Virulence Profiles of Wild-Type, P.1 and Delta SARS-CoV-2 Variants in K18-hACE2 Transgenic Mice.

Since December 2019, the world has been experiencing the COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and we now face the emergence of several variants. We aimed to assess the differences between the wild-type (Wt) (Wuhan) strain and the P.1 (Gamma) and Delta variants using infected K18-hACE2 mice. The clinical manifestations, behavior, virus load, pulmonary capacity, and histopathological alterations were analyzed. The P.1-infected mice showed weight loss and more severe clinical manifestations of COVID-19 than the Wt and Delta-infected mice. The respiratory capacity was reduced in the P.1-infected mice compared to the other groups. Pulmonary histological findings demonstrated that a more aggressive disease was generated by the P.1 and Delta variants compared to the Wt strain of the virus. The quantification of the SARS-CoV-2 viral copies varied greatly among the infected mice although it was higher in P.1-infected mice on the day of death. Our data revealed that K18-hACE2 mice infected with the P.1 variant develop a more severe infectious disease than those infected with the other variants, despite the significant heterogeneity among the mice.

Virulence profiles of wild-type, P.1 and delta SARS-CoV-2 variants in K18-hACE2 transgenic mice

Since December 2019, the world has been experiencing the COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and we now face the emergence of several variants. We aimed to assess the differences between the wild-type (Wt) (Wuhan) strain and the P.1 (Gamma) and Delta variants using infected K18-hACE2 mice. The clinical manifestations, behavior, virus load, pulmonary capacity, and histopathological alterations were analyzed. The P.1-infected mice showed weight loss and more severe clinical manifestations of COVID-19 than the Wt and Delta-infected mice. The respiratory capacity was reduced in the P.1-infected mice compared to the other groups. Pulmonary histological findings demonstrated that a more aggressive disease was generated by the P.1 and Delta variants compared to the Wt strain of the virus. The quantification of the SARS-CoV-2 viral copies varied greatly among the infected mice although it was higher in P.1-infected mice on the day of death. Our data revealed that K18-hACE2 mice infected with the P.1 variant develop a more severe infectious disease than those infected with the other variants, despite the significant heterogeneity among the mice.

Siringofibroadenoma écrino em paciente tetraplégico por mielite transversa / Eccrine syringofibroadenoma in a patient with quadriplegia following transverse myelitis

O siringofibroadenoma écrino (SFAE) é um tumor benigno raro que se origina das glândulas sudoríparas écrinas. Apresenta predileção pelas extremidades de indivíduos idosos e pode surgir em associação com várias doenças adquiridas ou hereditárias e com afecções cutâneas neoplásicas. Relatamos caso de homem de 48 anos, tetraplégico por mielite transversa há 30 anos, com tumoração plantar rapidamente progressiva de difícil diagnóstico

Eccrine syringofibroadenoma (EFAS) is a rare benign tumor that originates from the eccrine sweat glands. It has a predilection for the extremities of elderly individuals and may arise in association with various acquired or hereditary pathologies and neoplastic skin disorders. We report the case of a 48-year-old man who had been quadriplegic due to transverse myelitis for 30 years, with a rapidly progressive plantar tumor that was difficult to diagnose.

Anti-inflammatory Streptococcus thermophilus CNRZ160 limits sarcopenia induced by low-grade inflammation in older adult rats.

