PubMed Health⌕ Search

Biomedical subjects

L Molinari

Publications and source records attributed to L Molinari.

At least 37 records · Page 2Linked to original sources
PubMed1999

Low-energy epicardial pacing in children: the benefit of autocapture.

BACKGROUND: Permanent cardiac pacing in children results commonly in augmented energy consumption because of the high pacing rates and the ample stimulation safety margin applied in children. Cardiovascular anatomy and limited venous access sometimes preclude the otherwise preferred endocardial approach. In this multicenter patient series, we studied the feasibility, safety, and energy saving obtained by a combination of steroid-eluting epicardial leads with autocapture devices capable of ongoing adjustment of the stimulation output to the prevailing threshold. METHODS: Autocapture devices (Pacesetter Microny SR+/- and Regency SR+/-; Pacesetter, Solna, Sweden) and steroid-eluting epicardial pacing leads (Medtronic CapSure Epi 10366; Medtronic, Inc, Minneapolis, MN) were implanted in 14 children. Thresholds, telemetry data, evoked response, and polarization signals were obtained at discharge and follow-up, and battery service life was calculated. RESULTS: During a median follow-up of 6.5 months, autocapture pacing was applied in 12 of 14 children. The automatically adjusted pulse amplitude of autocapture devices demonstrated low-energy pacing with no significant changes between discharge and 6 months follow-up (1.1 +/- 0.3 versus 0.9 +/- 0.3 V). Autocapture-programmed pacemakers had calculated life spans of 7.8 +/- 1.4 years (Microny) and 21.0 +/- 1.6 years (Regency). No adverse effects were noted. CONCLUSIONS: Autocapture-controlled pacing with bipolar epicardial pacing leads is feasible and safe in children. Autocapture programming results in substantial energy savings and extends battery life markedly.

Child↗
PubMed1999

Body fat determined by skinfold measurements is elevated despite underweight in infants with Prader-Labhart-Willi syndrome.

Body composition and leptin were studied in 13 young, still underweight and 10 older overweight children with Prader-Labhart-Willi syndrome. Not only the older overweight children but also the young underweight children had elevated skinfold standard deviation scores for body mass index and elevated body mass index adjusted leptin levels, suggesting relatively increased body fat despite underweight. Our data indicate that body composition in Prader-Labhart-Willi syndrome is disturbed already in infancy, long before the onset of obesity. Leptin production appears to be intact.

Adipose Tissue↗
PubMed1999

Nonuniversality of compact support probability distributions in random matrix theory.

The two-point resolvent is calculated in the large-n limit for the generalized fixed and bounded trace ensembles. It is shown to disagree with that of the canonical Gaussian ensemble by a nonuniversal part that is given explicitly for all monomial potentials V(M)=M(2p). Moreover, we prove that for the generalized fixed and bounded trace ensemble all k-point resolvents agree in the large-n limit, despite their nonuniversality.

Journal Article↗
PubMed1998

Longitudinal monthly body measurements from 1 to 12 months of age: a study by practitioners for practitioners. Zurich Association of Practicing Paediatricians.

UNLABELLED: A longitudinal growth study with monthly measurements during the 1st year of life was conducted by nine paediatricians working in private practice in Zurich. Of 92 children, none was lost to the study and only 32 of 1104 planned visits were missed; the quality of the measurements was comparable to that of a specialised university clinic. Compared to the Zurich Longitudinal Growth Studies, children of this study were considerably heavier and taller. In 92% of the subjects, growth velocity was at least once outside the reference range (3rd 97th percentile). For weight increments, the corresponding proportion was 87%. CONCLUSIONS: The data indicate that current standards for the 1st year of life for the Zurich area might no longer be appropriate and need to be updated. The currently used velocity percentiles based on 3-monthly measurements are not suitable to assess individual height and weight increments calculated from monthly measurements.

Anthropometry↗
PubMed1998

Low insulin, IGF-I and IGFBP-3 levels in children with Prader-Labhart-Willi syndrome.

