Autonomous artificial intelligence versus teleophthalmology for diabetic retinopathy.

Purpose: To assess the role of artificial intelligence (AI) based automated software for detection of Diabetic Retinopathy (DR) compared with the evaluation of digital retinography by two double masked retina specialists. Methods: Two-hundred one patients (mean age 65 ± 13 years) with type 1 diabetes mellitus or type 2 diabetes mellitus were included. All patients were undergoing a retinography and spectral domain optical coherence tomography (SD-OCT, DRI 3D OCT-2000, Topcon) of the macula. The retinal photographs were graded using two validated AI DR screening software (Eye Art TM and IDx-DR) designed to identify more than mild DR. Results: Retinal images of 201 patients were graded. DR (more than mild DR) was detected by the ophthalmologists in 38 (18.9%) patients and by the AI-algorithms in 36 patients (with 30 eyes diagnosed by both algorithms). Ungradable patients by the AI software were 13 (6.5%) and 16 (8%) for the Eye Art and IDx-DR, respectively. Both AI software strategies showed a high sensitivity and specificity for detecting any more than mild DR without showing any statistically significant difference between them. Conclusions: The comparison between the diagnosis provided by artificial intelligence based automated software and the reference clinical diagnosis showed that they can work at a level of sensitivity that is similar to that achieved by experts.

Lipoprotein(a) Modulates Carotid Atherosclerosis in Metabolic Syndrome.

Background and Aim: High lipoprotein(a) [Lp(a)] is a well-established cardiovascular (CV) risk factor, but the effect of mildly elevated Lp(a) on CV health is largely unknown. Our aim was to evaluate if Lp(a) is associated with the severity of carotid atherosclerosis (CA) in the specific subset of metabolic syndrome (MetS). Patients and Methods: Subjects with diagnosed MetS and ultrasound-assessed CA were enrolled. Those patients were categorized according to the severity of CA (moderate vs. severe), and the circulating levels of Lp(a) alongside with clinical, anthropometric, and biochemical data were collected. Results: Sixty-five patients were finally included: twenty-five with moderate and forty with severe CA (all with asymptomatic disease). Intergroup comparison showed Lp(a) as the only significantly different variable [6 (2-12) mg/dl vs. 11.5 (6-29.5) mg/dl; p = 0.018]. Circulating levels of Lp(a) were also confirmed as the only variable independently associated with severity of CA at logistic regression analysis [OR 2.9 (95% CI 1.1-7.8); p = 0.040]. ROC curve analysis for Lp(a) confirmed a serum level of 10 mg/dl as the best cut-off value [AUC 0.675 (95% CI 0.548-0.786)]. Although sensitivity and specificity were suboptimal (69.0 and 70.4%, respectively)-likely due to the small sample size-this result is in line with those previously reported in the literature. Conclusion: Lp(a) is independently associated with severity of CA in the subgroup of MetS patients.

Baseline hs-CRP predicts hypertension remission in metabolic syndrome.

BACKGROUND: Inflammation, overweight and other cardiovascular risk factors might negatively impact on hypertension remission in metabolic syndrome (MetS), independently of the pharmacological treatment. Here, the potential influence of systemic inflammation (assessed by serum high-sensitivity C-reactive protein [hs-CRP]) on hypertension remission will be investigated in a cohort of hypertensive patients with MetS. MATERIAL AND METHODS: Hypertensive patients with MetS (n = 100) were enrolled, treated under current behavior/dietary/pharmacological recommendations and followed up for 12 months. All patients received medications and nutritional advice based on Mediterranean-like dietary pattern in addition to psychological and physical activity counselling. At baseline (T0), 6 (T1) and 12 (T2) months of follow-up, clinical data, haematological and biochemical profiles and serum hs-CRP were measured. RESULTS: As compared to T0, at T2 patients displayed improvements in anthropometric and metabolic profiles. At T2, the hypertension remission rate was 13.0%. Serum hs-CRP did not change overtime in the overall cohort. Surprisingly, patients who experienced hypertension remission were less treated with antihypertensive drugs, but developed a weak improvement in anthropometric measures during follow-up. The hypertension remission group had lower baseline levels of hs-CRP as compared to non-remission. Low baseline hs-CRP (<2 µg/mL, cut-off value identified by ROC curve) predicted hypertension remission, independently of antihypertensive treatment implementation, baseline systolic blood pressure and waist circumference improvement. CONCLUSIONS: Remission of hypertension in MetS is independently associated with baseline low CRP levels, which might suggest a critical role for inflammation in sustaining high blood pressure levels.

