Search PubMed⌕ Search

Biomedical subjects

M Elia

Publications and source records attributed to M Elia.

At least 163 records · Page 9Linked to original sources
PubMed1994

Arginine-supplemented diets improve survival in gutderived sepsis and peritonitis by modulating bacterial clearance: the role of nitric oxide Gianotti L, Alexander J W, Pyle T, and Fukushima R. Ann Surg 1993; 217: 644-654.

The effects of arginine on survival rates and host defence mechanisms were studied using two models of infection that included allogeneic transfusion-induced immunosuppression. Mice were fed for 10 days with chow, or a semi-purified commercial diet (AIN-76A), which was either unsupplemented or supplemented with arginine (2%; test diet) or glycine. After allogeneic blood transfusions and feeding for a further 5 days, the mice were subjected to caecal ligation and puncture (CLP), or 20% burn injury plus gavage with 10(10), (14)C-radiolabelled E. coli. Survival rate after CLP (AIN-76A diets) was 56% in the arginine supplemented group (AIN-76A) versus 28% in the AIN-76A unsupplemented group and 20% in the animals fed chow (P 0.02). After burn injury and gavage survival was 100% in the arginine-supplemented group versus 50% in both the chow and AIN-76A glycine supplemented group, and 35% in the AIN-76A unsupplemented group (P 0.01). Quantitative colony counts and % viable bacteria remaining in mesenteric lymph nodes, liver, and spleen suggested that the ability to kill translocated bacteria was significantly enhanced in animals receiving arginine. Treatment with the nitric oxide inhibitor, Nw-Nitro-L-arginine, reversed the beneficial effects or arginine. It is concluded that the benefit of arginine appears to be mediated by improved bactericidal mechanisms via the arginine nitric-oxide pathway.

Journal Article↗
PubMed1994

BIT-mapped somatosensory evoked potentials in the fragile X syndrome.

Middle-latency somatosensory evoked potentials (MLSEPs) were recorded from 19 scalp electrodes in ten male patients with the fragile X (fraX) syndrome and nine normal controls. One fraX patient was found presenting the so-called "giant" MLSEPs with an amplitude of N60 of about 60 microV and of 40 microV after stimulation of the right and left median nerves, respectively. Tapping of the right hand, in the same patient, induced the appearance of left parietal evoked EEG spikes. These findings further support the already suggested similarity between the epileptic picture of several fraX patients with that of the benign childhood epilepsy with centrotemporal spikes. Color mapping of the MLSEPs recorded in the remaining nine patients, when compared with the control group, showed an abnormally large N30 over the frontal regions, together with an increase in amplitude of P27, over the parietal areas, and of N60 and P100 which also presented abnormal field distributions, being represented preferentially over the frontal regions. These data could suggest the existence of a cortical dysfunction mostly involving the frontal lobes (supplementary motor area, in particular) in the fraX syndrome which could support many behavioral changes usually observed in these patients.

Adolescent↗
PubMed1994

Bit-mapped somatosensory evoked potentials in Down's syndrome individuals.

Middle-latency somatosensory evoked potentials (MLSEPs) were recorded from 19 scalp electrodes in 19 patients with Down's syndrome (DS), in 13 age-matched normal controls and in 11 aged normal individuals. DS patients showed an increase in amplitude of P22, N30, P45, and N60. P100 latency was significantly shortened. After this potential, DS subjects showed the occurrence of a high voltage negative potential at around 100-110 msec followed by another high-voltage positive deflection; both these components showed a frontal-central distribution and were not observed in the two control groups. MLSEPs of DS subjects show peculiar alterations which could be supported by particular neurometabolic and/or neuropathologic changes.

Adolescent↗
PubMed1994

Giant somatosensory evoked potentials and pathophysiology of hyperekplexia. Neurophysiological study of one patient.

EEG during wakefulness and sleep and somatosensory evoked potentials from the median nerve were recorded in a 3 year-old boy with hyperekplexia and his close relatives (parents and two sisters). Centro-temporal spikes during sleep were found in the patient and in the older sister, while somatosensory evoked potentials, in the patient, showed abnormally high amplitude over the centroparietal regions. Pathophysiological mechanisms of hyperekplexia are discussed and the existence of symptomatic forms is suggested.

Child↗
PubMed1994

5-fluorouracil and folinic acid-induced mucositis: no effect of oral glutamine supplementation.

