Effectiveness of intensive neurorehabilitation in obese subacute stroke patients.

The relationship between abdominal subcutaneous adipose tissue thickness (aSAT), body fat percentage (BFP), waist-to-hip ratio (WHR) and body mass index (BMI) and outcome measures of neurological deficit and functional recovery was evaluated in obese subacute stroke patients before and after neurorehabilitation. Decreased National Institutes of Health Stroke Scale (p = 0.0001) and modified Rankin Scale (mRS) (p= 0.002) scores, as well as increased Barthel Index (p= 0.0001) scores were detected after neurorehabilitation. Decreased BMI, aSAT, BFP and WHR observed after neurorehabilitation did not penalize the overall functional recovery as shown by correlations between the clinical measure scores and fat mass indices. The correlation observed after neurorehabilitation between BMI and mRS (rho = 0.4526, p < 0.05) suggests that a high BMI may compromise functional recovery. Monitoring of body fat mass indices may provide information aimed at improving the disability of obese stroke patients.

Impairment of plasma nitric oxide availability in senescent healthy individuals: apparent involvement of extracellular superoxide dismutase activity.

To verify the potential involvement of the age-dependent modifications of EC-SOD activity in the impairment of plasma NO availability with advancing age, 40 healthy men divided into 4 age groups for the purpose of comparison (young: 27.4 +/- 1.5 years; middle: 50.8 +/- 2.2, years; old: 70.0 +/- 1.8 years; very old: 86.1 +/- 1.1 years) were enrolled in this study. Plasma samples were used for measurements of the stable end-product nitrite/nitrate (NOx), as an expression of NO availability, EC-SOD activity, thiobarbituric acid reactive substances (TBARS) as a marker of lipid peroxidation, low density lipoprotein (LDL) copper-mediated oxidation in vitro and total antioxidant capacity (TEAC). Our results indicated a significant age-related progressive decrease of plasma NOx content and EC-SOD activity and their values were positively correlated (r = 0.713, p < 0.001). Increased TBARS amount together with reduced lag time for in vitro oxidation of LDL and decreased content of TEAC were observed with advancing age. Finally, EC-SOD values were negatively correlated with plasma TBARS values (r = -0.855, p < 0.001). Findings of the present study suggest that the decrease of antioxidant defence strategies play a primary role by compromising NO availability in normally aged individuals, particularly through a progressive decrease of EC-SOD activity.

Deep venous thrombosis: behaviour of the polymorphonuclear leukocyte integrin pattern at baseline and after in vitro activation.

In a group of 18 subjects with acute deep venous thrombosis (DVT), evidenced by clinical examination and echo-color-Doppler, we examined the phenotypical expression of the polymorphonuclear leukocyte (PMN) beta2-integrins (CD11a, CD11b, CD11c, CD18), obtained by using a flow cytofluorimeter. The evaluation was performed before and after in vitro activation (prolonged for 5 and 15 minutes) with 4-phorbol 12-myristate 13-acetate (PMA) and N-formyl-methionyl-leucyl-phenylalanine (fMLP). In DVT subjects, at baseline, the phenotypical expression of CD11b was decreased and that of CD11c was increased when compared with normal controls; no difference was found in CD11a and CD18 expression. In normal subjects PMN activation with both activators led to a constant increase of all PMN adhesion molecules; in DVT subjects CD11b, CD11c and CD18 increased, while CD11a expression did not show any change. These data indicate the presence of a functional alteration in circulating PMN cells from patients with DVT.

Influence of aging and exercise-induced stress on human platelet function.

Ten healthy nonsmoking old men (age 52-70 years, OM) and ten healthy nonsmoking young men (age 20-30 years, YM) were submitted to an exercise test on a bicycle ergometer to examine the combined influence of aging and exercise-induced stress on platelet function. Data were analyzed by two-way ANOVA test to determine the statistical significance of differences between baseline, after exercise and after recovery values, and by Mann-Whitney test to compare differences between young and old groups. Our results show in OM at rest an increased platelet aggregability induced by the higher values of intraplatelet basal free calcium (143.3 +/- 4.8 vs. 121.5 +/- 6.0 nM, p < 0.05) and a statistically significant increase of plasma oxidative by-products evaluated as thiobarbituric acid-reactive substances (TBA-RS: 5.9 +/- 0.7 vs. 1.5 +/- 0.1 micromol/l, p < 0.05). Further, significant modifications of calcium and TBA-RS levels were found in both groups because of exercise-induced stress. The positive relationships between calcium amount and plasma values of TBA-RS in OM before (r = 0.728, p = 0.017) and after (r = 0.772, p = 0.009) physical test and in YM only at the end of exercise (r = 0.853, p = 0.002), underline that oxidative stress may modulate platelet function by influencing calcium homeostasis and platelet membrane permeability.