Effects of High Glucose Levels and Glycated Serum on GIP Responsiveness in the Pancreatic Beta Cell Line HIT-T15.

Glucose-dependent insulinotropic peptide (GIP) is an incretin hormone produced in the gastrointestinal tract that stimulates glucose dependent insulin secretion. Impaired incretin response has been documented in diabetic patients and was mainly related to the inability of the pancreatic beta cells to secrete insulin in response to GIP. Advanced Glycation End Products (AGEs) have been shown to play an important role in pancreatic beta cell dysfunction. The aim of this study is to investigate whether the exposure to AGEs can induce GIP resistance in the pancreatic beta cell line HIT-T15. Cells were cultured for 5 days in low (CTR) or high glucose (HG) concentration in the presence of AGEs (GS) to evaluate the expression of GIP receptor (GIPR), the intracellular signaling activated by GIP, and secretion of insulin in response to GIP. The results showed that incubation with GS alone altered intracellular GIP signaling and decreased insulin secretion as compared to CTR. GS in combination with HG reduced the expression of GIPR and PI3K and abrogated GIP-induced AKT phosphorylation and GIP-stimulated insulin secretion. In conclusion, we showed that treatment with GS is associated with the loss of the insulinotropic effect of GIP in hyperglycemic conditions.

Evidence for the gut microbiota short-chain fatty acids as key pathophysiological molecules improving diabetes.

In type 2 diabetes, hyperglycemia, insulin resistance, increased inflammation, and oxidative stress were shown to be associated with the progressive deterioration of beta-cell function and mass. Short-chain fatty acids (SCFAs) are organic fatty acids produced in the distal gut by bacterial fermentation of macrofibrous material that might improve type 2 diabetes features. Their main beneficial activities were identified in the decrease of serum levels of glucose, insulin resistance as well as inflammation, and increase in protective Glucagon-like peptide-1 (GLP-1) secretion. In this review, we updated evidence on the effects of SCFAs potentially improving metabolic control in type 2 diabetes.

Advanced glycation end products play adverse proinflammatory activities in osteoporosis.

Osteoporosis is a major public health burden that is expected to further increase as the global population ages. In the last twenty years, advanced glycation end products (AGEs) have been shown to be critical mediators both in the pathogenesis and development of osteoporosis and other chronic degenerative diseases related to aging. The accumulation of AGEs within the bone induces the formation of covalent cross-links with collagen and other bone proteins which affects the mechanical properties of tissue and disturbs bone remodelling and deterioration, underlying osteoporosis. On the other hand, the gradual deterioration of the immune system during aging (defined as immunosenescence) is also characterized by the generation of a high level of oxidants and AGEs. The synthesis and accumulation of AGEs (both localized within the bone or in the systemic circulation) might trigger a vicious circle (in which inflammation and aging merged in the word "Inflammaging") which can establish and sustain the development of osteoporosis. This narrative review will update the molecular mechanisms/pathways by which AGEs induce the functional and structural bone impairment typical of osteoporosis.

Update on the protective molecular pathways improving pancreatic beta-cell dysfunction.

