Effects of Modified Glucosamine on the Chondrogenic Potential of Circulating Stem Cells under Experimental Inflammation.

Glucosamine (GlcN) is a glycosaminoglycan (GAGs) constituent in connective tissues. It is naturally produced by our body or consumed from diets. In the last decade, in vitro and in vivo trials have demonstrated that the administration of GlcN or its derivates has a protective effect on cartilage when the balance between catabolic and anabolic processes is disrupted and cells are no longer able to fully compensate for the loss of collagen and proteoglycans. To date, these benefits are still controversial because the mechanism of action of GlcN is not yet well clarified. In this study, we have characterized the biological activities of an amino acid (AA) derivate of GlcN, called DCF001, in the growth and chondrogenic induction of circulating multipotent stem cells (CMCs) after priming with tumor necrosis factor-alpha (TNFα), a pleiotropic cytokine commonly expressed in chronic inflammatory joint diseases. In the present work, stem cells were isolated from the human peripheral blood of healthy donors. After priming with TNFα (10 ng/mL) for 3 h, cultures were treated for 24 h with DCF001 (1 µg/mL) dissolved in a proliferative (PM) or chondrogenic (CM) medium. Cell proliferation was analyzed using a Corning® Cell Counter and trypan blue exclusion technique. To evaluate the potentialities of DCF001 in counteracting the inflammatory response to TNFα, we measured the amount of extracellular ATP (eATP) and the expression of adenosine-generating enzymes CD39/CD73, TNFα receptors, and NF-κB inhibitor IκBα using flow cytometry. Finally, total RNA was extracted to perform a gene expression study of some chondrogenic differentiation markers (COL2A1, RUNX2, and MMP13). Our analysis has shed light on the ability of DCF001 to (a) regulate the expression of CD39, CD73, and TNF receptors; (b) modulate eATP under differentiative induction; (c) enhance the inhibitory activity of IκBα, reducing its phosphorylation after TNFα stimulation; and (d) preserve the chondrogenic potentialities of stem cells. Although preliminary, these results suggest that DCF001 could be a valuable supplement for ameliorating the outcome of cartilage repair interventions, enhancing the efficacy of endogenous stem cells under inflammatory stimuli.

The kinesin Eg5 inhibitor K858 exerts antiproliferative and proapoptotic effects and attenuates the invasive potential of head and neck squamous carcinoma cells.

Our group recently demonstrated that K858, an inhibitor of motor kinesin Eg5, has important antiproliferative and apoptotic effects on breast cancer, prostatic cancer, melanoma and glioblastoma cells. Since high levels of kinesin Eg5 expression have been correlated with a poor prognosis in laryngeal carcinoma, we decided to test the anticancer activity of K858 toward this tumor, which belongs to the group of head and neck squamous cell carcinomas (HNSCCs). These cancers are characterized by low responsiveness to therapy. The effects of K858 on the proliferation and assembly of mitotic spindles of three human HNSCC cell lines were studied using cytotoxicity assays and immunofluorescence for tubulin. The effect of K858 on the cell cycle was analyzed by FACS. The expression levels of cyclin B1 and several markers of apoptosis and invasion were studied by Western blot. Finally, the negative regulation of the malignant phenotype by K858 was evaluated by an invasion assay. K858 inhibited cell replication by rendering cells incapable of developing normal bipolar mitotic spindles. At the same time, K858 blocked the cell cycle in the G2 phase and induced the accumulation of cytoplasmic cyclin B and, eventually, apoptosis. Additionally, K858 inhibited cell migration and attenuated the malignant phenotype. The data described confirm that kinesin Eg5 is an interesting target for new anticancer strategies and suggest that this compound may be a powerful tool for an alternative therapeutic approach to HNSCCs.

Biochemical Functions and Clinical Characterizations of the Sirtuins in Diabetes-Induced Retinal Pathologies.

