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Biomedical subjects

A Di Franco

Publications and source records attributed to A Di Franco.

52 records · Page 3Linked to original sources
PubMed1994

Prognosis of occupational asthma.

Several studies on the prognosis of occupational asthma have shown that a significant proportion of patients continue to experience asthmatic symptoms and nonspecific bronchial hyperresponsiveness after cessation of work. The determinants of this unfavourable prognosis of asthma are: long duration of exposure before the onset of asthma; long duration of symptoms before diagnosis; baseline airway obstruction; dual response after specific challenge test; and the persistence of markers of airway inflammation in bronchoalveolar lavage fluid and bronchial biopsy. The relevance of immunological markers in the outcome of occupational asthma has not yet been assessed. Further occupational exposure in sensitized subjects leads to persistence and sometimes to progressive deterioration of asthma, irrespective of the reduction of exposure to the specific sensitizer, and only the use of particular protective devices effectively prevents the progression of the disease. A long-term follow-up study of toluene diisocyanate (TDI)-induced asthma showed that the improvement in bronchial hyperresponsiveness to methacholine occurred in a small percentage of subjects and only a long time after work cessation. Bronchial sensitivity to TDI may disappear, but non-specific bronchial hyperresponsiveness often persists unchanged, suggesting a permanent deregulation of airway tone. Steroid treatment significantly reduces nonspecific bronchial hyperresponsiveness only when started immediately after diagnosis.

Adult↗
PubMed1994

Peak expiratory flow monitoring in diagnosis and management of occupational asthma.

The role of peak expiratory flow (PEF) monitoring in the diagnosis of occupational asthma has recently been assessed by several studies, which agree that this procedure should always be used to confirm the relationship between symptoms and occupational exposure. Some specific issues should be satisfied: a minimum number of four PEF measurements in a day; several weeks of monitoring in and out of work; and the presence of specific patterns of PEF changes. The sensitivity and specificity of PEF monitoring to detect occupational asthma, in comparison with the specific challenge test in the laboratory (the "gold standard") have been shown to be fairly high, although many authors believe that PEF monitoring cannot substitute for the specific challenge test. Limitations include: the low sensitivity of PEF to detect mild changes in airway calibre with respect to forced expiratory volume in one second (FEV1); the blunting effect of pharmacological treatment; the episodic and irregular exposure to the sensitizer in the workplace; and the compliance and honesty of the subject. Further studies are required to select the best indices of daily and day-to-day variability to be used in the evaluation of PEF changes between work and out-of-work periods.

Asthma↗
PubMed1993

Role of cucumber mosaic virus and its satellite RNA in the etiology of tomato fruit necrosis in Italy.

A cucumber mosaic virus (CMV) isolate supporting a natural 390-ribonucleotide satellite was used to reproduce under experimental conditions a disease of processing tomatoes called fruit necrosis. The virus induced incomplete differentiation of the vascular tissue of fruit stalks, which was the likely cause of the disease. On the other hand, the satellite RNA attenuated viral symptoms on tomato leaves reproducing the disease pattern typically observed in the field. The biological properties of this seemingly new variant of cucumoviral satellite RNAs were determined.

Base Sequence↗
PubMed1993

Duration of preventive effect of inhaled salbutamol on early airway response to allergen in asthmatic subjects.

Salbutamol is known to effectively prevent early asthmatic response (EAR) after specific bronchial provocation test (sBPT) in asthmatic subjects, but the time-course of this protection is not known. In this study the effects of 200 micrograms salbutamol inhaled 2 h before sBPT were compared with 200 micrograms salbutamol inhaled 10 min before sBPT in eight asthmatic subjects sensitized to Phleum pratensis (PP) or Dermatophagoides pteronyssinus (DP). All subjects showed an EAR (% decrease in FEV1 from baseline value: 30.4 +/- 11%) in a preliminary sBPT performed with cumulated doses of extracts of PP or DP titrated in biological units (BU). Each subject performed, on two different days, in a random, double-blind, cross-over study, two puffs of placebo 2 h before sBPT and two puffs of salbutamol 10 min before sBPT (treatment A) or two puffs of salbutamol 2 h before sBPT and two puffs of placebo 10 min before sBPT (treatment B). Baseline FEV1 were similar in both tests. In treatment B, 10 min, 1 h and 2 h after salbutamol inhalation, FEV1 increased significantly with respect to placebo inhalation in treatment A. Ten minutes after salbutamol inhalation in treatment A, FEV1 became similar to that obtained 2 h after salbutamol inhalation and 10 min after placebo in treatment B. Allergen inhalation induced an EAR in only one out of eight subjects after treatment A, and five of the eight subjects after treatment B.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1993

Bronchial hyperresponsiveness and toluene diisocyanate. Long-term change in sensitized asthmatic subjects.

