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Biomedical subjects

A Micco

Publications and source records attributed to A Micco.

12 recordsLinked to original sources
PubMed1997

Endothelin abnormalities in patients with pulmonary embolism.

BACKGROUND: Endothelin (ET) is an endothelium-derived multifunctional peptide involved in the local regulation of the vascular tone. STUDY OBJECTIVES: To assess changes of endogenous ET production/excretion in the acute phase (36 h from the event) of pulmonary embolism (PE). PARTICIPANTS: Ten patients with acute PE, nine patients with acute lung injury (ALI), and 12 healthy volunteers (HVs). MEASUREMENTS AND RESULTS: ET was detected by radioimmunoassay in venous and arterial blood as well as in 24-h urine specimens. For each subject, arterial/venous immunoreactive ET (ir-ET) ratio was evaluated as an index of its pulmonary extraction/synthesis. Creatinine clearance was employed in each case to obtain a corrected renal ir-ET clearance. Renal ir-ET clearance was comparable in all three groups. Arterial/venous ir-ET ratio was comparable in PE and in ALI patients (1.31 +/- 0.25 vs 1.24 +/- 0.20; p = 0.7), while it was significantly higher in PE patients than in HV subjects (0.85 +/- 0.07; p = 0.0001). Accordingly, 24-h urine ir-ET excretion was higher in PE (120.50 +/- 27.36 ng/24 h) and ALI patients (135.80 +/- 21.60 ng/24 h) than in HV subjects (68.33 +/- 9.31 ng/24 h; p = 0.0001). CONCLUSIONS: Abnormalities of ET metabolism-mainly related to increased synthesis and/or defective pulmonary handling-occur in the acute phase of PE. The relevance of this finding with respect to the pathogenesis and/or management of pulmonary thromboembolism remains to be elucidated.

Acute Disease↗
PubMed1997

Urinary endothelin excretion in patients with acute lung injury.

Increase in circulating levels of endothelin (ET), a potent vasoconstrictive and mitogenic endothelium-derived peptide, has been proposed as a marker of endothelium dysfunction in acute lung injury (ALI). In the present study, we have measured levels of immunoreactive ET (irET) by radioimmunoassay, in arterial (irETart), venous (irETven) and urine (irETur) samples obtained from 10 patients with ALI and 10 healthy volunteers. Arterovenous ratio, 24 h urine excretion and renal clearance of the peptide were calculated, to obtain indices of endogenous ET metabolism. The arterovenous ratio of irET was significantly higher in patients with ALI than in healthy volunteers (1.20 +/- 0.20 and 0.85 +/- 0.06, respectively; p < 0.05)). Twenty four hour urinary excretion of the peptide was increased in patients with ALI as compared to healthy volunteers (134.10 +/- 21.0 and 71.70 +/- 9.30 ng.24 h-1, respectively; p < 0.001). Renal clearance of irET was similar in patients with ALI and healthy volunteers, indicating that the increase in excretion as well as in arterovenous gradient observed in patients with ALI was related mainly to pulmonary abnormalities of peptide handling. Urinary excretion of endothelin might be a useful marker of endothelial dysfunction occurring in acute lung injury.

Adult↗
PubMed1996

IgA immune response against the mycobacterial antigen A60 in patients with active pulmonary tuberculosis.

Searching for IgG and IgM against the mycobacterial antigen A60 has been recognized as a potential diagnostic tool for pulmonary tuberculosis. The role of detection of anti-A60 IgA in improving diagnostic accuracy of serology is not well known. In this study we measured with ELISA serum levels of both anti-A60 IgG and IgA in 216 subjects. 88 healthy volunteers (44 PPD- and 44 PPD+), 44 patients suffering from nontuberculous lung disease and 15 subjects with healed pulmonary tuberculosis constituted the control population; 69 patients with active pulmonary tuberculosis (35 cavitary forms, 26 productive forms and 8 miliary forms) were examined. The sensitivity of IgG test was 73.9% in pulmonary tuberculosis (77.1% in cavitary forms, 65.4% in productive forms, 87.5% in miliary forms); the specificity of the test was 95.9%. For the IgA test we observed a sensitivity of 72.5% (74.3 in cavitary forms, 69.2% in productive forms, 75.0 in miliary forms) and a specificity of 93.9%. Combination of the two tests increased the sensitivity to 84.0% (+10.1% compared to IgG test, +11.5% compared to IgA test); the specificity decreased to 92.5% (-3.4% vs. IgG test; -1.4 vs. IgA test). In conclusion, the combined use of evaluation of anti-A60 IgG and IgA increases the accuracy of serological diagnosis of pulmonary tuberculosis.

