarian cancer. On these bases, the present study aimed to provide an update of the current knowledge on the frequency of BRCA1/2 mutations and cancer susceptibility, focusing on the diagnostic potential of the most recent methods, such as ddPCR.

Overview of the Clinical and Molecular Features of Legionella Pneumophila: Focus on Novel Surveillance and Diagnostic Strategies

Legionella pneumophila (L. pneumophila) is one of the most threatening nosocomial pathogens. The implementation of novel and more effective surveillance and diagnostic strategies is mandatory to prevent the occurrence of legionellosis outbreaks in hospital environments. On these bases, the present review is aimed to describe the main clinical and molecular features of L. pneumophila focusing attention on the latest findings on drug resistance mechanisms. In addition, a detailed description of the current guidelines for the disinfection and surveillance of the water systems is also provided. Finally, the diagnostic strategies available for the detection of Legionella spp. were critically reviewed, paying the attention to the description of the culture, serological and molecular methods as well as on the novel high-sensitive nucleic acid amplification systems, such as droplet digital PCR.

Bowel ischemia as onset of COVID-19 in otherwise asymptomatic patients with persistently negative swab

BACKGROUND

Asymptomatic patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can develop hypercoagulable conditions and acute vascular events. The objective of this study is to determine whether SARS-CoV-2 was present in resected specimens from patients with acute bowel ischemia, but asymptomatic for Coronavirus Disease 2019 (COVID-19) and with persistently real-time polymerase chain reaction negative pharyngeal swab.

METHODS

Three consecutive patients presented severe abdominal symptoms due to extensive ischemia and necrosis of the bowel, with co-existent thrombosis of abdominal blood vessels. None had the usual manifestations of COVID-19, and repeated pharyngeal swabs tested negative. They underwent emergency surgery with intestinal resection. Immunohistochemical testing for SARS-CoV-2 on resected tissue was performed.

RESULTS

All tested samples were strongly positive for SARS-CoV-2.

CONCLUSIONS

This is the first case report in which patients with severe intestinal symptoms presented a marked SARS-CoV-2 positivity in the resected tissues, without any usual clinical manifestations of COVID-19. These results suggest that the patients might be infected with SARS-CoV-2 presenting acute abdominal distress but without respiratory or constitutional symptoms.

Factors associated with fertility abnormalities in women with systemic lupus erythematosus: a systematic review and meta-analysis

BACKGROUND

Fertility is thought to be not affected in women with systemic lupus erythematosus (SLE), however disease-related factors, psychosocial effects of chronic disease, as well as medications exposure might impair gonadal function.

OBJECTIVE

This systematic literature review (SLR) aimed to explore clinical, hormonal, serological and treatment factors associated with fertility outcomes in women of childbearing age with SLE.

METHODS

This SLR was conducted following the Preferred Reporting Items for systematic reviews and Meta-analysis (PRISMA) statement. All articles available in English (1972 - 30th April 2021) in Pubmed, EMBASE, Scopus and Cochrane Library were screened. Study selection and data collection were performed by two independent reviewers. All data were extracted using a standardized template. The risk of bias of the included studies was assessed using the NIH risk-of-bias tool.

RESULTS

Of 789 abstracts evaluated, we included in this review 46 studies, of which 1 SLR, 16 cross-sectional studies, 18 cohort studies, 10 observational studies and 1 case-series, with data pertaining to 4704 patients (mean age 31.5 ± 3.7 years, disease duration 83.27 ± 38.3 months). Definitions of premature ovarian failure (POF) adopted in the studies varied in terms of the number of months of amenorrhea considered and the age of onset of amenorrhea. Clinical factors associated with the development of POF were older age at the time of initiation of therapy, and older age at the onset of SLE disease. Cyclophosphamide exposure (CYC) and its cumulative dose influenced gonadal function in SLE women, leading to amenorrhoea and POF, as reported in 19 studies. Mycophenolate, azathioprine, calcineurin inhibitors and steroids associated with a lower risk of POF compared to CYC. POF was less frequent in patients co-treated with CYC and gonadotropin-releasing hormone analogues (GnRH-a) compared with patients not receiving GnRH-a (risk ratio 0.798, 95%-CI [0.1417; 0.5525]). 11 studies evaluated the impact of damage accrual and disease activity on ovarian reserve with conflicting evidence. Finally, 18 studies investigated exposure to hormonal and serological factors and, among others, neither Anti-Müllerian Hormone nor anti-corpus luteum antibodies were associated with POF.

