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Biomedical subjects

G Mastella

Publications and source records attributed to G Mastella.

At least 73 records · Page 4Linked to original sources
PubMed1990

Transcutaneous blood gas analysis during sleep and exercise in cystic fibrosis.

Forty patients with cystic fibrosis (CF) (mean age, 13 +/- 2.5 years) were studied with transcutaneous (tc) blood gas monitoring (TCM) during sleep and exercise. By comparing arterial blood samples and TCM in 24 of them (27 samples), a mean bias of tcO2 -15.91 mmHg with a precision of 8.4 mmHg was found. The mean bias of tcCo2 was 7.21 mmHg with a precision of 3.9 mmHg. A standardized submaximal exercise test (1.7 W/kg) was performed in all 40 CF patients and in 14 healthy control subjects (mean age, 13 +/- 0.5 years). The typical tc trend during exercise for CF and healthy subjects was a slight increase of tcO2 levels and tcCO2 stability. A minor decrease of tcO2 values occurred in four CF patients (no greater than 7 mmHg). In 28 patients (mean age, 13 +/- 3 years), tcO2 and tcCO2 were recorded during sleep. In 13 of them, apparent hypoxemic episodes were noted, without relation to the degree of airway obstruction. There were simultaneous episodes of hypercapnia in ten patients. Some difficulties were encountered in analyzing long-term recordings. TcO2 drifts upward and tcCO2 decreases during the recordings over several hours. The change in electrode position after 4 h of sleep modified tcO2 and tcCO2 values. Such difficulties limit the usefulness of long-term but not short-term recordings.

Adolescent↗
PubMed1990

An evaluation of an enzyme immunoassay method for immunoreactive trypsin in dried blood spots.

A novel monoclonal antibody based enzyme immunoassay (EIA) method for the measurement of the human cationic trypsinogen (NeoScreen, AGEN Biomedical Ltd., Acacia Ridge, Australia) in dried blood spots for the neonatal screening of cystic fibrosis was evaluated. The calibration standards provided as dried blood spots by AGEN are highly unstable and must be replaced with user prepared materials. Reference values from control individuals were obtained by parametric methods. A preliminary comparison with a polyclonal antibody based RIA method (Trypsik, SORIN Biomedica, Saluggia, Italy) was performed. Regression analysis between the RIA and the EIA methods gave a coefficient of correlation of 0.58 for RIA values less than 40 micrograms/L and of 0.77 for RIA values greater than or equal to 40 micrograms/L. Average CV of the within-run imprecision for the EIA method was 19.6% and for the RIA method 28.8%. CVs of the between-run imprecision at low, intermediate and high values for the EIA method were 23.7%, 15.8%, 15.6% and for the RIA method 20.6%, 14.4%, 11.2%. The diagnostic accuracy analyzed by a Receiver Operating Characteristics (ROC) curve of the RIA method gave a maximum accuracy of 190.9 while that of a simulated ROC curve for the EIA method was 193.0. We found that the precision and the diagnostic accuracy of the EIA method (AGEN) are equal to or better than those of one of the RIA methods.

Calibration↗
PubMed1990

IgA anti-gliadin antibodies in the monitoring of gluten challenge in celiac disease.

The aim of this study was to evaluate the reliability of serum IgA anti-gliadin antibodies (IgA-AGA) in the monitoring of gluten challenge and in the prediction of mucosal relapse in children with celiac disease (CD) in order to reduce the challenging procedure to a minimum. Serial evaluations of serum IgA-AGA titers and 1-h blood xylose levels were performed in 17 children with celiac disease during gluten challenge. Jejunal biopsy was generally done after two consecutive measurements of positive IgA-AGA. The morphological appearance of the mucosa and intraepithelial lymphocyte infiltration were also evaluated. A serum positive for IgA-AGA was observed in 16 of 17 patients between the 15th and 35th day of challenge. The challenge was concluded in all children after 20-45 days from the introduction of a gluten-containing diet after histological confirmation of CD. Plasma xylose test was less reliable in this respect. We conclude that IgA-AGA measurement by gluten challenge is likely to simplify and allow earlier diagnostic confirmation of celiac disease in children, without intestinal biopsy.

Celiac Disease↗
PubMed1990

Development of a screening system for cystic fibrosis: meconium or blood spot trypsin assay or both?

