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Biomedical subjects

A M Cangiotti

Publications and source records attributed to A M Cangiotti.

13 recordsLinked to original sources

Nasal nitric oxide is low early in life: case study of two infants with primary ciliary dyskinesia.

Nasal nitric oxide levels are low in patients with primary ciliary dyskinesia, but it is not known whether this defect is already present in the first months of life. The current authors measured nasal nitric oxide in two infants with situs inversus and primary ciliary dyskinesia, diagnosed by electron microscopy at 4 and 6 months of age, and in five healthy control infants. Nasal nitric oxide values in the primary ciliary dyskinesia infants (85 and 115 parts per billion (ppb)) were markedly lower than in the healthy controls (mean: 295 ppb, range: 225-379 ppb). This is the first report to show that nasal nitric oxide values are already low in early life in primary ciliary dyskinesia children, supporting the hypothesis that a reduced production of nasal nitric oxide is an intrinsic feature of this disease. The current authors suggest that the nasal nitric oxide test may be a useful, noninvasive method for screening young children for primary ciliary dyskinesia in clinical practice.

Ciliary Motility Disorders↗

"Cyst-like" structures within the ciliary shafts in children with bronchiectasis.

"Cyst-like" structures within the ciliary shafts were considered in four adults as a primary defect involved in the development of bronchiectasis. In this study, the presence and the primary or secondary nature of this abnormality were assessed in children with bronchiectasis. High resolution computed tomography (HRCT) and nasal biopsies for motion analysis and transmission electron microscopy (TEM) evaluation of cilia were obtained in 45 children with recurrent lower airway infections and abnormal chest radiography. HRCT disclosed bronchiectasis in 35 out of 45 (77.8%) children and cyst-like structures were demonstrated with TEM in 29 out of 45 (64.4%) patients. Cyst-like structures were constantly associated with other ultrastructural abnormalities commonly observed in chronic inflammation, and were found both in subjects with primary and with secondary ciliary dyskinesia. When considering only patients with bronchiectasis, a significant correlation between prevalence of cyst-like structures and the severity of bronchiectasis was demonstrated. Follow-up (2-22 months) of seven patients demonstrated that in the five children with secondary dyskinesia, the ultrastructural defect completely disappeared and there was a small reduction in the abnormality in the two patients with primary dyskinesia. In contrast to one previous report, the reversibility of the defect suggests its secondary origin, which is most likely related to chronic airway inflammation.

Adolescent↗

Primary ciliary dyskinesia: diagnosis in children with inconclusive ultrastructural evaluation.

The purpose of this study was to distinguish between acquired and genetically determined ciliary abnormalities in children with severe chronic respiratory diseases. Samples of nasal ciliated epithelium from 50 subjects (25 male, 25 female; age-range 2-19 years) with severe chronic respiratory diseases were examined using transmission electron microscopy (TEM). Based on TEM findings, patients were divided into two groups: A and B. Group A comprised 39 children with ciliary alterations compatible with a condition probably occurring secondary to chronic inflammation (alterations of peripheral pairs, swollen cilia, and compound cilia). The other 11 patients, Group B, exhibited a greater number of alterations of the central pair and dynein arms (p< 0.001), which were qualitatively similar to, but less numerous than, those observed in primary ciliary dyskinesia (PCD). In both groups, analysis of ciliary beat frequency and waveform was performed by phase contrast microscopy (PCM). All the children with a ciliary beat frequency of < 7 Hz were treated with daily physiotherapy and with antibiotics, as recommended for PCD, for a 6-month period. After this treatment, the children were reexamined by PCM. Almost 50% of the children from Group B (i.e. those with a small proportion of specific ultrastructural defects) showed permanence of low ciliary beat frequency. This was also observed in two children of Group A. These children were considered to be affected by PCD. Our study describes a method for the diagnosis of PCD in the absence of specific ultrastructural defects or when these defects are present in only a small proportion of the cilia.

Adolescent↗

CT-guided radiolabelled aerosol studies for assessing pulmonary impairment in children with bronchiectasis.