Background and aims: Aging is characterized, at the systemic level, by the development of low-grade inflammation, which has been identified as determining sarcopenia by blunting postprandial muscle anabolism. The causes of this "inflammageing" is still not clearly defined. An increased intestinal permeability, a microbiota dysbiosis and subsequent generation of intestinal then generalized inflammation have been hypothesized. The objective of this study was to test in vivo during aging if (1) a chronic low-grade intestinal inflammation can lead to anabolic resistance and muscle loss and (2) if a bacterial strain presenting anti-inflammatory properties could prevent these adverse effects. Methods: Young adult (6 m) and elderly rats (18 m) received Dextran Sodium Sulfate (DSS) for 28 days to generate low-grade intestinal inflammation, and received (PB1 or PB2 groups) or not (DSS group) one of the two S. Thermophilus strains (5 × 109 CFU/day) previously shown to present an anti-inflammatory potential in vitro. They were compared to pair fed control (PF). Muscle and colon weights and protein synthesis (using 13C Valine) were measured at slaughter. Muscle proteolysis, gut permeability and inflammatory markers were assessed only in old animals by RT-PCR or proteins quantifications (ELISA). Results: In both adult and old rats, DSS reduced absolute protein synthesis (ASR) in gastrocnemius muscle [-12.4% (PB1) and -9.5% (PB2) vs. PF, P < 0.05] and increased ASR in colon (+86% and +30.5%, respectively vs. PF, P < 0.05). PB1 (CNRZ160 strain) but not PB2 resulted in a higher muscle ASR as compared to DSS in adults (+18%, P < 0.05), a trend also observed for PB1 in old animals (+12%, P = 0.10). This was associated with a blunted increase in colon ASR. In old rats, PB1 also significantly decreased expression of markers of autophagy and ubiquitin-proteasome pathways vs. DSS groups and improved gut permeability (assessed by Occludin, Zonula Occludens 1 and Claudin 1 expression, P < 0.05) and alleviated systemic inflammation (A2M: -48% vs. DSS, P < 0.05). Conclusion: The loss of muscle anabolism associated with low-grade intestinal inflammation can be prevented by supplementation with anti-inflammatory CNRZ160 strain. We propose that the moderated gut inflammation by CNRZ160 may result in curtailed amino acids (AA) utilization by the gut, and subsequent restored AA systemic availability to support muscle protein accretion. Therefore, CNRZ160 could be considered as an efficient probiotic to modulate muscle mass loss and limit sarcopenia during aging.

Siringoma condroide: apresentação incomum de tumor raro / Chondroid syringoma: unusual presentation of a rare tumor

O siringoma condroide, também conhecido como tumor misto cutâneo, é uma neoplasia benigna rara, originada das glândulas sudoríparas, composta por estruturas epiteliais imersas em um estroma mixocondroide. Geralmente, apresenta-se como tumor sólido, único, localizado em face ou pescoço, com evolução crônica e assintomática. Relata-se caso de mulher, 75 anos, com lesão discretamente elevada na fronte, cujo diagnóstico foi definido pela análise histopatológica.

Chondroid syringoma, also known as a cutaneous mixed tumor, is a rare benign neoplasm originating from the sweat glands, composed of epithelial structures immersed in a myxochondroid stroma. It usually presents as a solid, single tumor located on the face or neck with a chronic and asymptomatic course. We report the case of a 75-year-old woman with a slightly elevated lesion on the forehead, whose diagnosis was defined by histopathological analysis.

Mutational profile confers increased stability of SARS-CoV-2 spike protein in Brazilian isolates.

Spike (S) protein has been recognized as a promising molecular target for diagnostic, vaccines and antiviral drugs development for COVID-19. In this study, we analyzed the most predominant mutations in the S protein of Brazilian isolates and predicted the effect of these amino acid alterations to protein conformation. A total of 25,924 sequences were obtained from GISAID for five regions of Brazilian territory (Midwest, North, Northeast, South, and Southeast), according to exclusion criteria. Most of the SARS-CoV-2 isolates belongs to the G clade and showed a large occurrence of D614G, N501Y and L18F substitutions. Prediction effects of these amino acid substitutions on the structure dynamics of the spike protein indicated a positive ΔΔG values and negative ΔΔSVib in most cases which is associated to structural stabilization and flexibility reduction of the S protein. Mutations E484K, N501Y and K417N belong to several SARS-CoV-2 variants of concern such as Alpha, Beta, Gamma and Delta, and showed high incidence among Brazilian isolates. These mutations have been described to increase RBD affinity to ACE-2 host and abolishment of RBD affinity to potent neutralizing ant-RBD. The increase in rates of infection and reinfection requires continuous genomic surveillance studies in order to characterize emerging mutations and monitor vaccine efficacy, and thus consideration structural data and dynamics in the observed phenotypes.Communicated by Ramaswamy H. Sarma.

Efficacy of ILIB on periodontal clinical parameters and glycemic control in patients with periodontitis and type II diabetes-randomized clinical trial.

