Oxidative Stress and Gut-Derived Lipopolysaccharides in Neurodegenerative Disease: Role of NOX2.

BACKGROUND: Neurodegenerative diseases (ND) as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis represent a growing cause of disability in the developed countries. The underlying physiopathology is still unclear. Several lines of evidence suggest a role for oxidative stress and NADPH oxidase 2 (NOX2) in the neuropathological pathways that lead to ND. Furthermore, recent studies hypothesized a role for gut microbiota in the neuroinflammation; in particular, lipopolysaccharide (LPS) derived from Gram-negative bacteria in the gut is believed to play a role in causing ND by increase of oxidative stress and inflammation. The aim of this study was to assess NOX2 activity as well as serum 8-iso-prostaglandin F2α (8-iso-PGF2α (8-iso-PGF2. METHODS: One hundred and twenty-eight consecutive subjects, including 64 ND patients and 64 controls (CT) matched for age and gender, were recruited. A cross-sectional study was performed to compare serum activity of soluble NOX2-dp (sNOX2-dp), blood levels of isoprostanes, serum H2O2, and LPS in these two groups. Serum zonulin was used to assess gut permeability. RESULTS: Compared with CT, ND patients had higher values of sNOX2-dp, 8-iso-PGF2α (8-iso-PGF2p < 0.001), zonulin (Rs = 0.411; p < 0.001), zonulin (Rs = 0.411; p < 0.001), zonulin (Rs = 0.411; α (8-iso-PGF2p < 0.001), zonulin (Rs = 0.411; p < 0.001), zonulin (Rs = 0.411; α (8-iso-PGF2p < 0.001), zonulin (Rs = 0.411; ß, 0.459; p < 0.001), zonulin (Rs = 0.411; α (8-iso-PGF2ß, 0.459; p < 0.001), zonulin (Rs = 0.411; R 2 = 57%). CONCLUSION: This study provides the first report attesting that patients with ND have high NOX2 activation that could be potentially implicated in the process of neuroinflammation.

The effects of the glycaemic control on the severity of the delirium in the advanced phase of Alzheimer's disease.

BACKGROUND: Behavioral and psychological symptoms of dementia (BPSD) and delirium are common in advanced phases of Alzheimer's disease (AD). METHODS: Thirty-eight moderate-severe AD patients were enrolled (n=16 affected by type 2 diabetes). Each patient received a comprehensive geriatric assessment (CGA) (including evaluation of BPSD and frailty), and a complete metabolic evaluation (including the measurement of the glycated hemoglobin, HbA1c). RESULTS: Both the hyper- and hypo-glycemic extremes of the glycemic spectrum worsened BPSD, but delirium was more susceptible to hypoglycemic events. The severity of delirium was significantly related to cognitive function (r = -0.585, p<0.001) and frailty (r = +0.440, p<0.05). CONCLUSIONS: The measurement of HbA1c was useful for evaluating the risk of delirium in relationship to glycemic control and nutritional status.

Esculentin-1a Derived Antipseudomonal Peptides: Limited Induction of Resistance and Synergy with Aztreonam.

BACKGROUND: The massive use of antibiotics has led to the selection of resistant bacterial strains that are difficult to eradicate. Among these, Pseudomonas aeruginosa most frequently colonizes and infects the airways of cystic fibrosis patients. Cationic Antimicrobial Peptides (AMPs) represent interesting molecules for the development of new antimicrobial agents. Thanks to their mechanism of action that involves the permeabilization of the bacterial cytoplasmic membrane, the induction of resistance is quite limited. OBJECTIVE: The evaluation of the capability of two frog-skin derived AMPs, i.e. Esc(1-21) and its diastereomer Esc(1-21)-1c, to induce resistance in P. aeruginosa and synergize with aztreonam. METHOD: The induction of resistance was evaluated after 15 cycles of exposure to non-inhibitory growth concentrations of antibiotics and peptides. Subsequently, the Minimal Inhibitory Concentration (MIC) was calculated and compared to that obtained before drug exposure. Furthermore, MICs of AMPs and antibiotics were evaluated in Artificial Sputum Medium (ASM). Finally, the ability of the two peptides to synergize with aztreonam was determined by the checkerboard titration method. RESULTS: Pseudomonas aeruginosa acquired resistance to antibiotics, as evidenced by the increased MICs compared to the initial ones (from 8 to 128-fold higher), while no change in MICs was observed after multiple treatments with the Esc-peptides. In addition, both peptides showed significantly lower MICs than aztreonam in ASM. Finally, the diastereomer Esc(1-21)-1c had the ability to synergize with aztreonam in inhibiting growth and in killing Pseudomonas cells. CONCLUSION: Both peptides represent promising candidates for the development of new antipseudomonal compounds, which do not induce resistance.

A new tool for the evaluation of the rehabilitation outcomes in older persons: a machine learning model to predict functional status 1 year ahead.