CONCLUSION

The strongest evidence regarding management factors associated with fertility in SLE women of childbearing age remains the treatment with CYC, as well as its cumulative dosage. Hormonal and serological factors appeared not to impact fertility outcomes, but they might be used as a surrogate of fertility, especially during the treatment with disease-specific drugs.

Pituitary apoplexy and COVID-19 vaccination: a case report and literature review

A 50-year-old man was admitted to our hospital for vomit, nausea, diplopia, and headache resistant to analgesic drugs. Symptoms started the day after his third COVID-19 mRNA vaccine (Moderna) whereas SARS-CoV-2 nasal swab was negative. Pituitary MRI showed recent bleeding in macroadenoma, consistent with pituitary apoplexy. Adverse Drug Reaction was reported to AIFA (Italian Medicines Agency).A stress dexamethasone dose was administered due to the risk of adrenal insufficiency and to reduce oedema. Biochemistry showed secondary hypogonadism; inflammatory markers were elevated as well as white blood cells count, fibrinogen and D-dimer. Pituitary tumour transsphenoidal resection was performed and pathology report was consistent with pituitary adenoma with focal haemorrhage and necrosis; we found immunohistochemical evidence for SARS-CoV-2 proteins next to pituitary capillaries, in the presence of an evident lymphocyte infiltrate.Few cases of pituitary apoplexy after COVID-19 vaccination and infection have been reported. Several hypotheses have been suggested to explain this clinical picture, including cross-reactivity between SARS-CoV-2 and pituitary proteins, COVID-19-associated coagulopathy, infection-driven acutely increased pituitary blood demand, anti-Platelet Factor 4/heparin antibodies development after vaccine administration. Ours is the first case of SARS-CoV-2 evidence in pituitary tissue, suggesting that endothelial infection of pituitary capillaries could be present before vaccination, possibly due to a previous asymptomatic SARS-CoV-2 infection. Our case underlines that SARS-CoV-2 can associate with apoplexy by penetrating the central nervous system, even in cases of negative nasal swab. Patients with pituitary tumours may develop pituitary apoplexy after exposure to SARS-CoV-2, therefore clinicians should be aware of this risk.

Synthesis and biological evaluation of novel rhodanine-based structures with antiviral activity towards HHV-6 virus

An increased awareness of diseases associated with Human herpesvirus 6 (HHV-6) infection or reactivation has resulted in a growing interest in the evaluation of the best treatment options available for the clinical management of HHV-6 disease. However, no compound has yet been approved exclusively for HHV-6 infection treatment. For this reason, the identification of anti-HHV6 compounds provides a valuable opportunity for developing efficient antiviral therapies. A possible target for antiviral drugs is the virus-cell fusion step. In this study, we synthetized potential fusion intermediates inhibitors based on the rhodanine structure. The obtained derivatives were tested for cytotoxicity and for antiviral activity in human cells infected with HHV6. Level of infection was monitored by viral DNA quantification at different time points up to 7 days post infection. Among the synthetized derivatives, 9e showed a significative inhibitory effect on viral replication that lasted over 7 days, probably attributable to the particular combination of hydrophilic and hydrophobic substituents to the rhodanine moiety. Our results support the use of these amphipathic fusion inhibitors for the treatment of HHV-6 infections.

