Obesity in Severe COVID-19 Patients Has a Distinct Innate Immune Phenotype

Obesity alters the capacity of effective immune responses in infections. To further address this phenomenon in the context of COVID-19, this study investigated how the immunophenotype of leukocytes was altered in individuals with obesity in severe COVID-19. This cross-sectional study enrolled 27 ICU COVID-19 patients (67% women, 56.33 ± 19.55 years) that were assigned to obese (BMI ≥ 30 kg/m2, n = 9) or non-obese (BMI < 30kg/m2, n = 18) groups. Monocytes, NK, and both Low-Density (LD) and High-Density (HD) neutrophils were isolated from peripheral blood samples, and surface receptors' frequency and expression patterns were analyzed by flow cytometry. Clinical status and biochemical data were additionally evaluated. The frequency of monocytes was negatively correlated with BMI, while NK cells and HD neutrophils were positively associated (p < 0.05). Patients with obesity showed a significant reduction of monocytes, and these cells expressed high levels of PD-L1 (p < 0.05). A higher frequency of NK cells and increased expression of TREM-1+ on HD neutrophils were detected in obese patients (p < 0.05). The expression of receptors related to antigen-presentation, phagocytosis, chemotaxis, inflammation and suppression were strongly correlated with clinical markers only in obese patients (p < 0.05). Collectively, these outcomes revealed that obesity differentially affected, and largely depressed, innate immune response in severe COVID-19.

Association between different soy lecithin-based extenders and freezing rates in ram semen cryopreservation

The aim of the study was to evaluate the effect of the association between glycine-milk (GM) based extenders made with different concentrations of soy lecithin (SL) and freezing rates (FR) on semen quality after thawing. Pooled semen from rams (n = 12) were diluted in GM extenders with 20% egg yolk (EY-20%) or with different concentrations of SL: 0.5% (SL-0.5%), 1.0% (SL-1.0%), and 2.0% (SL-2.0%). The diluted semen (150 ×10⁶ spermatozoa/0.25 mL) was frozen at three FR of - 10, - 20, and - 60 °C/min, and subsequently thawed and analyzed. Results revealed that EY-20% and SL-2.0% had better kinetic parameters, and showed higher proportions of viable, non-apoptotic, plasma-membrane-intact spermatozoa (A^-/PI^-) and non-capacitated spermatozoa (F), and had lower acrosome-reacted spermatozoa (AR) in the EY-20% and satisfactory values for SL-2.0% compared to SL-0.5% and SL-1.0% (P < 0.05). The FR at - 20 and - 60 °C/min maintained higher A^-/PI^- and viable spermatozoa compared to - 10 °C/min. The combination EY-20% and - 60 °C/min showed the highest A^-/PI^- and F (P < 0.05) and the lowest AR, and it did not differ from the combinations EY-20% at - 20 °C/min and SL-2.0% at - 20 °C/min (P > 0.05). In conclusion, the combination EY-20% and - 60 °C/min, showed the best cryoprotective effects on ram spermatozoa. Changes in spermatozoa after thawing were related to the use of the type of extender, the amounts of the same compound in the extender, and the freezing rates to which they were subjected.

Chitosan-functionalized nanostructured lipid carriers containing chloroaluminum phthalocyanine for photodynamic therapy of skin cancer

The objective of this study was to obtain optimized nanostructured lipid carriers (NLC) functionalized with chitosan containing chloroaluminum phthalocyanine (ClAlPc) as a photosensitizer. Initially, the optimization of the preparation method of the NLC was performed, where the influence of different surfactants such as PVA and Tween 80, as well as different solid lipids such as stearic acid and Glycerol Monostearate (GM) was evaluated. The formulation containing GM and PVA (NLC10) was considered promising. Following, by the adsorption method (NLC10q), the formulation was functionalized with chitosan and characterized. NLC10 and NLC10q presented sizes of 131.5 and 231.5 nm, and ZP of -24.30 and + 19.96 mV, respectively. The encapsulation efficiency of NLC10q was 96 %, higher than NLC10 (79 %). The formulations were able to promote significant cutaneous retention of ClAlPc, after 2 h and 4 h of the study, and showed to be non-toxic to fibroblasts (biocompatible). PDT in BF16-F10 melanoma resulted in reduced cell viability to 70 % and 50 % for NLC10 and NLCq, respectively. In view of the results obtained, NLC showed to be promising in the treatment of skin cancer through PDT. NLC10q showed higher encapsulation efficiency and stability than NLC10, but, contrary to what was expected, it presented lower photodynamic efficiency.