Diabetic retinopathy (DR) is undoubtedly one of the most prominent causes of blindness worldwide. This pathology is the most frequent microvascular complication arising from diabetes, and its incidence is increasing at a constant pace. To date, the insurgence of DR is thought to be the consequence of the intricate complex of relations connecting inflammation, the generation of free oxygen species, and the consequent oxidative stress determined by protracted hyperglycemia. The sirtuin (SIRT) family comprises 7 histone and non-histone protein deacetylases and mono (ADP-ribosyl) transferases regulating different processes, including metabolism, senescence, DNA maintenance, and cell cycle regulation. These enzymes are involved in the development of various diseases such as neurodegeneration, cardiovascular pathologies, metabolic disorders, and cancer. SIRT1, 3, 5, and 6 are key enzymes in DR since they modulate glucose metabolism, insulin sensitivity, and inflammation. Currently, indirect and direct activators of SIRTs (such as antagomir, glycyrrhizin, and resveratrol) are being developed to modulate the inflammation response arising during DR. In this review, we aim to illustrate the most important inflammatory and metabolic pathways connecting SIRT activity to DR, and to describe the most relevant SIRT activators that might be proposed as new therapeutics to treat DR.

Design, Synthesis and Biological Evaluation of New Pyrimidine Derivatives as Anticancer Agents.

BACKGROUND: Anticancer drug resistance is a challenging phenomenon of growing concern which arises from alteration in drug targets. Despite the fast speed of new chemotherapeutic agent design, the increasing prevalence of this phenomenon requires further research and treatment development. Recently, we reported a new aminopyrimidine compound-namely RDS 344-as a potential innovative anticancer agent. METHODS: Herein, we report the design, synthesis, and anti-proliferative activity of new aminopyrimidine derivatives structurally related to RDS 3442 obtained by carrying out substitutions at position 6 of the pyrimidine core and/or on the 2-aniline ring of our hit. The ability to inhibit cell proliferation was evaluated on different types of tumors, glioblastoma, triple-negative breast cancer, oral squamous cell carcinomas and colon cancer plus on human dermal fibroblasts chosen as control of normal cells. RESULTS: The most interesting compound was the N-benzyl counterpart of RDS 3442, namely 2a, that induced a significant decrease in cell viability in all the tested tumor cell lines, with EC50s ranging from 4 and 8 µM, 4-13 times more active of hit. CONCLUSIONS: These data suggest a potential role for this class of molecules as promising tool for new approaches in treating cancers of different histotype.

Discovery of a pyrimidine compound endowed with antitumor activity.

Recently, some synthetic nitrogen-based heterocyclic molecules, such as PJ34, have shown pronounced antitumor activity. Therefore, we designed and synthesized new derivatives characterized by a nitrogen-containing scaffold and evaluated their antiproliferative properties in tumor cells. We herein report the effects of three newly synthesized compounds on cell lines from three different human cancers: triple-negative breast cancer, colon carcinoma and glioblastoma. We found that two of these compounds did not affect proliferation, while the third significantly inhibited replication of the three cell lines. Moreover, this third molecule at 20 µM led to the upregulation of p21 and p27 and blockage of the cell cycle at G0/G1; in addition, it induced apoptosis in all three cell lines when used at higher concentrations (30-50 µM). The results demonstrate that this compound is a potent inhibitor of replication, an inducer of apoptosis and a negative regulator of cell cycle progression for cancer cells of different histotypes. Our data suggest a potential role for this new molecule as an interesting and powerful tool for new approaches in treating various cancers.

Osteopontin in vitreous and idiopathic epiretinal membranes.

