PubMed Health⌕ Search

Biomedical subjects

L Sala

Publications and source records attributed to L Sala.

At least 19 recordsLinked to original sources
PubMed2005

Field efficacy of minidosed eprinomectin against Hypoderma spp. in dairy cattle.

A chemoprophylactic field trial was conducted to assess the efficacy of pour-on eprinomectin applied at the approximate dose of 50 mcg/kg to dairy cattle with naturally occurring hypodermosis. Two-hundred-eleven cattle, selected from two herds with a high prevalence of Hypoderma spp. infestation, were divided in three groups: Group A (N = 71) was treated with pour-on eprinomectin at the recommended dosage of 500 mcg/kg, Group B (N = 64) at the lower dose of 50 mcg/kg, a third group (Group C, N = 76) served as untreated control group. Treatments were performed in November-December 2002 and the animals were examined for the presence of warbles in the following April and June. No larvae emerged in the treated groups, whereas a variable number of warbles (ranging from 1 to 28) were found in control animals. Adverse reactions were not observed in any animal, and only minor side effects were observed. A larger field trial carried out in the following year (1064 treated and 131 untreated control cattle) confirmed the chemoprophylactic efficacy of minidosed eprinomectin against Hypoderma spp. Administration of eprinomectin minidoses in dairy cattle is interesting because of the low costs involved and no need for milk withdrawal.

Administration, Topical↗
PubMed2004

Towards sustainability in water recycling.

Those like us who believe in and spread the gospel of planned wastewater reclamation and reuse usually emphasize that this is a step towards sustainability in water resource management, but this is something that is very seldom analyzed. This paper discusses, from a critical point of view, issues such as goals in water reuse and influence on water demands, ecological analysis of the cycle of the main pollutants, health aspects and treatment requirements, energy consumption and measurable environmental benefits, in order to provide a set of criteria to assess sustainability in water recycling projects and to decrease the impact of the cultural water cycle on the environment.

Conservation of Natural Resources↗
PubMed2003

Changes of autonomic cardiac profile after a 3-week integrated body weight reduction program in severely obese patients.

The autonomic control of the heart is abnormal in obese subjects due to a prevalence of sympathetic over parasympathetic limb of the autonomic balance. We evaluated the effects of a short-term (3 weeks) integrated body weight reduction program (consisting of energy restricted diet and high-intensity exercise training) on heart rate variability (HRV) in severely obese, normotensive patients. The HRV was evaluated both in the time and frequency domain over a 18-hour Holter recording period obtained before and at the end of the third week. Three-week body weight reduction program reduced BMI (from 41.4 +/- 4.6 to 39.5 +/- 4.3 kg/m2, -4.6%, p<0.0001) and heart rate (from 77.8 +/- 8.6 to 73.6 +/- 8.7 b/min, p=0.0003). Significant changes in the autonomic profile were observed both in the time and frequency domain (SD of RR interval, SDRR: +16.1%; mean squared successive difference: (MSSD) +16.7%; percentage of RR intervals differing more than 50 msec from the preceding one, pNN50: +31.8%; low frequency oscillation, LF: +17.1%; high frequency oscillation, HF: +/- 18.2%). In conclusion, this study demonstrates that a short-term, integrated body weight reduction program is able to favorably modify the autonomic profile in a population of normotensive, severely obese subjects. The reduction of heart rate and the increase in parasympathetic activity may consistently contribute to a reduction of the risk of cardiovascular morbidity and of sudden cardiac death, still high in this patients' group.

Adult↗
PubMed2001

Radial artery flow-mediated dilatation in heart failure patients: effects of pharmacological and nonpharmacological treatment.