Our study aimed to study the efficacy of ILIB on periodontal parameters and glycemic control in patients with periodontitis and type II diabetes. Twenty-one patients in a randomized clinical trial were divided into 2 groups: control group (CG), conventional periodontal therapy, and test group (TG), conventional periodontal treatment associated with 10 laser applications by the ILIB-Modified (ILIB-M) technique. Fasting blood glucose levels and glycated hemoglobin (HbA1c), visible plaque index (VPI), gingival bleeding index (GBI), and periodontal clinical parameters were evaluated at baseline and after 4 months (T4). Regarding periodontal parameters, the intragroup analysis showed a statistically significant reduction (p < 0.05) between baseline and T4, for the VPI, GBI, BOP, PD, and CAL indexes. However, in the intergroup analysis, no statistically significant improvements (p > 0.05) were observed between the TG and CG for the VPI, GBI, BOP, PD, and CAL indexes. Regarding HbA1C and fasting blood glucose values, no statistically significant improvements were observed in intergroup and intragroup analyses (p > 0.05). The Modified ILIB did not improve the periodontal clinical parameters and glycemic control in patients with type II diabetes.

Efficacy of antimicrobial photodynamic therapy with chloro-aluminum phthalocyanine on periodontal clinical parameters and salivary GSH and MDA levels in patients with periodontitis.

The purpose of this study was to evaluate the efficacy of antimicrobial photodynamic therapy (aPDT) with chloro-aluminum phthalocyanine (AlClPc) on several periodontal parameters includingsalivary glutathione (GSH) and MDA (malondialdehyde) levels in periodontal sites presenting with periodontitis. Randomized clinical trial, comprising 40 test group (TG) sites and 23 control group (CG) sites. The TG was treated with scaling and root planning (SRP) and aPDT, and CG, only with SRP. Visible plaque index [VPI], gingival bleeding index [GBI], bleeding on probing [BOP], probing depth [PD] and clinical attachment level [CAL] were calculated and saliva samples were taken at baseline (T0), three (T3) and six months (T6). Data was analyzed by the Wilcoxon and Mann-Whitney tests. An intragroup analysis indicated significant differences at T3 and T6 for GBI, CAL and GSH only in the CG (p < 0.05). For BOP, a significant decrease was observed only in the TG between T0 and T6 (p = 0.008). No significant differences were observed for VPI, BOP and MDA. In the intergroup analysis, significant differences were observed for GBI at T6 (p = 0.041), and for GSH at T3 (p = 0.031), being higher in the TG. Although aPDT with AlClPc did not present statistically proven benefits, but the employed periodontal treatment resulted in decreased BOP, PD, CAL and MDA after 3 and 6 months of treatment. In addition, the lower need for glutathione production may initially suggest an additional benefit of AlClPc aPDT in the early reestablishment of the balance between oxidative and non-oxidative agents related to oxidative stress.

Biosafety of Non-Return Valves for Infusion Systems in Radiology.

Cross-infection in contrast injectors is still a subject under discussion with little understanding. This study evaluated the biosafety of non-return valves (NRVs). Initially, the maximum pressure during backflow of intact and disrupted flexible diaphragms (FDs) from NRVs, as well as the functionality of connectors with NRVs were verified. The performance of air columns interposed by water in connectors with NRVs was analyzed, and the diffusion distance of crystal violet through connectors with NRVs was measured. The efficacy of NRVs as a barrier to bacterial contamination from backflow was evaluated. Finally, a clinical study of bacteriological contamination from syringes was conducted. There were differences among the maximum tolerated pressure by intact and disrupted FDs. Disrupted FDs showed no failures in the functionality of connectors with NRVs based on the lack of air bubbles released. Air columns could move through connectors with NRVs with intact and disrupted FDs. The longest diffusion distance of crystal violet was 6 cm of connector length, and NRVs showed efficacy as a barrier to bacterial contamination. In the clinical study, there was no bacterial growth in any of the evaluated samples. In conclusion, biosafety depends on the functionality of NRVs as well as proper practical clinical performance.

Oral Health Implications of Bariatric Surgery in Morbidly Obese Patients: An Integrative Review.

