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Biomedical subjects

M Elia

Publications and source records attributed to M Elia.

At least 217 records · Page 12Linked to original sources

Inter-observer variability in the measurement of body composition.

The inter-observer variation in simple bedside assessments of body composition has been evaluated in 12 healthy adult subjects (6 male and 6 female) by 6 observers. Systematic bias between observers was found to be evident in each of the basic measurements (except height) and in each of the estimates of body composition (except those derived from weight and height alone). The largest residual coefficients of variation (rCV) for the basic measurements were found for skinfold thickness (11-18 per cent for individual skinfold thicknesses, and 9 per cent for the sum of four skinfold thicknesses), and the lowest for weight (0.01 per cent for digital scales, and 0.05 per cent for beam balance) and height (0.4 per cent). The rCV for whole-body resistance (1.2 per cent), forearm resistance (5.4 per cent) and near infra-red interactance (optical density 1: 5.6 per cent and optical density 2: 6.2 per cent) measurements were found to have intermediate values. The variability in the estimate of body fat obtained by skinfold thickness (rCV = 4.6 per cent) and near infra-red interactance methods (rCV = 4.2 per cent) was found to be greater than that from the resistance method (rCV = 2.6 per cent) and by methods based on weight and height alone (rCV = 1.1 per cent). The variability in the estimate of fat-free mass showed the same trend as that for body fat, but the rCVs were less due to the greater mass of the fat-free body compared to body fat.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Quantifying intermediary metabolites in whole blood after a simple deproteinization step with sulfosalicylic acid.

We assessed the reproducibility, recovery, and stability of several circulating metabolites--glucose, pyruvate, lactate, alanine, glutamate, glutamine, 3-hydroxybutyrate, acetoacetate, and glycerol--in the presence of sulfosalicylic acid (SSA), which was used to deproteinize blood. The assays, which involved reactions linked to NADH/NAD+, were carried out at 37 degrees C and measured at 355 nm with a Cobas-Bio centrifugal analyzer. The intra- and interbatch CVs were less than 2.1%, except for the interbatch CV for 3-hydroxybutyrate at low concentration (15-30 mumol/L), which was 5.4%. Analytical recovery of metabolites added to blood ranged from 96.4% to 103.0%. Of the metabolites studied, all were stable at -20 degrees C for 90 days in the SSA-blood extract, except for glutamine and acetoacetate, which progressively decreased with time. We conclude that these nine circulating metabolites can be satisfactorily measured after a single deproteinizing step with SSA. This single-step procedure has several advantages over many of the currently used methods.

Amino Acids↗

A case of epidermal nevus syndrome with carotid malformation.

Epidermal Nevus Syndrome (ENS) is characterized by linear verrucous lesions of the skin and congenital anomalies including bone deformities, eye and central nervous system (CNS) malformations. We describe a case of ENS associated with an abnormality of the carotid artery which is considered a risk for stroke.

Adult↗

Ketone body metabolism in lean male adults during short-term starvation, with particular reference to forearm muscle metabolism.

1. Thirty-three arteriovenous forearm catheterization studies were carried out in 19 lean subjects starving for 12-14 h (n = 13), 30-36 h (n = 7) and 60-66 h (n = 13). Forearm blood flow was measured in order to calculate the flux of various substrates. At the same time, whole-body oxidation of fat, carbohydrate and protein was calculated using indirect calorimetry and urinary nitrogen excretion. 2. After an overnight fast (12-14 h), whole-body resting energy expenditure was accounted for by the oxidation of protein (15%), carbohydrate (17%) and fat (68%). At 30-36 h and 60-66 h of starvation, essentially all the non-protein energy was derived from the oxidation of fat (directly plus indirectly via ketone bodies). 3. After an overnight fast, acetoacetate and 3-hydroxybutyrate were taken up by forearm muscle at a rate which could account for 5% of the resting O2 consumption of this tissue. As starvation progressed, forearm muscle took up more acetoacetate and released 3-hydroxybutyrate so that the net uptake of ketone bodies was sufficient to account for about 10% of the resting O2 consumption at 30-36 h of starvation and about 20% at 60-66 h of starvation.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxybutyric Acid↗

Protein metabolism after injury with turpentine: a rat model for clinical trauma.

