Dextran-shelled oxygen-loaded nanodroplets modulate macrophages killing and inflammatory response to Enterococcus faecalis

Chronic wounds are associated with inflammation, infections, and hypoxic environment. Macrophages play a crucial role in wound healing removing bacteria and secreting signal molecules to coordinate tissue repair. Recently, dextran-shelled Oxygen-Loaded NanoDroplets (OLNDs) have been proposed as new tools to counteract hypoxia in chronic wounds. Here we investigated the effects of OLNDs on Enterococcus faecalis (E. faecalis) killing and the secretion of inflammatory and angiogenic factors by murine (BMDM) and human (dTHP-1, differentiated THP-1) macrophages, in normoxia and hypoxia. Both OLNDs and Oxygen-Free NanoDroplets (OFNDs) significantly increased reactive oxygen species production by BMDM in normoxia (4.1 and 4 fold increase by 10% OLNDs and OFNDs, respectively, after 120 min) and hypoxia (3.8 and 4 fold increase by 10% OLNDs and OFNDs respectively) but not by dTHP-1. Moreover, only OLNDs induced nitric oxide secretion by BMDM in normoxia. Consequently, both nanodroplets improved E. faecalis killing by BMDM in normoxia (% of killing OLNDs = 44.2%; p < 0.01; OFNDs = 41.4%; p < 0.05) and hypoxia (% of killing OLNDs = 43.1%; p < 0.01; OFNDs = 37.7%; p < 0.05), while dTHP-1-mediated killing was not affected. The secretion of the inflammatory cytokines (TNFα, IL-6, IL-1β) induced by E. faecalis infection in dTHP-1 was reduced by both types of nanodroplets, suggesting a novel anti-inflammatory activity of the dextran shell. Instead, the increase of VEGF induced by hypoxia was reduced only by OLNDs. These data provide new knowledge on the effects of OLNDs as innovative adjuvant in chronic wounds healing promoting bacterial killing and reducing inflammation.

Antiparasitic Drugs against SARS-CoV-2: A Comprehensive Literature Survey

More than two years have passed since the viral outbreak that led to the novel infectious respiratory disease COVID-19, caused by the SARS-CoV-2 coronavirus. Since then, the urgency for effective treatments resulted in unprecedented efforts to develop new vaccines and to accelerate the drug discovery pipeline, mainly through the repurposing of well-known compounds with broad antiviral effects. In particular, antiparasitic drugs historically used against human infections due to protozoa or helminth parasites have entered the main stage as a miracle cure in the fight against SARS-CoV-2. Despite having demonstrated promising anti-SARS-CoV-2 activities in vitro, conflicting results have made their translation into clinical practice more difficult than expected. Since many studies involving antiparasitic drugs are currently under investigation, the window of opportunity might be not closed yet. Here, we will review the (controversial) journey of these old antiparasitic drugs to combat the human infection caused by the novel coronavirus SARS-CoV-2.

VIRAL AGENTS AND SYSTEMIC LEVELS OF INFLAMMATORY CYTOKINES IN VULNERABLE AND STABLE ATHEROSCLEROTIC CAROTID PLAQUES

BACKGROUND

To investigate the presence of genetic material of viral agents and the serum level of inflammatory cytokines in patients submitted to carotid endarterectomy having vulnerable versus stable atherosclerotic plaques.

METHODS

Data of patients consecutively submitted to carotid endarterectomy for a significant stenosis from 07/2019 to 12/2019 were prospectively collected. The genetic material of Epstein-Barr (EBV), CitoMegalo (CMV), Herpes Simplex (HSV), Varicella-Zoster (VZV) and Influenza (IV) Viruses was searched in the patient's plaques, both in the "mid" of the plaque and in an adjacent lateral portion of no-plaque area. The serum levels of TNF-α, IL-1β, IL-6, IL10 and CCL5 were determined. The obtained results were then correlated to the histologic vulnerability of the removed carotid plaque. P values <0.05 were considered statistically significant.

RESULTS

Data of 50 patients were analyzed. A vulnerable plaque was found in 31 patients (62%). The genome of CMV, HSV, VZV and IV was not found in any of the vascular samples, while the EBV genome was found in the "mid" of two vulnerable plaques, but not in their respective control area. Eighty-two percent of patients who did not receive anti-IV vaccination (23/28) had vulnerable carotid plaque, compared with 36% of vaccinated patients (8/22, p=0.001). Serum levels of TNF-α and IL-6 were higher in patients with a vulnerable plaque compared to patients with a stable plaque (73.6±238.2 vs 3.9±13.1 pg/ml, p=0.01, and 45.9±103.6 vs 10.1±25.3 pg/ml, p=0.01, respectively), independent of comorbidities, viral exposure or flu vaccination.