Nisin Induces Cell-Cycle Arrest in Free-Living Amoebae Acanthamoeba castellanii

PURPOSE

Acanthamoeba spp. are free-living amoebas with worldwide distribution and play an important role as disease-causing agents in humans. Drug inability to completely eradicate these parasites along with their toxic effects suggest urgent need for new antimicrobials. Nisin is a natural antimicrobial peptide produced by Lactococcus lactis. Nisin is also the only bacteriocin approved for use in food preservation. In this work, we analyzed the effect of nisin on the growth of Acanthamoeba castellanii trophozoites.

METHODS

A total of 8 × 10⁴ trophozoites were exposed to increasing concentrations of nisin to determine its activity. Changes in cell membrane and cellular cycle of trophozoites were investigated by flow cytometry, and nisin cytotoxicity in mammalian cells was evaluated in L929 cells by MTT method.

RESULTS

After 24 h exposure to increasing nisin concentrations, an IC₅₀ of 4493.2 IU mL^-1 was obtained for A. castellanii trophozoites. However, after 72 h a recovery in amoebic growth was observed, and it was no longer possible to determine IC₅₀. Flow cytometry analysis showed that nisin has no effect on the membrane integrity. Treatment with nisin induced cell-cycle arrest during G1 and S phases in A. castellanii trophozoites, which recovered their growth after 72 h.

CONCLUSION

This is one of the first studies showing the effect of internationally approved nisin against A. castellanii trophozoites. Nisin caused cell-cycle arrest in trophozoites, momentarily interfering with the DNA replication process. The data highlight the amoebostatic activity of nisin, and suggest its use as an adjuvant for the treatment of infections caused by Acanthamoeba spp.

Aberrant Phenotypes in Acute Myeloid Leukemia and Its Relationship with Prognosis and Survival: A Systematic Review and Meta-Analysis

Background: The aim of this review was to evaluate the influence of aberrant phenotypes in prognosis and survival in acute myeloid leukemia (AML) patients by multiparametric flow cytometry.

Materials and Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a review of PubMed, Scopus, Science Direct and Web of Science was carried out through 1998 to 2016, conducted by two reviewers independently, evaluating titles, abstracts and full-texts of the selected studies.

Results: Ten studies were included on this review, in which the aberrant phenotype expression of 17 markers were detected in AML patients. From these, 11 aberrant phenotypes were associated with prognosis, which eight had shown negative impact on prognosis: CD7, CD56, CD15, CD2, CD3, CD90^low, CD123^high, CD117^high, and three others were associated with good prognosis: CD19, CD98^high and CD117⁺/CD15⁺. Meta-analysis showed that aberrant expression of CD56 as a poor prognostic marker with unfavorable outcomes is implicated in decreased overall survival in AML patients in 28 months (95% CI: 0.62 to 0.92).

Conclusion: This was observed when there was association between CD56 expression and other prognostic factors, influencing on patients’ management care and treatment.

In situ photocrosslinkable formulation of nanocomposites based on multi-walled carbon nanotubes and formononetin for potential application in spinal cord injury treatment

Carbon nanotubes (CN) have been studied to treat spinal cord injuries because of its electrical properties and nanometric dimensions. This work aims to develop a photopolymerizable hydrogel containing CN functionalized with an anti-inflammatory molecule to be used in situ on spinal cord injuries. The CN functionalization step was done using the drug (formononetin). The nanocomposites were characterized by morphological analysis, FTIR, Raman Spectroscopy, thermal analysis and cytotoxicity assays (MTT and HET-CAM). The nanocomposites were incorporated into gelatin methacryloyl hydrogel and exposed to UV light for photopolymerization. The volume of the formulation and the UV exposition time were also analyzed. The CN characterization showed that formononetin acted as a functionalization agent. The functionalized CN showed safe characteristics and can be incorporated in photocrosslinkable formulation. The UV exposition time for the formulation photopolymerization was compatible with the cell viability and also occurred in the injury site.