BACKGROUND: To identify the implications of bariatric surgery on the oral health of patients with morbid obesity. METHODS: Two reviewers independently performed a search of the electronic databases: MedLine, PubMed, SciELO, LILACS, and Scopus, for clinical trials in humans and cohort studies. The search strategy used was Bariatric Surgery and Oral Health or Mouth Disease and Humans and Periodontitis. A total of 26 articles were obtained, and after title screening and full reading, 8 articles were included in this review. RESULTS: Increased food intake at shorter intervals and increased frequency of regurgitation in these patients were associated with the increased development of dental caries, dental erosion, and increased salivary flow rate. CONCLUSION: Intense oral control is recommended for the prevention and early treatment of these conditions and to avoid nonsystemic effects in these patients.

The effectiveness of photodynamic therapy as a complementary therapy to mechanical instrumentation on residual periodontal pocket clinical parameters: A clinical split-mouth test.

The purpose of this study was to evaluate the effectiveness of photodynamic therapy as complementary therapy to mechanical instrumentation on periodontal residual pockets. This longitudinal, prospective, double-blind and controlled split-mouth clinical trial included one hundred and fourteen residual periodontal sites with probing depth ≥ 4 mm and bleeding on probing, which were distributed into two groups: 57 in the test group (SRP + aPDT) - using a low power laser application Therapy XT (DMC Equipamentos Ltda, São Carlos, São Paulo, Brazil) with operational parameters of 660 nm and 110 mW for 15s, and 57 in the control group (SRP). Oral hygiene conditions were evaluated, through the Visible Plaque Index (VPI) and Gingival Bleeding Index (GBI), as well as periodontal clinical outcomes, comprising the Bleeding on Probing (BOP), Probing Depth (PD) and Clinical Attachment Level (CAL) at baseline and after 3 months. Decrease of 17.74% was observed for the VPI after 3 months of follow-up, while the GBI was reduced by 19.91%, thus indicating statistically significant decreases for both parameters (p < 0.001). Decreases in VPI per site, BOP and PD and CAL gain between T0 and T3 in both treatment groups (p < 0.001) were observed, but no statistically significant intergroup differences were found (p > 0.05). Within the parameters used in this study, adjuvant aPDT to SRP did not lead additional benefits regarding the assessed clinical parameters after three months.

Antimicrobial Photodynamic Therapy Using a Chloro-Aluminum Phthalocyanine Adjuvant to Nonsurgical Periodontal Treatment Does Not Improve Clinical Parameters in Patients with Chronic Periodontitis.

Background and objective: To evaluate the effects of antimicrobial photodynamic therapy (aPDT) with chloro-aluminum phthalocyanine (AlClFc) adjuvant to scaling and root planing (SRP) on periodontal clinical parameters of patients with chronic periodontitis. Materials and methods: Fifty-four periodontal sites were randomly distributed into two groups: 27 in the test group (SRP+aPDT)-using a low-power laser application Photon Lase III (DMC Equipamentos Ltda, São Carlos, São Paulo, Brazil) with operational parameters of 660 nm and 100 mW for 15 sec, and 27 in the control group (SRP). SRP was performed in a single session and the periodontal clinical parameters such as visible plaque index, bleeding on probing (BOP), probing depth (PD), and clinical attachment level were assessed at the baseline (T0) and 3 months after aPDT (T3). Results: Regarding BOP, a decrease in both treatment groups, the test group (p = 0.003) and control group (p = 0.001), was reported between T0 and T3. A reduction in PD and clinical insertion gain for both treatment groups (p < 0.05) after 3 months of therapy was observed, although nonsignificant (p > 0.05) in intergroup comparison. Conclusions: aPDT with AlClFc adjuvant to SRP did not provide additional benefits in reducing PD and clinical insertion gain.

Oral delivery of pancreatitis-associated protein by Lactococcus lactis displays protective effects in dinitro-benzenesulfonic-acid-induced colitis model and is able to modulate the composition of the microbiota.