Congestive heart failure (CHF) is associated with an impaired flow-mediated vasodilation that reflects an impaired endothelial function. Limited information is available, however, on whether and to what extent this impairment is improved by pharmacological or nonpharmacological treatment. We measured radial artery diameter and blood flow by an echo-tracking Doppler device both at baseline and after 4 minutes of hand ischemia, which increases diameter through NO secretion mediated by an increase in flow and shear stress. Data were collected from 44 CHF patients (New York Heart Association class I to III) under standard treatment (diuretic, digitalis, and enalapril, 20 mg/d), in whom CHF severity was assessed by a cardiopulmonary stress test, and from 16 age- and sex-matched controls. CHF patients were then randomized to maintain for (A) 2 months of standard treatment (n=11), (B) treatment with double the ACE inhibitor dose (n=11), (C) standard treatment with an angiotensin II antagonist (losartan, 50 mg/d; n=11), or (D) standard treatment with bicycle training for 30 minutes, 3 times a week (n=11). At baseline, radial artery diameter and flow were similar in CHF patients and controls; CHF patients had a modest although significant impairment in flow increase (-36%) and a striking impairment (-78%) in diameter increase following the 4 minutes of ischemia. After 2 months, baseline diameter and flow remained unaltered in the 4 groups. After the 4 minutes of ischemia, radial artery flow and diameter increased as before in the group under standard treatment (A), whereas in the other 3 groups, the increase was significantly (P<0.05) and, for diameter, markedly (B, 83%; C, 92%; and D, 95%) greater. The vasodilatation induced by trinitroglycerin was similar in CHF and control subjects and not affected by treatments. In CHF, radial artery shows a marked reduction in flow-mediated vasodilation, reflecting impairment of endothelial function. This impairment can be markedly improved by treatments that effectively block the renin-angiotensin system either at ACE or at ACE plus angiotensin receptor level. This is the case also with nonpharmacological treatment of CHF.

Angiotensin II↗
PubMed2001

Predicting toxicity: a mechanism of action model of chemical mutagenicity.

The increasing importance of theoretical studies for predicting toxicology has aroused the interest of many computational chemists. A new approach has been developed, based on studying at the molecular level two potential mechanisms of action that are related to compound mutagenicity. This approach is the first example that considers both the toxicant and the biological target molecules involved in the interaction. Using some calculated descriptors and a simulation of the interaction chemical, compounds can be classified. More important, the approach helps in understanding and explaining both the correct and the incorrect results, and gives a deeper understanding of the toxic mechanisms. The model has been applied to many compounds and the results are compared with experimental results reported for the corresponding Salmonella tests.

Algorithms↗
PubMed2001

Different baseline sympathovagal balance and cardiac autonomic responsiveness in ischemic and non-ischemic congestive heart failure.

BACKGROUND: A profound autonomic unbalance is present in heart failure: its correlation with the etiology of the disease has never been investigated. AIMS: We characterized the sympatho-vagal balance and autonomic responsiveness of 42 patients (21 with ischemic heart failure, 21 with idiopathic dilated cardiomyopathy). Patients had comparable NYHA class, ejection fraction, exercise pVO(2), exercise ventilatory response, incidence of beta-blocking treatment. None showed periodic breathing or nocturnal arterial desaturation. METHODS: Heart rate variability was assessed in the time and frequency domain during: (1) 10 min of quiet supine resting and free breathing; (2) 10 min of regular breathing at a frequency of 20 acts/min (=parasympathetic stimulus); and (3) 10 min of active standing (=sympathetic stimulus). The ratio of the low- to high-frequency components of each autospectrum obtained in the frequency domain (LF/HF) was used as an index of sympathovagal balance. RESULTS: Patients with ischemic heart failure had a greater baseline sympathetic activation (higher LF/HF) than those with idiopathic dilated cardiomyopathy, maintaining some parasympathetic responsiveness as well (reduced LF/HF with regular breathing). CONCLUSIONS: There is a distinct autonomic control according to the etiology of heart failure, a finding that may help understanding its pathophysiology, and could be useful in the clinical management of patients.

Aged↗
PubMed2001

Novel HLA allele, HLA-B*4013, identified from a potential bone marrow recipient. Putative gene conversion events with donor sequence.