High blood trypsin levels during early days of life are found in newborns subsequently diagnosed to be affected by cystic fibrosis. The authors compared the validity of the traditional meconium test with the blood immunoreactive trypsin (IRT) assay, carried out in parallel on 113,302 neonates from three regions of North-eastern Italy. The meconium test showed a sensitivity of 57.7%. The sensitivity of the IRT test was higher (96.1%). It was possible to identify by IRT 10 out of 11 false negative CFs at the meconium test. A shortcoming of neonatal IRT, however, is its low specificity; 1.6% of the newborns had to be retested. A new screening policy was therefore proposed and carried out on 69,640 newborns: the Lactase test (LACT) on meconium was introduced as a complementary assay in IRT positive newborns. If LACT exceeded 2 U/g dry meconium, a confirmatory sweat test was immediately requested; if LACT test was negative and IRT exceeded 85 micrograms/l, IRT was repeated. Postneonatal retesting values above 25 micrograms/l required a sweat test. As a result, the estimated prevalence of CF was 1:4,352, the sensitivity was 93.3%; the specificity turned out to be 99.6%, considering all false positive newborns investigated with retesting and/or direct sweat test.

Albumins↗
PubMed1990

Pancreatic function and gene deletion F508 in cystic fibrosis.

In view of the possible relation between pancreatic function and cystic fibrosis (CF) gene mutations, a detailed study on Italian patients was performed. Seventy pancreatic insufficient and 48 pancreatic sufficient patients were included after very accurate characterisation of their pancreatic and digestive function, all performed in the same CF centre. The CF gene deletion F508 was tested to define the patients' genotypes. The results confirm that the mutation correlates with pancreatic insufficiency, and is recessive to other, as yet unreported, mutant alleles that determine pancreatic sufficiency. An indication that duodenal bicarbonate output is more severely reduced in the presence of deletion F508 is also presented. The data are discussed in relation to a hypothesis on the primary effects of CF gene deletion F508.

Adolescent↗
PubMed1990

Adherence to gluten-free diet and serum antigliadin antibodies in celiac disease.

In 134 patients with celiac disease the compliance with a gluten-free diet (GFD) and the presence of antigliadin antibodies (AGA) were evaluated. Compliance with the GFD was good in 71%, moderate in 11% and poor in 18%. High levels of AGA (IgA and IgG) were found in 24.2% of patients with good GFD, in 40% of those with moderate GFD and in 75% of those with poor GFD compliance. Our data suggest that the presence of AGA is correlated with the degree of adherence to the GFD, and that AGA measurement may be of some value in the monitoring of GFD in patients with celiac disease.

Antibodies↗
PubMed1989

Exercise tolerance and effects of training in young patients with cystic fibrosis and mild airway obstruction.

We evaluated the effects of an 8-week aerobic training (1 hr, three times a week) on physical performance of ten patients with cystic fibrosis (CF) (median age, 12.5 yr; range 11.1-15.3 yr), with mild airway obstruction (FEV1 = 77 +/- 22% pred.), and ten healthy age-matched children (CONTR) (median age, 12.7 yr; range 12.2-15.2 yr). Physical performance was tested with maximal incremental (MAX) and submaximal (SMAX) (fixed workload of 1.7 W/kg during 6 min) exercise tests on a cycle ergometer. These and standard spirometric and anthropometric measurements were performed at the beginning and end of a period with usual daily activity and one with the training program. The kinetics of ventilatory parameters at the onset and end of SMAX were displayed by fitting data on oxygen uptake and minute ventilation by monoexponential curves (least-squares method). At the start and the end of the training period, all children were timed for endurance run to voluntary exhaustion and for sprinting through an obstacle course. A pattern of relative hyperventilation during SMAX and of poor performance in endurance and obstacle runs were evident at the start of the training period in patients with CF. The effects of training on MAX and SMAX were small and partial; the improvement in field test performances was significant only for CF and could be attributed to improvement of skill and motivation.

Adolescent↗
PubMed1989

Prenatal diagnosis of cystic fibrosis. Analytical evaluation of microvillar enzyme determinations in amniotic fluid.

The activity of gamma-glutamyltranspeptidase and total alkaline phosphatase and its isoenzymes has been determined in 261 amniotic fluid samples taken from pregnant women with known normal outcome and in 30 amniotic fluid samples from pregnant women with a 1:4 risk for cystic fibrosis (CF). Preliminarily, 114 amniotic fluid samples were assayed in parallel in three different laboratories, and a good correlation was found even though different assays were used. From the results obtained in control amniotic fluids, normal range and CF-predictive cutoff values were established. No false-negative results were found in this study. Among the predicted affected pregnancies 7 were terminated, and 3 went to term: 1 resulting in a CF-affected child and the other 2 in healthy children. CF was confirmed in all the aborted fetuses. In 1 case the results were inconclusive. In this study numerical results obtained for samples with a 1:4 risk of CF analyzed in the three laboratories were always virtually identical.