Adult↗
PubMed1996

Lung volumes and respiratory muscle strength in adult patients with childhood- or adult-onset growth hormone deficiency: effect of 12 months' growth hormone replacement therapy.

We have described impairment of the respiratory function in adult patients with childhood-onset growth hormone (GH) deficiency. The aim of the present study was to evaluate lung volumes and respiratory muscle strength in patients diagnosed as GH deficient before and after 6 and 12 months of recombinant GH treatment. Ten adults diagnosed as GH deficient in childhood, ten adults diagnosed as GH deficient in adulthood and ten healthy subjects entered the study. For each subject, evaluation of respiratory function followed the same standard approach, consisting of respiratory muscle strength assessment, record of flow-volume curves, measurement of static lung volumes and lung diffusing capacity. Childhood-onset GH-deficient patients had a significant reduction of maximal inspiratory (p < 0.01) and maximal expiratory (p < 0.05) mouth pressures. Total lung capacity, vital capacity and functional residual capacity were significantly reduced compared to healthy subjects (p < 0.05). Conversely, residual volume and diffusing lung capacity did not show any significant change. No significant change of the ratio between the percentage forced expiratory volume in 1 s and the forced vital capacity was observed. The decrease of respiratory mouth pressures was not correlated to the decrease of lung volumes. Adult-onset GH-deficient patients had only a significant reduction of maximal expiratory pressure compared to healthy subjects (p < 0.05). After 6 months of treatment no significant differences in any of the evaluated parameters were found. After 12 months of treatment patients with childhood-onset GH deficiency show a significant improvement of lung volumes (p < 0.01) and maximal respiratory mouth pressures (p < 0.005), whereas adult-onset GH-deficient patients show a significant improvement of maximal expiratory pressure (p < 0.05). In conclusion, the results of this study showed that adult patients affected with childhood-onset GH deficiency suffer from an impairment of the ventilatory function due to a reduction of lung volumes and a decrease of respiratory pressures probably due to a reduction of respiratory muscle strength. This impairment was reversed after 12 months of treatment with recombinant GH. Conversely, adult-onset GH-deficient patients had only an impairment of the maximal expiratory pressure, probably due to respiratory muscle weakness re-established after 12 months of GH therapy.

Adult↗
PubMed1995

Impairment of lung volumes and respiratory muscle strength in adult patients with growth hormone deficiency.

Little is known of the respiratory function in patients with growth hormone (GH) deficiency. The aim of the present study was to evaluate lung volumes and respiratory muscle strength in patients diagnosed as GH deficient in childhood. Ten patients diagnosed as GH deficient in childhood and ten healthy subjects entered the study. For each subject the evaluation of respiratory function followed the same standard approach, consisting of respiratory muscle strength assessment, recording of flow-volume curves, measurement of static lung volumes and lung diffusing capacity. Both maximal inspiratory and expiratory mouth pressures were decreased in GH deficiency. Vital capacity, N2 functional residual capacity and total lung capacity were significantly reduced when compared to healthy subjects. Conversely, the residual volume and diffusing lung capacity to CO did not show any significant change. No significant change of percentage forced expiratory volume in 1 s/forced vital capacity ratio was observed. The decrease of respiratory mouth pressures was not correlated to the decrease of lung volumes. In conclusion, the results of this study show that adult patients affected with childhood onset GH deficiency suffer from impairment of ventilatory function and a decrease of respiratory muscle pressures, probably due to reduction of respiratory muscle strength.

Adult↗
PubMed1995

Case manager attitudes toward client-directed care.

Advocates for individuals with severe and long-term physical disabilities have lobbied aggressively in the U.S. and Canada for the implementation of Independent Provider Care (IPC). In this model of home support service delivery, the client assumes sole responsibility for the management and scheduling of his or her personal care and home support. This article reports on the findings of a Canadian survey that assessed case managers' beliefs regarding the efficacy, benefits, and risks to clients of an IPC program. Survey results indicated that case managers generally believed that IPC would not significantly improve their clients' well-being and quality of care, would pose risks of abuse to both the client and support attendant, and would result in greater job demands for case managers. Possible sources of their apprehension are identified, and measures that may help to alleviate their concerns are discussed.

Attitude of Health Personnel↗
PubMed1993

Speech-evoked cortical potentials in children.