A new B40 allele was identified in a leukemic Caucasian patient. This allele, designated B*4013, differs in alpha 1 domain from B*4002 at six amino acidic positions: 67, 77, 80, 81, 82 and 83. Most of this substitutions could alter the antigen binding site of the HLA-B molecule. B*4013 may have originated by gene conversion or reciprocal recombination involving B*4002 as the recipient allele of sequence donated by B*4406. The new allele was serologically typed as a "blank" associated with the Bw4 epitope.

Alleles↗
PubMed2001

Distribution of CCR5-Delta 32 and CCR2-64I alleles in an Argentine Amerindian population.

In order to evaluate the frequency distributions of CCR5-Delta 32 and CCR2-64I polymorphisms in an Amerindian population, we tested a total of 42 Chiriguanos individuals that are aboriginal inhabitants of the north west of Argentina. Only one carried the CCR5-Delta 32 allele (0.0238), while 17 out of 35 carried the CCR2-64I mutation, including one homozygous for the mutated allele (0.2571). Although the cohort studied is considered highly endogamic, the HLA genotyping revealed that 8 out of 42 subjects had a gene flow from Caucasian populations. The only heterozygous CCR5+/Delta 32 found and three heterozygous CCR2+/64I belonged to the admix group. In conclusion, the protective deletion CCR5-Delta 32 is practically absent in Chiriguanos whereas the CCR2-64I allele is highly frequent.

Alleles↗
PubMed2001

Protracted, but not acute, hepatitis A virus infection is strongly associated with HLA-DRB*1301, a marker for pediatric autoimmune hepatitis.

HLA alleles are known to be associated with susceptibility to develop autoimmune hepatitis (AH), and hepatitis A virus (HAV) infection is postulated as a putative trigger for AH. We investigated whether HLA may influence the outcome of the HAV infection by studying 67 children with self-limited and 39 children with protracted forms of this infection. HLA typing of the uncomplicated forms showed no significant increase of any HLA class I or II alleles. In contrast, DRB1*1301 was present in 46.1% of the children with protracted forms (vs. 9.8% in healthy controls; relative risk [RR]: 7.6; chi(2) = 33.3; P = 2 x 10(-9)). In uncomplicated hepatitis, 45% developed anti-smooth muscle antibody (SMA)/actin antibodies, but only 1 child had detectable antibodies after 3 months of infection onset. In contrast, after 1 year, 69% of the patients suffering protracted forms had titers of anti-SMA/actin antibodies that ranged between 1:40 and 1:160. Within their follow-up, 2 patients developed a Hashimoto's thyroiditis, but the remaining patients showed no signs of developing autoimmune hepatitis. We conclude that the DRB1*1301 haplotype is strongly associated with the protracted forms of HAV infection and suggest that the infection allows a sustained release of liver self-antigens. However, other still-unknown susceptibility genes are required for the full development of pediatric AH.

Acute Disease↗
PubMed2001

Cultural eutrophication control through water reuse.

The increasing use of mineral fertilisers over the last decades has contributed to the appearance of numerous cases of water eutrophication, a new form of water pollution. The starting point of eutrophication is the increase of nutrient concentration (nitrogen and phosphorus) in a water mass, which is subsequently followed by an uncontrolled growth of primary producers and episodes of oxygen depletion due to microbial decomposition of algal organic matter. The excess nutrient loads reaching surface waters are usually associated to discharges from anthropogenic activities, which normally involve direct water usage instead of reuse of reclaimed effluents. Agriculture activities and livestock breeding are two of the main nutrient sources responsible for water eutrophication, as well as human--urban and industrial--wastewater discharges. Wastewater reclamation and reuse can be a suitable strategy for preserving the quality of natural waters, by suppressing effluent discharges and the associated nutrient contributions to receiving waters. Reuse of reclaimed water for agricultural and landscape irrigation as well as for environmental enhancement offers an adequate strategy for preserving natural water systems from eutrophication.