Subcutaneous injections of turpentine induced discrete aseptic abscesses in rats without detectable injury to other tissues. Hypoalbuminemia and high circulating concentrations of alpha 2-macroglobulin were present after 48 h. Liver size, protein content, and protein fractional synthetic rate (FSR) were all increased, whereas loss of muscle protein occurred together with similar (45-50%) reductions in both intramuscular glutamine concentrations ([Gln]i, mmol/l intracellular water) and FSR. The rats became anorexic, but pair feeding (50% ad libitum for 48 h) produced a 22% increase in muscle [Gln]i and only an 18% reduction in muscle FSR. Dietary restriction therefore did not demonstrate the positive relationship between muscle [Gln]i and FSR, which has been observed in animal trauma studies. It is concluded that subcutaneous injections of turpentine produce many of the features of the acute-phase response to injury, and therefore this technique is recommended as a convenient laboratory model for studying various aspects of the protein metabolic response to injury.

Acute-Phase Reaction↗

The relationship between the circulating concentrations of interleukin 6 (IL-6), tumor necrosis factor (TNF) and the acute phase response to elective surgery and accidental injury.

The possible role of Interleukin 6 (IL-6) and tumour necrosis factor (TNF) in the regulation of the acute phase response to injury was studied in thirteen subjects undergoing elective surgery or suffering from multiple accidental injuries. The temporal changes in the circulating concentrations of these cytokines were related to the circulating acute phase protein concentrations (C-reactive protein and alpha 1 antichymotrypsin), white cell count, blood loss and duration of surgery. Circulating acute phase protein concentrations rose in all subjects during a thirty hour period following injury but none of the subjects showed a detectable rise in circulating concentrations of TNF. Peak circulating concentrations of IL-6 were detected between 4-6 hours after surgery/trauma but these showed a poor correlation with blood loss, fever, white cell count or duration of surgery. The peak concentrations of IL-6 typically occurred before the rise in circulating acute phase protein concentration. The data do not suggest a role for circulating TNF in the regulation of the acute phase response to injury. In contrast, IL-6 appears to be variably involved in the acute phase response but its precise role in mediating fever, leucocytosis and synthesis of acute phase proteins is as yet uncertain.

Acute-Phase Proteins↗

Evaluation of near infra-red interactance as a method for predicting body composition.

The ability of near infra-red interactance (NIRI) to predict body composition, as measured by whole-body densitometry, was assessed in a group of 29 healthy volunteers; 15 m, 14 f, aged 18-40 years, body mass index (BMI) 18.3-28.5 kg/m2. The results were compared with those obtained by five other predictive methods: whole-body impedance/resistance, skinfold thicknesses, and methods based on weight and height or BMI. The correlation between densitometry and the alternative methods, including NIRI, were found to be remarkably similar, both with respect to fat (r = 0.90-0.92, s.e.e. = 2.12-2.47 kg), and fat-free mass (r = 0.96-0.97, s.e.e. = 2.13-2.71 kg). Percentage body fat (densitometry) correlated better with the near infrared measurements made in the biceps area than with those made in the triceps or thigh areas, or with a combination of measurements made at two or three sites. The 95 per cent limits of agreement between NIRI and densitometry for the estimation of body constituents were slightly greater than those between densitometry and the other methods. NIRI was also found to underestimate body fat increasingly as the degree of adiposity increased. This under-estimation was found to be particularly marked (16 per cent body weight) in a small and separate group of grossly obese women, BMI greater than 50 kg/m2, whose body composition was assessed by total body potassium as well as by densitometry. This study suggests that, in the healthy group of subjects examined, NIRI has little or no advantage over other simple methods in predicting body composition measured by classical whole-body densitometry.

Adolescent↗

Bedside and field methods for assessing body composition: comparison with the deuterium dilution technique.

Estimates of body composition by the deuterium dilution technique were made in 55 healthy subjects (38 men and 17 women) with a mean age of 28.4 years, weight 65.5 kg and height 173.7 cm (body mass index 16.9-29.4 kg/m2). The results were compared with estimates obtained in the same subjects by 5 bedside techniques (skinfold thickness, impedance, resistance and 2 equations predicting body composition from weight and height). The results of all the bedside predictive methods were found to differ significantly from those of the deuterium dilution method (P less than 0.001). The Holtain impedance method underestimated the fat-free mass (FFM) obtained by deuterium dilution (50.8 +/- 7.9 kg) by a mean difference (mean bias) of 4.1 kg while the other methods overestimated FFM (mean bias or mean difference of -1.3 to -2.4 kg). The resistance (Valhalla equations) and skinfold methods showed the narrowest 95 per cent limits of agreement, when compared with the deuterium dilution technique, while the weight and height equations showed the widest limits of agreement. It is concluded that in this population, the resistance (Valhalla equations) and the skinfold thickness methods were the best predictors of body composition as measured by deuterium dilution. Discrepancies between the bedside methods and deuterium dilution method may be due to (a) methodological or biological differences between the test population used in this study and the original population used to validate the method, (b) differences in the structure of the equations used to interpret the measured biological variables, such as impedance and resistance, and (c) the use of predictive equations that are based on different 'reference' methods, such as deuterium dilution or densitometry, and on different assumptions. Predictive equations based on a combination of these reference methods are preferable to those based on single methods.