CONCLUSION

The EBV genome was found in the "core" of two vulnerable carotid plaques, but not in their respective adjacent control. Influenza vaccination was associated with a lower incidence of carotid plaque vulnerability. Serum levels of TNF-α and IL-6 were higher in patients with a vulnerable plaque compared to patients with a stable plaque.

Phagocytosis and activation of bone marrow-derived macrophages by Plasmodium falciparum gametocytes

Background

The innate immune response against various life cycle stages of the malaria parasite plays an important role in protection against the disease and regulation of its severity. Phagocytosis of asexual erythrocytic stages is well documented, but little and contrasting results are available about phagocytic clearance of sexual stages, the gametocytes, which are responsible for the transmission of the parasites from humans to mosquitoes. Similarly, activation of host macrophages by gametocytes has not yet been carefully addressed.

Methods

Phagocytosis of early or late Plasmodium falciparum gametocytes was evaluated through methanol fixed cytospin preparations of immortalized mouse C57Bl/6 bone marrow-derived macrophages treated for 2 h with P. falciparum and stained with Giemsa, and it was confirmed through a standardized bioluminescent method using the transgenic P. falciparum 3D7elo1-pfs16-CBG99 strain. Activation was evaluated by measuring nitric oxide or cytokine levels in the supernatants of immortalized mouse C57Bl/6 bone marrow-derived macrophages treated with early or late gametocytes.

Results

The results showed that murine bone marrow-derived macrophages can phagocytose both early and late gametocytes, but only the latter were able to induce the production of inflammatory mediators, specifically nitric oxide and the cytokines tumour necrosis factor and macrophage inflammatory protein 2.

Conclusions

These results support the hypothesis that developing gametocytes interact in different ways with innate immune cells of the host. Moreover, the present study proposes that early and late gametocytes act differently as targets for innate immune responses.

Lanadelumab demonstrates rapid and sustained prevention of hereditary angioedema attacks

Background

Lanadelumab demonstrated efficacy in preventing hereditary angioedema (HAE) attacks in the phase 3 HELP Study.

Objective

To assess time to onset of effect and long‐term efficacy of lanadelumab, based on exploratory findings from the HELP Study.

Methods

Eligible patients with HAE type I/II received lanadelumab 150 mg every 4 weeks (q4wks), 300 mg q4wks, 300 mg q2wks, or placebo. Ad hoc analyses evaluated day 0‐69 findings using a Poisson regression model accounting for overdispersion. Least‐squares mean monthly HAE attack rate for lanadelumab was compared with placebo. Intrapatient comparisons for days 0‐69 versus steady state (days 70‐182) used a paired t test for continuous endpoints or Kappa statistics for categorical endpoints.

Results

One hundred twenty‐five patients were randomized and treated. During days 0‐69, mean monthly attack rate was significantly lower with lanadelumab (0.41‐0.76) vs placebo (2.04), including attacks requiring acute treatment (0.33‐0.61 vs 1.66) and moderate/severe attacks (0.31‐0.48 vs 1.33, all P ≤ .001). More patients receiving lanadelumab vs placebo were attack free (37.9%‐48.1% vs 7.3%) and responders (85.7%‐100% vs 26.8%). During steady state, the efficacy of lanadelumab vs placebo was similar or improved vs days 0‐69. Intrapatient differences were significant with lanadelumab 300 mg q4wks for select outcomes. Lanadelumab efficacy was durable—HAE attack rate was consistently lower vs placebo, from the first 2 weeks of treatment through study end. Treatment emergent adverse events were comparable during days 0‐69 and 70‐182.

Conclusion

Protection with lanadelumab started from the first dose and continued throughout the entire study period.

Leishmania infantum infection reduces the amyloid β42-stimulated NLRP3 inflammasome activation

Activation of the NLRP3 inflammasome has been shown to play a major role in the neuroinflammation that accompanies Alzheimer's disease (AD); interventions that down regulate the NLRP3 inflammasome could thus be beneficial in AD. Parasite infections were recently shown to be associated with improved cognitive functions in Apolipoprotein E4 (ApoE4)-expressing members of an Amazonian tribe. We verified in an in vitro model whether Leishmania infantum infection could reduce NLRP3. Results obtained in an initial experimental model in which PBMC were LPS primed and nigericin-stimulated showed that L. infantum infection significantly reduced ASC-speck formation (i.e. intracellular inflammasome proteins assembly), as well as the production of activated caspase 5 and IL-1β, but increased that of activated caspase 1 and IL-18. Moreover, L. infantum infection induced the generation of an anti-inflammatory milieu by suppressing the production of TNFα and increasing that of IL-10. These results were replicated when cells that had been LPS-primed were stimulated with Aβ₄₂ and infected with L. infantum. Results herein indicate that Leishmania infection favors an anti-inflammatory milieu, which includes the down-regulation of NLRP3 inflammasome activation, possibly to facilitate its survival inside host cells. A side effect of Leishmaniasis would be the hampering of neuroinflammation; this could play a protective role against AD development.