The primary function of pancreatic beta-cells is to produce and release insulin in response to increment in extracellular glucose concentrations, thus maintaining glucose homeostasis. Deficient beta-cell function can have profound metabolic consequences, leading to the development of hyperglycemia and, ultimately, diabetes mellitus. Therefore, strategies targeting the maintenance of the normal function and protecting pancreatic beta-cells from injury or death might be crucial in the treatment of diabetes. This narrative review will update evidence from the recently identified molecular regulators preserving beta-cell mass and function recovery in order to suggest potential therapeutic targets against diabetes. This review will also highlight the relevance for novel molecular pathways potentially improving beta-cell dysfunction.

An emerging role of glucagon-like peptide-1 in preventing advanced-glycation-end-product-mediated damages in diabetes.

Glucagon-like peptide-1 (GLP-1) is a gut hormone produced in the intestinal epithelial endocrine L cells by differential processing of the proglucagon gene. Released in response to the nutrient ingestion, GLP-1 plays an important role in maintaining glucose homeostasis. GLP-1 has been shown to regulate blood glucose levels by stimulating glucose-dependent insulin secretion and inhibiting glucagon secretion, gastric emptying, and food intake. These antidiabetic activities highlight GLP-1 as a potential therapeutic molecule in the clinical management of type 2 diabetes, (a disease characterized by progressive decline of beta-cell function and mass, increased insulin resistance, and final hyperglycemia). Since chronic hyperglycemia contributed to the acceleration of the formation of Advanced Glycation End-Products (AGEs, a heterogeneous group of compounds derived from the nonenzymatic reaction of reducing sugars with free amino groups of proteins implicated in vascular diabetic complications), the administration of GLP-1 might directly counteract diabetes pathophysiological processes (such as pancreatic ß-cell dysfunction). This paper outlines evidence on the protective role of GLP-1 in preventing the deleterious effects mediated by AGEs in type 2 diabetes.

Update on the Pathophysiological Role of Intracellular Signaling Pathways in Atherosclerotic Plaques and Ischemic Myocardium.

Acute atherosclerotic complications, such as myocardial infarction, are often provoked by the rupture of an atherosclerotic plaque and the subsequent thrombotic occlusion of the arterial lumen, which interrupts the blood flow and renders ischemic the downstream peripheral tissue. Several inflammatory mediators (including cytokines, chemokines and matrix metalloproteases) have been shown to orchestrate common pathophysiological mechanisms regulating both plaque vulnerability and myocardial injury. In particular, the selective activation of certain protective intracellular signaling pathways might represent a promising target to reduce the dramatic consequences of an ischemic cardiac event. In the present review we will update evidence on the active role of intracellular kinase cascades (such as mitogen-activated protein kinases [MAPKs], Akt, Janus kinase [JAK]-signal transducer and activator of transcription [STAT]) to reduce the global patient vulnerability for acute myocardial infarction.

Role of cytokines and chemokines in non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) includes a variety of histological conditions (ranging from liver steatosis and steatohepatitis, to fibrosis and hepatocarcinoma) that are characterized by an increased fat content within the liver. The accumulation/deposition of fat within the liver is essential for diagnosis of NAFLD and might be associated with alterations in the hepatic and systemic inflammatory state. Although it is still unclear if each histological entity represents a different disease or rather steps of the same disease, inflammatory processes in NAFLD might influence its pathophysiology and prognosis. In particular, non-alcoholic steatohepatitis (the most inflamed condition in NAFLDs, which more frequently evolves towards chronic and serious liver diseases) is characterized by a marked activation of inflammatory cells and the upregulation of several soluble inflammatory mediators. Among several mediators, cytokines and chemokines might play a pivotal active role in NAFLD and are considered as potential therapeutic targets. In this review, we will update evidence from both basic research and clinical studies on the potential role of cytokines and chemokines in the pathophysiology of NAFLD.

The activation of the cannabinoid receptor type 2 reduces neutrophilic protease-mediated vulnerability in atherosclerotic plaques.