Relevance of VEGF and CD147 in different SARS-CoV-2 positive digestive tracts characterized by thrombotic damage

Several evidence suggests that, in addition to the respiratory tract, also the gastrointestinal tract is a main site of severe acute respiratory syndrome CoronaVirus 2 (SARS-CoV-2) infection, as an example of a multi-organ vascular damage, likely associated with poor prognosis. To assess mechanisms SARS-CoV-2 responsible of tissue infection and vascular injury, correlating with thrombotic damage, specimens of the digestive tract positive for SARS-CoV-2 nucleocapsid protein were analyzed deriving from three patients, negative to naso-oro-pharyngeal swab for SARS-CoV-2. These COVID-19-negative patients came to clinical observation due to urgent abdominal surgery that removed different sections of the digestive tract after thrombotic events. Immunohistochemical for the expression of SARS-CoV-2 combined with a panel of SARS-CoV-2 related proteins angiotensin-converting enzyme 2 receptor, cluster of differentiation 147 (CD147), human leukocyte antigen-G (HLA-G), vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 was performed. Tissue samples were also evaluated by electron microscopy for ultrastructural virus localization and cell characterization. The damage of the tissue was assessed by ultrastructural analysis. It has been observed that CD147 expression levels correlate with SARS-CoV-2 infection extent, vascular damage and an increased expression of VEGF and thrombosis. The confirmation of CD147 co-localization with SARS-CoV-2 Spike protein binding on gastrointestinal tissues and the reduction of the infection level in intestinal epithelial cells after CD147 neutralization, suggest CD147 as a possible key factor for viral susceptibility of gastrointestinal tissue. The presence of SARS-CoV-2 infection of gastrointestinal tissue might be consequently implicated in abdominal thrombosis, where VEGF might mediate the vascular damage.

Transparent Polymeric Formulations Effective against SARS-CoV-2 Infection

The main route of the transmission of the SARS-CoV-2 virus is through airborne small aerosol particles containing viable virus as well as through droplets transmitted between people within close proximity. Transmission via contaminated surfaces has also been recognized as an important route for the spread of SARS-CoV-2 coronavirus. Among a variety of antimicrobial agents currently in use, polymers represent a class of biocides that have become increasingly important as an alternative to existing biocidal approaches. Two transparent polymeric compounds, containing silver and benzalkonium ions electrostatically bound to a polystyrene sulfonate backbone, were synthesized, through simple procedures, and evaluated for their antimicrobial properties against Gram-positive and Gram-negative bacteria and Candida albicans (ISO EN 1276) and for their antiviral activity toward 229E and SARS-CoV-2 coronaviruses (ISO UNI EN 14476:2019). The results showed that the two tested formulations are able to inhibit the growth of (1.5-5.5) × 1011 CFU of Gram-positive bacteria, Gram-negative bacteria, and of the fungal species Candida albicans. Both compounds were able to control the 229E and SARS-CoV-2 infection of a target cell in a time contact of 5 min, with a virucidal effect from 24 to 72 h postinfection, according to the European Medicines Agency (EMA) guidelines, where a product is considered virucidal upon achieving a reduction of 4 logarithms. This study observed a decrease of more than 5 logarithms, which implies that these formulations are likely ideal candidates for the realization of transparent surface coatings that are capable of maintaining remarkable antibacterial activity and SARS-CoV-2 antiviral properties over time.

76 PREDICTIVE MODEL FOR MOBILITY DECLINE: INDIVIDUAL TRIAL MISTAKE THRESHOLDS IN SUSTAINED ATTENTION TO RESPONSE TASK (SART)

Background

The Sustained Attention to Response Task (SART) is a standard computer-based cognitive test designed to measure the sustained attention, fundamental for completing tasks that require supervision over time (Robertson et al., 1997). However, commonly used average features may result in loss of information and data misinterpretation, leading to inability to detect clinically expected associations (O’Halloran et al., 2014).

Methods

Here, we present a new method to visualise the full information obtained from the SART test, ordering by age, and categorising in groups based on mobility status in a large population-based study of ageing in Ireland. A new threshold, derived from the visualisation and based on the individual trial number of mistakes, was employed to individuate poorer SART performances, and to predict mobility and cognitive decline after 4 years in binary logistic regression models.

Results

Raw SART data were available for 4,864 participants aged 50 years and over at baseline. The new variable bad performances, expressing the number of SART trials with at least 4 mistakes, was the most significant predictor of mobility decline, defined as the transition from Timed Up-and-Go (TUG) < 12 to TUG ≥12 seconds (Odds Ratio (OR) = 1.29; 95% Confidence Interval (CI) 1.14–1.46; p < 0.001), and the only significant predictor of new falls (OR = 1.11; 95% CI 1.03–1.21; p = 0.011) compared to traditional SART variables in models adjusted for multiple covariates. No SART-related variables resulted significant predictors of cognitive decline, defined as a decrease of at least 2 points in the Mini-Mental State Examination (MMSE) score.

