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Biomedical subjects

R Ferrari

Publications and source records attributed to R Ferrari.

At least 127 records · Page 7Linked to original sources
PubMed1999

Beneficial effects of propionyl L-carnitine on sarcolemmal changes in congestive heart failure due to myocardial infarction.

OBJECTIVE: Earlier studies have revealed sarcolemmal (SL) defects in congestive heart failure due to myocardial infarction; however, the mechanisms of SL changes in the failing heart are poorly understood. Since congestive heart failure is associated with various metabolic abnormalities including a deficiency of carnitine, we examined the effects of propionyl L-carnitine, a carnitine derivative, in animals with congestive heart failure. METHODS: For this purpose, heart failure in rats was induced by occluding the coronary artery and 3 weeks later the animals were treated with 100 mg/kg (i.p. daily) propionyl L-carnitine for 4 weeks. The sham control group received saline injections. The animals were assessed for their left ventricular function. SL membranes were examined for Na(+)-K+ ATPase, Na(+)-Ca2+ exchange and adenylate cyclase activities. RESULTS: A marked improvement in the attenuated left ventricular function of the experimental animals was seen upon treatment with propionyl L-carnitine. The SL adenylyl cyclase activities in control, untreated failing hearts and treated failing hearts were 590 +/- 36, 190 +/- 22 and 320 +/- 21 pmol cAMP/mg/10 min, whereas the SL Na(+)-K+ ATPase activities were 35.7 +/- 2.8, 22.5 +/- 2.4 and 30.1 +/- 2.8 mumol Pi/mg/h, respectively. Furthermore, the SL Na(+)-dependent Ca(2+)-uptake activity, which decreased in the failing hearts (4.6 +/- 0.4 vs. 9.3 +/- 0.7 nmol Ca2+/mg/2 s for control), was improved (6.8 +/- 0.5 nmol Ca2+/mg/2 s) significantly following treatment with propionyl L-carnitine. CONCLUSION: These results indicate that metabolic therapy with propionyl L-carnitine may attenuate defects in the SL membrane and thus may improve heart function in congestive heart failure due to myocardial infarction.

Adenylyl Cyclases↗
PubMed1999

Clozapine lacks previous clinical efficacy when restarted after a period of discontinuation: a case series.

No data are available in the literature about clozapine clinical efficacy when the drug is administered to schizophrenic patients who relapsed after discontinuation of long-term clozapine treatment and who had previously been responsive to the drug. In this study, three chronic schizophrenic patients are presented, who, in spite of a good clinical efficacy, decided to stop long-term clozapine treatment. Soon after their relapse they were again treated with clozapine: follow-up of these patients showed that clozapine partially lost its clinical efficacy since all three patients got worse compared with their initial clinical response.

Adult↗
PubMed1999

Changes in oxidative stress and cellular redox potential during myocardial storage for transplantation: experimental studies.

BACKGROUND: Cardioplegic solutions assure only a sub-optimal myocardial protection during prolonged storage for transplantation. The ultimate cause of myocardial damage during storage is unknown, but oxygen free radicals might be involved. We evaluated the occurrence of oxidative stress and changes in cellular redox potential after different periods of hypothermic storage. METHODS: Langendorff-perfused rabbit hearts were subjected to a protocol mimicking each stage of a cardiac transplantation procedure: explantation, storage and reperfusion. Three periods of storage were considered: Group A = 5 hours, Group B = 15 hours, and Group C = 24 hours. Oxidative stress was determined in terms of myocardial content and release of reduced (GSH) and oxidized (GSSG) glutathione, and cellular redox potential as oxidized and reduced pyridine nucleotides ratio (NAD/NADH). Data on mechanical function, cellular integrity and myocardial energetic status were collected. RESULTS: At the end of reperfusion, despite the different timings of storage, recovery of left ventricular developed pressure (46.1+/-7.0, 54.7+/-6.7, and 45.7+/-7.4% of the baseline pre-ischaemic value), energy charge (0.81+/-0.02, 0.81+/-0.02, and 0.77+/-0.01) and NAD/NADH ratio (8.87+/-1.08, 9.39+/-1.72, and 10.26+/-1.98) were similar in all groups (A, B and C). On the contrary, the rise in left ventricular resting pressure (LVRP) and GSH/GSSG ratio were significantly different between Group C, and Groups A and B (p<0.0001, analyzed by Generalized Estimating Equations model for repeated measures, and p<0.05, respectively). CONCLUSIONS: The pathophysiology of myocardial damage during hypothermic storage cannot be considered as a normothermic ischaemic injury and parameters other than energetic metabolism, such as thiolic redox state, are more predictive of functional recovery upon reperfusion.