The Use of Antimalarial Drugs against Viral Infection

In recent decades, drugs used to treat malaria infection have been shown to be beneficial for many other diseases, including viral infections. In particular, they have received special attention due to the lack of effective antiviral drugs against new emerging viruses (i.e., HIV, dengue virus, chikungunya virus, Ebola virus, etc.) or against classic infections due to drug-resistant viral strains (i.e., human cytomegalovirus). Here, we reviewed the in vitro/in vivo and clinical studies conducted to evaluate the antiviral activities of four classes of antimalarial drugs: Artemisinin derivatives, aryl-aminoalcohols, aminoquinolines, and antimicrobial drugs.

Novelties in the Diagnosis and Treatment of Angioedema

Angioedema is defined as local, noninflammatory, self-limiting edema that is circumscribed owing to increased leakage of plasma from the capillaries located in the deep layers of the skin and the mucosae. Two mediators, histamine and bradykinin, account for most cases of angioedema. Angioedema can occur with wheals as a manifestation of urticaria, and this form is frequently allergic. In the present review, we discuss nonallergic angioedema without wheals, which can be divided into 3 acquired and 4 hereditary forms. Histamine is the mediator in acquired angioedema of unknown etiology (idiopathic histaminergic acquired angioedema), whereas in other forms the main mediator is bradykinin. Angioedema can be caused by C1-inhibitor deficiency (C1-INH-hereditary angioedema and C1-INH-acquired angioedema), mutations in coagulation factor XII (FXII-hereditary angioedema), and treatment with angiotensin-converting enzyme inhibitors (ACEI-acquired angioedema). Etiology remains unclear in acquired angioedema (idiopathic nonhistaminergic acquired angioedema) and in 1 type of hereditary angioedema (hereditary angioedema of unknown origin). Several treatments are licensed for hereditary C1-INH deficiency. Plasma-derived and recombinant C1-INHs, the bradykinin receptor blocker icatibant, and the plasma kallikrein inhibitor ecallantide have been approved for on-demand treatment to reverse angioedema symptoms. Attenuated androgen and plasma-derived C1-INH are approved for prophylaxis.

Does the metabolic syndrome predict subclinical atherosclerotic damage in an asymptomatic population at intermediate cardiovascular risk?

BACKGROUND AND AIMS

It is not clear whether the metabolic syndrome (MetS) is a distinct entity or a combination of risk factors. Several studies showed the association between MetS and cardiovascular disease (CVD). Subclinical target organ damage (TOD) is a recognized marker of atherosclerosis and predictor of cardiovascular events. Increased burden of subclinical atherosclerosis was detected in individuals with MetS. We thus aimed to examine the association between MetS and cumulative or specific TOD and to assess whether MetS predicts TOD better than the risk factors included in current definitions.

METHODS AND RESULTS

We recorded TOD in 979 patients at intermediate cardiovascular risk with and without MetS according to IDF and NCEP criteria. We measured common carotid intima-media thickness, left ventricular mass index (LVMI), urine albumin to creatinine ratio (UACR), and ankle-brachial index. We found no correlation between having at least one TOD and being positive for MetS. A high UACR was associated with MetS using both IDF and NCEP criteria, while only NCEP identified individuals with increased LVMI. Using a multivariate logistic regression model including MetS, age, sex, waist circumference, triglycerides, HDL cholesterol, blood pressure and blood glucose levels we found no correlations between the presence of MetS and at least one TOD. The associations with high UACR and LVMI disappeared when age, blood pressure and glycemia were counted in.

CONCLUSION

Although MetS showed some relation with subclinical renal and cardiac damage, it does not predict TOD any better than the risk factors specified in the definitions.