Event-related potentials (ERPs) were obtained to synthesized speech stimuli in 16 school-aged children (7-11 years) and compared to responses in 10 adults. P1, N1, and P2 event-related potentials were elicited by the phoneme /ga/. The mismatch negativity (MMN) was elicited by variants of /da/ and /ga/, which differ in the onset frequency of the second and third formant transitions. In general, the well-defined N1/P2 complex characteristic of the adult response, was not found in children. Waves P1 and N1 had longer peak latencies in children than in adults. Wave P2 amplitude was smaller in children than in adults. In contrast to the often poorly delineated earlier cortical potentials, the MMN was well defined in children. Significant MMNs were obtained in all subjects tested. MMN magnitude (peak amplitude and area) was significantly larger in the children. No significant differences were found in peak latency and duration of the MMN in children compared to the adult response. Another negative wave occurring at 400 msec was also observed in response to the deviant stimuli. This negative wave occurred at a similar latency in adults and children and was significantly larger and more robust in children. Results support the view that development of ERPs does not involve a hierarchical process with respect to latency. That is, earlier occurring waves do not necessarily mature before later occurring waves. The latencies of P1, N1, and P2 and overall morphology of these waves may provide a measure of maturation of central pathways. The early development of the MMN, its apparent robustness in school-aged children, and its reflection of the processing of acoustic differences in speech stimuli suggest its possible use in the assessment of central auditory function.

Acoustic Stimulation↗
PubMed1992

Age-related differences in the specificity of verbal encoding.

A communication paradigm was used as an analogue to cued recall to separate age-related differences in encoding and retrieval. Younger and older adults (senders) generated a series of one-word clues that would enable other subjects (receivers) to generate a designated target word. Clue and target generation tasks, analogous to the encoding and retrieval components of cued recall, were conducted in the context of either a strong or a weak associate of the target. Clues generated by older senders were less effective than clues generated by younger senders in enabling receivers to generate targets, especially when clues or targets were generated in the context of a weak associate. A deficit among older receivers was also obtained, especially when a weak-rather than a strong-associate context word was given to the receiver. Older adults experience difficulty with encoding and retrieval tasks that require processing of context-specific information that is not part of the generic information typically associated with a stimulus.

Adult↗
PubMed1988

Early partial systolic closure of the pulmonic valve relates to severity of pulmonary hypertension.

Ultrasound studies in pulmonary hypertension often show systolic partial closure of the pulmonic valve and early peaking of Doppler pulmonary flow velocity, but these findings are poorly understood. Our initial observations of earlier systolic partial closure with higher pulmonary pressures suggested that this phenomenon might relate to pressure. In 30 patients with documented pulmonary hypertension, the timing of systolic partial closure and the corresponding decrease in Doppler flow velocity related inversely to pulmonary artery pressure at catheterization. Peak flow preceded the systolic velocity decrease and also related inversely to pressure. Since changing flow velocity might reflect a changing driving force across the valve, we examined simultaneous high-fidelity catheter pressure tracings from the right ventricle and pulmonary artery from 24 patients with and without pulmonary hypertension. In 30 studies, a positive right ventricular to pulmonary artery pressure gradient was present early in systole, but the gradient decreased to a minimum value in mid-to-late systole. The timing of this minimum also related inversely to pressure. We conjectured that forces opposing ejection occur earlier in pulmonary hypertension, thereby decreasing the forward driving force and allowing earlier partial systolic closure.

Adult↗
PubMedDate not supplied

Mismatch negativity in school-age children to speech stimuli that are just perceptibly different.

The mismatch negativity event-related potential (MMN) was elicited in normal school-age children in response to just perceptibly different variants of the speech phoneme /da/. A significant MMN was measured in each subject tested. Child and adult MMNs were similar with respect to peak latency and duration. Measures of MMN magnitude (peak-to-peak amplitude and area) were significantly larger in children than in adults. The results of the present study indicate that the MMN can be elicited in response to minimal acoustic stimulus differences in complex speech signals in school-age children. The results support the feasibility of using the MMN as a tool in the study of deficient auditory perception in children.

Acoustic Stimulation↗
PubMedDate not supplied

[Changes of lung volumes and respiratory muscle strength in patients with growth hormone deficiency].

The relationship between growth hormone deficiency (GHd) and ventilatory function is not well understood. We studied 7 patients with GHd since childhood who had been adequately treated with replacement therapy until cartilage fusion. Together with 7 well-matched (age and body-type) healthy control subjects, they underwent spirometry including determination of residual volume, and lung diffusing capacity. Also recorded were maximal respiratory muscle pressure during inspiration (PImax) and expiration (PEmax). Patients with GHd showed a significant reduction in total lung capacity and vital capacity while residual volume and lung diffusing capacity remained unchanged. All patients had a significant reduction of both PImax and PEmax. Previously treated adult subjects with GHd present a persistent decrease in lung mobilizing volumes associated with reduced respiratory muscle strength. These alterations may have implications in the management of GHd in adult patients.

Adult↗