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Biomedical subjects

M Elia

Publications and source records attributed to M Elia.

At least 91 records · Page 5Linked to original sources
PubMed1999

Seizures in Chiari I malformation: a clinical and electroencephalographic study.

Seven subjects with Chiari I malformations and seizures (four males, three females; age range 11 years, 7 months to 36 years; mean, 22.28 +/- 7.58 years; median, 21) were identified in four different centers from among a group of 10 patients. Our aim was to analyze clinical and electroencephalographic characteristics of seizures in this etiologically homogeneous group of patients. Most of the seizures were of the complex partial type, and paroxysmal abnormalities were mainly localized over the frontal and temporal regions. The course of the epilepsy was rather benign, with complete control of seizures in four patients and an important reduction in frequency in the remaining three subjects. Other cortical alterations are not usually associated with the typical abnormalities of the posterior fossa in Chiari I malformation; thus, it is possible to hypothesize that cerebral microdysgenesis or, alternatively, a cerebellar dysfunction could underlie epileptogenesis in these patients.

Adolescent↗
PubMed1999

Predicting composition of leg sections with anthropometry and bioelectrical impedance analysis, using magnetic resonance imaging as reference.

Magnetic resonance imaging (MRI) was used to evaluate and compare with anthropometry a fundamental bioelectrical impedance analysis (BIA) method for predicting muscle and adipose tissue composition in the lower limb. Healthy volunteers (eight men and eight women), aged 41 to 62 years, with mean (S.D.) body mass indices of 28.6 (5.4) kg/m2 and 25.1 (5.4) kg/m2 respectively, were subjected to MRI leg scans, from which 20-cm sections of thigh and 10-cm sections of lower leg (calf) were analysed for muscle and adipose tissue content, using specifically developed software. Muscle and adipose tissue were also predicted from anthropometric measurements of circumferences and skinfold thicknesses, and by use of fundamental BIA equations involving section impedance at 50 kHz and tissue-specific resistivities. Anthropometric assessments of circumferences, cross-sectional areas and volumes for total constituent tissues matched closely MRI estimates. Muscle volume was substantially overestimated (bias: thigh, -40%; calf, -18%) and adipose tissue underestimated (bias: thigh, 43%; calf, 8%) by anthropometry, in contrast to generally better predictions by the fundamental BIA approach for muscle (bias: thigh, -12%; calf, 5%) and adipose tissue (bias: thigh, 17%; calf, -28%). However, both methods demonstrated considerable individual variability (95% limits of agreement 20-77%). In general, there was similar reproducibility for anthropometric and fundamental BIA methods in the thigh (inter-observer residual coefficient of variation for muscle 3.5% versus 3.8%), but the latter was better in the calf (inter-observer residual coefficient of variation for muscle 8.2% versus 4.5%). This study suggests that the fundamental BIA method has advantages over anthropometry for measuring lower limb tissue composition in healthy individuals.

Adipose Tissue↗
PubMed1999

The use of infrared spectrophotometry for measuring body water spaces.

BACKGROUND: The conventional method of measuring total body water by the deuterium isotope dilution method uses gas isotope ratio mass spectrometry (IRMS), which is both expensive and time-consuming. We investigated an alternative method, using Fourier transform infrared spectrophotometry (FTIR), which uses less expensive instrumentation and requires little sample preparation. METHOD: Total body water measurements in human subjects were made by obtaining plasma, saliva, and urine samples before and after oral dosing with 1.5 mol of deuterium oxide. The enrichments of the body fluids were determined from the FTIR spectra in the range 1800-2800 cm-1, using a novel algorithm for estimation of instrumental response, and by IRMS for comparison. RESULTS: The CV (n = 5) for repeat determinations of deuterium oxide in biological fluids and calibrator solutions (400-1000 micromol/mol) was found to be in the range 0.1-0.9%. The use of the novel algorithm instead of the integration routines supplied with the instrument gave at least a threefold increase in precision, and there was no significant difference between the results obtained with FTIR and those obtained with IRMS. CONCLUSION: This improved infrared method for measuring deuterium enrichment in plasma and saliva requires no sample preparation, is rapid, and has potential value to the clinician.

Body Water↗
PubMed1999

Effect of mixed meal ingestion on fuel utilization in the whole body and in superficial and deep forearm tissues.

