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Biomedical subjects

M Celli

Publications and source records attributed to M Celli.

At least 19 recordsLinked to original sources
PubMed2006

Absence of severe recurrent infections in glycogen storage disease type Ib with neutropenia and neutrophil dysfunction.

We describe a 10-year-old boy with glycogen storage disease type Ib (GSD Ib) with neutropenia and neutrophil dysfunction who never suffered from severe recurrent infections. Lymphocyte subpopulations and assay of intracellular cytokines (IL-2, IL-4 and IFN-gamma) showed a pattern of lymphocyte activation suggesting a shift of T(H)1/T(H)2 balance towards a T(H)1 response. This is the first report of GSD Ib without severe recurrent infections in spite of neutropenia and neutrophil dysfunction.

Child↗
PubMed2004

Microscopic self-dynamics in liquid hydrogen and in its mixtures with deuterium.

We have measured the dynamic structure factor of liquid parahydrogen, pure and mixed with deuterium, in various thermodynamic conditions using incoherent inelastic neutron scattering. The experiments were carried out on TOSCA-II, a new time-of-flight, inverse-geometry, crystal-analyzer spectrometer. After an accurate data reduction, the high-energy parts of the neutron spectra recorded in backward scattering were studied through the modified Young and Koppel model, from which the mean kinetic energy values for a hydrogen molecule were estimated. In addition the low-energy parts of the neutron spectra recorded in forward scattering were analyzed in the framework of the Gaussian approximation and fitted through a Levesque-Verlet model for the velocity autocorrelation function. Thus various physical quantities are determined and compared with accurate path integral Monte Carlo simulations. Despite the excellent quality of these fits, the velocity autocorrelation functions derived from the forward-scattering data appear totally unable to properly describe the backward-scattering ones. These findings prove an unquestionable breakdown of the Gaussian approximation in semiquantum liquids. The present results appear of great interest and suggest further investigation on the limits of the widely used Gaussian approximation.

Journal Article↗
PubMed2004

Density of phonon states in solid parahydrogen from inelastic neutron scattering.

We have measured the inelastic neutron scattering spectrum of solid parahydrogen (at low pressure and T=13.3 K) using the thermal original spectrometer with cylindrical analyzers spectrometer at the ISIS pulsed neutron source (UK). From the experimental spectrum we have obtained the parahydrogen density of phonon states which has been compared with the estimates available in the literature. The present determination improves substantially the previous experimental scenario from the point of view of both statistics and accuracy. The comparison with the most recent estimate obtained from a quantum mechanical simulation of the molecular dynamics calls for an improvement of the computational methods..

Journal Article↗
PubMed2003

Fatty acid profile of oesophageal mucosa in children with gastro-oesophageal reflux disease.

BACKGROUND: Polyunsaturated fatty acids, as precursors of eicosanoids, are involved in the pathogenesis of oesophageal mucosal damage and healing. AIMS: To evaluate a possible role of polyunsaturated fatty acids in the pathogenesis of gastro-oesophageal reflux, we assayed fatty acids profile of oesophageal mucosal specimens obtained by endoscopy in children without oesophageal disease and children affected by gastro-oesophageal reflux disease. PATIENTS: Eighteen children with normal 24-h oesophageal pH monitoring (GOR- group) and 18 children with gastro-oesophageal reflux disease (GOR+ group, eight with oesophagitis and 10 without), were included in the study. METHODS: Fatty acids were extracted from oesophageal mucosal specimens obtained by endoscopy and assayed by gas chromatography. RESULTS: In the GOR+ group we observed an increased percentage of mucosal polyunsaturated fatty acids, mainly arachidonic and docosohexaenoic acids (p<0.01), without differences between groups with and without oesophagitis. Significant positive correlation was found between reflux index and docosahexaenoic acid (r=0.805; p<0.001). CONCLUSIONS: The results obtained show that the current methods are able to reveal changes between normal and pathological mucosa that could be relevant in the pathogenesis of gastro-oesophageal reflux disease.

Arachidonic Acid↗
PubMed2002

Direct experimental access to microscopic dynamics in liquid hydrogen.

We have obtained the double-differential incoherent neutron scattering cross section of liquid and solid parahydrogen in various thermodynamic conditions using TOSCA, a time-of-flight, inverse geometry, crystal analyzer spectrometer, operating at the pulsed neutron source ISIS. The measured cross section provides direct experimental access to the self part of the center-of-mass inelastic structure factor of the parahydrogen molecules in the system. Data have been corrected for the experimental effects and then analyzed in the framework of the Young-Koppel model and the Gaussian approximation. The velocity autocorrelation functions and their energy spectra have been obtained from a fitting procedure, making use of the quantum generalized Langevin equation and of model memory functions, and finally compared to the most recent results of both molecular centroid dynamics and self-consistent quantum mode-coupling theory. Some dynamic quantities were also related to simple equilibrium properties and simulated through a standard path integral Monte Carlo code. Results are very interesting but still urge for further developments of theoretical and dynamic simulation approaches, as well as for more extensive experimental efforts.