Conclusion

This multimodal visualisation and the new threshold approach could help clinicians to easily develop relevant hypotheses, and better identify subjects at higher risk of future mobility decline.

136 ASSOCIATIONS OF FRAILTY WITH CONSECUTIVE GAIT SPEED TRAILS MEASURED BOTH WITH AND WITHOUT ADDITIONAL STRESSORS

Background

Frailty is associated with gait speed and is defined as increased vulnerability to stressors. While usual gait speed is often measured, gait speed under additional stressors such as simultaneously reciting alternate letters of the alphabet (cognitive dual task) or walking at maximum pace are also measured. Consecutive trials may introduce an additional temporal stressor and we hypothesise that frailty may be associated with a greater reduction in walking speed across trials.

Methods

Data from community-dwelling adults aged 50+ years at Wave 3 of The Irish Longitudinal Study on Ageing were utilized. Using a 32-item frailty index (FI) we derived non-frail, pre-frail and frail groups. Gait speeds were measured using a 4.88 m walkway (GAITRite, CIR Systems, NY, USA). We examined differences in gait speed between two consecutive walks in three conditions (usual pace, cognitive dual task, and maximum pace) for the entire cohort, and by frailty group. Related-samples Wilcoxon signed rank tests were employed, with statistical significance set at P < 0.05.

Results

For the entire cohort, walk 2 speed for usual and cognitive conditions was higher by 1.0 cm/s (N = 4,097) and 1.1 cm/s (N = 3,927) respectively, and lower by 1.9 cm/s for maximum (N = 3,926). Stratified by FI, all groups walked more quickly in normal (1.0, 1.1, 1.2, respectively) and cognitive (1.3, 0.8, 0.5), and more slowly in maximum (−2.2, −1.6, −1.0).

Conclusion

In our analyses, higher frailty seemed to be associated with a higher increase for the usual walk, a smaller increase for the cognitive walk, and a smaller decrease in maximum speed. The clinical significance of the differences was very small. However, our results support that in research and clinical practice, frailty by FI should not be expected to lead to a different pattern of gait speed change across consecutive trials.

81 LONGER CHAIR-STAND TIME IS ASSOCIATED WITH ORTHOSTATIC INTOLERANCE IN AN OLDER IRISH POPULATION

Background

Hospital admissions for orthostatic hypotension (OH) have risen more than two-fold in the past ten years. OH can lead to orthostatic intolerance (OI), and both OH and OI are common causes of falls and injuries in older persons. Sarcopenia is also common in older persons and associated with adverse health outcomes. The 5-chair stand test (5-CST) can be used as a marker of sarcopenia and a cut-off of 15 s has been proposed. We hypothesized that those with a worse performance on the 5-CST would be at greater risk of OH and sought to investigate this in an older Irish population cohort study.

Methods

5-CST was measured in keeping with a standardised protocol. Beat-to-beat blood pressure was measured with the Finometer device according to the active stand protocol. Multivariable logistic regressions were performed to investigate the associations between OH at 40 seconds after standing (OH40), OI (dizziness after standing), and 5-CST time. Potential confounders were controlled for in the model including age, sex, education, body mass index and medications.

Results

Data from 3,119 participants were available for analysis. Mean age was 63.8 years, 55% were female, 25% took longer than 15s on the 5-CST and mean baseline blood pressure was 141/76 mmHg. Proportion of OH40 was 12.5% and 4.4% reported OI. In the multivariable model, OH40 was not independently associated with 5-CST time after controlling for age (p > 0.05). Worse performance on the chair stands test was however an independent predictor of OI (odds ratio 1.06, p = 0.039).

Conclusion

Longer time taken on the 5-CST, a marker of sarcopenia, was an independent predictor of OI in a large population study. The relationship between sarcopenia and orthostatic blood pressure response is not well elucidated. We plan to further investigate this area in a future clinical cohort.