Alkaline Phosphatase↗
PubMed1989

Pulmonary hemosiderosis in a child with cystic fibrosis.

Two episodes of acute iron deficiency anemia with blood-stained sputum and symptoms of severe acute pulmonary exacerbation were observed in a child with cystic fibrosis (CF). Hemosiderin laden macrophages (siderophages) were repeatedly found in sputum and gastric juice, suggesting the coexistence of pulmonary hemosiderosis (PH). The possibility that pulmonary immune-mediated mechanisms characteristic of CF may have played a role in the development of PH is considered.

Cystic Fibrosis↗
PubMed1989

Neutrophil function and humoral immunity in children with recurrent infections of the lower respiratory tract and chronic bronchial suppuration.

Neutrophil motility and superoxide anion production and serum immunoglobulin levels were assessed in 51 children with recurrent infections of the lower respiratory tract and chronic bronchial suppuration, not due to anatomic or functional cause. In 26 children (50.9%), a significant defect of the immunologic defenses, likely to be responsible for the disease, was observed. A precocious diagnosis and an adequate therapy could result, at least in some patients, in the prevention of progressive lung damage.

Adolescent↗
PubMed1988

The saccharin method for testing mucociliary function in patients suspected of having primary ciliary dyskinesia.

In order to evaluate the clinical value of the saccharin test as a practical and simple measure of mucociliary clearance, nasal mucociliary clearance (NMCC) and ciliary ultrastructure were studied in 22 patients suspected of having primary ciliary dyskinesia (PCD) based on the saccharin test. Ten patients fulfilling the diagnostic criteria of PCD had a pathological response to the saccharin test (transport time greater than 60 minutes), and this was consistently associated with ultrastructural defects, specific for PCD. These results validate the suitability of the clinical use of the saccharin test as a screening procedure for NMCC. The false-negative results obtained in three cases of PCD, all with borderline values, cannot be ascribed to ineffectiveness of the test, but rather to the persistence of some motility by certain defective cilia, detectable by microphoto-oscillographic investigation of specimens obtained by nasal biopsy or brushing.

Adolescent↗
PubMed1988

Cilia-lacking respiratory cells in ciliary aplasia.

This report describes the ultrastructural alterations observed in the nasal and bronchial mucosa of an 11-yr-old male suffering from immotile cilia syndrome (ICS). The morphological features observed in this patient are consistent with a ciliary aplasia. In fact, ciliated cells appeared to be replaced by columnar cells lacking cilia and basal bodies, and bearing on their surface cilium-like projections without any internal axonemal structure. In spite of the absence of basal bodies, centrioles, and kinocilia, these cells unexpectedly showed mature striated roots and centriolar precursor material scattered throughout the apical cytoplasm. These data suggest that control over basal body assembly is distinct from control over striated root formation. The presence of the above-reported structures in cells otherwise presenting many morphological features of normal ciliated cells is discussed on the basis of current knowledge of respiratory cilia biogenesis.

Bronchi↗
PubMed1988

The assay of chymotrypsin in stool as a simple and effective test of exocrine pancreatic activity in cystic fibrosis.

The study evaluates two methods of assay of fecal chymotrypsin (titrimetric and spectrophotometric method) as an index of exocrine pancreatic function. The assay was performed on 101 control subjects and 128 cystic fibrosis (CF) patients by the first method, and 75 controls and 102 CF patients by the second method. CF subjects were subdivided into four groups based on pancreatic function: total pancreatic insufficiency in the first group, partial pancreatic insufficiency in the second group, normal pancreatic function in the third group, and pancreatic insufficiency plus enzymatic treatment in the fourth group. Fifty-four CF patients were examined in the first group, 27 in the second group, 19 in the third group, and 28 in the fourth group by the titrimetric method; 23, 25, 50, and 65, respectively by the spectrophotometric method. The spectrophotometric method was highly reproducible and more sensitive and specific. With such a method the assay on stool random sampling correlated with the duodenal output of chymotrypsin after hormonal stimulation as well as fecal output of 72 h. The test had sensitivity and specificity of 100% if referred to CF patients with total pancreatic insufficiency. It was calculated that CF patients with normal fecal chymotrypsin have a probability of 76% to have a normal pancreatic function and a probability of 24% to have a partially compromised pancreatic function. The assay separates distinctly CF patients with a fat absorption coefficient greater than 90% from those with a coefficient less than 90%. The test is proposed for current clinical use in diagnosis and treatment of pancreatic insufficiency in cystic fibrosis.

Adolescent↗