Adolescent↗

Induction of sister-chromatid exchanges by polycyclic aromatic hydrocarbons following metabolic activation with phorbol ester-stimulated human polymorphonuclear leukocytes.

We have previously observed that the interaction of an oxidant generated by polymorphonuclear leukocytes (PMNs) with (+-)-trans benzo[a]pyrene-7,8-dihydrodiol (BP-7,8-diol) resulted in covalent binding to DNA and elicited bacterial mutagenesis (PNAS 82:5194, 1985). We now report that this interaction also induces sister chromatid exchanges (SCEs) in Chinese hamster V-79 cells. This genotoxic response required stimulation of the PMNs by phorbol ester as no effect was observed with unstimulated cells. Likewise, no intrinsic activity of BP-7,8-diol alone was noted. The addition of azide, CuDIPS, or taurine markedly inhibited the induction of SCEs by the combination of BP-7,8-diol and stimulated PMNs, further suggesting the involvement of myeloperoxidase in the activation of the polycyclic aromatic hydrocarbon. The (-) isomer of BP-7,8-diol as well as 7,8-dihydro-BP were more active than (+)-BP-7,8-diol in inducing SCEs. By contrast, benzo[a]pyrene or derivatives lacking a double bond at the 9,10 position were not effective in inducing SCEs above the level seen with phorbol ester-stimulated PMNs. These observations serve to underscore the potential for myeloperoxidase-dependent activation of xenobiotics by PMNs to result in a localized genotoxic environment.

Animals↗

Multiple sclerosis. Magnetic resonance imaging, evoked potentials and cerebrospinal fluid analysis.

We have studied 27 patients with multiple sclerosis (22 definite, 5 probable) by magnetic resonance imaging (MRI), visual evoked potentials (VEPs), brainstem auditory evoked potentials (BAEPs), and oligoclonal bands (OBs) in cerebrospinal fluid (CSF), MRI was altered in 92.5% of the cases, the presence of OBs in CSF was revealed in 73.1% of the examined patients, the frequency of evoked potentials (EPs) alteration was VEPs = 59.3% and BAEPs = 29.6%, at least one of the two EPs occurred positive in 66.6% of the cases. Our data confirm the more sensitive value of MRI compared with OBs and EPs studies in assessing MS, and stress the utility of the combined use of these tests.

Adolescent↗

[Complications of septorhinoplasty].

A review of the literature on complications in septorhinoplasty is presented. Though rare, complications may arise in the surgical treatment of such a delicate anatomical area as the nasal septum and both theoretical and practical knowledge of the problem is necessary in order to prevent and/or handle such unexpected events. Complications are grouped according to aetiopathogenesis into infectious, haemorrhagic, traumatic, systemic and miscellaneous.

Humans↗

Amino acid metabolism in muscle and in the whole body of man before and after ingestion of a single mixed meal.

Whole-body energy expenditure, protein oxidation, and exchange of amino acids, glutathione, and other metabolites across forearm muscle were assessed before and for 4 h after ingestion of a single meal containing 3274 kJ (783 kcal) and 25.5 g protein (4.08 g nitrogen). The study 1) demonstrates the dominance of glutamine over all other amino acids in carrying N out of skeletal muscle (1.33 mumol.L muscle-1.min-1 between 0 and 4 h--equivalent to 71% of the amino acid release or 82% of the amino acid N release); 2) suggests that glucose-alanine recycling between muscle and liver is not increased in the postprandial period despite the large uptake of glucose by muscle; 3) provides no support for the hypothesis that a substantial amount of N is exchanged between blood and muscle in the form of glutathione; and 4) considers the overall quantitative importance of amino acid oxidation in the whole body and the accompanying exchange of amino acids in skeletal muscle.

Adult↗

Does mitochondrial compartmentation of CO2 exist in man?

A comparison was made between the specific radioactivity of urea, and that of CO2 in breath, in urine and in arterialized blood, during a 36-h continuous infusion of 0.5 mCi and 100 mmol of sodium bicarbonate (NaH14CO3) into six normal male volunteers. After a period of equilibration, the mean specific radioactivity of urea was found to be only 16% below that of end expiratory CO2 and a similar amount below that of CO2 both in arterialized blood and in urine. This difference may be explained by isotopic dilution of 14CO2 by metabolic CO2 produced in the splanchnic tissues. It is concluded that, in these normal subjects, there is little or no compartmentation between cytosolic CO2 and the mitochondrial CO2 used for urea synthesis.

Adult↗