In some clinical situations the endogenous production of glutamine may be insufficient to maintain optimal tissue structure and function such that glutamine becomes a conditionally essential amino acid. Studies in laboratory animals have demonstrated that glutamine supplementation can reduce the incidence and severity of cytotoxic-induced mucositis. This study examined the role of oral glutamine supplementation in the management of mucositis caused by 5-fluorouracil (5-FU) and folinic acid. Twenty-eight patients with gastrointestinal cancers were randomised to receive 16 g of glutamine per day for 8 days, or placebo, in a randomised double-blind trial before crossing over to the alternative supplement during the second treatment cycle. The supplement was well tolerated with no apparent adverse effects, but failed to have any significant effect on oral mucositis assessed by the patients or investigator. The possible reasons for this apparent lack of benefit are discussed.

Administration, Oral↗
PubMed1994

Effect of noradrenaline on glycerol turnover and lipolysis in the whole body and subcutaneous adipose tissue in humans in vivo.

1. The effect of infusion of noradrenaline (0.42 mumol min-1 kg-1) on the exchange of nonesterified fatty acids, glycerol and other metabolites across subcutaneous abdominal adipose tissue was investigated in five healthy subjects using an arteriovenous catheterization technique and measurement of adipose tissue blood flow using the 133Xe clearance technique. At the same time, the net rate of fat oxidation in the whole body was assessed by indirect calorimetry, and the turnover of glycerol in the whole body and in subcutaneous adipose tissue was estimated using [5-2H]glycerol, which was administered as a primed constant infusion for 1 h before (basal turnover) noradrenaline administration and continued during the 1 h of noradrenaline infusion. 2. The noradrenaline infusion increased the plasma noradrenaline concentration from a basal value of 0.9 +/- 0.1 to 12.6 +/- 1.2 nmol/(mean +/- SEM) at 60 min. It also increased the arterialized concentration of glycerol by 50% (basal value 81 +/- 11 mumol/l-1) and that of plasma non-esterified fatty acids three-fold (basal value 357 +/- 86 mumol/l). 3. Noradrenaline increased the net release of glycerol by adipose tissue three-fold and that of non-esterified fatty acids three- to four-fold. Although the ratio of non-esterified fatty acid to glycerol release by adipose tissue increased in all subjects from a mean value of 2.7 in the basal period to 3.6 and 3.9 at 50 and 60 min of the noradrenaline infusion, respectively (P < 0.02), at no time point did the ratio differ significantly from 3.0.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗
PubMed1994

The effect of arterialization of blood by hand warming on the interpretation of forearm metabolic studies.

Although sampling of arterialized blood is widely used as an alternative to arterial sampling in metabolic studies, the arterialization procedures have been criticized because they may produce metabolic and haemodynamic effects that confound interpretation of results, especially in studies involving arteriovenous exchange of metabolites across the contralateral forearm. This study aimed to assess the effect of warming the hand for 10 or 20 min (a procedure which may be used to arterialize superficial venous blood) on the blood flow to the skin and muscle of the whole of the contralateral forearm. Hand warming, produced by placing the hand in a box kept at 67 +/- 3 degrees C for 10 min (standard errors of mean, SEM), produced no significant change in the blood flow of the whole forearm (4.14 +/- 0.28 versus 4.34 +/- 0.26 ml per 100 ml forearm min-1, measured with the hand circulation occluded), muscle (1.9 +/- 0.12 versus 1.82 +/- 0.15 ml per 100 ml forearm min-1, measured by 133Xe) or skin (5.2 +/- 4.0 versus 4.6 +/- 2.9 arbitrary units, measured by photoplethysmography). After 20 min of hand warming, there was no significant change in the concentration of a variety of metabolites in the deep venous blood draining the contralateral forearm. It is concluded that, unlike other 'arterialization' procedures, that used in this study had no important effect on the blood flow to the contralateral forearm or its distribution between muscular and non-muscular tissues. Therefore, this procedure of arterialization can be employed in arteriovenous studies that aim to assess the exchange of metabolites between blood and forearm tissues.

Adult↗
PubMed1994

Measurements of resting energy expenditure and body composition before and after treatment of small cell lung cancer.

BACKGROUND: Many patients with small cell lung cancer are reported to lose weight, but the mechanism of this effect is unclear. PATIENTS AND METHODS: Measurements of resting energy expenditure (REE), using indirect calorimetry and body composition (fat, fat-free mass and organ mass), using dual energy X-ray absorptiometry (DXA) and abdominal CT scans were measured in 38 patients with newly-diagnosed small cell lung cancer. Twenty-eight patients were restudied at the end of treatment. RESULTS: In those who responded to treatment there was no change in body weight, but a decrease in REE of 15.7 +/- 11.7 kJ/kg fat free mass/day, whilst in the non-responders body weight decreased 4.33 +/- 5.4 kg, but REE was unchanged. CONCLUSIONS: This study provides evidence for tumour-induced hypermetabolism which is independent of changes in gross body composition, although the absolute increase is small, approximately 0.8 MJ/day. However since body weight was maintained in those patients who responded to treatment either total energy expenditure was decreased, implying decreases in physical activity, or energy intake was increased.