Conservation of Natural Resources↗
PubMed2000

Long-term lifestyle changes maintain the autonomic modulation induced by rehabilitation after myocardial infarction.

The altered autonomic balance observed after myocardial infarction is shifted toward a higher parasympathetic tone by rehabilitation. This effect persists after 1 year, however we observed a discrete variability in the long-term sympathovagal balance among patients. We postulated that such variability derives from the disparate adherence of patients to lifestyle prescriptions regarding exercise continuance and smoking avoidance. To test this hypothesis, we reviewed the data of 40 patients, who completed with a favourable autonomic modulation the initial rehabilitation phase after myocardial infarction and underwent the annual follow-up. One year after infarction, 23 patients complied to the advice about regular exercise and smoking avoidance (adherent, Group 1); 17 did not (non-adherent, Group 2). Groups were similar for age, site of infarction, left ventricular function, stress test duration and therapy. The ratio LF/HF, derived from the power spectral density of RR intervals variability, was used as an index of the sympathovagal balance. It was obtained from 15 min of ECG at rest, assessed 1 month after MI (baseline), and repeated 3 months (rehabilitation) and 1 year (follow-up) afterwards. Rehabilitation increased parasympathetic tone in all patients, reducing LF/HF by 33%. At follow-up, this potentially favourable autonomic profile persisted only in Group 1 patients. In conclusion, after a first myocardial infarction, the persistence of the potentially beneficial effect of rehabilitation on the sympathovagal balance depends on the compliance to the lifestyle changes proposed during the initial phase.

Analysis of Variance↗
PubMed2000

Relationship between baseline sympatho-vagal balance and the autonomic response to cardiac rehabilitation after a first uncomplicated myocardial infarction.

BACKGROUND: After a first uncomplicated myocardial infarction, cardiac rehabilitation increases the parasympathetic tone, in a direction linked to a reduced risk of sudden cardiac death. This change in sympatho-vagal balance may be related to other clinical variables. The aim of this study was to define the factors implicated in determining the autonomic response to cardiovascular rehabilitation after myocardial infarction. METHODS: In 55 patients (39-80 years) we evaluated the modulation of the autonomic profile induced by 8 weeks of rehabilitation: we analyzed the changes in pNN50 derived from time-domain analysis (deltapNN50) and in the low frequency/high frequency (LF/HF) ratio derived from autoregressive power spectral analysis (deltaLF/HF). A control group of 15 patients not undergoing rehabilitation was also studied. Variables considered at 4 weeks postinfarction and related to deltapNN50 and deltaLF/HF ratio were: age, site of myocardial infarction, previous thrombolysis, ejection fraction, stress test duration, baseline LF/HF ratio. RESULTS: Patients not undergoing rehabilitation did not change their autonomic profile. On the contrary, rehabilitation induced a higher vagal tone (pNN50 from 6.5 +/- 1.5 to 16.2 +/- 3.1; LF/HF ratio from 8.3 +/- 5.2 to 5.1 +/- 2.9, p < 0.05). Eleven patients (20%) had baseline LF/HF ratio exceeding the mean value by 1.5 SD (19.4 +/- 1.4): in this subgroup, pNN50 was very low. In these patients, rehabilitation increased pNN50 and decreased LF/HF ratio. Indeed, both deltapNN50 and deltaLF/HF ratio were significantly related to their baseline values (p < 0.001), even considering thrombolysis, site of myocardial infarction, age, and beta-blocker therapy. CONCLUSIONS: After a first uncomplicated myocardial infarction, sympatho-vagal balance may be very disturbed in some patients, despite a preserved ventricular function, good exercise capability and beta-blockers. These patients should be encouraged to undergo rehabilitation, since the significant improvement in the parasympathetic tone may protect them against subsequent arrhythmic events.

