Repeatability of calibration of the respiratory inductive plethysmograph and its stability with time were investigated in young healthy subjects. Eight were submitted to sequential runs of calibration-validation by simultaneous equation (SEM) and least squares methods (LSM) (30 in all): in five subjects, after an initial acceptable calibration, accuracy and precision were repeatedly checked over three hours (a total of 50 trials). Although mean errors for the whole sample seemed acceptably low (7.6%, SD 7.0 for SEM; 7.3%, SD 7.3 for LSM), a marked inconsistency of apparently comparable calibrations and a wide variability of results along but independently of the time in steady conditions (ranging up to 30%) were discovered. An analysis of factors interfering with the response of the equipment was made. The unreliability of the current calibration procedure was related to the fact that in most cases the calibration line derived by the change-in-posture technique, as currently applied, may not be adequately representative of the full range of relationships between the participant variables, as they occur in the selected posture. To overcome this difficulty, two suggestions are made: a) prolong the calibration procedure so as to use more data points, and b) investigate alternative procedures of calibration in any one position.

Adult↗

PubMedDate not supplied

Theophylline pharmacokinetics in patients with mild or severe airway obstruction.

A standard loading dose of aminophylline, followed by constant rate infusion for 3 h was used to study theophylline pharmacokinetics in 36 patients (age range 27-73 years) admitted to hospital during an exacerbation of chronic airway obstruction. The severity of the disease was assessed by peak expiratory flow rate and blood gas analysis. It was assumed that the severity of the disease and the patients' age, sex and smoking habits were relevant in predicting individual kinetics and hence in establishing individual theophylline dosage. Multiple regression analysis of the results failed to confirm this hypothesis and showed no significant relationship between the severity of the disease and pharmacokinetics even when other biological variables were taken into account. The results confirm the importance of careful monitoring of blood levels of theophylline since they cannot be predicted from functional indices of the severity of obstructive lung disease.

Acidosis, Respiratory↗

PubMedDate not supplied

Evaluation of a test of density-dependence of the expiratory flows in the screening of peripheral airways obstruction.

A test of density-dependence of flow at 50% of vital capacity has been investigated in two groups of subjects (86 in total) in order to evaluate respectively: a) influences that on it may be exerted by altered mechanical properties of the lung in chronic airflow obstruction; b) accuracy and precision of the test in latent and clinical asthma. Lung elastic recoil pressure does not seem to be related to the intensity of density-dependence. Relationships between MEF50 on air and on He-O2, expressed as means of groups allow distinguish between each other, whereas a definite overlap between groups is patent; absolute flows, either on air or on He-O2 are quite satisfactorily reproducible, both in health and disease. Delta% MEF50 shows a good specificity but a poor sensitivity; reproducibility is unacceptable, unless when using on a qualitative scale of figure of 20% as borderline to distinguish subjects responders from non responders.

Airway Obstruction↗

PubMedDate not supplied

Depolarized expression of episialin (EMA, MUC1) in lung adenocarcinoma is associated with tumor progression.

Carcinoma cell detachment is an important step in tumor progression and metastasis. Episialin (EMA), if expressed throughout the entire cell surface, may inhibit cell-cell and cell-matrix adhesion. We investigated whether the cellular distribution of episialin in non-small cell lung cancer (NSCLC) is associated with tumor progression. We evaluated the expression of episialin by immunohistochemical staining, in surgical specimens from 122 adenocarcinomas and 99 squamous cell carcinomas. Episialin was present in most NSCLC, with a higher percentage of immunoreactive neoplastic cells in adenocarcinoma than in squamous cell carcinoma (p = 0.0001). In adenocarcinoma the depolarized pattern was significantly associated with nodal metastasis (p = 0.005) and with advanced stage (p = 0.007). In conclusion, nodal metastasis and advanced pathological stage in adenocarcinoma are associated with a depolarized cellular distribution of episialin, suggesting a possible involvement of the molecule in cancer metastasis.

Adenocarcinoma↗