Possible involvement of increased susceptibility of LDL to oxidation in age-related platelet activation.

Fifteen long-lived and fifteen young healthy subjects were enrolled in this study to verify the involvement of age-associated oxidative challenge in the mechanisms that control platelet activation. Our results showed in old subjects an enhancement of ex vivo platelet responsiveness to ADP and collagen, measured both in whole blood and in platelet rich plasma, an increased cytosolic calcium content, a decreased membrane fluidity and a lower intraplatelet nitrate/nitrite (NO(x)) amount. Additionally, an increased plasma content of peroxidative by-products (TBARS) and a decreased antioxidant plasma capacity together with a reduced lag time for in vitro oxidation of low density lipoprotein (LDL) and a diminished plasma NO(x) bioavailability were observed in aged subjects. Lag time for LDL oxidation was negatively correlated with plasma TBARS level, and positively correlated with intraplatelet NO(x) content. Findings of this study may support the speculation that advancing age increases the susceptibility of LDL to oxidative modifications and favors platelet activation by oxidized LDL-induced decrease of nitric oxide bioactivity.

Possible involvement of oxidative stress in exercise-mediated platelet activation.

In this study, we have attempted to verify whether a single bout of strenuous exercise performed by sedentary healthy individuals may interfere with the mechanisms controlling platelet sensitivity through exercise-related modifications of plasma oxidant/antioxidant equilibrium. Strenuous exercise resulted in an increased ADP- and collagen-evoked platelet aggregation associated with modified membrane fluidity and ion homeostasis. We also observed an enhanced plasma accumulation of secondary products of lipid peroxidation together with an increased susceptibility of low density lipoprotein (LDL) to in vitro oxidation and a decreased total plasma antioxidant potential. Notably, an acute elevation of nitrite/nitrate (NOx) amount was detected in plasma, whilst a decreased NOx content was measured in platelets. Findings of the current study suggest that oxidative stress induced by acute strenuous exertion may interfere with platelet responsiveness by promoting ox-LDL-mediated platelet activation and by decreasing platelet-derived nitric oxide bioactivity.

In vitro short-term response of human erythrocytes to implant materials used in maxillo-facial rigid internal fixation.

A short-term in vitro experimental study was performed to analyze the effects of metallic miniplates used in maxillo-facial rigid internal fixation on some functional features of human erythrocytes that represent a pivotal rheological component for correct blood flow in the tissular area surrounding metallic implants. In our working conditions, no interference on osmotic fragility, intracellular ATP content and spontaneous hemolysis was observed. Conversely, a statistically significant increase of rigidity in the deeper lipid region of erythrocyte membrane was verified. On the basis of our results, the in vitro erythrocyte modifications after 18 h of whole blood/metallic device contact are relatively small and negligible.

Modifications of whole blood filterability during acute myocardial infarction.

Experimental evidences underline that hemorheological alterations observed in acute myocardial infarction (AMI) are strictly involved in the decreased perfusion of the damaged area and in the extension of the necrotic regions. We have analyzed whole blood filterability as an index of erythrocyte deformability in 60 AMI patients compared with 30 patients with non-acute coronary artery disease and 52 healthy subjects. Nucleopore polycarbonate membranes with a pore diameter of 5 microm and a filtering pressure of -20 cm H2O were used. The results are expressed as the volume of whole blood filtered in 1 minute (index of filterability, IF). In normal subjects IF was 1.16 +/- 0.24. Among AMI patients IF was 0.70 +/- 0.30 at admission, 0.68 +/- 017 at day 10 and 0.78 +/- 0.14 at day 20. These values were significantly lower than those obtained in normal subjects and in patients with non-acute coronary artery disease. In addition, AMI patients treated with thrombolytic therapy showed, at admission, a significantly higher IF value than that obtained in patients who did not receive thrombolytic treatment (0.85 +/- 0.34 vs 0.60 +/- 0.22; p < 0.01). These results demonstrate an evident reduction of whole blood filterability in AMI patients that may be considered as an index of erythrocyte deformability. Thrombolytic therapy seems to have a positive effect on blood filterability and may produce beneficial effects through its therapeutical action other than the lysis of the coronary thrombus.