Journal Article↗
PubMed2001

Increased taurine content in esophageal mucosa of children affected by gastroesophageal reflux.

We studied the possible involvement of mucosal amino acid metabolism in the pathogenesis of gastroesophageal reflux disease in children. Eighteen children with gastroesophageal reflux disease (8 with reflux esophagitis and 10 without) and 10 children with normal 24-h esophageal pH monitoring as a comparative group underwent esophagogastroduodenoscopy with biopsies. Plasma and esophageal mucosa amino acids were assayed by liquid chromatography. In children affected by gastroesophageal reflux disease we found an increase of mucosal taurine (P < 0.01) and a decrease of serine (P < 0.01). No differences were noted between patients with and without esophagitis. Significant positive correlations (P < 0.001; r = 0.626) were found between mucosal taurine content and reflux index. Plasma amino acid concentrations did not show any significant differences among groups. Our results indicate that biochemical alterations precede the histological findings of inflammation, likely reflecting the adaptive response of the esophageal mucosa to the gastric contents exposure.

Adolescent↗
PubMed2000

Sandifer's syndrome in a breast-fed infant.

Sandifer's syndrome is a rare manifestation of gastroesophageal reflux (GER) in children, occurring in association with abnormal movements of the head, neck, and upper part of the trunk. Out of 65 children with Sandifer's syndrome described in literature, only 2 were breast-fed. We report on a 15-day-old breast-fed girl affected by Sandifer's syndrome. Pathological GER was diagnosed with 24 h pH esophageal monitoring. In our patient, all the symptoms of Sandifer's syndrome disappeared when she was cow's milk formula-fed. The role of food allergy to dietary proteins ingested by a lactating mother is discussed.

Breast Feeding↗
PubMed1999

Determination of urinary orotic acid and uracil by capillary zone electrophoresis.

We describe a simple method for measuring orotic acid and uracil concentration in urine by capillary zone electrophoresis in 20 mM Na-borate buffer, pH 9.2. The method was applied for studying a patient with HHH (hyperomithinemia, hyperammonemia and homocitrullinuria) syndrome. A high value of uracil excretion was found during periods of relatively low orotic acid excretion and normal ammonemia. The orotic acid level in urine was increased by increasing protein intake.

Amino Acid Metabolism, Inborn Errors↗
PubMed1999

Effect of D-ribose on purine synthesis and neurological symptoms in a patient with adenylosuccinase deficiency.

Oral supplementation of 10 mmol/kg/day of D-ribose to a patient with an inherited deficit of adenylosuccinase, severe psychomotor retardation, and epilepsy caused a marked increase in plasma concentration and urinary excretion of urate, while minor changes in succinylpurine levels were observed. D-Ribose administration was accompanied by a slight improvement of behaviour and a progressive reduction of seizure frequency, which increased dramatically upon two attempts to withdraw the drug. Substitution of D-ribose with an equivalent amount of D-glucose did not result in an increase of seizure frequency.

Adenylosuccinate Lyase↗
PubMed1998

Usefulness of cyanide-nitroprusside test in detecting incomplete recessive heterozygotes for cystinuria: a standardized dilution procedure.

We present the results of a cyanide-nitroprusside test (CNT) after a standardized dilution procedure of urine samples and report the efficiency of this method in detecting heterozygotes for cystinuria when applied on an open pediatric population. In the preliminary study we assayed by quantitative determination of amino acids 162 urine samples from a hospital population identifying 24 type III heterozygotes and 2 type II heterozygotes for cystinuria. The classic CNT gave 38 false positive results and 5 false negative results showing a sensitivity and specificity of 0.808 and 0.721, respectively. When progressively diluted, all samples of heterozygotes remained CNT positive up to a creatinine concentration of 90 mg/dl. At this level of dilution 31 out of 38 false positive turned to negative, thus obtaining a specificity of 0.922 without a lowering of the sensitivity in detecting heterozygotes. The standardized dilution at 90 mg/dl of creatinine concentration was applied to 74.7% of a population of 1024 schoolchildren. In this way 163 out of 210 positive results were eliminated and thus the specificity of CNT rose from 0.789 to 0.953. On the basis of these results, the method proposed can be regarded as reliable and useful for a screening program in detecting heterozygotes for cystinuria.