PURPOSE: To investigate osteopontin (OPN) expression in vitreous and in related idiopathic epiretinal membranes (ERMs), with respect to VEGF-A, IL8, MIP1α, IL6, and IL33, and correlate OPN expression with disease staging. METHODS: Fifteen (15) vitreous and allied ERMs were collected at the time of therapeutic vitreoretinal surgery. Additional 5 vitreous and 10 ERMs (historical collection) were used. Biochemical and molecular analysis of OPN was performed in clear vitreous, vitreal pelleted cells, and ERMs. Double-immunofluorescence analysis (OPN - GFAP and OPN - αSMA) was performed on paraffin and whole-mounted ERMs. Vitreal OPN levels were correlated to those of VEGF-A, IL8, MIP1α, IL6, and IL33. RESULTS: High OPN levels were observed in vitreal samples, and OPN transcripts were amplified in vitreal cells and related ERMs. OPN immunoreactivity was found in ERMs, mainly in GFAP-bearing (Muller cells) and to a less extend in αSMA-expressing (myofibroblasts) cells. OPN levels were highest at early stages of ERM formation and positively correlated to VEGF-A and MIP1α. CONCLUSIONS: High OPN levels in vitreous, OPN transcripts in vitreal cells/ERMs, OPN immunoreactivity in activated Müller cells and contractile myofibroblasts, as well as the correlation with VEGF-A and MIP1α fulfill the potential involvement of OPN in both inflammation and tissue remodeling that takes part in vitreoretinal interface disorders. The highest OPN levels at early stages of ERM formation would prospect OPN as a potential biomarker for disease severity.

Age related changes seen in human cornea in formalin fixed sections and on biomicroscopy in living subjects: A comparison.

The purpose of our experimental research was to assess the effects of aging on the main corneal structures in healthy corneas. Small, human cornea samples were collected from 20 Caucasian subjects during surgery for traumatic lesions to the eye. Ten subjects were adults (mean age 28 years) and 10 were elderly (mean age 76 years). Morphological analysis was carried out using light microscopy and electron microscopy. Another 40 patients (20 young: mean age < 30 years; 20 elderly: mean age > 70 years) were studied in vivo by confocal microscopy. The resulting images were analyzed qualitatively, quantitatively, and statistically. The basic light microscope revealed a decrease in endothelial cell density with age accompanied by an increase in endothelial cell size. Transmission electron microscopy revealed a corneal thinning and a decrease in the number of corneal stromal cells. A marked decrease in stromal nerve fibers was observed in the older subjects compared to the younger ones. Variable pressure scanning electron microscopy (VP-SEM) was used to make surface morphological observations and to determine the chemical composition of in vivo hydrated human corneas. Our results showed the effects of aging on normal corneal morphology highlighting the structural diversity of the corneal layers and revealing an age-related reduction in nerve fibers, thus explaining the decreased corneal sensitivity that may be observed in the elderly. Clin. Anat. 33:245-256, 2020. © 2019 Wiley Periodicals, Inc.

Role of parnaparin in atherosclerosis.

Atherosclerosis is characterized by a proliferation of vascular smooth muscle cells (VSMCs) and their migration to the intima, which induces thickening of the intima itself, but the mechanism remains poorly understood. Low molecular weight heparin (LMWH) inhibits the proliferation of VSMCs. Previous studies have shown that a LMWH, parnaparin (PNP), acts on the processes of atherogenesis and atheroprogression in experimental animal models. The aim of this study was to investigate the involvement of oxidative stress, inflammation and VSMCs in the regulation of vascular wall homeostasis. We also considered the possibility of restoring vascular pathological changes using PNP treatment. In order to evaluate vascular remodelling in this study we have analysed the morphological changes in aortas of an animal model of atherosclerosis, apolipoprotein E-deficient mice (ApoE-/-) fed with a normal or a western diet without treatment or treated with PNP. We also analysed, by immunohistochemistry, the expression of proteins linked to atherogenesis and atheroprogression - an enzyme involved in oxidative stress, iNOS, examples of inflammatory mediators, such as tumour necrosis factor alpha (TNF-α), interleukins 1 and 6 (IL-1 and IL-6), and markers of VSMC changes, in particular plasminogen activator inhibitor-1 and thrombospondin-1 (PAI-1 and TSP-1). Our results could suggest that PNP downregulates VSMC proliferation and migration, mediated by PAI-1 and TSP-1, and reduces inflammation and oxidative stress in vessels. These data suggested that LMWH, in particular PNP, could be a theoretically practical tool in the prevention of atherosclerotic vascular modification.

Age and diabetes related changes of the retinal capillaries: An ultrastructural and immunohistochemical study.