123 ACUTE-PHASE BED-REST DURATION WAS ASSOCIATED WITH LOWER GRIP STRENGTH IN A POST-COVID-19 COHORT

Background

Though age-related muscle loss is traditionally associated with older cohorts, strong evidence suggests a life-spanning precipitation of decreasing muscle mass and strength beginning as early as the fourth decade of life, with established deleterious consequences for later-life morbidity and mortality. Periods of low activity and bed rest (LA/BR) can further compound this depletion of muscle strength. Our aim was to examine such associations in a post-COVID-19 cohort.

Methods

Participants reporting ongoing symptomatology and fatigue post COVID-19 underwent assessments of grip strength via hand-held dynamometry (2 measures on each hand). Demographics of COVID-19 illness, including time since diagnosis, duration of LA/BR during acute illness, and levels of fatigue were captured via self-reported questionnaires. Independent predictors of mean grip strength were investigated using a linear regression model.

Results

Forty-nine participants underwent assessments (69% female, mean age 44(12) years). At the time of assessment, days post COVID-19 diagnosis ranged from 39–522 (mean 262(140)). The mean self-reported period of LA/BR during the acute illness was 15(18) days. In general, participants reported significant levels of fatigue (median Chalder Fatigue Scale score 22(8)). Mean grip strength was 41.3(6.3) Kg for men and 22.8(6.7) Kg for women. When predictors of grip strength were investigated, an increased duration of LA/BR was found to be associated with lower grip strength, independently of age, gender, time since COVID-19 diagnosis, and self-reported fatigue (Beta = −0.158, 95% Confidence Interval − 0.242 to −0.074, p = 0.001).

Conclusion

In this cohort, every day of LA/BR during acute COVID-19 illness was independently associated with subsequent lower grip strength of approximately 150 g. These results underscore the importance of early mobilization and discouraging bed rest in the acute phase of COVID-19. Patients who are isolating should be encouraged to maintain physical activity and muscle strength as part of a modified isolation-friendly rehabilitation programme.

78 HIGHER NEUROVASCULAR SIGNAL ENTROPY IS ASSOCIATED WITH ACCELERATED BRAIN AGEING

Background

Often chronological age is not the most accurate marker of an individual’s health status since ageing is a heterogeneous process across individuals. Machine learning can be used to quantify the relationship between structural brain MRI data and chronological age, to estimate an individual’s ‘brain age’, which, when subtracted from chronological age, provides a brain predicted-age difference score (BrainPAD) [1]. BrainPAD reflects the biological ageing of the brain. Increased complexity in neurovascular signals has been shown to be associated with poorer cognitive performance and physical frailty [2]. The aim of this study was to investigate associations between the complexity of frontal-lobe oxygenation (tissue saturation index (TSI)) data and BrainPAD in a cohort of older community-dwelling adults.

Methods

To calculate BrainPAD, machine learning was applied to 1,359 T1-weighted MRI brain scans from various open-access repositories, and this model was subsequently applied to MRI data acquired from the study cohort. TSI was non-invasively measured in the left frontal lobe using near-infrared spectroscopy. TSI data were acquired continuously during five minutes of supine rest and the last minute was utilized in this analysis. The complexity of TSI signals was quantified using sample entropy (SampEn). Multivariable linear regression was employed, controlling for age, sex, education, antihypertensive medications, diabetes, cardiovascular conditions, smoking, alcohol, depression, BMI, physical activity, and blood pressure.

Results

Complete data were available for 397 individuals (age: 67.9 ± 7.7 years; 53.7% female). An increase in TSI SampEn of 0.1 was associated with an increase in BrainPAD of 0.9 years (P = 0.007, 95%CIs: 0.3 to 1.6). Similar results were found with and without the inclusion of chronological age in the models.

Conclusion

This study reports significant associations between higher complexity in peripherally measured frontal lobe oxygenation concentration and accelerated brain ageing.