Aged↗
PubMed1998

Effects of cardiac rehabilitation and beta-blocker therapy on heart rate variability after first acute myocardial infarction.

After acute myocardial infarction (AMI), rehabilitation with physical training increases parasympathetic tone. It is unknown whether such a favorable effect of exercise on the sympathovagal balance interacts with effects of other widespread therapies, such as beta blockers. In 53 patients after a first, uncomplicated AMI, we studied the combined short- and long-term influence on heart rate variability (HRV) of rehabilitation and beta blockade. Patients were divided into 3 groups: group 1 (n = 19) underwent rehabilitation with physical training; group 2 (n = 20) was taking beta blockers and underwent rehabilitation; group 3 (n = 14) was taking beta blockers and did not enter the rehabilitation program for logistic reasons. Patients were similar as to age, site of infarction, ejection fraction, left ventricular diameter, and baseline stress test duration. Measures of HRV (obtained from a 15-minute resting electrocardiogram) were the standard deviation of the mean RR interval (RRSD), the mean squared successive differences (MSSD), the percent of RR intervals differing >50 ms from the preceding one (pNN50), the low-(LF) and high-(HF) frequency components of the autoregressive power spectrum of the RR intervals and their ratio (LF/HF). Four weeks after AMI, there was less sympathetic predominance in groups 2 and 3 (i.e., patients taking beta blockers [p <0.05]). Rehabilitation modified HRV in groups 1 and 2 (p <0.05), with signs of increased parasympathetic tone (group 1: MSSD +25%, pNN50 +69%, LF/HF -40%; group 2: MSSD +41%, pNN50 +48%, LF/HF -39%). These changes persisted in the long term. In group 3, HRV was unchanged over time. Hence, after AMI, the effects of rehabilitation and beta blockers on HRV are not redundant: their association induces a more favorable sympathovagal balance, accelerating the recovery of a normal autonomic profile.

Adrenergic beta-Antagonists↗
PubMed1996

Short and long term effects of exercise training on the tonic autonomic modulation of heart rate variability after myocardial infarction.

We studied the effects of cardiac rehabilitation on the sympathovagal control of heart rate variability in 30 patients after a first, uncomplicated myocardial infarction. Twenty-two patients completed 8 weeks of endurance training (trained), while eight decided not to engage in the rehabilitation programme for logistical reasons, and were taken as untrained controls. Age, site of infarction, ejection fraction, ventricular diameter and stress test duration were similar in the two groups at baseline. Heart rate variability was evaluated 4 weeks after infarction before starting rehabilitation, and repeated 8 weeks and one year later in both trained and untrained patients. Measures of heart rate variability, obtained from both time- and frequency-domain analysis of a 15 min ECG recording in resting conditions, were as follows: mean RR interval and its standard deviation (RRSD), the mean square successive differences (MSSD), the percent of RR intervals differing > 50 ms from the preceding RR (pNN50), the low and high frequency components of the autoregressive power spectrum of the RR intervals and their ratio (LF/HF). At baseline, heart rate variability was similar in trained and untrained patients. In the short term (8 weeks after infarction), training increased RRSD by 25% (P < 0.01), MSSD by 69% (P < 0.01), pNN50 by 120% (P < 0.01), and reduced LF/HF ratio by 30% (P < 0.01). The effects persisted after one year in trained patients. In untrained patients, the autonomic control of heart rate variability did not change 8 weeks after myocardial infarction and was only slightly modified by time. Thus, exercise training, performed for 8 weeks after a myocardial infarction, modifies the sympathovagal control of heart rate variability toward a persistent increase in parasympathetic tone, known to be associated with a better prognosis. This may partly account for the favourable outcome of patients who undergo rehabilitation.

Aged↗
PubMed1993

Long-term physical training and left ventricular remodeling after anterior myocardial infarction: results of the Exercise in Anterior Myocardial Infarction (EAMI) trial. EAMI Study Group.