Antimicrobial peptides secreted by intestinal immune and epithelial cells are important effectors of innate immunity. They play an essential role in the maintenance of intestinal homeostasis by limiting microbial epithelium interactions and preventing unnecessary microbe-driven inflammation. Pancreatitis-associated protein (PAP) belongs to Regenerating islet-derived III proteins family and is a C-type (Ca+2 dependent) lectin. PAP protein plays a protective effect presenting anti-inflammatory properties able to reduce the severity of colitis, preserving gut barrier and epithelial inflammation. Here, we sought to determine whether PAP delivered at intestinal lumen by recombinant Lactococcus lactis strain (LL-PAP) before and after chemically induced colitis is able to reduce the severity in two models of colitis. After construction and characterization of our recombinant strains, we tested their effects in dinitro-benzenesulfonic-acid (DNBS) and Dextran sulfate sodium (DSS) colitis model. After the DNBS challenge, mice treated with LL-PAP presented less severe colitis compared with PBS and LL-empty-treated mice groups. After the DSS challenge, no protective effects of LL-PAP could be detected. We determined that after 5 days administration, LL-PAP increase butyrate producer's bacteria, especially Eubacterium plexicaudatum. Based on our findings, we hypothesize that a treatment with LL-PAP shifts the microbiota preventing the severity of colon inflammation in DNBS colitis model. These protective roles of LL-PAP in DNBS colitis model might be through intestinal microbiota modulation.

Atypical clinical presentation of visceral leishmaniasis: a rare case without splenomegaly.

Clinical manifestations of visceral leishmaniasis (VL) usually include splenomegaly. We report a case of a woman from an endemic area with fever but normal splenic size. This is rare, especially in patients not immunocompromised.

Heat-induced extracellular HSP72 release is blunted in elderly diabetic people compared with healthy middle-aged and older adults, but it is partially restored by resistance training.

Recent evidence suggests that the anti-inflammatory heat shock response (HSR) is reduced in aging and diabetes. In this study we compared HSR between healthy middle-aged adults, healthy elderly and type 2 diabetic (T2DM) elderly, and tested whether resistance training (RT) could improve the HSR in T2DM group. Thirty sedentary participants volunteered for this study. HSR (assessed as the capacity to export HSP72 during heat stress) was measured in the blood and compared between the groups. HSR was similar between healthy middle-aged and healthy elderly volunteers, but diminished in elderly T2DM (p < 0.001). Hence, T2DM subjects (n = 12) were submitted to a 12-week RT program, because exercise is a physiological HSR inducer. HSR, cytokines, metabolic parameters and visceral adipose tissue (VAT) were measured before and after the RT. Remarkably, VAT was negatively correlated with HSR (r = - 0.49, p < 0.01) while RT improved the HSR and reduced inflammation [TNF-α: from 51.5 ±â€¯9 to 40.7 ±â€¯4 pg/mL and TNF-α/IL-10 ratio: from 1.55 ±â€¯0.3 to 1.16 ±â€¯0.2 (p < 0.001)], without affecting other parameters. All together, these findings confirm the hypothesis that the anti-inflammatory HSR is depressed in elderly diabetic people, but can be partially restored by RT.

Biossegurança: avaliação da eficácia de válvulas antirrefluxo em sistemas de infusão na radiologia / Biosafety: efficacy evaluation of non-return valves in infusion systems in radiology

