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Biomedical subjects

F Zacchello

Publications and source records attributed to F Zacchello.

At least 91 records · Page 5Linked to original sources
PubMed1992

Determination of 8-methoxypsoralen in plasma by gas chromatography-mass spectrometry using selected-ion monitoring.

A sensitive and accurate assay was developed for the measurement of 8-methoxypsoralen in plasma using electron-impact positive-ion mass fragmentography. 4,5,8-Trimethylpsoralen was used as an internal standard. Sample preparation consisted of a two-step liquid phase extraction using acetonitrile and methylene chloride. The calibration curve showed a linear relationship between the peak areas of 8-methoxypsoralen and 4,5,8-trimethylpsoralen over a wide range of 8-methoxypsoralen concentrations (1-500 ng/ml). With-in- and between-run precisions, measured at five different drug concentrations, varied from 0.82 to 1.41% and from 0.82 to 1.86%, respectively.

Gas Chromatography-Mass Spectrometry↗
PubMed1992

Gas exchange during exercise in diabetic children.

The purpose of this study was to evaluate the cardiorespiratory and metabolic response to exercise in 33 children, aged 9 to 15 years, affected by type I diabetes mellitus, in comparison with 47 age-, sex-, weight-, and height-matched healthy children. All diabetic children were on a mixed split-dose insulin regimen, consisting of both regular and long-acting insulin in the morning and evening. The last insulin injection was administered on average 6 hours before the test. The mean duration of diabetes mellitus was 5.0 +/- 3.1 years. The metabolic control was evaluated on the basis of HbA1 levels (mean, 8.9 +/- 1.8%). Pulmonary function tests and progressive exercise tests on the treadmill were performed. Gas exchange, ventilation, and heart rate (HR) were monitored during the tests. The O2 pulse (VO2/HR) was calculated. There was no difference in the baseline oxygen uptake (VO2) between the diabetic children and the control group. VO2 peak was significantly lower (P less than 0.01) in the diabetic adolescents (41.2 +/- 5.9 mL/min/kg) compared to control subjects (46.3 +/- 9.6 mL/min/kg) and it was achieved at an earlier (P less than 0.01) time of run (7.5 +/- 1.8 vs. 9.1 +/- 2.8 min). Anaerobic threshold and minute ventilation were similar in the two groups. The O2 pulse throughout the test was significantly lower (ANOVA, P less than 0.001) in the diabetic group compared to the controls. No differences were found in resting and post-exercise spirometric values. In conclusion, our study shows that well-controlled diabetic adolescents have a reduced working capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Screening for cystic fibrosis gene mutations by multiplex DNA amplification.

We have developed a simple rapid DNA screening test that allows us simultaneously to analyze seven CF mutations (delta F508, R347P, S549N, G551D, R553X, R334W, 444delA) that together account for about 60% of all CF mutations in the Italian population. It consists of three steps: multiplex polymerase chain reaction (PCR) amplification of exons 4, 7, 10 and 11; restriction endonuclease digestion of the PCR products; and vertical polyacrylamide gel electrophoresis analysis. We have used our multiplex assay for analyzing 15 CF chromosomes (non delta F508) and have found 3 cases of the R553X mutation; the latter have been confirmed by amplification and digestion of exon 11.

Amino Acid Sequence↗
PubMed1992

Allopurinol challenge test in children.

The allopurinol challenge test was performed on 44 healthy subjects (28 children and 16 adolescents) in order to establish normal values of urinary orotic acid excretion following allopurinol ingestion in the paediatric population. The subjects were divided into three groups according to their age: 6 months to 6 years; 6 years to 10 years; and 10 years to 17 years. They were given 100 mg, 200 mg, or 300 mg of allopurinol, respectively (based on age) in a single oral dose. Maximum peak urinary orotic acid levels following ingestion of allopurinol were 13.0 (n = 14), 9.3 (n = 14), and 10.2 (n = 16) mumol/mmol creatinine in the three groups, respectively. In all children tested the peak orotic acid level was 3.1 +/- 2.7 mumol/mmol creatinine (mean +/- SD, n = 44). This allopurinol challenge test was also performed in six children with urea-cycle disorders, including five females with ornithine transcarbamylase (OTC) deficiency, all of whom demonstrated abnormally elevated levels of urinary orotic acid (peak levels of 26-134 mumol/mmol creatinine) following allopurinol ingestion.

Adolescent↗
PubMed1992

Hyperthyroid-induced chorea in an adolescent girl.

Hyperthyroidism is invariably accompanied by nervous system dysfunctions. Irritability, emotional lability and hyperkinesia are the signs and symptoms most frequently observed. Chorea or choreoathetosis are only rarely associated with hyperthyroidism. It is the purpose of this work to describe the case of a young girl in whom chorea was the main manifestation of thyrotoxicosis. The chorea receded and disappeared as the patient became euthyroid. Hyperthyroidism, therefore, is to be considered an unusual cause of chorea and every patient with choreiform movements should be examined also for thyroid function.

Adolescent↗
PubMed1992

Early and rapid diagnosis of CMV infection by nonradioactive in situ hybridization in pediatric kidney transplant recipients.