OBJECTIVES: The aim of this multicenter randomized study was to investigate whether long-term physical training would influence left ventricular remodeling after anterior myocardial infarction. BACKGROUND: Exercise is currently recommended for patients after myocardial infarction; however, the effects of long-term physical training on ventricular size and remodeling still have to be defined. METHODS: Patients with no contraindications to exercise were studied 4 to 8 weeks after anterior Q wave myocardial infarction and 6 months later by echocardiography at rest and bicycle ergometric testing. After the initial study, patients were randomly allocated to a 6-month exercise training program (n = 49) or a control group (n = 46). A computerized system was used to derive echocardiographic variables of ventricular size, function and topography. RESULTS: After 6 months, a significant (p < 0.01) increase in work capacity (from 4,596 +/- 1,246 to 5,508 +/- 1,335 kp-m) was observed only in the training group, whereas global ventricular size, regional dilation and shape distortion did not change in either the control or the training group. However, compared with patients with an ejection fraction > 40%, patients with an ejection fraction < or = 40% had more significant (p < 0.001) ventricular enlargement at entry and demonstrated further (p < 0.01) global and regional dilation after 6 months, in both the control and the training group (end-diastolic volume from 77 +/- 14 to 85 +/- 17 ml/m2 in the control group and from 74 +/- 11 to 77 +/- 15 ml/m2 in the training group; regional dilation from 46 +/- 18% to 57 +/- 21% in the control group and from 42 +/- 18% to 44 +/- 26% in the training group). Ventricular size and topography did not change in patients with an ejection fraction > 40%. CONCLUSIONS: Patients with poor left ventricular function 1 to 2 months after anterior myocardial infarction are prone to further global and regional dilation. Exercise training does not appear to influence this spontaneous deterioration. Thus, postinfarction patients without clinical complications, even those with a large anterior infarction, may benefit from long-term physical training without any additional negative effect on ventricular size and topography.

Electrocardiography↗
PubMed1992

EAMI--exercise training in anterior myocardial infarction: an ongoing multicenter randomized study. Preliminary results on left ventricular function and remodeling. The EAMI Study Group.

To determine the effects of a 6-month exercise training program on left ventricular (LV) function and remodeling, 49 consecutive patients (pts) with first Q anterior myocardial infarction (51 +/- 8 years), in I-II NYHA class, were studied 4 to 8 weeks after the acute episode and 6 months later by 2D-ECHO and upright bicycle ergometric test. At entry, pts were randomly allocated to physical training (T = 25pts) or control (C = 24pts). Global endocardial surface area (ESA), LV volumes and EF, extent of abnormal wall motion (%WMA), of regional dilatation (%REG DIL), and the shape distortion (DIST) index were analyzed. After 6 months, a significant increase in work capacity (4,589 +/- 1,417 to 5,379 +/- 1,485 KPM/min, p less than 0.03) and in lactic anaerobic threshold (45 +/- 13 to 63 +/- 15 W, p less than 0.01) was observed only in T. Initial ESA, EDV, EF, %WMA, %REG DIL, and DIST index were similar and they did not change after 6 months in both groups. However, pts with less than 40%EF had greater (p less than 0.0001) EDV and %WMA with marked DIST index at entry and showed further (p less than 0.01) deterioration after 6 months both in C and in T (EDV, ml/m2: 68 +/- 12 to 77 +/- 18 in C, 71 +/- 12 to 74 +/- 18 in T; %REG DIL: 39 +/- 20 to 49 +/- 24 in C, 32 +/- 12 to 35 +/- 23 in T; DIST index: 0.16 +/- 0.07 to 0.21 +/- 0.09 in C, 0.2 +/- 0.07 to 0.22 +/- 0.1 in T). These variables did not change in pts with greater than 40%EF. Thus, from these preliminary data, pts with less than 40%EF at entry are prone to further global and regional LV deterioration. Physical training does not seem to increase this spontaneous deterioration.

Anaerobic Threshold↗