Effectiveness of intensive neurorehabilitation in patients with Huntington's disease.

BACKGROUND: Huntington's disease (HD) is a neurodegenerative disorder characterized by motor, cognitive, and behavioral impairments that differ in their presentation and progression across subjects. Studies validating the effectiveness of intensive neurorehabilitation such as a strategy to reducing functional impairments and to improving motor capacities in HD patients are limited and heterogeneous. AIM: To design and test an intensive multifunctional neurorehabilitative protocol in symptomatic patients with HD in the attempt to limit the progression of neurological deficits and to preserve and maintain independence in the activities of daily living. DESIGN: Case series. SETTING: Rehabilitation nursing home. POPULATION: Thirty-four patients (12 men and 22 women) with HD. METHODS: Three-week in-hospital intensive multifunctional neurorehabilitation. The evaluation of patients was performed before and at the end of the 3-week neurorehabilitative treatment by the Barthel Index (BI) and the Total Functional Capacity Scale (TFCS) assessing independence in the activities of daily living, by the Physical Performance Test (PPT) assessing motor performances on functional tasks, and by the Tinetti Scale (TS) assessing balance and gait. A telephone follow-up interview evaluating individual autonomy by the BI was scheduled 3 months after discharge in order to evaluate the short-term results. RESULTS: We found a significant increase (P<0.001) of the mean scores of BI, TS, PPT and TFCS in all patients at the end of the 3-week in-hospital intensive multifunctional neurorehabilitation with respect to the score values obtained before rehabilitative treatment. The differences of BI, TS, PPT and TFCS scores (Δ scores) observed in HD patients assuming tetrabenazine and in patients not assuming the drug, before and after rehabilitation, were not statistically different. The improvement in independence in the activities of daily living evaluated by BI vanished 3 months after discharge (P<0.05). CONCLUSION: Rehabilitative treatment in HD patients needs to be multifunctional and continuous to improve or maintain motor performances and functional independence. CLINICAL REHABILITATION IMPACT: Despite Huntington's disease is a progressive and incurable disease intensive neurorehabilitation lessens patients' disability and improves their quality of life ameliorating autonomy and delaying the progression of motor dysfunction.

Relationship between biofeedback and oxidative stress in patients with chronic migraine.

Chronic migraine (1.5.1) is burdened with headache-related disability. During noxious stimulation, changes of cerebral blood flow enhance the release of oxygen free radicals that react with nitric oxide (NO). We investigated the role of biofeedback in limiting migraine disability by influencing oxidative stress. Peroxides, NO and superoxide dismutase (SOD) were analysed in 20 female subjects with chronic migraine and in 20 female healthy controls before and after biofeedback sessions. NO(x) levels (23.7 +/- 4.2 vs. 34.9 +/- 4.6 microm; P < 0.05) and SOD activity (6.5 +/- 1.0 vs. 8.0 +/- 0.7 U/ml; P < 0.05) were lower in migraine sufferers before treatment than in healthy controls, whereas peroxide levels (145.8 +/- 40.3 vs. 78.0 +/- 20.0 microm; P < 0.05) were higher in migraine sufferers before treatment than in healthy controls. In migraine sufferers NO(x) levels (23.7 +/- 4.2 vs. 31.3 +/- 7.1 microm; P < 0.05) and SOD activity (6.5 +/- 1.0 vs. 7.9 +/- 0.9 U/ml; P < 0.05) were lower before than after treatment, whereas peroxide levels (145.8 +/- 40.3 vs. 82.4 +/- 21.1 microm; P < 0.05) were higher before than after treatment. SOD serum activity correlated positively with NO(x) serum levels and negatively with peroxide serum levels in healthy controls and in chronic migraine sufferers before and after biofeedback. The mean Migraine Disability Assessment Score before biofeedback sessions was higher than after treatment (36.9 +/- 13.9 vs. 18.8 +/- 10.4; P < 0.001). The effectiveness of biofeedback in limiting chronic migraine may be related to muscular relaxation associated with decreased oxidative stress accompanied by psychological well-being.

Aging of human erythrocytes: the role of membrane perturbations induced by in vitro ATP-depletion.