Na radiologia, válvulas antirrefluxo (VARs) são utilizadas em tubos de infusão para realização de exames de ressonância magnética e tomografia computadorizada. O objetivo desta pesquisa foi investigar procedimentos associados ao uso de VARs em exames radiológicos, a fim de contribuir para a biossegurança, controles da contaminação e do risco de infecção em sistemas de infusão. Uma Revisão Integrativa (RI) a respeito das VARs utilizadas na área da saúde foi realizada no que concerne os aspectos físicos, de funcionalidade e microbiológicos. A pressão máxima, em contra fluxo, dos diafragmas flexíveis (DFs) íntegros e rompidos das VARs foi determinada com auxílio do equipamento Hydraulic Burst-Leak Tester (HB-LT). A funcionalidade das VARs foi verificada por inspeção visual, em contra fluxo, mediante a liberação de bolhas de ar em um recipiente com água, por meio de simulação artificial da pressão da corrente sanguínea humana (SAPCSH). A estrutura e integridade das VARs foram identificadas por inspeção visual. A performance de colunas de ar interpostas por água em conectores com VARs foi analisada por inspeção visual (SAPCSH). A distância da difusão de um contaminante (cristal violeta) através de conectores com VARs foi mensurado por inspeção visual e espectrofotômetro (SAPCSH). A eficácia das VARs, em contra fluxo, como barreira de contaminação bacteriana foi avaliada em um experimento bacteriológico (SAPCSH). Um procedimento operacional padrão (POP) foi elaborado para direcionar a prática adequada do manuseio dos conectores com VARs, visando a biossegurança, controles da contaminação e do risco de infeção em sistemas de infusão em radiologia. Os resultados demostraram que houve diferença entre as pressões máximas suportadas pelos DFs dos Patient-set®: íntegros (média e desvio padrão: 595,44 ± 39,38psi) e rompidos (média e desvio padrão: 90,22 ± 31,26psi), em contra fluxo (p<0,0001). Por outro lado, os Patient-set® com os DFs rompidos não demonstraram falha na funcionalidade das VARs, mediante a ausência da liberação de bolhas de ar. Ainda, as VARs dos Patient-set® demonstraram DFs rompidos, entretanto as outras estruturas continuaram íntegras. As colunas de ar podem ser comprimidas e se deslocar através dos Patient-set® com DFs íntegros e rompidos. Além disso, a maior distância de difusão do cristal violeta foi de 30% (6cm) do comprimento do conector (20cm) do Patient-set®. Outrossim, a técnica de mensuração por espectrofotômetro (absorbância) foi mais sensível do que por inspeção visual para esse propósito. As VARs dos Patient-set® mostraram eficácia como barreira de contaminação bacteriana (Staphylococcus aureus resistente à meticilina, 10psi por 2h30min). Ademais, um POP foi elaborado e validado para a utilização e manuseio dos Patient-set®, visando a biossegurança na prática clínica, controles da contaminação e do risco de infecção em sistemas de infusão em radiologia como recomendação original a ser disponibilizada a todos os profissionais da área. Em suma, a biossegurança dos sistemas de infusão na radiologia depende de vários aspectos físico, de funcionalidade e microbiológico das VARs atrelados à execução adequada na prática clínica. Além disso, pesquisas adicionais são necessárias para elucidar questionamentos futuros sobre o uso seguro das VARs

In radiology, non-return valves (NRV) are used in infusion tubes to perform magnetic resonance imaging and computed tomography scan exams. The objective of this research was to investigate procedures associated to NRV usage in radiologic exams, in order to contribute to biosafety, contamination and infection risk controls in infusion systems. An Integrative Review (IR) about NRVs utilized in health field was performed concerning physical, functionality, and microbiological aspects. The maximum pressure, in backflow, of whole and broken flexible diaphragms (FDs) from NRVs was determined with Hydraulic Burst-Leak Tester (HB-LT) equipment help. The NRVs functionality was verified by visual inspection, in backflow, by means of air bubbles release in a water container, through human bloodstream pressure artificial simulation (HBPAS). The NRVs structure and integrity were identified by visual inspection. The performance of air columns interposed by water in connectors with NRVs was analyzed by visual inspection (HBPAS). Diffusion distance of a contaminant (crystal violet) through connectors with NRVs was measured by visual inspection and spectrophotometer (HBPAS). The NRVs efficacy, in backflow, as barrier to bacterial contamination was evaluated in a bacteriological experiment (HBPAS). A standard operating procedure (SOP) was elaborated to direct the proper handling of connectors with NRVs, aiming at biosafety, contamination and infection risk controls in infusion systems in radiology. The results showed that there was difference among maximum tolerated pressures by FDs of Patient-set®: whole (mean and standard deviation: 595.44 ± 39.38psi) and broken (mean and standard deviation: 90.22 ± 31.26psi), in backflow (p<0.0001). On the other hand, the Patient-set® with broken FDs didn't show failure in NRVs functionality, through the lack of air bubbles release. Moreover, NRVs showed broken FDs, but the other structures remained whole. The air columns can be compressed and move through Patient-set® with whole and broken FDs. Besides, the longest diffusion distance of crystal violet was 30% (6cm) of connector length (20cm) of Patient-set®. Furthermore, the measure technique by spectrophotometer (absorbance) was more sensitive than by visual inspection for this purpose. Patientset® NRVs showed efficacy as barrier to bacterial contamination (Methicillin-resistant Staphylococcus aureus, 10psi for 2h30min). Moreover, a SOP was elaborated and validated for Patient-set® utilization and handling, aiming at biosafety in clinical practice, contamination and infection risk controls in infusion systems in radiology as original recommendation to be made available to all professionals in the field. In conclusion, the biosafety depends on various physical, functionality, and microbiological aspects of NRVs coupled with proper practical clinical performance. Besides, further researches are needed to elucidate future questionings about NRVs safe use