It is well established that insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein-3 (IGFBP-3) and insulin are low in growth hormone deficiency, but due to their dependence on nutrition, they are elevated in healthy obese children. As the presence of growth hormone deficiency in Prader-Labhart-Willi syndrome (PWS) is still controversial, we studied insulin, IGF-I and IGFBP-3 levels in 19 children with PWS (age range 0.5-14.6 years). Serum concentrations of insulin (SDS: -0.7+/-0.9, P = 0.01) and IGF-I (SDS: -0.7+/-0.8, P = 0.002) were low, but IGFBP-3 (SDS: -0.3+/-1.2, P = 0.2) was normal compared to normal weight age-matched children. Since children with PWS are typically obese, insulin, IGF-I and IGFBP-3 levels should be compared to normal obese children who present increased levels of these hormones. In comparison to data of healthy obese children reported in the literature, not only IGF-I, but also IGFBP-3 levels are low and fasting insulin levels even very low, suggesting a growth hormone deficiency.

Child↗
PubMed1998

Serum and CSF levels of neuron-specific enolase (NSE) in cardiac surgery with cardiopulmonary bypass: a marker of brain injury?

We investigated whether neuron-specific enolase (NSE) in serum or cerebrospinal fluid (CSF) reflects subtle or manifest brain injury in children undergoing cardiac surgery using cardiopulmonary bypass (CPB). NSE was measured in serum (s-NSE) before, and up to, 102 h after surgery in 27 children undergoing cardiac surgery with CPB. In 11 children, CSF-NSE was also measured 48 or 66 h post-surgery. As erythrocytes contain NSE, hemoglobin concentration in the samples was determined spectrophotometrically at 550 nm (cut-off limit: absorbance 0.4 = 560 mg/l) in 14 children and in a further 13 children by spectroscopic multicomponent analysis (cut-off limit 5 micromol/l = 80 mg/l). One hundred and one of 214 post-operative serum samples (47%) had to be discarded because of hemolysis (18% spectrophotometrically at 550 nm and 88% with spectroscopic multicomponent analysis). On the first and second post-operative day, the median s-NSE values were significantly higher when compared with samples taken after 54 h or longer (P = 0.008 and P = 0.002). All CSF-NSE levels were within the normal range and below the s-NSE measured in the same patient. Although in our study elevated s-NSE seems to indicate brain injury in CPB-surgery, the low concentration of NSE in the post-operative CSF of 11 children puts the neuronal origin of s-NSE in question. NSE from other non-neuronal tissues probably contributes to the elevated s-NSE. Additionally, normal post-operative CSF-NSE values in two children with post-operative neurological sequelae might question the predictive value of CSF-NSE with regard to brain injury.

Biomarkers↗
PubMed1998

The relationship of serum-eosinophil cationic protein and eosinophil count to disease activity in children with bronchial asthma.