The in vitro metabolic depletion of the erythrocytes has been often utilized to mimic the oxidative stress responsible of their in vivo senescence process. The present study is focused to detect the extent to which the modifications of the whole cell and/or of its membrane, consequent to in vitro ATP-depletion, could trigger a mechanism similar to that verified during in vivo aging. From our data it appears that the shape changes and the increased osmotic fragility could be related to physico-chemical alterations that take place at membrane level. Main alterations concern the significant decrease of negative charges of membrane surface, as evidenced by fluorescence intensity enhancement of membrane-associated ANS, and of the increase of fluidity in the lipid/protein membrane region, suggesting a close analogy with the progressive in vivo senescence of the RBC. Furthermore, the ATP-depletion erythrocyte can efficiently remove exogenous hydrogen peroxide differently from old RBC that showed, as well reported, a severe decrease of enzymic protection against oxidative insult.

Influence of acute exercise on human platelet responsiveness: possible involvement of exercise-induced oxidative stress.

The aim of this study was to evaluate in sedentary male subjects the effects of an acute bout of strenuous and moderate exercise on ex vivo platelet responsiveness and its possible relationship with exercise-associated modifications of oxidant-antioxidant status. An increased ADP- and collagen-evoked platelet aggregation associated with modified membrane fluidity and ion homeostasis was observed after exhaustive exercise. After moderate exercise, we found a decrease of platelet aggregation evoked by low concentrations of agonists. Strenuous exercise, but not moderate exertion, resulted in the enhanced accumulation of secondary products of lipid peroxidation, decreased total antioxidant capacity, including a diminished superoxide dismutase activity, and increased susceptibility of low-density lipoprotein (LDL) to in vitro oxidation. Acute elevation of plasma nitrite/nitrate (NOx) content was observed following each single session of physical test, whilst the platelet NOx content was decreased after strenuous exercise and increased after moderate exercise. Findings of the present study suggest that oxidative stress induced by acute strenuous exercise may interfere with platelet responsiveness most likely by promoting oxidized LDL-mediated platelet activation and by decreasing plasma and platelet-derived nitric oxide (NO) bioactivity. Moreover, our results further suggest that platelet responsiveness following an acute moderate physical stressor may depend on the efficiency of plasma and intraplatelet NO to desensitize platelets to agonist stimulation.

Controlled human RBC modifications affecting the binding of cationic liposomes.

Cationic liposomes were prepared either by sonication or by detergent dialysis and used to deliver the antioxidative enzyme glutathione peroxidase into human erythrocytes in vitro. The enrichment ability of these two preparations was similar, amounting to about 30% of the control cells. The lysis of enzyme-treated erythrocytes induced by photoirradiation in the presence of PPIX was compared with that of cells incubated with empty liposomes. Erythrocytes enriched with GPX appear to be more resistant toward photohemolysis. Pre-treatment of cells with neuraminidase or proteinase K suggests that: a) sialic acid seems to be essential for the cell-liposome fusion process, no enrichment being found with the neuraminidase-treated cells; b) hydrolysis of the outer membrane proteins leads to an increased fragility with respect to controls even in GPX-enriched cells. These results were confirmed by extrinsic fluorescence polarization experiments, using isolated erythrocyte membranes and specific fluorescent probes.

Photodynamic damage induced by bilirubin on human platelets: possible relevance to newborn pathology.

Several reports have appeared showing the possibility of bilirubin-sensitized photodamage. We have extended these observations to platelets. In the presence of 300 microM bilirubin the in vitro irradiation of isolated platelets or platelet-rich plasmas with visible light induced significant lysis as determined by the release of lactate dehydrogenase (LDH). The extent of LDH release was a function of irradiation time, being about 20% after 2 h of irradiation. A loss membrane-bound ATPase activity was also observed at earlier times, indicating that membrane damage was preliminary to the lytic effect. The release of beta-thromboglobulin, induced by close cell-to-cell contact, was lower in bilirubin- and light-treated platelets with respect to controls. Our results suggest that bilirubin may act as a photodynamic agent producing some damage on human blood platelets.

Urinary nitric oxide metabolites and lipid peroxidation by-products in migraine.