References

1. Boyle R. et al. Brain Imaging and Behavior. 15,327–345 (2021) https://doi.org/10.1007/s11682-020-00260-3.

2. Knight S. et al. Entropy. 23(1):4 (2021) https://doi.org/10.3390/e23010004.

Increased sHLA-G Is Associated with Improved COVID-19 Outcome and Reduced Neutrophil Adhesion

Human leukocyte antigen (HLA) is a group of molecules involved in inflammatory and infective responses. We evaluated blood sHLA-E and sHLA-G levels in hospitalized COVID-19 patients with respiratory failure and their relationship with clinical evolution, changes in endothelial activation biomarker profile, and neutrophil adhesion. sHLA-E, sHLA-G, and endothelial activation biomarkers were quantified by ELISA assay in plasma samples. Neutrophil adhesion to endothelium was assessed in the presence/absence of patients’ plasma samples. At admission, plasma levels of sHLA-G and sHLA-E were significantly higher in COVID-19 patients with respiratory failure compared to controls. COVID-19 clinical improvement was associated with increased sHLA-G plasma levels. In COVID-19, but not in control patients, an inverse correlation was found between serum sICAM-1 and E-selectin levels and plasma sHLA-G values. The in vitro analysis of activated endothelial cells confirmed the ability of HLA-G molecules to control sICAM-1 and sE-selectin expression via CD160 interaction and FGF2 induction and consequently neutrophil adhesion. We suggest a potential role for sHLA-G in improving COVID-19 patients’ clinical condition related to the control of neutrophil adhesion to activated endothelium.

TLR3 and TLR7 RNA Sensor Activation during SARS-CoV-2 Infection

(1) Background: Acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent for the coronavirus disease (COVID-19) that has led to a pandemic that began in March 2020. The role of the SARS-CoV-2 components on innate and adaptive immunity is still unknown. We investigated the possible implication of pathogen-associated molecular patterns (PAMPs)-pattern recognition receptors (PRRs) interaction. (2) Methods: We infected Calu-3/MRC-5 multicellular spheroids (MTCSs) with a SARS-CoV-2 clinical strain and evaluated the activation of RNA sensors, transcription factors, and cytokines/interferons (IFN) secretion, by quantitative real-time PCR, immunofluorescence, and ELISA. (3) Results: Our results showed that the SARS-CoV-2 infection of Calu-3/MRC-5 multicellular spheroids induced the activation of the TLR3 and TLR7 RNA sensor pathways. In particular, TLR3 might act via IRF3, producing interleukin (IL)-1α, IL-1β, IL-4, IL-6, and IFN-α and IFN-β, during the first 24 h post-infection. Then, TLR3 activates the NFκB transduction pathway, leading to pro-inflammatory cytokine secretion. Conversely, TLR7 seems to mainly act via NFκB, inducing type 1 IFN, IFN-γ, and IFN-λ3, starting from the 48 h post-infection. (4) Conclusion: We showed that both TLR3 and TLR7 are involved in the control of innate immunity during lung SARS-CoV-2 infection. The activation of TLRs induced pro-inflammatory cytokines, such as IL-1α, IL-1β, IL-4, and IL-6, as well as interferons. TLRs could be a potential target in controlling the infection in the early stages of the disease.

Genetic and Epigenetic Alterations Induced by Pesticide Exposure: Integrated Analysis of Gene Expression, microRNA Expression, and DNA Methylation Datasets

Environmental or occupational exposure to pesticides is considered one of the main risk factors for the development of various diseases. Behind the development of pesticide-associated pathologies, there are both genetic and epigenetic alterations, where these latter are mainly represented by the alteration in the expression levels of microRNAs and by the change in the methylation status of the DNA. At present, no studies have comprehensively evaluated the genetic and epigenetic alterations induced by pesticides; therefore, the aim of the present study was to identify modifications in gene miRNA expression and DNA methylation useful for the prediction of pesticide exposure. For this purpose, an integrated analysis of gene expression, microRNA expression, and DNA methylation datasets obtained from the GEO DataSets database was performed to identify putative genes, microRNAs, and DNA methylation hotspots associated with pesticide exposure and responsible for the development of different diseases. In addition, DIANA-miRPath, STRING, and GO Panther prediction tools were used to establish the functional role of the putative biomarkers identified. The results obtained demonstrated that pesticides can modulate the expression levels of different genes and induce different epigenetic alterations in the expression levels of miRNAs and in the modulation of DNA methylation status.