BACKGROUND: The serum-eosinophil cationic protein level (S-ECP) has been promoted as a biomarker of asthma that reflects the degree of bronchial eosinophilic inflammation. PATIENTS AND METHODS: To investigate whether S-ECP is indeed a clinically useful objective parameter, especially in mild or moderate chronic childhood asthma, we studied 100 outpatient children with chronic asthma symptoms (63 boys and 37 girls, aged three to 15 years, median of age eight) and 25 controls (12 boys and 13 girls aged three to 15 years, median of age eight). Symptom scores, lung function parameters and atopy were compared with S-ECP determined by commercially available tests and eosinophils measured by an autoanalyser. RESULTS: Asthma symptom scores in the patient group ranged between one and 13 (median of 8), S-ECP between 2.1 and 75.6 microg/l (median of 13.3 microg/ l), and eosinophils between 30/microl and 2002/microl (median of 314). Symptom scores and S-ECP were correlated significantly (P < 0.001) as were symptom scores and eosinophils (P = 0.001). S-ECPs were significantly higher in children with chronic asthma symptoms compared with non-asthmatic, non-atopic children (P = 0.005 for non-atopic chronic asthmatics and P < 0.001 for atopic asthmatics); similar results were found comparing eosinophils in these groups. There was no difference in S-ECP between atopic and non-atopic asthmatic children, but the 25 polysensitised asthmatic children especially with sensitisations to mite, pollen and pet allergens were found to have significantly higher S-ECP compared to 15 monosensitised children (P = 0.002). Similar results were found when correlating eosinophil numbers with atopy. Polysensitised (mite, pollen, pet) asthmatics had significantly higher eosinophil counts compared with monosensitised (pollen) asthmatics (P = 0.01); there was, however, a better discrimination between atopic and non-atopic asthmatics (P = 0.001). Non-asthmatic, non-atopic controls had significantly lower eosinophil counts compared with asthmatics (P < 0.001 for both non-atopic and atopic asthmatics). No correlation between S-ECP or eosinophils and any of the lung function parameters measured (FEV1, FEV1/FVC, MEF50, airway resistance and ITGV) was found. SUMMARY: Our data thus indicate that 1) S-ECP is higher than normal in children with asthma symptoms and correlates with asthma symptom score. 2) S-ECP is better correlated to symptom score than to lung function parameters especially in children with mild and moderate asthma symptoms. 3) Raised S-ECP appears to reflect the extent of allergen sensitivity and may also reflect current allergen exposure. 4) Similar correlations were seen when measuring eosinophil number by an autoanalyser instead of S-ECP. CONCLUSIONS: Although S-ECP and eosinophils are not diagnostic of asthma they are useful inflammation markers especially in the context of clinical studies. However, both methods are not yet suitable for use in daily practice because they require extensive procedures and special equipment.

Adolescent↗
PubMed1997

The effect of the N-methyl-D-aspartate receptor antagonist dextromethorphan on perioperative brain injury in children undergoing cardiac surgery with cardiopulmonary bypass: results of a pilot study.

Experimental evidence indicates a role of the N-methyl-D-aspartate receptor in the pathogenesis of brain injury occurring during cardiac surgery with cardiopulmonary bypass (CPB). Dextromethorphan is a noncompetitive antagonist of this receptor with a favorable safety profile. Thirteen children age 3-36 months undergoing cardiac surgery with expected CPB of 60 minutes or more were randomly assigned to treatment with dextromethorphan (36-38 mg/kg/day) or placebo administered by naso-gastric tube. Dextromethorphan was absorbed well and reached putative therapeutic levels in blood and cerebrospinal fluid. Adverse effects were not observed. Mild hemiparesis developed after operation in one child of each group, and severe encephalopathy in one of the placebo group. Sharp waves were recorded in postoperative continuous electroencephalography in all placebo (n = 7) but only in 2/6 dextromethorphan treated children (p = 0.02). Pre- and postoperative cranial magnetic resonance imaging (MRI) revealed less pronounced ventricular enlargement in the dextromethorphan group (not significant). An increase of periventricular white matter lesions was visible in two placebo-treated children only. No elevations of cerebrospinal fluid enzymes were observed in either group. Although children with dextromethorphan showed less abnormalities in electroencephalography and MRI, dissimilarities of the treatment groups by chance diminished conclusions to possible protective effects of dextromethorphan at this time.

Brain Chemistry↗
PubMed1996

Long-term transcutaneous monitoring of oxygen tension and carbon dioxide at 42 degrees C in critically ill neonates: improved performance of the tcpo2 monitor with topical metabolic inhibition.