Long-term change in nonspecific and specific bronchial hyperresponsiveness was studied in 16 subjects with asthma induced by toluene diisocyanate (TDI). A significant positive correlation between months of follow-up and provocative dose inducing a 20 percent fall in FEV1 (PD20FEV1) methacholine was observed in 5 of 16 subjects. In 4 of these 5 subjects, a PD20FEV1 > 1 mg of methacholine was observed 30 to 48 months after the end of TDI exposure. In most subjects, nonspecific bronchial hyperresponsiveness did not change. Nine of 16 subjects became nonresponsive to TDI at follow-up examination, but only 3 of these showed a significant increase in PD20FEV1 methacholine. Seven subjects were still responsive to TDI. Recovery from TDI-induced asthma can occur and only after long-term work cessation. Nonspecific bronchial hyperresponsiveness to methacholine can persist even in the absence of bronchial hyperresponsiveness to TDI, suggesting permanent chronic damage to mechanisms controlling airway tone.

Adult↗
PubMed1987

Cytopathology in the identification and classification of tombusviruses.

Ten recognized members of the tombusvirus group, including two strains of tomato bushy stunt virus, were compared for their ultrastructural effects in Nicotiana clevelandii, Gomphrena globosa, and Chenopodium quinoa. The cytopathic inclusions known as multivesicular bodies and tonoplast evaginations containing virus particles were induced by all the viruses in all three hosts. Some of the viruses could be differentiated from each other (especially in C. quinoa) by other characters, such as the accumulation of membranes in cell nuclei, or the type of organelle (chloroplasts, mitochondria or peroxisomes) from which multivesicular bodies developed. The usefulness of these characters for virus identification and grouping is discussed.

Cell Nucleus↗
PubMed1983

The fine structure of Cymbidium ringspot virus infections in host tissues. III. Role of peroxisomes in the genesis of multivesicular bodies.

Ultrastructural studies of Nicotiana clevelandii plants systemically infected with Cymbidium ringspot virus, a member of the tombusvirus group, have shown that a clear-cut relationship exists between perioxisomes and multivesicular bodies (MVB). In infected cells, peroxisomes undergo a progressive vesiculation of the bounding membrane through the possible addition of membranous material by the endoplasmic reticulum and become very plastic. Portions of the ground cytoplasm are engulfed either through the invagination of the limiting membrane or the production of membranous appendages that fold back on the main body. Cytochemical tests have shown MVB to possess catalase and glycolate oxidase activity in the matrix. The vesicles contain RNA, a substantial amount of which is double stranded, as indicated by differential RNase digestion tests in high- and low-salt media. The double-stranded RNA may consist of replicative forms or replicative intermediates of the viral nucleic acid. If so, MVB (i.e., modified peroxisomes) may be directly involved in the replication of Cymbidium ringspot virus.

Catalase↗
PubMedDate not supplied

[Urinary tract infections in the first 2 years of life. Usefulness of anamnesis in the identification of at risk subjects with malformation uropathies].

We have retrospectively studied 101 patients with an age below 24 months consecutively hospitalized, for symptomatic urinary tract infections, in the "Ospedale dei Bambini" of Palermo and subjected to radiological studies (urography and voiding cystouretrography). We have considered if the symptoms and the clinical objectivity could have given useful indications in the choice of the patients to be subjected to radiological studies. The clinical-anamnestic data have not allowed to distinguish, among patients with U.T.I., between the individuals with an abnormal conformation those with a normal one; however they have allowed to focus our attention on patients with U.T.I. through the singling out of some symptoms such as fever, vomit, cyanosis and anomaly micturition. Another datum standing out from our study is that the beginning of the symptoms in patients with U.T.I. was more precocious if at their basis there was urinary malformation.

Age Factors↗
PubMedDate not supplied

Abnormal migratory activity of peripheral neutrophils from asthmatic patients and its modulation by inhaled glucocorticoids.

In order to investigate if bronchial asthma is associated with enhanced markers of activation in peripheral neutrophils, the migratory capacity of neutrophils in venous blood was measured by means of the Boyden chamber technique in 29 subjects with bronchial asthma of differing severity. Random migration (random motility), but not locomotion toward 10% Escherichia coli supernatant as chemoattractant (chemotaxis), was increased in asthmatic subjects with respect to 11 normal subjects (98 +/- 20 microns vs. 85 +/- 6 microns; p < 0.05). When asthmatic subjects were subdivided into groups of different disease severity, subjects with mild and mild to moderate asthma showed significantly higher values for random motility and chemotaxis than normal subjects; on the other hand, subjects with more severe disease showed the lowest values for migratory activity. No correlation was found between migratory activity and clinical findings of asthma, except for baseline FEV1 (% of the predicted value), which showed a slight but significant positive correlation with chemotaxis (r = 0.44, p < 0.05). Subjects with atopic or occupational asthma had higher values for migratory activity than subjects with nonallergic asthma. Thirteen asthmatic subjects repeated all evaluations after 1 month of treatment with high doses of inhaled glucocorticoids (beclomethasone dipropionate 1500 micrograms/day). Random motility (95 +/- 24 microns vs. 75 +/- 15 microns; p < 0.05) and chemotaxis (130 +/- 22 microns vs. 105 +/- 25 microns; p < 0.05) were significantly reduced after treatment, as well as the symptom score; on the other hand, symptom score but not bronchial hyperresponsiveness to methacholine challenge significantly changed.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