Protective effect of carvacrol on acetic acid-induced colitis

The pharmacological therapy for inflammatory bowel diseases continues to be problematic, and requires new alternative options. In this study, we tested the hypothesis that carvacrol (CAR), a phenolic monoterpene with anti-inflammatory and antioxidant activities, can treat experimental colitis in mice. C57BL/6 mice (n=8/group) were subjected to intrarectal administration of acetic acid (5%) to induce colitis. Mice were pretreated with CAR (25, 50 or 100mg/kg, p.o.) every 12h for three days prior to the induction. Abdominal hyperalgesia, macroscopic and microscopic colon damage, myeloperoxidase (MPO) activity, tumor necrosis factor (TNF)-α and interleukin (IL)-1β levels, oxidative stress markers, and antioxidant enzyme activities were evaluated. Pretreatment with all doses of CAR significantly decreased abdominal hyperalgesia and colon MPO activity and TNF-α and IL-1β levels. A reduction in macroscopic and microscopic damage (p<0.05) was observed at doses of 50 and 100mg/kg CAR. Pretreatment with CAR significantly reduced lipid peroxidation (for all doses) and increased sulfhydryl groups (at 100mg/kg). This effect was accompanied by a significant increase in catalase, superoxide dismutase, and glutathione peroxidase activities. These findings indicate that CAR protected mice from acetic acid-induced colitis by reducing inflammatory, nociceptive, and oxidative damages.

F1 Domain of the Leishmania (Leishmania) donovani Nucleoside Hydrolase Promotes a Th1 Response in Leishmania (Leishmania) infantum Cured Patients and in Asymptomatic Individuals Living in an Endemic Area of Leishmaniasis

The Leishmania (Leishmania) donovani nucleoside hydrolase NH36 is the main antigen of the Leishmune® vaccine and one of the promising candidates for vaccination against visceral leishmaniasis. The antigenicity of the N-terminal (F1), the central (F2), or the C-terminal recombinant domain (F3) of NH36 was evaluated using peripheral blood mononuclear cells (PBMC) from individuals infected with L. (L.) infantum from an endemic area of visceral leishmaniasis of Spain. Both NH36 and F1 domains significantly increased the PBMC proliferation stimulation index of cured patients and infected asymptomatic individuals compared to healthy controls. Moreover, F1 induced a 19% higher proliferative response than NH36 in asymptomatic exposed subjects. In addition, in patients cured from visceral leishmaniasis, proliferation in response to NH36 and F1 was accompanied by a significant increase of IFN-γ and TNF-α secretion, which was 42-43% higher, in response to F1 than to NH36. The interleukin 17 (IL-17) secretion was stronger in asymptomatic subjects, in response to F1, as well as in cured cutaneous leishmaniasis after NH36 stimulation. While no IL-10 secretion was determined by F1, a granzyme B increase was detected in supernatants from cured patients after stimulation with either NH36 or F1. These data demonstrate that F1 is the domain of NH36 that induces a recall cellular response in individuals with acquired resistance to the infection by L. (L.) infantum. In addition, F1 and NH36 discriminated the IgG3 humoral response in patients with active visceral leishmaniasis due to L. (L.) donovani (Ethiopia) and L. (L.) infantum (Spain) from that of endemic and non-endemic area controls. NH36 showed higher reactivity with sera from L. (L.) donovani-infected individuals, indicating species specificity. We conclude that the F1 domain, previously characterized as an inducer of the Th1 and Th17 responses in cured/exposed patients infected with L. (L.) infantum chagasi, may also be involved in the generation of a protective response against L. (L.) infantum and represents a potential vaccine candidate for the control of human leishmaniasis alone, or in combination with other HLA epitopes/antigens.

