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Biomedical subjects

G Ferrara

Publications and source records attributed to G Ferrara.

At least 91 records · Page 5Linked to original sources
PubMed1986

Early estimate of theophylline clearance during intravenous infusion.

We examined two rapid methods of measuring theophylline clearance using pairs of serum concentration measurements, and compared them with the steady-state values in 31 patients with acute asthma. A constant intravenous aminophylline infusion was started at a rate given by current guidelines. Theophylline clearance was estimated from two serum measurements made with an interval of at least 4 h, providing clearance estimates 5 h from commencement. Duplicate estimates were made, using either a 3rd serum measurement at 12 h or a 3rd and 4th at 7 and 14 h. A steady-state estimate was finally made after 48 h constant infusion. The two rapid estimates agreed well both between themselves and with the steady-state determination despite wide variations in the clinical status of the patients. These methods provide a rapid means of monitoring dosage in the individual patient. This is particularly important when the predicted dose is inappropriate.

Acute Disease↗
PubMed1984

Is it possible to predict pulmonary arterial hypertension from an exercise test?

In patients with chronic lung disease, the response to exercise can be impaired by ventilatory and/or circulatory disturbances. The response to a standard exercise varies according to the load in relation to the maximum load the subject can tolerate. Thus it seems more suitable to study the maximum tolerated, i.e. maximum workload expressed as VO2 max. We compared the results of VO2 max and pulmonary haemodynamic variables in 43 patients with chronic bronchitis. VO2 max ranged from 0.720 to 3.010 l/min. The relation between VO2 max and pulmonary artery pressure at rest or its increase with low level exercise was very poor, but there was a trend towards an increase in pulmonary vascular resistance in patients with low VO2 max, although a number of patients with low VO2 max had normal pulmonary vascular resistance. The ratio between heart rate at maximum workload and maximum heart rate according to age (heart rate obs/pred) was above 95% in the patients with pulmonary vascular resistance above 250 dyn.s. cm-5; it varied widely in the patients with normal or slightly elevated pulmonary vascular resistance. When VO2 max was below normal, and heart rate obs/pred low, it is probable that the decrease in VO2 max was due to ventilation impairment, or to a lack of cooperation. Oxygen pulse at VO2 max was also reduced in patients with high pulmonary vascular resistance, but a large range of values was observed in the rest of the patients. A high oxygen pulse at VO2 max however allows to rule out severe pulmonary artery hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1981

Cell surface marker analysis in diagnosis of the early phase of chronic lymphocytic leukaemia.

Cell surface marker analysis was carried out in 50 CLL patients; 15 were preclinical or low count, that is with a total peripheral lymphocyte count well below 15,000/cmm and little or no infiltrative syndrome. Data of the cell surface marker in these 15 patients were compared with those of 15 patients with non-neoplastic benign lymphocytosis. Monoclonal B-cell compartment proliferation was found in low count cases, with analogous immnofunctional characteristics to typical CLL. On the other hand, there was a symmetrical increase in both T and B cell compartments in non-neoplastic lymphocytosis. This suggests that cell marker analysis is a very useful diagnostic tool during the preclinical phase of CLL, as it permits it to be readily differentiated from non-neoplastic lymphocytosis.

Aged↗
PubMed1980

Reproducibility of maximum flows in air and He-O2 and of delta Vmax50 in the assessment of the site of airflow limitation.

Maximum expiratory flows at 50% of vital capacity while breathing air and a He-O2 mixture and delta Vmax50 observed during three sittings (morning, noon and morning the day after) in reference subjects and in patients with bronchial hyperreactivity were submitted to statistical analysis by between sittings comparison, looking for correlation coefficients, paired "t" test and variation coefficient. Results of paired "t" test ruled out the influence of fatigue and of training in performing forced expiratory manoeuvres. Correlation coefficients relevant to absolute flows are highly significant in both groups, whereas coefficients of variation are satisfactory in reference subjects and slightly higher although still acceptable in patients with bronchial hyperreactivity. As far as delta Vmax50 is concerned, the results of statistical analysis are positively unacceptable, thus demonstrating that this arithmetic manipulation of absolute flows is the ground for a poor reproducibility of results.

Adult↗
PubMed1978

"Silent" alleles at the HLA-C locus.

Defined specificities of the HLA-C locus possess a significantly lower immunogenicity as compared with the HLA-A and HLA-B specificities. HLA-C "blanks" are not immunogenic at all. Among the possible explanations, the most likely one appears to be a low phenotypic expression of these alleles. C locus antigens as a whole are thus likely to be of minor relevance in donor/recipient matching for transplantation.

Alleles↗
PubMed1976

[Oxygen therapy in pneumology].

Circumstances under which the use of oxygen-therapy in lung disease can be effective and harmless, depend upon a careful evaluation of its indications: they are suggested by the clinical need of correction of hypoxaemia as well as by the awareness of factors determining respiratory failure and of problems concerning O(2) transport and supply to tissues in health and disease. Blood gases monitoring enables to control the effects of treatment on arterial O2 and CO2 tensions thus giving all the useful data for oxygen administering particularly as far as components of hyperoxygenated mixtures, flow rate, duration, use of very effective low-risk devices (Venturi masks) are concerned. Correction of hypoxaemia involves the reduction of hypertension of the pulmonary circulation and hyperglobulia, improvement of tolerance of exertion, and attention to the metabolic compensation of respiratory acidosis. These results are influenced by the nature of the pathogenetic factors behind broncho-obstructive disease, which may lead to either a primarily "bronchitis" or a primarily "emphysematous" syndrome. An interesting feature relates to prognosis in the case of patients making home use of hyperoxygenated mixtures as part of a rehabilitation program, or to improve their quality of life. The cost and benifits of such treatment should be carefully weighed. Lastly, in the event of protracted treatment, attention must be paid to the possibility of toxicity and the means to be adopted for its prevention.

Acidosis, Respiratory↗
PubMed1976

[Gas exchange and acid-base equilibrium in chronic bronchitis and in emphysema].

Blood gas data for HbO2% and PaCO2 and determination of acid-base balance enable the biochemical features of bronchial obstruction to be related to primarily "intrinsic" or "extrinsic" factors. Long-term gas studies and ventilation mechanics data (lung elastic recoil pressure, maximum expiratory flow at different volumes and the corresponding recoil pressures) are also of assistance in this respect. Each type of bronchial obstruction thus has its own peculiarities, and these are also reflected in the level of metabolic compensation for respiratory acidosis.

Acid-Base Equilibrium↗
PubMed1975

Constancy of cross reactivity patterns during the anti-HL-A response.

Three immunizations yielding cross reacting anti-HL-A antibodies were followed for 1 year or more. The specificities of the antisera obtained at different times were determined from their reactivity against a selected cell panel. Each antiserum was titrated against cells presenting different degrees of cross reaction. An extensive absorption study of each antiserum, diluted to one cytotoxic unit, was also performed. The data obtained suggest that the cross reactivity pattern in each response is rather rigidly established from the beginning and that it has little chance to vary even after secondary stimulation from the same donor.

Absorption↗