[Syncope and occupational risk survey: the role of continuing education and multidisciplinary approach]

Syncope is a common disorder characterized most of the times by a positive clinical outcome. However, it may turn to a life threatening event even for working colleagues and third party when occurring during an high risk job. We have recently found that, out of 670 patients admitted to the Emergency Department (ED) for syncope, about 50% were potential workers, being their age between 18 and 65 years. Also, we found that in this group of patients syncope recurrence was as high as 11% at 6 months. It is unknown how physicians address the problem of the occupational risk in patients suffering from syncope and how occupational aspects are taken into account in the clinical judgment before work readmission. One hundred eighty five doctors (149 occupational physicians, OP), participating in a work-shop on syncope, were asked to fulfill a questionnaire about their clinical experience and their attention to the occupational aspects in patients after syncope. Despite long lasting clinical experience, 41% of OP did not scrutinize syncope as a relevant symptom in their daily activity. 65% of the other specialists were used to address the occupational risk aspects in their syncope patients. A multidisciplinary approach involving continuing education on safety at work might reduce work accidents due to syncope relapse and promote a safe and suitable re-employment of patients with syncope. scrutinize syncope as a relevant symptom in their daily activity. 65% of the other specialists were used to address the occupational risk aspects in their syncope patients. A multidisciplinary approach involving continuing education on safety at work might reduce work accidents due to syncope relapse and promote a safe and suitable re-employment of patients with syncope.

[Syncope and work: role of the occupational physician and global risk stratification]

Safety risk for subjects suffering from syncope while working has not been as yet addressed by occupational medicine. The present study was aimed at evaluating a new developed methodology for job tasks risk stratification in patients with syncope. During a work-shop on syncope and occupational risk, 149 occupational physicians (OP) with about 10 years of clinical experience were asked to fulfil a Visual Analogue Scale (VAS) concerning the doctor's estimated potential damage (D) to the worker and the probability of a damage to occur (P) should syncope take place during the job task. Five job tasks characterized by different risk for safety (1, driving; 2, toxic products handling; 3, job performed closed to hot surfaces o free flames; 4, surgical activity; 5, office job) were identified. OP correctly stratified the risk associated to the different job tasks in patients with syncope. Unexpectedly, task #3 was given a risk similar to that obtained in drivers. This might be of paramount clinical and social importance when patients with syncope have to return to their job tasks.

[Syncope and work. STePS study (Short Term Prognosis of Syncope)]

BACKGROUND

Recurrent syncope is a common medical problem responsible for 3-5% of emergency department (ED) accesses and 1-6% of hospital admissions. If syncope occurs in a subject working in a critical safety task, the consequences of this event might be very dangerous for the worker, colleagues, others or for the environment. Therefore, syncope management is a major problem for occupational medicine, converning the general safety at work.

AIMS

To evaluate the syncope events in a group of potential workers aged 18 to 65 years; to evaluate the symptoms preceding syncope and the presence of associated illnesses and recurrent events.

POPULATION AND RESULTS

This study is part of the prospective study STePS (Short Term Prognosis of Syncope), and included 305 consecutive patients (aged 18-65 years, female 56%) who had syncope as a main symptom and presented at ED of four general hospitals in the Milan area, Italy, between the 23rd of January and 30th of June 2004. The 24% of subjects were hospitalized. In 21% the syncope occurs suddenly without any preceding symptom. The 67% of subjects didn't have any important illness at the time. 50% of subjects had recurrent syncope. In four subjects another syncope occurred in a 10 day follow-up.

CONCLUSIONS

occupational medicine should consider syncope scrupulously. Proper diagnostic management is important to permit a correct evaluation of work safety issues.

Blood fetal microchimerism in primary biliary cirrhosis

The autoimmune nature of primary biliary cirrhosis (PBC) is well established. We tested the hypothesis that fetal microchimerism indicated by the persistence of circulating fetal cells in women years after pregnancy might contribute to the aetiopathogenesis of PBC through a graft-versus-host-like response. We extracted DNA from the peripheral blood cells of 36 women carefully selected from 173 consecutive PBC patients, who were matched with 36 healthy women by age, age of last son, and number of children. Both patients and controls had to have male offspring, and no history of miscarriages or blood transfusions; they could not be twins. We tested all of the samples for the presence of two specific Y-chromosome sequences (SY154 and SRY) by amplifying DNA in a nested polymerase chain reaction. Y-chromosome-specific DNA was detected in the peripheral blood cell DNA of 13 (36%) of the 36 women with PBC and in 11 (31%) of the 36 healthy controls. The two groups of PBC patients with and without male DNA sequences were similar in terms of their clinical, biochemical, and serological features. Y-chromosome sequences were found in three of the four PBC women with associated systemic sclerosis. All of the 24 Y-positive samples contained SY154 sequences, but only three PBC patients and six controls showed the presence of both SY154 and SRY sequences. This discrepancy may suggest that not only fetal cells but also fragments of fetal DNA are present in maternal circulation. Overall, our data do not support the hypothesis that fetal microchimerism plays a significant role in the onset or progression of PBC.