AIMS: The activation of cannabinoid receptor type 2 (CB(2))-mediated pathways might represent a promising anti-atherosclerotic treatment. Here, we investigated the expression of the endocannabinoid system in human carotid plaques and the impact of CB(2) pharmacological activation on markers of plaque vulnerability in vivo and in vitro. METHODS AND RESULTS: The study was conducted using all available residual human carotid tissues (upstream and downstream the blood flow) from our cohort of patients symptomatic (n = 13) or asymptomatic (n = 27) for ischaemic stroke. Intraplaque levels of 2-arachidonoylglycerol, anandamide N-arachidonoylethanolamine, N-palmitoylethanolamine, N-oleoylethanolamine, and their degrading enzymes (fatty acid amide hydrolase and monoacylglycerol lipase) were not different in human plaque portions. In the majority of human samples, CB(1) (both mRNA and protein levels) was undetectable. In downstream symptomatic plaques, CB(2) protein expression was reduced when compared with asymptomatic patients. In these portions, CB(2) levels were inversely correlated (r = -0.4008, P = 0.0170) with matrix metalloprotease (MMP)-9 content and positively (r = 0.3997, P = 0.0174) with collagen. In mouse plaques, CB(2) co-localized with neutrophils and MMP-9. Treatment with the selective CB(2) agonist JWH-133 was associated with the reduction in MMP-9 content in aortic root and carotid plaques. In vitro, pre-incubation with JWH-133 reduced tumour necrosis factor (TNF)-α-mediated release of MMP-9. This effect was associated with the reduction in TNF-α-induced ERK1/2 phosphorylation in human neutrophils. CONCLUSION: Cannabinoid receptor type 2 receptor is down-regulated in unstable human carotid plaques. Since CB(2) activation prevents neutrophil release of MMP-9 in vivo and in vitro, this treatment strategy might selectively reduce carotid vulnerability in humans.

Receptor activator of NF- κB ligand (RANKL) increases the release of neutrophil products associated with coronary vulnerability.

The "blood vulnerability", resulting from the complex balance between serum molecules and inflammatory cell atherosclerotic activities, is a major determinant in the evaluation of the "global patient cardiovascular vulnerability". In the present study, we focused on the role of the soluble receptor activator of nuclear factor kappa-B (NF-κB) ligand (RANKL, a potential marker of coronary calcification and vulnerability) in the release of neutrophilic proteases. Then, the association between these mediators and the degree of coronary calcification (assessed by coronary calcium score [CCS]) was investigated in 20 subjects (aged ≥65 years) asymptomatic for cardiovascular disease. Results showed that RANKL dose-dependently induced matrix metalloprotease (MMP)-8 and MMP-9 release from human primary neutrophils cultured in Teflon dishes (suspension condition, mimicking cells circulating in the blood stream). Conversely, when adherent to polystyrene, neutrophils became unresponsive to RANKL. RANKL did not influence the release of other neutrophilic products in suspension and adherence cultures as well as neutrophil migration. RANKL-induced release of MMPs was dependent on the activation of defined intracellular signalling pathways (PI3K/Akt and ERK1/2). In asymptomatic subjects, serum levels of RANKL, MMP-8 and MMP-9 positively correlated with CCS, reflecting a potential relationship between circulating RANKL and coronary calcification. In conclusion, RANKL increased the release of neutrophilic products potentially related to the "blood" vulnerability via defined intracellular pathways. Serum levels of RANKL might represent a potential biomarker of coronary calcification and related cardiovascular risk.

Statins in the treatment of acute ischemic stroke.