Enhanced endothelium nitric oxide (NO) and superoxide anion release may cause migraine through related cerebral blood flow changes. Thirty subjects suffering from migraine with and without aura and 20 healthy controls were investigated. Urine samples collected for 24 h during and after the migraine attack, and during the headache-free period, were assayed for urinary NO stable metabolites (NOx) and thiobarbituric acid reactive substances (TBARS). During the headache-free period urinary NOx and TBARS levels were higher in migraine sufferers than in controls (NOx 0.77 +/- 0.14 vs. 0.28 +/- 0.15 mmol/mmol creatinine, P < 0.05; TBARS 0.40 +/- 0.19 vs. 0.26 +/- 0.13 micro mol/mol creatinine, P < 0.05). Also, NOx excretion was higher during the headache-free period than during or after the migraine attack (P < 0.05). Urinary TBARS were increased during the attack with respect to the headache-free period (P < 0.05). No differences were observed in the same parameters between sufferers of migraine with and without aura. Urinary NOx and TBARS might be promising as markers of their systemic levels to evaluate the increased vulnerability to oxidative stress in migraine sufferers.

In vitro effects of alloplastic biomaterials on the functional features of human erythrocytes and platelets.

In vitro experiments were performed to evaluate the biocompatibility of metallic plates used in reconstructive maxillofacial surgery, analyzing the effect of titanium, nickel-chromium-molybdenum and stainless steel plates on some functional features of human erythrocytes and platelets, being rheological properties and platelet responsiveness pivotal for the perfusion of the tissues surroding the metallic implants. Our data underline that the tested plates are not responsible for significant alterations of the erythrocyte rheological features and of platelet reactivity.

Possible involvement of plasma antioxidant defences in training-associated decrease of platelet responsiveness in humans.

The aim of this study was to evaluate in sedentary individuals the effects of a 20-week exercise training program on ex vivo platelet responsiveness and the possible involvement of plasma antioxidant defences in relation to the mechanisms controlling platelet sensitivity. A statistically significant decrease in ADP- and collagen-evoked platelet aggregation was observed after physical training together with an increase in plasma total antioxidant capacity (TEAC), superoxide dismutase activity, and high-density lipoprotein cholesterol (HDL-C) concentration. Additionally, a rise in lag time for in vitro low-density lipoprotein (LDL) oxidation as well as a decreased plasma level of secondary products of lipid peroxidation were observed after training, and the values for lag time were significantly correlated with TEAC and HDL-C. Nitrate/nitrite (NOx) content both in plasma and in platelet cytosol was significantly enhanced at the end of the training period and a significant positive correlation was found between plasma and intraplatelet NOx values. Furthermore, intraplatelet NOx content was positively correlated with HDL-C levels. The findings of the current study suggest that the improvement of antioxidant defences induced by moderate regular exercise may be involved in desensitising blood platelets most likely through the inhibition of LDL oxidation and the simultaneous enhancement of plasma and intraplatelet NOx bioavailability and HDL-C level.

Flunarizine effects on oxidative stress in migraine patients.

Prophylactic activity of flunarizine in migraine is attributed to its antioxidant properties and to the relief of cerebral vasospasm in which nitric oxide (NO) is involved. We investigated the antimigraine activity of flunarizine and its influence on NO and oxidative marker bioavailability in 25 subjects suffering from migraine without aura and in 25 healthy controls. Urinary samples collected before and after treatment with flunarizine (5 mg orally per day for 6 months) were assayed for NO stable metabolites (NOx) and thiobarbituric acid reactive substances (TBARS). Urinary levels of NOx and TBARS were higher in migraine sufferers before treatment than in healthy controls. No differences were observed in NOx levels in migraine sufferers, before and after flunarizine treatment; urinary TBARS levels were decreased after flunarizine treatment (P < 0.05) and remained persistently higher than in healthy controls (P < 0.05). Our results suggest that flunarizine did not prevent NO-mediated vasodilatation, while it proved effective in limiting the oxidative reactions occurring in migraine sufferers.

PPIX induced photohemolysis of erythrocytes partially-depleted of cholesterol.

The protoporphyrin IX (PPIX)-sensitized hemolysis of erythrocytes depleted of cholesterol was investigated. From 20% to 30% of the total membrane cholesterol was removed from cells by incubation with old autologous plasma or by means of interaction with L-alpha-phosphatidylcholine dipalmitoyl (DPPC) liposomes. As expected, after this treatment, the cells show an overall increase in membrane fluidity revealed by means of specific fluorescent probes. The same cells are more susceptible to the photohemolysis induced by PPIX excited by visible light, but gave no lysis in the absence of the sensitizer. As a consequence, the primary oxidative damage which is produced during irradiation can be possibly assigned to the phospholipidic and/or proteic moiety instead of the steroidal moiety.