PURPOSE: To date, the assessment of disability in older people is obtained utilizing a Comprehensive Geriatric Assessment (CGA). However, it is often difficult to understand which areas of CGA are most predictive of the disability. The aim of this study is to evaluate the possibility to early predict-1 year ahead-the disability level of a patient using machine leaning models. METHODS: Community-dwelling older people were enrolled in this study. CGA was made at baseline and at 1 year follow-up. After collecting input/independent variables (i.e., age, gender, schooling followed, body mass index, information on smoking, polypharmacy, functional status, cognitive performance, depression, nutritional status), we performed two distinct Support Vector Machine models (SVMs) able to predict functional status 1 year ahead. To validate the choice of the model, the results achieved with the SVMs were compared with the output produced by simple linear regression models. RESULTS: 218 patients (mean age = 78.01; SD = 7.85; male = 39%) were recruited. The combination of the two SVMs is able to achieve a higher prediction accuracy (exceeding 80% instances correctly classified vs 67% instances correctly classified by the combination of the two linear regression models). Furthermore, SVMs are able to classify both the three categories, self sufficiently, disability risk and disability, while linear regression model separates the population only in two groups (self-sufficiency and disability) without identifying the intermediate category (disability risk) which turns out to be the most critical one. CONCLUSIONS: The development of such a model can contribute to the early detection of patients at risk of self-sufficiency loss.

[Resistant hypertension in the elderly.] / L'ipertensione arteriosa resistente nell'anziano.

Actually, in literature there are no epidemiologic studies on the prevalence of resistant hypertension in the elderly; however the National Health and Nutrition Examination Survey observed in the adult population prevalence of 12.8% to clinical measurement. But, especially in elderly, it's necessary exclude pseudoresistance forms due to white coat hypertension, arterial stiffness, poor patient compliance to therapy, excessive salt intake, abuse of non-steroidal ant-inflammatory drugs and the forms of secondary hypertension. Arterial hypertension, which is really resistant, it is a greater cardiovascular risk and thus the need to implement adherence to healthy lifestyle and therapy and to implement a pharmacological therapy to block the renin-angiotensin system or a dihydropyridine calcium channel, if they are not already present in the therapy and/or aldosterone antagonists. Currently experimental clinical therapeutic studies are examining such methods as renal denervation and the stimulation of the baroreflex.

Montelukast therapy and psychological distress in chronic obstructive pulmonary disease (COPD): a preliminary report.

Chronic obstructive pulmonary disease (COPD) is an alteration in which ventilatory function, exercise capacity and health status of patients progressively decline and it is characterized by an increase of inflammatory cytokines such as TNF-α, LTB4, IL-8, etc. In this study we considered twenty patients (15 males and 5 females; mean age: 72.8 ± 6.3) with stable COPD. All patients were performed evaluation of psychological stress at enrollment and were treated with leukotriene receptor antagonists (montelukast tablets) 10mg/day for 12 months. After 12 months we observed a significant decrease of serum levels of LTB4, IL-8 and also a decrease of the number of outpatient clinic visits, of the number of hospitalizations and of the duration of hospitalization.

The influence of lifestyle on cardiovascular risk factors. Analysis using a neural network.

The cardiovascular pathologies are the most common causes of death in the elderly patient. To single out the main risk factors in order to effectively prevent the onset of the disease, the authors experimented a special computerized tool, the neural network, that works out a mathematical relation that can obtain certain data (defined as output) as a function of other data (defined as input). Data were processed from a sample of 276 subjects of both sexes aged 26-69 years old. The output data were: high/low cholesterolemia, HDL cholesterol, triglyceridemia with respect to an established cut-off; the input data were: sex, age, build, weight, married/single, number of children, number of cigarettes smoked/day, amount of wine and number of cups of coffee. We conclude that: (i) a relationship exists, deduced from a neural network, between a set of input variables and a dichotomous output variable; (ii) this relationship can be expressed as a mathematical function; (iii) a neural network, having learned the data on a sufficiently large population, can provide valid predictive data for a single individual with a high probability (up to 93.33%) that the response it gives is correct. In this study, such a result is found for two of the three cardiovascular risk indicators considered (cholesterol and triglycerides); (iv) the repetition of the neural network analysis of the cases in question after a "pruning" operation provided a somewhat less good performance; (v) a statistical analysis conducted on those same cases has confirmed the existence of a strong relationship between the input and the output variables. Therefore the neural network is a valid instrument for providing predictive in a single subject on cardiovascular pathology risks.

Heart rate and blood pressure variability in subjects with vasovagal syncope.