3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (also known as statins) are drugs active in the blockade of cholesterol synthesis and thus lowering cholesterol serum levels. Since their discovery, experimental evidence showed that statins strongly reduced atherogenesis and the risk of acute ischemic complications, such as acute myocardial infarction and stroke. More recently, direct anti-atherosclerotic effects of statins (independently of lipid profile improvement) have been also shown, suggesting new potential applications for these drugs in both primary and secondary prevention of acute cardiovascular events. Despite some controversies exist, the use of statins has been shown to improve both incidence and survival in acute ischemic stroke. The molecular mechanisms underlying statin-mediated clinical benefits were recently identified in the reduction of carotid plaque vulnerability and the increase of neuroprotection. In the present review, we will update evidence on the promising results with statins to improve ischemic stroke outcomes.

Acipimox reduces circulating levels of insulin and associated neutrophilic inflammation in metabolic syndrome.

Metabolic syndrome is a proatherosclerotic condition clustering cardiovascular risk factors, including glucose and lipid profile alterations. The pathophysiological mechanisms favoring atherosclerotic inflammation in the metabolic syndrome remain elusive. Here, we investigated the potential role of the antilipolytic drug acipimox on neutrophil- and monocyte-mediated inflammation in the metabolic syndrome. Acipimox (500 mg) was orally administered to metabolic syndrome patients (n = 11) or healthy controls (n = 8). Serum and plasma was collected before acipimox administration (time 0) as well as 2-5 h afterward to assess metabolic and hematologic parameters. In vitro, the effects of the incubation with metabolic syndrome serum were assessed on human neutrophil and monocyte migration toward the proatherosclerotic chemokine CCL3. Two to five hours after acipimox administration, a significant reduction in circulating levels of insulin and nonesterified fatty acid (NEFA) was shown in metabolic syndrome patients. At time 0 and 2 h after acipimox administration, metabolic syndrome serum increased neutrophil migration to CCL3 compared with healthy controls. No effect was shown in human monocytes. At these time points, serum-induced neutrophil migration positively correlated with serum levels of insulin and NEFA. Metabolic syndrome serum or recombinant insulin did not upregulate CCR5 expression on neutrophil surface membrane, but it increased intracellular JNK1/2 phosphorylation. Insulin immunodepletion blocked serum-induced neutrophil migration and associated JNK1/2 phosphorylation. Although mRNA expression of acipimox receptor (GPR109) was shown in human neutrophils, 5-500 µM acipimox did not affect insulin-induced neutrophil migration. In conclusion, results suggest that acipimox inhibited neutrophil proatherosclerotic functions in the metabolic syndrome through the reduction in circulating levels of insulin.

CC and CXC chemokines are pivotal mediators of cerebral injury in ischaemic stroke.

The definition of ischaemic stroke has been recently updated as an acute episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischaemia in the presence of a cerebral infarction. This "tissular" definition has highlighted the importance of pathophysiological processes underlying cerebral damage. In particular, post- ischaemic inflammation in the brain and in the blood stream could influence crucial steps of the tissue injury/repair cascade. CC and CXC chemokines orchestrate the inflammatory response in atherosclerotic plaque vulnerability and cerebral infarction. These molecules exert their activities through the binding to selective transmembrane receptors. CC and CXC chemokines modulate crucial processes (such as inflammatory cell recruitment and activation, neuronal survival, neoangiogenesis). On the other hand, CXC chemokines could also modulate stem cell homing, thus favouring tissue repair. Given this evidence, both CC and CXC chemokines could represent promising therapeutic targets in primary and secondary prevention of ischaemic stroke. Only preliminary studies have been performed investigating treatments with selective chemokine agonists/antagonists. In this review, we will update evidence on the role and the potential therapeutic strategies targeting CC and CXC chemokines in the pathophysiology of ischaemic stroke.

New evidence for nicotinic acid treatment to reduce atherosclerosis.