UNLABELLED: Whereas during the last few years handling of the transcutaneous PO2 (tcPO2) and PCO2 (tcPCO2) sensor has been simplified, the high electrode temperature and the short application time remain major drawbacks. In order to determine whether the application of a topical metabolic inhibitor allows reliable measurement at a sensor temperature of 42 degrees C for a period of up to 12 h, we performed a prospective, open, nonrandomized study in a sequential sample of 20 critically ill neonates. A total of 120 comparisons (six repeated measurements per patient) between arterial and transcutaneous values were obtained. Transcutaneous values were measured with a control sensor at 44 degrees C (conventional contact medium, average application time 3 h) and a test sensor at 42 degrees C (Eugenol solution, average application time 8 h). Comparison of tcPO2 and PaO2 at 42 degrees C (Eugenol solution) showed a mean difference of +0.16 kPa (range +1.60 to -2.00 kPa), limits of agreement +1.88 and -1.56 kPa. Comparison of tcPO2 and PaO2 at 44 degrees C (control sensor) revealed a mean difference of +0.02 kPa (range +2.60 to -1.90 kPa), limits of agreement +2.12 and -2.08 kPa. Comparison of tcPCO2 and PaCO2 at 42 degrees C (Eugenol solution) showed a mean difference of +0.91 (range +2.30 to +0.10 kPa), limits of agreement +2.24 and -0.42 kPa. Comparison of tcPCO2 and PaCO2 at 44 degrees C (control sensor) revealed a mean difference of +0.63 kPa (range 1.50 to -0.30 kPa), limits of agreement +1.73 and -0.47 kPa. CONCLUSION: Our results show that the use of an Eugenol solution allows reliable measurement of tcPO2 at a heating temperature of 42 degrees C; the application time can be prolongued up to a maximum of 12 h without aggravating the skin lesions. The performance of the tcPCO2 monitor was slightly worse at 42 degrees C than at 44 degrees C suggesting that for the Eugenol solution the metabolic offset should be corrected.

Blood Gas Monitoring, Transcutaneous↗
PubMed1996

Response to a single oral dose of all-rac-alpha-tocopheryl acetate in patients with cystic fibrosis and in healthy individuals.

Biochemical vitamin E deficiency and low plasma lipids are frequent findings in patients with cystic fibrosis (CF). The response to a single oral dose of all-rac-alpha-tocopheryl acetate [100 IU (100 mg)/kg body wt] was studied over 24 h in 25 CF patients with exocrine pancreatic insufficiency and in 23 healthy individuals. Patients received pancreatic enzymes together with the vitamin E test dose. At baseline, plasma alpha-tocopherol concentrations correlated with cholesterol concentrations; both were lower in patients than in control subjects, as were erythrocyte alpha-tocopherol concentrations (all P < 0.0001). Plasma and erythrocyte alpha-tocopherol concentrations were significantly higher than baseline concentrations from 3 and 6 h onward, respectively, and peaked most frequently at 6 and 12 h, respectively, in both patients and control subjects. Maximum increases and areas under the concentration time curves for plasma alpha-tocopherol concentrations were smaller in patients than in control subjects (P < 0.0001). When ratios of plasma alpha-tocopherol to cholesterol (to correct for differences in cholesterol concentrations) or erythrocyte alpha-tocopherol concentrations were applied, patients were shown to respond as efficiently as control subjects. On the basis of these results, we recommend vitamin E supplements in doses high enough to achieve vitamin E status in CF patients well within the range of healthy individuals; these supplements should be given with appropriate amounts of pancreatic enzymes. However, for long-term supplementation much lower doses than those used in this test situation may be sufficient.

Absorption↗
PubMed1996

Does a profound change in toilet-training affect development of bowel and bladder control?

A major change in toilet-training was observed in two successive generations. The median onset of toilet-training was postponed by 13 months between the First Zürich Longitudinal Study (320 children born between 1954 and 1956) and the Second Zürich Longitudinal Study (309 children born between 1974 and 1984). Bladder control, both day and night, was not affected, but bowel control was delayed by 16 months, due not to a lack of training, but to the abandonment of maternal control. The results strongly confirm earlier findings that the development of bowel and bladder control is a maturational process which cannot be accelerated by early onset and high intensity of potty-training. The child's initiative proved to be a reliable indicator that the child was developmentally capable of being clean and dry. Girls were consistently earlier than boys, indicating different maturation rates. No significant correlations were noted between the socioeconomic status and start and intensity of toilet-training, onset of the child's initiative or development of bladder and bowel control.

Age Distribution↗
PubMed1996

Methodology for the establishment of growth standards.