A nonradioactive in situ hybridization technique was utilized for the rapid and early diagnosis of cytomegalovirus (CMV) infection in children undergoing kidney transplantation. The cellular samples were obtained directly from the organs thought to be affected on the basis of clinical findings: bronchoalveolar lavage during interstitial pneumonia (7 samples from 6 cases); fine-needle aspiration biopsy (FNAB) of the liver during acute hepatitis (1 case); kidney FNAB and peripheral blood where there was a greater than or equal to 25% creatinine rise with or without fever (26 episodes). Standard virus isolation procedures and an immunofluorescent technique on short-term cultures of human fibroblast cells were performed as a control. 6/23 children followed had a symptomatic CMV infection (4 had interstitial pneumonia; 1 had acute hepatitis, and there was 1 case of creatinine rise with fever). In all cases, the diagnosis was provided by in situ hybridization in less than 24 h. These results were confirmed 48 h later by immunofluorescence and after 5-25 days by standard viral cultures. In situ hybridization with a biotinylated probe proved to be a rapid and sensitive method for diagnosis of CMV disease, when performed on specimens obtained from the involved organs at an early stage of the infection. This diagnostic approach allowed a specific antiviral therapy to be undertaken promptly.

Biopsy, Needle↗
PubMed1992

Evoked potentials before and after anemia correction with recombinant human erythropoietin in end-stage renal disease.

Subclinical involvement of the nervous system in uremic adults has been detected by modern neurophysiological techniques. Chronic anemia is one of the possible factors responsible for neural dysfunction in uremia. We evaluated neurophysiological (brainstem auditory and somatosensory evoked potential) abnormalities and their possible modification following anemia correction with recombinant human erythropoietin in 14 children with end-stage renal disease maintained by hemodialysis. Only peripheral and 8th cranial nerve electrophysiological data are significantly abnormal in our patients, and they are not acutely modified by anemia correction. These data confirm the importance of electrophysiological testing of uremic children for detecting nervous system involvement at an early stage and for monitoring the efficacy of its management.

Adolescent↗
PubMed1991

Linkage analysis of neurofibromatosis type 1. Study of a homogeneous North Italian population with five DNA markers of chromosome 17.

The authors report the results of a genetic analysis performed in 34 neurofibromatosis type 1 (NF1) Italian families using five loci tightly linked to NF1: D17S33, D17S82, D17S83, D17S37, and D17S36. A two-point linkage analysis was performed with the LINKAGE and the CRI-MAP programs. The map of the region was constructed using the MAP90 program. Data from the present study lend further support to evidence that all NF1 mutations are allelic and that the NF1 locus resides in the proximal region of chromosome 17q. Close linkage of NF1 to all the markers was found. Two of them, namely D17S82 and D17S83, showed the highest linkage with a value of 0 recombination frequency and lod scores of 3.77 and 4.02, respectively. The best map found is D17S33-D17S82-NF1-D17S83-D17S37-D17S36+ ++. The authors stress that knowledge of precise order is essential; if D17S82 and D17S83 are proved to flank the NF1 gene, they allow an acceptable presymptomatic diagnosis in informative families.

Chromosomes, Human, Pair 17↗
PubMed1991

Exercise performance in very low birth weight children at the age of 7-12 years.

Fifteen very low birth weight children, 9 appropriate for gestational age (AGA, mean birth weight 1302 +/- 164 g) and 6 small for gestational age children (SGA, mean birth weight 1263 +/- 117 g), were studied at the age of 7-12 years, and compared to a group of 26 healthy, age-, sex-, and height-matched children born at term. None of the VLBW children had developed chronic bronchopulmonary disease. Pulmonary function tests and progressive exercise tests on a treadmill were performed. Forced vital capacity, forced expiratory volume at 1 s and forced expiratory flow between 25% and 75% of vital capacity were normal for all subjects. No differences were found in maximum oxygen consumption, anaerobic threshold and maximal heart rate between the AGA and SGA children and the respective controls. Both in the AGA and SGA subgroups, the pre-exercise oxygen uptake results were comparable to those of the controls. In the SGA subgroup the energy cost of running was significantly higher with respect to the controls, while no difference was found between the AGA and the control children. In conclusion, children with birth weight less than 1501 g have normal values of aerobic fitness. In SGA children the efficiency of running is slightly reduced.

Anaerobic Threshold↗
PubMed1991

Somatosensory pathway dysfunction in uremic children.

Neurophysiological studies have shown defects in peripheral conduction in up to 75% of adults with end-stage renal disease (ESRD), though abnormalities of central conduction seem more variable. There are no comparable pediatric data. We therefore measured median nerve somatosensory evoked potentials (SEPs) in 10 children with ESRD, maintained by hemodialysis, who had no neurological signs or symptoms, and compared the results with those for age-matched controls. The latencies of N9, P14, N20 and P22, and interpeak latencies, N9-N20, N9-P14 and P14-N20, were not significantly different between the two groups (Student's t test). However, the children with ESRD were significantly retarded in growth and when arm length was taken into account, a significant difference in peripheral conduction was revealed. There was no correlation with other indexes of disease severity (parathormone, aluminium, Hb, Na, K, Cl, BUN and creatinine). SEPs appear to reflect subclinical changes in peripheral conduction in sensory pathways in children with ESRD which are not correlated with other measures of disease severity.

Adolescent↗
PubMed1991

Development of language in 18-30-month-old HIV-1-infected but not ill children.

Thirty-six children (age range, 18-30 months) born to HIV-1-infected mothers were studied for speech development by matching 18 infected with 18 non-infected subjects for age, sex and socioeconomic status. All the children were in good health. Each child was given three comprehension and three production tasks. In addition, each child's mean length of utterance (MLU) was obtained by observation of natural child-parent interactions. The development quotients (DQ) were assessed by Brunet-Lézine's tests. Infection significantly affected children's MLU, the infected children being less advanced than those non-infected. Both infected and non-infected children progressed in language acquisition from the second to the third year of age, but infected children had significantly greater production difficulty than non-infected children in the second year of life. The matched subjects design adopted gives some strength to the conclusion that HIV-1 infection impairs the genesis rather than the later development of language in infected but not ill children.

Analysis of Variance↗