Six healthy lean male adults, given a mixed meal containing 3190 kJ (16% from protein, 44% from carbohydrate and 40% from fat) were studied for the next 370 min using arteriovenous cannulation techniques across superficial and deep forearm tissues. The meal produced no significant change in forearm blood flow or skin temperature. The major differences between superficial and deep forearm tissues were (a) creatinine release by deep tissues but not superficial tissues; (b) the release of non-esterified fatty acids (NEFA) by superficial tissues and uptake by deep tissues; and (c) the more prolonged large positive arteriovenous concentration difference for glucose across deep than superficial tissues. The similarities were (a) general pattern of individual amino acid exchanges and transient positive amino acid N balance after meal ingestion; (b) consistent uptake of glutamate and release of glutamine (the main carrier of N out of superficial and deep forearm tissues); (c) the magnitude of the arteriovenous concentration differences for glucose, NEFA and total amino acids were related to the changes in their circulating concentrations and to the oxidation of carbohydrate, fat, and protein in the whole body; and (d) increases in the arterio-deep venous and arterio-superficial venous differences for glucose did not result in increased release of lactate, alanine or pyruvate, implying no increase in the activity of glucose-lactate and glucose-alanine cycles between forearm tissues and the liver. This study suggests that in a number of ways superficial and deep tissues can be regarded, at least qualitatively, as behaving as a 'single metabolic unit'.

Adipose Tissue↗
PubMed1999

Glutamine oxidation and utilization by rat and human oesophagus and duodenum.

The rates of utilization and oxidation of glutamine and glucose by oesophageal and duodenal tissues have been investigated in both rats and human subjects. In the rat, glutamine utilization by oesophageal tissue was 2-3-fold lower than that in the duodenum, and this substrate contributed less than 10% to the total oxidative metabolism of the tissue, even when glutamine was the only substrate provided. In contrast, rat duodenal tissue derived about 34% of the total CO2 production from glutamine-C, and this contribution was not suppressed by the addition of either glucose or a mixture of the other substrates. Rates of glucose utilization and oxidation by the duodenum were lower than those for glutamine, and were significantly (P < 0.001) suppressed by addition of glutamine. In both oesophageal and duodenal tissues, less than 10% of the glutamine-C utilized was fully oxidized, approximately 60-70% was converted to glutamate, and 30-40% to alanine. Results obtained using human biopsy tissue samples were similar to those observed in the rat. Glutamine oxidation contributed 34 (SD 4)% of the total CO2 production by the duodenal tissue, but only 8 (SD 4)% to oesophageal tissue oxidation. The findings suggest that glutamine is not an important or preferred fuel for oesophageal tissue, whereas it is for duodenal tissue. Thus, these tissues can be expected to respond differently to glutamine administration.

Analysis of Variance↗
PubMed1998

Abnormal colonic fermentation in irritable bowel syndrome.

BACKGROUND: The cause of irritable bowel syndrome (IBS) is unknown. It may follow gastroenteritis and be associated with an abnormal gut flora and with food intolerance. Our study was designed to assess whether these factors were associated with colonic malfermentation. METHODS: We carried out a crossover controlled trial of a standard diet and an exclusion diet matched for macronutrients in six female IBS patients and six female controls. During the final 72 h on each diet, faecal excretion of fat, nitrogen, starch, and non-starch polysaccharide NSP was measured, and total excretion of hydrogen and methane collected over 24 h in a purpose-built 1.4 m3 whole-body calorimeter. Breath hydrogen and methane excretion were then measured for 3 h after 20 g oral lactulose. FINDINGS: The maximum rate of gas excretion was significantly greater in patients than in controls (2.4 mL/min IQR 1.7-2.6 vs 0.6, 0.4-1.1). Although total gas production in patients was not greater than in controls (median 527 mL/24 h IQR 387-660 vs 412, 234-507), hydrogen production was higher (332, 318-478 vs 162, 126-217, p=0.009). In patients, the exclusion diet reduced symptoms and produced a fall in maximum gas excretion (0.5 mL/min IQR 0.3-0.7). After lactulose, breath hydrogen was greater on the standard than on the exclusion diet. INTERPRETATION: Colonic-gas production, particularly of hydrogen, is greater in patients with IBS than in controls, and both symptoms and gas production are reduced by an exclusion diet. This reduction may be associated with alterations in the activity of hydrogen-consuming bacteria. Fermentation may be an important factor in the pathogenesis of IBS.

Adult↗
PubMed1998

Familial cortical tremor, epilepsy, and mental retardation: a distinct clinical entity?

OBJECTIVE: To describe a European family with cortical tremor, epilepsy, and mental retardation, the pedigree of which indicates an autosomal dominant inheritance of the disease. DESIGN: Clinical, laboratory, neurophysiological, and neuroimaging data were studied. SETTING: Institute for research on mental retardation. PATIENTS: Two siblings (aged 25 and 28 years) and their 49-year-old mother had postural and action tremor, seizures, and mental retardation. Only tremor was present in the maternal grandmother (aged 68 years). The electroencephalogram showed diffuse spike-and-wave complexes and/or posterior spikes, and a photoparoxysmal response in the 4 subjects. The typical electrophysiologic features of cortical reflex myoclonus, such as giant somatosensory evoked potentials, enhancement of the C-reflex, and jerk-locked premyoclonus spikes, were found in all patients. CONCLUSION: This syndrome may represent a specific form of familial cortical tremor with a benign form of epilepsy and a new genetic model of cortical hyperexcitability inherited with an autosomal dominant mechanism.