Animals↗
PubMed1999

Prevalence of temporomandibular disorders associated with whiplash injury in Lithuania.

OBJECTIVE: The purpose of this study was to ascertain the prevalence of symptoms of temporomandibular disorders in whiplash victims in Lithuania and compare it with the prevalence in otherwise healthy control subjects. STUDY DESIGN: In a controlled historical cohort study in Lithuania, we asked each of 210 victims of vehicular rear-end collisions (at 14-27 months after the accident) to report the presence and frequency of a number of temporomandibular disorder symptoms. The results were compared with those for an age-matched and gender-matched control group, sampled randomly from the local population. RESULTS: In the accident group, 2.4% of subjects (4/165) reported jaw pain for 1 day or more per month; this compared with 3.3% of the controls (6/180). One (0.6%) of the accident victims and 2 (1.1%) of the controls had daily jaw pain. In both groups there was a low prevalence of jaw sounds, pain in or near the ear(s), jaw locking, tinnitus, and facial pain. CONCLUSIONS: Unlike whiplash claimants in many Western societies, Lithuanian accident victims do not appear to report the chronic symptoms of temporomandibular disorders despite their acute whiplash injuries.

Accidents, Traffic↗
PubMed1999

Induction of functional inducible nitric oxide synthase in monocytes of patients with congestive heart failure. Link with tumour necrosis factor-alpha.

AIMS: We studied the induction of monocytic inducible nitric oxide synthase expression and the tumour necrosis factor-alpha system in patients with congestive heart failure. METHODS AND RESULTS: Forty-three congestive heart failure patients and 15 healthy subjects were studied. Antigenic tumour necrosis factor-alpha and its soluble receptors, measured by ELISA, were increased in chronic heart failure and the increase was related to the clinical severity of the syndrome (tumour necrosis factor-alpha from 8.2+/-5.2 in NYHA class II to 18.2+/-7.2 in class III and 26.9+/-13.2 pg. ml(-1)in class IV, P<0.0001 classes III and IV vs class II; soluble tumour necrosis factor receptor I from 1.0+/-0.2 in class II to 2.3+/-1.1 in class III and 5.5+/-3.2 ng. ml(-1)in class IV, P<0.0001 classes III and IV vs class II; soluble tumour necrosis factor receptor II from 2.7+/-0.7 in class II to 4.9+/-1.9 in class III and 8.4+/-5.0 ng. ml(-1)in class IV, P<0.002 classes III and IV vs class II). Monocytic inducible nitric oxide synthase assessed by Western blot, was expressed only in congestive heart failure patients (13 out of 43). The association among monocytic inducible nitric oxide synthase expression, tumour necrosis factor-alpha system activation, neurohormones and other clinical parameters was studied. The univariate logistic regression showed that inducible nitric oxide synthase expression was strictly associated with NYHA class (P<0.05), antigenic tumour necrosis factor-alpha (P<0.01) and its soluble receptors (P<0.05). The multivariate analysis showed that antigenic tumour necrosis factor-alpha was the only predictor for monocytic inducible nitric oxide synthase expression (P<0.05, RR=2.75, CI 1. 34-5.43). CONCLUSIONS: Inducible nitric oxide synthase is expressed in circulating monocytes of patients with severe congestive heart failure. This phenomenon is linked to the activation of the tumour necrosis factor-alpha system.

Adult↗
PubMed1999

Unmasking anti-endomysial antibodies in coeliac subjects positive for anti-smooth muscle antibodies.