Normal human aging and diabetes are associated with a gradual decrease of cerebral flow in the brain with changes in vascular architecture. Thickening of the capillary basement membrane and microvascular fibrosis are evident in the central nervous system of elderly and diabetic patients. Current findings assign a primary role to endothelial dysfunction as a cause of basement membrane (BM) thickening, while retinal alterations are considered to be a secondary cause of either ischemia or exudation. The aim of this study was to reveal any initial retinal alterations and variations in the BM of retinal capillaries during diabetes and aging as compared to healthy controls. Moreover, we investigated the potential role of vascular endothelial growth factor (VEGF) and pro-inflammatory cytokines in diabetic retina.Transmission electron microscopy (TEM) was performed on 46 enucleated human eyes with particular attention to alterations of the retinal capillary wall and Müller glial cells. Inflammatory cytokines expression in the retina was investigated by immunohistochemistry.Our electron microscopy findings demonstrated that thickening of the BM begins primarily at the level of the glial side of the retina during aging and diabetes. The Müller cells showed numerous cytoplasmic endosomes and highly electron-dense lysosomes which surrounded the retinal capillaries. Our study is the first to present morphological evidence that Müller cells start to deposit excessive BM material in retinal capillaries during aging and diabetes. Our results confirm the induction of pro-inflammatory cytokines TNF-α and IL-1ß within the retina as a result of diabetes.These observations strongly suggest that inflammatory cytokines and changes in the metabolism of Müller glial cells rather than changes in of endothelial cells may play a primary role in the alteration of retinal capillaries BM during aging and diabetes.

Involvement of pro-inflammatory cytokines and growth factors in the pathogenesis of Dupuytren's contracture: a novel target for a possible future therapeutic strategy?

Dupuytren's contracture (DC) is a benign fibro-proliferative disease of the hand causing fibrotic nodules and fascial cords which determine debilitating contracture and deformities of fingers and hands. The present study was designed to characterize pro-inflammatory cytokines and growth factors involved in the pathogenesis, progression and recurrence of this disease, in order to find novel targets for alternative therapies and strategies in controlling DC. The expression of pro-inflammatory cytokines and of growth factors was detected by immunohistochemistry in fibrotic nodules and normal palmar fascia resected respectively from patients affected by DC and carpal tunnel syndrome (CTS; as negative controls). Reverse transcription (RT)-PCR analysis and immunofluorescence were performed to quantify the expression of transforming growth factor (TGF)-ß1, interleukin (IL)-1ß and vascular endothelial growth factor (VEGF) by primary cultures of myofibroblasts and fibroblasts isolated from Dupuytren's nodules. Histological analysis showed high cellularity and high proliferation rate in Dupuytren's tissue, together with the presence of myofibroblastic isotypes; immunohistochemical staining for macrophages was completely negative. In addition, a strong expression of TGF-ß1, IL-1ß and VEGF was evident in the extracellular matrix and in the cytoplasm of fibroblasts and myofibroblasts in Dupuytren's nodular tissues, as compared with control tissues. These results were confirmed by RT-PCR and by immunofluorescence in pathological and normal primary cell cultures. These preliminary observations suggest that TGF-ß1, IL-1ß and VEGF may be considered potential therapeutic targets in the treatment of Dupuytren's disease (DD).

Psychophysical, electrofunctional, and morphological evaluation in naïve neovascular AMD patients treated with intravitreal anti-VEGF.

Objectives: The aim of this study was to investigate the retinal morpho-functional characteristics of patients with neovascular wet age-related macular degeneration (nAMD) treated with intravitreal injection (IV) of aflibercept (AFL). Methods: The study was conducted on 35 patients previously diagnosed with type 1 nAMD who received a fixed-dosing regimen of aflibercept injections over 12 months. The goal was to assess trends in visual abilities over time by measuring visual acuity (VA), contrast sensitivity (CS), visual evoked potentials (VEPs), and spectral domain-optical coherence tomography (SD-OCT). The same psychophysical, electro-functional, and morphological tests administered at baseline (T0) were repeated 4 to 8 weeks after the last aflibercept injection (Tn), resulting in a total of six examinations. Results: At Tn, all subjects exhibited improved VA for both far and near distances compared to values detected at T0. Similarly, VEP amplitude and latency values at Tn showed a greater P100 improvement than those observed at T0. Additionally, the CS examination at Tn demonstrated improvement, particularly at high spatial stimulation frequencies. The Tn SD-OCT results highlighted a reduction in macular thickness compared to T0 values. Conclusions: This exploratory research indicates that intravitreal injections of AFL, following a fixed-dosing regimen, represent a valuable therapeutic approach for enhancing visual performance. This conclusion is supported by comprehensive statistical analysis of psychophysical, electro-functional, and morphological examinations within the same group of patients with nAMD, as demonstrated for the first time.