Absorptiometry, Photon↗
PubMed1994

Muscle and whole body metabolism after norepinephrine.

The effect of an infusion of norepinephrine (0.42 nmol.kg-1.min-1) on energy metabolism in the whole body (using indirect calorimetry and the arteriovenous forearm catheterization techniques in eight healthy young male adults. The activity of the triglyceride-fatty acid cycle, which mainly operates in nonmuscular tissues, was also assessed by measuring glycerol turnover using [2H5]glycerol (to indicate lipolysis) and indirect calorimetry (to indicate net fat oxidation). Norepinephrine increased whole body oxygen consumption by almost 10% (P < 0.01), but the estimated oxygen consumption of muscles tended to decrease. Muscle blood flow (measured by 133Xe) and forearm blood flow (measured by strain-gauge plethysmography) were not significantly affected by norepinephrine, but the rate of uptake of nonesterified fatty acids and beta-hydroxybutyrate increased severalfold (P < 0.05), whereas that of glucose did not. The activity of the triglyceride-fatty acid cycle increased fourfold after norepinephrine administration, having a marginal effect on resting energy expenditure (approximately 1.5%) but accounting for approximately 15% of the increase in whole body energy expenditure. This study provides no evidence that skeletal muscle is an important site for norepinephrine-induced thermogenesis and suggests that an increase in the activity of the triglyceride-fatty acid cycle contributes to the norepinephrine-induced increase in energy expenditure of nonmuscular tissues.

Adult↗
PubMed1994

Comparative evaluation of body composition methods and predictions, and calculation of density and hydration fraction of fat-free mass, in obese women.

The objective of this study was to apply a three-component model of body composition to a group of obese women in order to (a) establish the relative value of a number of readily available prediction equations by comparison of the extent of agreement between these predictions and body composition estimated by the model and other reference methods and (b) evaluate density and hydration of fat-free mass. Estimation of body composition was carried out by reference methods and prediction equations and the usefulness of these prediction equations for application specifically to obese women was evaluated. The subjects were 15 obese, otherwise healthy, Caucasian women (body mass index > 30kg/m2 and body fat > 40% of body weight, as originally determined using densitometry). Body composition was estimated using three established reference methods (deuterium dilution which primarily measures total body water, densitometry for body fat and fat-free mass and total body potassium) and the three component model constructed from deuterium dilution and densitometry. Density and hydration fraction of the fat-free mass were calculated from appropriate values obtained as integral parts of the three-component model. In addition, body composition was predicted from various prediction equations incorporating weight and height (some of which include a factor for age), from a number of prediction equations utilizing different terms involving the same whole-body bio-electrical impedance measurement and from measurements of skinfold thickness and near infrared interactance. The extent of agreement between methods was assessed using bias and 95% limits of agreement. Mean density of fat-free mass was found to be 1.104 kg/l (s.d. 0.006kg/l) with a range of 1.093 to 1.117 kg/l, and mean hydration fraction was 0.712 (s.d. 0.016) with a range of hydration from 68.2% to 75.1% (all values were calculated from the three-component model). In general, the reference methods (densitometry, deuterium dilution, the three-component model and total body potassium) demonstrated better agreement with each other than with the prediction methods or equations. In these obese women, skinfold thickness measurements are apparently less reliable (large bias and 95% limits of agreement) than in the lean subjects of a variety of other studies. A majority of interpretations of weight and height measurements and predictions incorporating impedance/resistance measurements are apparently not applicable to this group of obese women, due to large values for both bias and 95% limits of agreement.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

DXA measurements of fat and bone mineral density in relation to depth and adiposity.

Significant effects of depth and adiposity on measurements of fat have been observed, which if also true in-vivo, have important implications for studies at the extremes of body composition, or for longitudinal measurements in subjects who show large changes in tissue thickness. Measurements of BMD under similar circumstances appear to be more robust. However, assessments of the absolute accuracy of DXA measurements await comparison with chemical analysis of human or animal cadavers.

Absorptiometry, Photon↗
PubMed1993

Brainstem auditory evoked potentials in tuberous sclerosis.

Brainstem auditory evoked potentials were recorded in 4 subjects and pattern reversal evoked potentials in 1 subject, all with tuberous sclerosis. Alterations were found (absence or delay of components and prolonged interpeak intervals) which may suggest impaired nervous conduction also at brainstem level in patients with tuberous sclerosis.

Adolescent↗
PubMed1993

Total energy expenditure in intravenously fed patients measured by the doubly labeled water technique.