Can the alendronate dosage be altered when combined with high-frequency loading in osteoporosis treatment?

Alendronate therapy has been associated with serious side effects. Altering the alendronate concentration and combining with high-frequency loading as mechanical intervention was explored in this animal study as a treatment for osteoporosis. The bone anabolic potency of high-frequency loading was overruled by the different alendronate dosages applied in the present study. Further exploration of reduced hormonal therapy associated with mechanical interventions in osteoporosis treatment should be sought.

INTRODUCTION

The aim of the present study was to investigate the effect of alendronate (ALN) administration at two different dosages, associated or not with high-frequency (HF) loading, on the bone microstructural response.

METHODS

Sixty-four female Wistar rats were used, of which 48 were ovariectomized (OVX) and 16 were sham-operated (shOVX). The OVX animals were divided into three groups: two groups were treated with alendronate, at a dosage of 2 mg/kg (ALN(₂)) or at a reduced dosage of 1 mg/kg (ALN(₁)) three times per week. A third OVX group did not receive pharmaceutical treatment. All four groups were mechanically stimulated via whole body vibration (WBV) at HF (up to 150 Hz) or left untreated (shWBV). ALN and HF were administered for 6 weeks, starting at 10-week post-(sh)OVX. Tibia bone structural parameters were analyzed using ex vivo microcomputed tomography.

RESULTS

Trabecular bone loss and structural deterioration resulting from ovariectomy were partially restored by ALN administration, demonstrated by the improvement of trabecular patter factor (Tb.Pf), trabecular separation (Tb.Sp), and structure model index (SMI) of the ALN groups compared to that of the OVX group, regardless of the applied dosage [ALN(₂) or ALN(₁)] or mechanical loading regime (shWBV or WBV). However, a significant positive effect of the ALN(₁) administration on trabecular (decrease of Tb.Sp and SMI) and cortical bone (increase of cortical thickness) microarchitecture compared to that of the OVX status group was observed for both loading regimes was not seen for ALN(₂). Furthermore, HF loading resulted in cortical bone changes, with an increased trabeculary area and endocortical perimeter. Finally, the benefits of a combined therapy of ALN with HF loading could not be discerned in the present experimental conditions.

CONCLUSIONS

The bone anabolic potency of HF loading was overruled by the ALN dosages applied in the present study. Further altering the ALN dosage combined with robust mechanical stimuli needs to be considered in osteoporosis research and eventually therapy.

Fas ligand-dependent inflammatory regulation in acute myocarditis induced by Trypanosoma cruzi infection

Fas/Fas ligand (Fas-L) engagement, a potent inducer of apoptosis, is also important for cellular activation, regulation of effector and chemotactic activity, and secretion of chemokines and cytokines. We evaluated the relevance of Fas/Fas-L in the regulation of myocarditis induced by Trypanosoma cruzi infection and observed that in Fas-L(-/-) mice (gld/gld), cardiac infiltration was significantly reduced, accordingly showing less cardiomyocyte destruction. Fluorescence-activated cell sorting analysis of cardiac inflammatory cells showed higher numbers of CD8(+) T cells in BALB/c compared with gld/gld mice but similar levels of lymphocyte function-associated antigen-1, intercellular adhesion molecule, CD2, and CD69 expression; MAC-1(+) myeloid cells and mast cells were increased in BALB/c mice, whereas gld/gld mice exhibited an enrichment of CD4(+/low) T cells. Intracellular labeling of cytokines revealed no clear cardiac skewing of Th1 or Th2 responses, but we found a higher number of interleukin-10(+) cells in gld/gld mice and a deficient expression of vascular cell adhesion molecule-1 on cardiac endothelial cells in gld/gld mice. Finally, we found a population of CD3(+) but CD4/CD8 double negative cardiac T cells in both groups of infected mice, but down-regulation of some adhesion molecules and surface receptors was only observed in gld/gld mice, indicating a targeted T-cell population mostly affected by the lack of Fas-L engagement. These results point to a role for myocarditis regulation by Fas/Fas-L beyond its possible direct relevance in cellular death.