Providing reference values in the form of percentiles for the assessment of paediatric growth is of great practical importance. Extreme centiles are particularly important in the diagnostic process. On the other hand, their statistical variability is inherently large. When measurements approximate to a normal distribution-as for height-centiles can be obtained more accurately. Otherwise, empirical centiles and/or more refined methods are needed. To exploit the age-dependent nature of centiles, smoothing methods are recommended. Accounting for midparental height as a covariate in the calculation of centiles greatly improves their validity due to an increased sensitivity and specificity.

Adolescent↗
PubMed1996

Electroencephalographic evaluation of children without neuropsychiatric disturbances but with poor school performance.

The estimation of brain function using neurophysiologic methods is of importance because, besides neuropsychiatric diseases, a variety of systemic diseases can influence brain function. Several types of brain dysfunction, resulting from many kinds of influences on the central nervous system, can cause poor school performance. Besides these dysfunctions of organic origin, there may be others that do not have an organic basis but may reflect the adverse effects of the environment. Often, the differential diagnosis between them is difficult. We performed a neurologic examination and an evaluation using the Illinois Test of Psycholinguistic Abilities and questionnaires (Eysenck and Rutter) to assess the personality of 22 poor school performers aged 10 to 12 years and 22 controls with good school performance of similar age. In order to assess the possibility of using quantitative electroencephalographic methods to evaluate nonorganic poor school performers, we estimated the power spectrum and coherence of the electroencephalographic signals at rest and their changes during motor tasks and auditory stimulation. Our results indicate that there were no signs of organicity in the group of poor school performers.

Brain↗
PubMed1996

The analysis of the EEG.

The quantitative analysis of the electroencephalogram (EEG) relies heavily on methods of time series analysis. A quantitative approach seems indispensable for research (be it clinical or basic neurophysical research), but it can also be a useful information for purely clinical purposes. Apart from the ongoing spontaneous EEG, evoked potentials (EPs) also play an important role. They can be elicited by simple sensory stimuli or more complex stimuli. Their analysis requires methods which are different from those for the spontaneous EEG. Those methods operate usually in the time domain and offer many challenging problems to statisticians. Methods for analysing the spontaneous EEG usually work in the frequency domain in terms of spectra and coherences. Biomedical engineers who take care of the equipment are usually also trained in time series analysis. Thus, they have contributed much more to methodological progress for analysing EEGs and EPs, compared with statisticians. However, the availability of a sample of subjects, and the associated problems in modelling followed by an inferential analysis could make a larger influence from the statistical side quite profitable. This paper tries to give an overview of a fascinating area. In doing so we treat more extensively problems with some statistical appeal. This leads inevitably to some overlap with our own work.

Artifacts↗
PubMed1994

Somatosensory evoked potentials with high cortical amplitudes: clinical data in 31 children.

Between 1989 and 1993, somatosensory evoked potentials (SEP) were recorded as part of the diagnostic work-up in 282 children with different neurologic disorders. In thirty-one children with N20/P25/N35 amplitudes were enhanced compared to our control group (highest amplitude 14.1 microV). Four children had amplitudes > 40 microV ("giant"), fifteen between 20-39.9 microV ("elevated") and twelve between 14-19.9 microV ("borderline"). Enhanced cortical SEPs were seen in all patients with neuronal ceroid lipofuscinosis (5 late-infantile NCL > 20 microV, 1 juvenile NCL 14.7 microV). In addition, five of six NCL children showed bilaterally prolonged cervico-cortical conduction times, otherwise only seen in a 4-month-old child following hypoxia. "Borderline" and "elevated" SEPs occurred in patients with heterogeneous neurologic disorders. Follow-up recordings showed inconsistent results: seven children had amplitudes > 14 microV in all recordings, six only at the first examination, and six only at follow-up. In six children with hemiparesis enhanced SEPs were recorded over both (n = 2) or only over the unaffected hemisphere (n = 4). Myoclonic seizures were observed only in five children with NCL. Similar to other SEP parameters, enhanced amplitudes are an unspecific indicator of an ongoing neurologic disorder. However, in neuronal ceroid lipofuscinosis, enhanced SEP amplitudes may be a useful diagnostic criterium.

Adolescent↗