Adolescent↗
PubMed1998

[Jejunal enteral feeding in a severe case of reflux esophagitis in an infant with Pierre-Robin syndrome].

A case of Pierre-Robin syndrome associated with gastroesophageal reflux and oesophagitis is described. The infant was firstly fed with a hydrolysed-casein formula by gastrostomy, but there was not any improvement of his clinical status, in spite of an appropriate nutrient intake. For this reason, a jejunal enteral feeding, with a semi-elemental formula and then with a hydrolysed-casein formula was started. During this nutritional treatment, the infant showed an adequate weight gain and after 52 days the weight increased from 2880 g to 4580 g.

Enteral Nutrition↗
PubMed1997

Erythrocyte and plasma levels of glutamate and aspartate in children affected by migraine.

In this study we determined plasma and erythrocyte amino acids in children affected by migraine, in order to evaluate glutamate and aspartate metabolism in the pathogenesis of this disorder. Fifteen children with migraine with aura (mean age +/- SD = 10.3 +/- 1.56), 19 children with migraine without aura (mean age +/- SD = 10.4 +/- 1.48) and 16 healthy normal controls (mean age +/- SD 10.6 +/- 1.53) were investigated. In both migraine groups there were significantly lower plasma glutamate and aspartate levels and significantly higher erythrocyte/plasma concentration (E/P) ratios of these amino acids with respect to the controls. Erythrocyte aspartate concentrations were significantly elevated in migraine children compared to the controls, while erythrocyte glutamate concentrations showed no significant differences between groups. Similar results were observed in both migraine groups. These results seem to suggest the presence of a higher activity of the erythrocytes' glutamate/aspartate transport system that could reflect a similar alteration at the neuronal/glial cell level in the CNS. Our study suggests an imbalance of the excitatory amino acid turnover in the pathogenesis of migraine in children.

Analysis of Variance↗
PubMed1996

Abnormal intestinal permeability in children with autism.

We determined the occurrence of gut mucosal damage using the intestinal permeability test in 21 autistic children who had no clinical and laboratory findings consistent with known intestinal disorders. An altered intestinal permeability was found in 9 of the 21 (43%) autistic patients, but in none of the 40 controls. Compared to the controls, these nine patients showed a similar mean mannitol recovery, but a significantly higher mean lactulose recovery (1.64% +/- 1.43 vs 0.38% +/- 0.14; P < 0.001). We speculate that an altered intestinal permeability could represent a possible mechanism for the increased passage through the gut mucosa of peptides derived from foods with subsequent behavioural abnormalities.

Adolescent↗
PubMed1995

Low serum tryptophan to large neutral amino acids ratio in idiopathic infantile autism.

The serum tryptophan to large neutral amino acids ratio (Try/LNAA) is considered a reliable marker of tryptophan availability for brain serotonin synthesis. A dysfunction of brain serotonergic activity has been postulated to exist in autistic disorder and supported by recent studies. On this basis, we determined the serum amino acids levels in 40 children with idiopathic infantile autism as well as in 46 control children. A significantly lower serum Try/LNAA ratio was observed in the autistic subjects compared to the normal controls. In 14 autistic children (35%) this ratio was 2 SD below the mean value obtained in the control group. These results suggest that a low brain tryptophan availability due to a low serum Try/LNAA ratio could be one of the possible mechanisms involved in the alteration of serotonergic function in autism.

Adolescent↗
PubMed1995

Rapid gas-chromatographic assay of lactulose and mannitol for estimating intestinal permeability.

We developed a gas-chromatographic method to determine urinary mannitol and lactulose. The procedure for purification of urine by a resin was optimized for purification of analytes and high recovery; the aliquot of resin chosen (500 mg) was kept in contact with the urine for 1 min. The recoveries of mannitol and lactulose were > 85% at concentrations that include both normal and pathological values. Sugars were converted to oximes before the silylation step to avoid multiple peaks for the anomeric forms. The calibration was linear over the range 0.1-1 microgram of sugar injected. Analytical recovery of the sugars ranged from 90% to 95.3% for mannitol and from 90.4% to 95.8% for lactulose. The mean within-day imprecision (CV) was 6.2% for mannitol and 4.7% for lactulose; the between-day CV was 6.7% for mannitol and 5.1% for lactulose. A lactulose/mannitol ratio of 0.035 completely differentiated 28 normal children and 28 children with active gluten-sensitive enteropathy, whose mean ratios were 0.022 (SD 0.007) and 0.084 (SD 0.054), respectively.

Adolescent↗