Anti-endomysial antibodies assayed by indirect immunofluorescence presently represent the most advanced in vitro method for diagnosing coeliac disease. While testing the serum of patients affected by coeliac disease for anti-endomysial antibodies, we noticed in some samples the presence of anti-smooth muscle antibodies. This led us to the hypothesis that anti-smooth muscle antibodies might mask the presence of anti-endomysial antibodies. The aim of our research was to develop a method that could confirm our hypothesis. Here we show that the AEA response can be effectively unmasked by increasingly diluting anti-smooth muscle antibodies-positive serum.

Autoantibodies↗
PubMed1999

Role of A2A receptor in the modulation of myocardial reperfusion damage.

Adenosine protects myocardium from ischemia and reperfusion damage; however, the mechanism of action is still under discussion. We investigated whether (a) adenosine protects isolated crystalloid-perfused rabbit heart from ischemia/ reperfusion injury; (b) this action is receptor mediated and what receptor subtypes are involved, and (c) this action is dependent on an enhanced nitric oxide production. Our results showed a cardioprotective effect of adenosine (10(-4) M), of nonselective adenosine-receptor agonist 5'-N-ethyl-carboxamidoadenosine (NECA; 5 x 10(-6) M), and of A2A agonists CGS 21680 (10(-8) and 10(-6) M), 2-hexynylNECA (10(-7) M). On the contrary, A1 agonist CCPA (10(-8) and 10(-6) M) does not provide any protection. The effect has been achieved in terms of significant reduction in contracture development during reperfusion [diastolic pressure was 46.8 +/- 7.1 mm Hg (p < 0.01); 46.1 +/- 7.8 mm Hg (p < 0.01); 46.9 +/- 5.5 mm Hg (p < 0.01); and 59.3 +/- 6.7 mm Hg (p < 0.05) with 10(-4) M adenosine, 5 x 10(-6) M NECA, 10(-6) M CGS 21680, and 10(-7) M 2-hexynylNECA, respectively, versus 77.6 +/- 5.0 mm Hg in control]; reduced creatine phosphokinase release (13.5 +/- 1.6, 22.2 +/- 7.9, 14.2 +/- 3.3, and 14.1 +/- 4.5 U/gww in treated hearts vs. 34.6 +/- 7.2 U/gww in controls; p < 0.05); improved energy metabolism [adenosine triphosphate (ATP) content is 9.9 +/- 0.5, 10.4 +/- 0.6, 9.8 +/- 0.5, and 10.5 +/- 0.5 micromol/gdw in treated hearts vs. 7.6 +/- 0.2 micromol/gdw; p < 0.05]. Moreover, our data indirectly show a functional presence of A2A receptors on cardiomyocytes as the protection is A2A mediated and exerted only during reperfusion, although in the absence of blood and coronary flow changes. These activities appear independent of nitric oxide pathways, as adenosine and 2-hexynylNECA effects are not affected by the presence of a nitric oxide-synthase inhibitor (10(-4) M L-NNA).

Adenosine↗
PubMed1999

Effect of leisure time and working activity on principal risk factors and relative interactions in active middle-aged men.

DESIGN: This study was designed to evaluate, in a cohort of 1039 middle-aged men, the interaction between the duration and intensity of physical activity performed either during leisure time (competitive sports, walking, cycling) or work, and principal coronary disease risk factors. METHOD: A cohort of subjects aged 45-64 years were recruited in 1993. Subjects included both individuals who were physically active and those who were sedentary, and were age-matched. RESULTS: Leisure time physical activity was inversely related to levels of total cholesterol, triglycerides, and fibrinogen, and to diastolic and systolic blood pressure. High-density lipoprotein cholesterol level was directly related to leisure time activity. Working activity, even if strenuous, was not related to risk profile. Leisure time activity did not favorably influence lipid levels in smokers, obese subjects or those with known dyslipidemia. CONCLUSIONS: This study further reinforces the use of continuous diet and drug treatment in dyslipidemic subjects and in smokers, who have to refrain from smoking if they are to benefit fully from the effects of physical activity.

Body Mass Index↗