Adult↗
PubMed1998

Correlation dimension of EEG slow-wave activity during sleep in children and young adults.

In a recent work, the calculation of the correlation dimension (CD) of the profiles of EEG slow-wave activity during sleep in 7 young subjects, allowed us to conclude that sleep-regulation might be considered a deterministic non-linear process with an average dimension above 3. In this paper we report the results of the calculation of the CD of EEG slow-wave activity in 20 normal subjects (children and young adults) who slept in the laboratory for 3 consecutive nights. The results confirm that it is possible to calculate the CD in most normal profiles (33 out of 40) and to discriminate between chaos and noise. The lower limit of CD was found as ranging between approximately 2.5 and 4.5, it did not show significant changes across consecutive nights in the same subject and did not seem to change significantly with age in children and young adults.

Adolescent↗
PubMed1998

Trisomy 12p and epilepsy with myoclonic absences.

We report the case of a 6-year-2-month-old female affected by trisomy 12p syndrome. Seizures were typical myoclonic absences from both the clinical and EEG points of view. Our patient and other sporadic reports in the literature seem to support the hypothesis that, at least in some cases, myoclonic absences can be a direct or indirect effect of a chromosomopathy.

Brain↗
PubMed1998

Seizures in Klinefelter's syndrome.

This study describes the clinical spectrum of patients with Klinefelter's syndrome and seizures. Klinefelter's syndrome is a sex chromosomal abnormality and the most common cause of male hypogonadism. It is characterized by cognitive dysfunction, hypogonadism, and abnormalities of physical maturation. Neurologic impairment has been recognized, but seizures have received little attention. The authors describe three American patients and discuss nine additional patients from two European centers previously reported with Klinefelter's syndrome and seizures. The most common profile of patients with Klinefelter's syndrome and seizures includes mental retardation, behavior problems, epileptiform electroencephalograms (EEGs), and generalized tonic-clonic seizures. The seizures of six of 11 patients with epilepsy were well controlled with antiepileptic drugs. One patient had a single seizure and was not treated with medication. In patients with Klinefelter's syndrome and recurrent seizures, the electroclinical spectrum is heterogenous and outcome with antiepileptic drug treatment is favorable.

Adolescent↗
PubMed1998

Bioelectrical impedance analysis in human immunodeficiency virus-infected patients: comparison of single frequency with multifrequency, spectroscopy, and other novel approaches.

Bioelectrical impedance (BIA), a prediction method for estimating body water compartments and body cell mass (BCM), is being increasingly used in studies of human immunodeficiency virus (HIV)-related wasting, but there are few validation studies of the method in this group. The aim of this study is to examine the relationship between impedance measurements and body water compartments in patients with advanced HIV disease, and to investigate whether the newer approaches of multifrequency BIA, BIA spectroscopy, logarithmic transformation using a parallel circuit model, and direct calculation from electrical theory offer any advantage over traditional single-frequency BIA. We measured total body water (TBW) by deuterium dilution and extracellular water by bromide dilution in 33 patients with advanced HIV disease. Intracellular water and BCM were calculated from these results. Impedance was measured over a range of frequencies using a multifrequency analyzer. The relationship between impedance index at various frequencies and body water compartments was assessed by correlation and linear regression. We found that impedance index at higher frequencies had a closer relationship to TBW (r = 0.86, standard error of the estimate [SEE] = 2.96 at 1000 kHz) and at lower frequencies a closer relationship to extracellular water (ECW) (r = 0.47, SEE = 3.13 at 0 kHz) than the traditional 50 kHz measurement (r = 0.84, SE = 3.11 for TBW; r = 0.44 SEE = 3.19 for ECW), but the differences were marginal and not statistically significant. None of the other novel approaches tested were significantly better than traditional single frequency measurement. The 50 kHz equation for BCM developed in this study [BCM (kg) = (0.360331 x Ht2/Z50) + (0.151123 x Wt)-2.95] may be useful to investigators using BIA for hIV-wasting studies.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Glutamine and vitamin E in the treatment of hepatic veno-occlusive disease following high-dose chemotherapy.

Hepatic veno-occlusive disease (VOD) of the liver is a common complication following high-dose cytotoxic therapy for bone marrow transplantation (BMT). Liver injury is believed to occur following free radical damage to endothelial cells of the sinusoids and small hepatic veins. Glutathione the main antioxidant of the cytosol becomes depleted following chemotherapy. Animal studies have shown that glutamine infusions can maintain glutathione levels and protect against free radical injury. We present two cases of established VOD successfully treated with intravenous glutamine (as dipeptide) and oral vitamin E. Although both cases have possible confounding factors we believe that these give support to the notion that glutamine/vitamin E may have a role in the prophylaxis and treatment of VOD. Further formal trials are indicated.