Cerebral Vasospasm: Practical Review of Diagnosis and Management.

BACKGROUND: Cerebral vasospasm is one of the frequent complications that can occur following subarachnoid hemorrhage (SAH). With new protocols in the management of SAH, the combined risk of death and long-term disability have been reduced by about 10% compared with the past. OBJECTIVE: This work aims to report the latest updates on the vasospasm developing after the SAH in patients in the ICU department. In this short review, we reviewed the latest scientific findings on the mechanisms of vasospasm, and in addition, we considered it necessary to review the literature to report the tools for early diagnosis of vasospasm and the best treatment strategies to prevent the negative outcome in patients admitted to ICU. AIM: The aim of this narrative review is to report the main characteristics of vasospasm, new diagnostic methods, and, especially, more effective treatment of vasospasm. MATERIALS AND METHODS: The peer-reviewed articles analyzed were selected from PubMed, Google scholar, Embase, and Scopus databases published in the previous 20 years using the keywords "vasospasm", "vasospasm diagnosis", "vasospasm and SAH", "vasospasm treatment", and nontraumatic brain injury. Among the 78 papers identified, 43 articles were selected; after the title - abstract examination and removing the duplicates, only 31 articles were examined. RESULTS: Vasospasm can be classified according to clinical (asymptomatic vs. symptomatic) and diagnostic (angiographic vs. ultrasound) methods. Various procedures such as TCD and CT perfusion are used for early diagnosis and close monitoring of this condition. The treatment of vasospasm consists of both prevention (nimodipine, statitis, and magnesium sulphate) and active treatment (mainly endovascular). CONCLUSION: As the review shows, vasospasm is a complication of SAH, a complication that is difficult to recognize early and treat with the best outcome. However, with the equipment we have, it has been possible to improve the outcome, even if it is still not ideal, in patients who develop vasospasm. Several studies are in the final stages to improve the outcome of this unfortunately frequent condition.

Petroclival Clinoidal Folds and Arachnoidal Membranes of the Anteromedial Incisural Space: Clinical Anatomy for Neuro Critical Care.

A systematic and narrative literature review was performed, focusing attention on the anatomy of the area located at the junction of the sphenoid and the basal portion of the temporal bone (petrous bone, petrous apex, upper petro-clival region) encircled by the free edge of the tentorium, the insertion of the tentorium itself to the petrous apex and the anterior and posterior clinoid processes that give rise to three distinct dural folds or ligaments: the anterior petroclinoid ligament, the posterior petroclinoid ligament and the interclinoid ligament. These dural folds constitute the posterior portion of the roof of the cavernous sinus denominated "the oculomotor triangle". The main purpose of this review study was to describe this anatomical region, particularly in the light of the relationships between the anterior margin of the free edge of the tentorium and the above-mentioned components of the sphenoid and petrous bone.

Pyrrolyl and Indolyl α-γ-Diketo Acid Derivatives Acting as Selective Inhibitors of Human Carbonic Anhydrases IX and XII.