The potential clinical use of the doubly labeled water (DLW) technique to measure total energy expenditure (TEE) in intravenously fed patients was assessed by applying the technique to 13 stable patients receiving total parenteral nutrition (TPN). TEE was compared with resting energy expenditure (REE), which was measured using a ventilated hood (n = 13), and with 24-hour energy expenditure (24h EE) measured in a whole-body calorimeter (n = 6). Daily measurements of urinary enrichment in 2H and 18O showed predominantly small and covariant fluctuations in elimination rates of these two tracers. The standard error of the estimate (SEFCO2) for the CO2 production rate (FCO2), which includes additional errors due to variability in isotopic fractionation, was calculated to be 2.65% +/- 0.70% of FCO2. TPN-related changes in background isotopic enrichment in subjects who were not dosed with isotope virtually ceased 10 days after starting intravenous feeding. TEE (4.99 +/- 1.10 kJ/min), TEE/REE (1.21 +/- 0.16 kJ/min), TEE/basal metabolic rate (]BMR] 1.31 +/- 0.16 kJ/min), and TEE (isotopic)/24h EE (calorimetric; 1.07 +/- 0.18 kJ/min) showed wide variability. This study provides some evidence for the validity of the DLW method in selected patients receiving TPN, since significant deviations from the assumptions of the method were not found in the subjects studied. The error associated with 2H sequestration during fatty acid synthesis is likely to be small, but could not be accurately measured. The contributions of activity and thermogenesis to TEE varied greatly, but overlapped with those reported in normal subjects.

Adult↗
PubMed1993

Glycerol exchange across the human forearm assessed by a combination of tracer and arteriovenous exchange techniques.

1. Whole-body kinetics and regional exchange of glycerol across forearm muscle were assessed in eight lean subjects by a combination of a tracer method (infusion of [2H5]glycerol) and arteriovenous catheterization. 2. During an apparent steady state, the enrichment of glycerol in deep venous blood from the muscle bed of the forearm was about half (4.40 +/- 1.72 atom per cent excess) that observed in arterialized blood (8.41 +/- 4.30 atom per cent excess). Under the same conditions, the circulating concentrations of glycerol in arterialized (91 +/- 24 mumol/l) and venous (87 +/- 32 mumol/l) blood were similar. 3. In a further group of 37 subjects it was found that about half had a positive arteriovenous concentration difference and the other had half a negative arteriovenous concentration difference (mean -1.6 +/- 11.9 mumol/l; range -25 to +22 mumol/l). 4. These results suggest: (a) that human muscle does not always release glycerol and may take it up; (b) that there is substantial isotopic exchange of glycerol across forearm muscle tissue, which is not reflected by the net exchange of glycerol; this could be due to slow equilibrium of enriched glycerol from the circulation, with unenriched free glycerol in the muscle pool, or due to the simultaneous metabolic utilization of enriched glycerol and metabolic production of unenriched glycerol; (c) that the estimation of glycerol flux rates is strongly dependent on whether the blood is arterialized or deep venous.

Adult↗
PubMed1993

What is the blood flow to resting human muscle?

1. An investigation was carried out in five healthy lean adults to assess whether forearm and calf plethysmography largely reflect muscle blood flow as measured by 133Xe and whether there is substantial variability in the blood flow to muscles located at different sites in the body. 2. Blood flow to forearm and calf flexors and extensors, biceps, triceps and quadriceps was assessed using the 133Xe clearance technique. Blood flow to forearm skin and subcutaneous adipose tissue was also measured using the 133Xe clearance technique, whereas blood flow to the forearm and calf was measured using strain gauge plethysmography. 3. The mean blood flow to different muscles ranged from 1.4 +/- 0.6 (gastrocnemius) to 1.8 +/- 0.7 (forearm extensor) ml min-1 100 g-1 muscle (1.4 +/- 0.6 and 1.9 +/- 0.8 ml min-1 100 ml-1 muscle, respectively) but there were no significant differences between them. Forearm and calf blood flows (2.7 +/- 0.3 and 3.0 +/- 0.7 ml min-1 100 ml-1 limb tissue, respectively) were about 50% to more than 100% greater (P < 0.025) than blood flow to the muscles within them (1.7 +/- 0.5 and 1.4 +/- 0.5 ml min-1 100 g-1 muscle, respectively, or 1.8 +/- 0.6 and 1.5 +/- 0.5 ml min-1 100 ml-1 muscle, respectively). In contrast, the blood flows to 100 g of forearm skin (9.1 +/- 2.6 ml min-1 100 g-1) and adipose tissue (3.8 +/- 1.1 ml min-1 100 g-1) were higher than the blood flow to 100 g of forearm (P < 0.01 and not significant, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