OBJECTIVE: To determine whether CT-guided mucociliary clearance studies allow differentiation between bronchiectasis associated with primary ciliary dyskinesia (PCD) and those unrelated to congenital or genetically transmitted defects. MATERIALS AND METHODS: Fifteen children aged 4-18 years with a CT diagnosis of bronchiectasis were included in the study. Six had PCD, while in nine cases no congenital disorder was demonstrated. RESULTS: CT showed bronchiectasis in 26 (29%) of 90 lung regions. Radiolabelled aerosol studies were conducted globally for each lung and on the regions affected by bronchiectasis. Global half-time of activity (t 1/2) values of patients with PCD were significantly higher (P < 0.001) than those with bronchiectasis unrelated to congenital disorders. Among the 26 lung regions in which CT demonstrated bronchiectasis, regional clearance was abnormal in 24 cases. Patients with PCD showed no statistically significant difference between regional and global t 1/2 values. Patients with bronchiectasis unrelated to congenital disorders showed significantly higher regional t 1/2 values in the affected regions with respect to the corresponding global pulmonary t 1/2 (P < 0.06). CONCLUSIONS: The combination of morphological CT information with functional data concerning the clearance of radiolabelled aerosol adds to our understanding of pulmonary impairment in children with bronchiectasis. In particular, regional studies allow the recognition of different mucociliary clearance patterns in bronchiectasis associated with PCD and those unrelated to congenital or genetically transmitted defects.

Adolescent↗

[Percutaneous renal biopsy in children: use of a fine needle].

Percutaneous renal biopsies were performed on native kidneys in 40 children and adolescent, aged 1.7-13 (mean 6.7) years. Bleeding diatheses were excluded by the determination of Hb, blood platelets, PT, PTI and fibrinogen. Biopsies were performed under ultrasound imaging, using a semiautomated and thin needle (20 gauge in children with age under 5 years and 18 gauge for those over 5 years). All the patients were lightly sedated, except for 3 ones who received a general anesthesia. Diagnostically adequate tissue was retrieved in 38 of 40 biopsy procedures (95%). A macro-haematuria was observed with elimination of haematic coagula in 3 children (7.5%) and 24-h post-biopsy ultrasonography disciosed a small haematoma of the biopsied kidney in 2 one (5%). No mayor complications occurred. We conclude that the use of ultrasound imaging and a semiautomated needle is a safe and efficient method for performing renal biopsies in paediatric patients. The use of smaller (18 or 20-gauge) cutting needles would reduce the complications rate while allowing retrieval of sufficient tissue for histologic diagnosis.

Adolescent↗

Bile acids reversible effects on small intestinal permeability. An in vitro study in the rabbit.

To define the action of deconjugated bile acids on the small intestinal permeability in an in vitro system, we investigated the effects of chenodeoxycholic acid and ursodeoxycholic acid on the rate of transmural flux of lactulose in jejunal and ileal mucosa of rabbits, stripped of their muscle layers and mounted in Ussing chambers. In a series of experiments, tissue samples from small intestinal segments either exposed to bile acids or not also were examined by scanning and transmission electron microscopy to study the integrity of the tight junctions. Results show that chenodeoxycholate, starting at the concentration of 0.1 mM, enhanced in a dose-related manner the transepithelial flux of lactulose in the ileum. Both chenodeoxycholate (0.5 mM) and ursodeoxycholate (0.5 mM) significantly increased mucosal permeability to lactulose in jejunum and ileum; the effect of chenodeoxycholate was also shown to be reversible, as it completely disappeared within 40 min after its withdrawal and it did not result in permanent changes of epithelial transport function. Finally, the tight junctions appeared loosened by the addition of 1 mM chenodeoxycholate, suggesting that this is the major site of the transient bile acid increase of small intestinal permeability to compounds such as lactulose, having a molecular radius wider than 0.5 nm.

Animals↗

Increased tight junction width in two children with Ménétrier's disease.

Protein-losing enteropathy (PLE) and edema are usually the most prominent clinical features in children with Ménétrier's disease. However, the changes in gastrointestinal mucosa that can cause PLE have not been described yet in children. We studied by electron microscopy the mucosa of the gastric fundus, which is the site where macroscopic changes are most prominent, in two children with Ménétrier's disease. We found that tight junction width was increased to 10.5 +/- 0.94 nm (mean +/- 1 SD) in one child and to 9.7 +/- 0.7 in the other. Tight junction width returned to normal when PLE and edema subsided. These ultrastructural changes were similar to those described in adults with the disease, although the clinical course of Ménétrier's disease is very different in adults and in children. Both patients showed evidence of cytomegalovirus (CMV) infection, as indicated by increasing IgG antibodies against the virus or recovery of the virus in the urine. Although Helicobacter pylori was found in the antral mucosa of one patient, the clinical course of the disease was not related to this microorganism. We conclude that increased tight junction width plays a role in PLE seen in Ménétrier's disease in children and that CMV, rather than Helicobacter pylori, is associated with the disease.

Adolescent↗