Solid tumors are active tissues containing hypoxic regions and producing metabolic acids. By decreasing pH, cancer cells create a hostile environment for surrounding host cells and foster tumor growth and progression. By governing acid/base regulation, carbonic anhydrases (CAs) are involved in several physiological/pathological processes, including tumors. Indeed, CAs are clinically relevant in cancer therapy as among the fifteen human isoforms, two of them, namely CA IX (overexpressed in solid tumors and associated with increased metastasis and poor prognosis) and CA XII (overexpressed in some tumors) are involved in tumorigenesis. Targeting these two isoforms is considered as a pertinent approach to develop new cancer therapeutics. Several CA inhibitors (CAIs) have been described, even though they are unselective inhibitors of different isoforms. Thus, efforts are needed to find new selective CAIs. In this work, we described new diketo acid derivatives as CAIs, with the best acting compounds 1c and 5 as nanomolar inhibitors of CA IX and XII, being also two orders of magnitude selective over CAs I and II. Molecular modeling studies showed the different binding poses of the best acting CAIs within CA II and IX, highlighting the key structural features that could confer the ability to establish specific interactions within the enzymes. In different tumor cell lines overexpressing CA IX and XII, the tested compounds showed antiproliferative activity already at 24 h treatment, with no effects on somatic not transformed cells.

Complement Mediators in Development to Treat Age-Related Macular Degeneration.

Over recent years, great attention has been paid to the role of the complement system in the pathogenesis of age-related macular degeneration (AMD). In particular, several studies have highlighted a link between AMD development and complement dysregulation, which can probably be explained as a complement cascade hyperactivation resulting from the presence of a series of risk factors such as aging; smoking; obesity; alcohol consumption; exposure to pesticides, industrial chemicals, or pollution; and other causes of oxidative stress. This hypothesis has been mainly supported by the presence of complement mediators as constituents of drusen, representing one of the earliest and most characteristic signs of retinal damage in AMD. Additionally, activated complement mediators and some complement regulators, such as vitronectin, have been found not only in the drusen and adjacent retinal areas but also in the peripheral blood of patients with AMD. Therefore, we aim to provide a review of recently studied complement factors to highlight their role in the pathogenesis of AMD and to evaluate new potential therapeutic strategies.

Cellular Immuno-Profile in Septic Human Host: A Scoping Review.

Innate and adaptive immune system cells play a critical role in the host response to sepsis. Sepsis is a life-threatening disease characterized by apoptosis-induced depletion of immune cells and immunodepression, which contribute to morbidity and mortality. Many alterations in the expression of surface markers of neutrophils and monocytes have been described in septic patients. The aim of this study was to inspect the recently published literature to inform the clinician about the most up-to-date techniques for the study of circulating leukocytes. The impact on cell phenotypes and on the function of leukocytes of extracorporeal and non-blood purification treatments proposed for sepsis were also analyzed. We conducted a systematic review using Pubmed/Medline, Ovid/Willey, the Cochrane Library, the Cochrane Controlled Trials Register, and EMBASE, combining key terms related to immunological function in sepsis and selected the most relevant clinical trials and review articles (excluding case reports) published in the last 50 years. The most important alteration in neutrophils during sepsis is that they activate an anti-apoptotic survival program. In septic monocytes, a reduced characteristic expression of HLA-DR is observed, but their role does not seem to be significantly altered in sepsis. As regards adaptive immunity, sepsis leads to lymphopenia and immunosuppression in patients with septic shock; this process involves all types of T cells (CD4, CD8 and Natural Killer), except for regulatory T cells, which retain their function. Several promising therapies that target the host immune response are currently under evaluation. During the worldwide pandemic caused by SARS-CoV-2, it was useful to study the "cytokine storm" to find additional treatments, such as the oXiris® filter. This therapy can decrease the concentration of inflammatory markers that affect the severity of the disease.

Oxidative Stress Implication in Retinal Diseases-A Review.

Oxidative stress (OS) refers to an imbalance between free radicals (FRs), namely highly reactive molecules normally generated in our body by several pathways, and intrinsic antioxidant capacity. When FR levels overwhelm intrinsic antioxidant defenses, OS occurs, inducing a series of downstream chemical reactions. Both reactive oxygen species (ROS) and reactive nitrogen species (RNS) are produced by numerous chemical reactions that take place in tissues and organs and are then eliminated by antioxidant molecules. In particular, the scientific literature focuses more on ROS participation in the pathogenesis of diseases than on the role played by RNS. By its very nature, the eye is highly exposed to ultraviolet radiation (UVR), which is directly responsible for increased OS. In this review, we aimed to focus on the retinal damage caused by ROS/RNS and the related retinal pathologies. A deeper understanding of the role of oxidative and nitrosative stress in retinal damage is needed in order to develop targeted therapeutic interventions to slow these pathologies.