Nicotinic acid (at a daily dose of grams) has been shown to induce potent anti-atherosclerotic effects in human and animal models. Evidence from clinical studies performed in the 1950s has shown that nicotinic acid treatment remarkably improves the plasma lipid profile. Large clinical studies showed that nicotinic acid improves clinical cardiovascular outcomes. Given the protective effects of niacin, basic research studies were designed to explore additional anti-atherosclerotic pathways, such as those involved in cardiovascular inflammation. After the discovery of the nicotinic acid receptor GPR109A on adipocytes and immune cells, novel direct immunomodulatory properties of nicotinic acid have been identified. Importantly, the regulation of the release of inflammatory mediators from adipose tissue was observed, independent of lipid level amelioration. Less is known about the possible direct anti-inflammatory activities of nicotinic acid in other cells (such as hepatocytes, endothelial and vascular cells) previously indicated as key players in atherogenesis. Thus, further studies are needed to clarify this promising topic. Emerging evidence from clinical and basic research studies indicates that novel direct anti-atherosclerotic properties might mediate nicotinic acid-induced cardiovascular protection. Despite some limitations in its clinical use (mainly due to the incidence of adverse events, such as cutaneous flushing and hepatotoxicity), nicotinic acid should be considered as a very potent therapeutic approach to reduce atherosclerosis. Promising research developments are warranted in the near future.

Effects of valsartan therapy on protein glycoxidation.

Several lines of evidence suggest that both advanced glycation end products (AGEs) and oxidation processes play key roles in the physiology of aging and age-related pathologies, leading to irreversible proteins modifications in both tissues and the extracellular matrix. Such an accelerated accumulation of these modifications has been reported to be present in several age-related chronic diseases, such as atherosclerosis, diabetes, arthritis, and neurodegenerative diseases. The current literature reveals that the specific inhibition of AGEs may constitute an innovative therapeutic goal. In experimental animals, the use of sartans significantly reduces blood pressure and kidney pentosidine content, improving both histologic renal damage and proteinuria. In this study, 12 subjects who were affected by diabetes mellitus and hypertension were subjected to oral antihypertensive therapy with valsartan (class of sartans) with timed sampling of plasma and urine pentosidine, N(epsilon)-(carboxymethyl)lysine (CML), malondialdehyde, and isoprostanes levels, respectively, at baseline and after both 3 and 6 months, with parallel ongoing evaluation of glycemic control and blood pressure levels. Valsartan elicited a good antihypertensive effect with a 30% decrease in plasma pentosidine levels (P < .05) after 3 months of therapy, followed by a slight increase after 6 months. Urinary pentosidine concentrations exhibited a 40% decrease after 3 months (215 +/- 19 vs 129 +/- 23 nmol/24 h) and a further significant reduction after 6 months of therapy (105 +/- 24 nmol/24 h). Plasma CML levels showed a progressive decrease after 3 months (23.15 +/- 3.215 vs 19.88 +/- 1.684 micromol/mL) and achieved a further slight reduction after 6 months of therapy (19.48 +/- 1.339 micromol/mL); for urinary CML, a statistically significant reduction was gained after the sixth month of therapy (48.51 +/- 5.70 vs 30.30 +/- 2.77 micromol/24 h after 3 months and 27.02 +/- 4.13 micromol/24 h after 6 months; F = 7.62, P < .005). Plasma and urinary concentrations of malondialdehyde were slightly modified by valsartan treatment; the mean levels after both 3 and 6 months did not significantly differ from baseline. Urinary 15-F2t-isoprostanes (2.96 +/- 0.45 ng/24 h) levels displayed a progressive decrease after both 3 (2.27 +/- 0.31 ng/24 h) and 6 months (1.70 +/- 0.23 ng/24 h) with statistical significance achieved only at the end of the study (P < .05). The present data suggest interesting in vivo antiglycation and antioxidation effects of this angiotensin II receptor antagonist with reductions in plasma and urinary pentosidine, plasma CML, and urinary isoprostanes levels. The present study supports an antagonistic role of valsartan in the production of AGEs precursors through the chelation of transition metals and an antioxidant activity that scavenges reactive oxygen species. This property of valsartan may broaden the scope of newly developed pharmacologic inhibitors of advanced glycoxidation.