Adult↗
PubMed1998

Comparison of the traditional paper visual analogue scale questionnaire with an Apple Newton electronic appetite rating system (EARS) in free living subjects feeding ad libitum.

OBJECTIVE: Assessing the value of a newly developed electronic visual analogue scale questionnaire (Apple Newton Message Pad) with the traditional paper method for appetite rating. DESIGN: In a random, crossover design, subjects completed both electronic and paper questionnaires to compare results obtained by the two methods; individual methods were completed consecutively to assess test-retest reliability; preference was established using a questionnaire. SETTING/SUBJECTS: Healthy, free-living adults were studied for comparison of methods (n = 12), test-retest reliability (n = 8) and preference (n = 13). INTERVENTION: Visual analogue scales were completed each waking hour to assess appetite. Preference was assessed after both methods were completed. RESULTS: There was no significant difference in the hourly results obtained by the paper and electronic methods for 'desire to eat', 'how much can you eat now', 'urge to eat' and 'preoccupation with thoughts of food'. Small differences in 'hunger' and 'fullness' ratings were noted (approximately 5% mean difference between methods, P < 0.05), but patterns of change and sensitivity for these and all other parameters remained similar for both methods across the visual analogue scale. Test-retest reliability demonstrated was similar for both methods. Seven (54%) subjects preferred to use the paper questionnaire, five (38%) the electronic method and one (8%) had no preference. CONCLUSIONS: The electronic Apple Newton questionnaire is as sensitive and reliable as the paper method, has the advantage that it automatically records the time of data acquisition and data collection and processing are more efficient for the researcher. The two methods should not be used interchangeably.

Adult↗
PubMed1998

Distribution of glutaminase and glutamine synthetase activities in the human gastrointestinal tract.

1. The activities of the two key enzymes involved in glutamine metabolism, glutaminase and glutamine synthetase, were measured in mucosal biopsies taken from different sites throughout the human gastrointestinal tract, from oesophagus to rectum. 2. The specific activity of glutamine synthetase was highest in the stomach (4.5 nmol glutamine formed per minute per mg of protein), but both small and large intestine and the oesophagus had little synthesizing capacity (less than 0.3 nmol of glutamine formed per minute per mg of protein). 3. Glutaminase specific activity was highest in the small intestine (53 nmol glutamate formed per minute per mg of protein by duodenal mucosa), intermediate in the large intestine and lowest in the oesophagus and stomach (less than 13 nmol of glutamate formed per minute per mg of protein). 4. The glutamine concentration in the mucosa was lower in the duodenum than in the colon (0.62 and 0.95 mmol/kg wet weight respectively), but both were much lower than the measured K(m) values of glutaminases obtained from these sites (3.8 and 4.0 nmol/kg wet weight respectively). 5. The concentration of glutamine in saliva, stomach juice, bile and duodenal juice suggests that very little glutamine passes into the gastrointestinal tract via these secretions. 6. The study provides the most complete information on the distribution of glutamine synthetase and glutaminase along the human gastrointestinal tract, and suggests that (i) both the small and large intestines have a high potential for glutamine metabolism, but little synthesizing capacity, thus both must derive their glutamine from other sources, and (ii) neither the stomach nor the oesophagus have a high glutaminase activity, although the stomach has substantial capacity to synthesize glutamine. The distribution of the enzymes along the gastrointestinal tract may help rationalize the use of glutamine for treating diseases that affect different parts of the gastrointestinal tract.

Adult↗
PubMed1998

Heart rate variability and apnea during sleep in Down's syndrome.

Autonomic system dysfunction has been reported to occur frequently in patients with Down's syndrome (DS) and is constituted mainly by an imbalance between the sympathetic and vagal systems. The analysis of heart rate variability (HRV) during sleep is a quantitative reliable method for studying such a mechanism, but it has not yet been extensively and adequately applied in DS. In this study, HRV during sleep was evaluated in seven DS patients and in six normal controls, by also controlling for the presence of sleep apnea or arousal. The main results were an increased sympathetic function (low-frequency component of HRV) and a decreased vagal activity (high-frequency component of HRV) in DS with respect to normal controls, during apnea-free periods. Moreover, the presence of apnea, in DS, induced a further significant increase in low-frequency and very low-frequency components of HRV during sleep Stage 2. This study provides additional evidence of a brainstem dysfunctioning in DS, responsible for the abnormal imbalance between the sympathetic and vagal systems and confirms the brainstem involvement already suggested in the literature in order to explain brainstem-auditory evoked potential abnormalities and central sleep apnea in these patients.

Adolescent↗