Autonomic nervous system control in subjects with vasovagal syncope is controversial. In the present study, we used short-term spectral analysis to evaluate autonomic control in subjects with recurrent vasovagal syncope. We assessed the ability of spectral indices of HR (heart rate) variability to predict tilt-test responses. A series of 47 outpatients with recurrent vasovagal syncope and with positive responses to head-up tilt testing underwent a further study of RR variability during controlled breathing at rest and during tilt testing. During controlled breathing, RR interval variability of total power (TP(RR); P<0.001), low-frequency power (LF(RR); P<0.05), high-frequency power (HF(RR); P<0.001) and HF expressed in normalized units (HFnu(RR); P<0.001) were all higher, and LF expressed in normalized units (LFnu(RR)) and LF/HF ratio were lower in subjects with vasovagal syncope than in controls (P<0.001). To assess the ability of spectral components of RR variability to predict tilt-test responses, we prospectively studied 109 subjects with recurrent vasovagal syncope. The two normalized measures, HFnu(RR) and LFnu(RR), determined during controlled breathing alone predicted a positive tilt-test response (sensitivity, 76%; specificity, 99%; positive predictive value, 96%; and negative predictive value, 90%). During tilting, subjects with vasovagal syncope had lower SBP (systolic blood pressure; P<0.05), LF component of peak SBP variability (LF(SBP)) and LFnu(RR) than controls, and higher TP(RR), HF(RR), HFnu(RR) and alpha HF (P<0.001). These spectral data indicate that vagal sinus modulation is increased at rest in subjects with vasovagal syncope. Spectral analysis of RR variability during controlled breathing, a procedure that predicts tilt-test responses, could be a useful guide in choosing the method of tilt testing.

QT-interval variability and autonomic control in hypertensive subjects with left ventricular hypertrophy.

Left ventricular hypertrophy is a risk factor for sudden death. Malignant ventricular arrhythmias originate from altered cardiac repolarization. Ample data have described spatial abnormalities in cardiac repolarization [QT interval (QT) dispersion] in subjects with hypertension; more data are needed on temporal changes. This study was designed to assess the QT variability index (QTVI), the slope between QT and the RR interval (QT-RR(slope)) and spectral QT variability in subjects with arterial hypertension. The results were compared with those from a population at high risk of sudden death, i.e. patients with hypertrophic cardiomyopathy (HCM) who had received an implantable cardioverter/defibrillator (ICD), and those from normotensive control subjects. A total of 44 hypertensive subjects, six patients with HCM and an ICD and 33 control subjects underwent simultaneous short-term recording (256 beats) of QT, RR and systolic blood pressure variability, in the supine position, during controlled breathing. QTVI and spectral components of QT variability in the hypertensive group were significantly higher than in normotensive control subjects (P<0.001), but significantly lower than in patients with HCM and an ICD (P<0.001). The severity of left ventricular hypertrophy correlated significantly with QTVI and the ratio of low-frequency (LF) to high-frequency (HF) power obtained from the RR variability spectra (RR(LF/HF), slope=0.24, P<0.05; QTVI, slope=4.06, P<0.0001; intercept, slope=2.40, P<0.05; chi(2)=38.8; P<0.0001). The QT--RR slope was significantly higher only in patients with HCM and an ICD (P<0.001). In conclusion, the increased QTVI and the correlation of this index with left ventricular hypertrophy indicates that hypertension increases temporal cardiac repolarization abnormalities. At the level of the cardiac sinus node, this alteration is associated with increased sympathetic and reduced vagal modulation. As already noted in patients with HCM, the increased QTVI could be a factor responsible for triggering malignant ventricular arrhythmias in subjects with hypertension.

Effects of sildenafil citrate (viagra) on cardiac repolarization and on autonomic control in subjects with chronic heart failure.

BACKGROUND: Cases of sudden death associated with sildenafil citrate use have been reported in men with coronary artery disease. The aim of this study was to investigate the drug's effect on cardiac repolarization and sinus autonomic and vascular control in men with mild chronic heart failure (CHF; New York Heart Association classification II). Changes in these variables could predispose patients to malignant ventricular arrhythmias. METHOD: We measured QT dispersion, the QT-RR slope, and the index of QT variability (QTVI) and analyzed spectral power of RR and systolic blood pressure variability in 10 men with dilated cardiomyopathy and in 10 control subjects after administration of a single 50-mg oral dose of sildenafil citrate or placebo at rest (not followed with any attempt at intercourse). RESULTS: In both groups, oral sildenafil citrate decreased the systolic blood pressure (P <.05) and increased the heart rate (P <.05). In subjects with CHF, it also increased the QT-RR (P <.001) and QTVI (from -0.45 +/- 0.07 to -0.27 +/- 0.07; P <.001), but in controls, it increased the QTVI (from -1.20 +/- 0.08 to -0.78 +/-.014; P <.001). In these subjects and controls, oral sildenafil citrate induced a significant reduction in high frequency, expressed in absolute power (subjects with CHF: from 4.04 +/- 0.14 to 3.43 +/- 0.16 natural logarithm ms2; P <.001; controls: from 5.61 +/- 0.44 to 4.98 +/- 0.32 natural logarithm ms2; P <.05) and in normalized units (P <.05). In subjects with CHF but not in controls, it also significantly increased the low frequency to high frequency ratio (from 1.3 +/- 0.12 to 1.89 +/- 0.16; P <.001) and low frequency expressed in normalized units (P <.05). Sildenafil citrate caused no significant changes in the QT interval or dispersion. CONCLUSION: These findings indicate that, in men with heart failure, sildenafil citrate reduces vagal modulation and increases sympathetic modulation, probably through its reflex vasodilatory action. The autonomic system changes induced with sildenafil citrate could alter QT dynamics. Both changes could favor the onset of lethal ventricular arrhythmias. At the dose usually taken for erectile dysfunction, sildenafil citrate has no direct effect on cardiac repolarization (QT interval or dispersion).