Oxidative stress and visual system: a review.

Different types of tissues respond differently to the action of oxidative stress. The visual system is very sensitive to oxidative action due to continuous exposure to light. In consideration of the growing interest of scientific studies towards various compounds endowed with antioxidant and anti-inflammatory properties, we performed a review of the literature focusing on the use of some antioxidant molecules for the treatment of conditions affecting the visual system. In this study, we focused on the ability of two antioxidant agents, the small molecule α-lipoic acid (ALA) and the enzyme superoxide dismutase (SOD), to influence the neurodegenerative physiological processes related to aging and oxidative stress affecting the ocular segment. The literature data report that ALA and SOD can protect against neurodegenerative effects both the optic nerve and retina and, if administered together, they are able to lower the levels of oxidative stress, thus preventing neurodegeneration and reducing the apoptotic process.

A proposal for the reference intervals of the Italian microbiota "scaffold" in healthy adults.

Numerous factors, ranging from genetics, age, lifestyle, and dietary habits to local environments, contribute to the heterogeneity of the microbiota in humans. Understanding the variability of a "healthy microbiota" is a major challenge in scientific research. The gut microbiota profiles of 148 healthy Italian volunteers were examined by 16S rRNA gene sequencing to determine the range and diversity of taxonomic compositions in the gut microbiota of healthy populations. Possible driving factors were evaluated through a detailed anamnestic questionnaire. Microbiota reference intervals were also calculated. A "scaffold" of a healthy Italian gut microbiota composition was identified. Differences in relative quantitative ratios of microbiota composition were detected in two clusters: a bigger cluster (C2), which included 124 subjects, was characterized by more people from the northern Italian regions, who habitually practised more physical activity and with fewer dietary restrictions. Species richness and diversity were significantly higher in this cluster (C2) than in the other one (C1) (C1: 146.67 ± 43.67; C2: 198.17 ± 48.47; F = 23.40; P < 0.001 and C1: 16.88 ± 8.66; C2: 35.01 ± 13.40; F = 40.50; P < 0.001, respectively). The main contribution of the present study was the identification of the existence of a primary healthy microbiological framework that is only marginally affected by variations. Taken together, our data help to contextualize studies on population-specific variations, including marginal aspects, in human microbiota composition. Such variations must be related to the primary framework of a healthy microbiota and providing this perspective could help scientists to better design experimental plans and develop strategies for precision tailored microbiota modulation.

Oxidative Stress and Inflammation Biomarker Expression in Obstructive Sleep Apnea Patients.

Obstructive Sleep Apnea Syndrome (OSAS) is a respiratory sleep disorder characterised by repeated episodes of partial or complete obstruction of the upper airway during the night. This obstruction usually occurs with a reduction (hypopnea) or complete cessation (apnea) of the airflow in the upper airways with the persistence of thoracic-diaphragmatic respiratory movements. During the hypopnea/apnea events, poor alveolar ventilation reduces the oxygen saturation in the arterial blood (SaO2) and a gradual increase in the partial arterial pressure of carbon dioxide (PaCO2). The direct consequence of the intermittent hypoxia is an oxidative imbalance, with reactive oxygen species production and the inflammatory cascade's activation with pro and anti-inflammatory cytokines growth. Tumour necrosis factors, inflammatory cytokines (IL2, IL4, IL6), lipid peroxidation, and cell-free DNA have been found to increase in OSAS patients. However, even though different risk-related markers have been described and analysed in the literature, it has not yet been clarified whether specified inflammatory bio-markers better correlates with OSAS diagnosis and its clinical evolution/comorbidities. We perform a scientific literature review to discuss inflammatory and oxidative stress biomarkers currently tested in OSAS patients and their correlation with the disease's severity and treatment.