Displacement and recovery of the vesical neck position during pregnancy and after childbirth.

AIMS: (i) To describe the displacement and recovery of the vesical neck position during pregnancy and after childbirth and (ii) to discriminate between compliance of the vesical neck supporting structures with and without pelvic floor contraction. METHODS: We focussed on the biomechanical properties of the vesical neck supporting structures during pregnancy and after childbirth by calculating the compliance and the hysteresis as a result from of abdominal pressure measurements and simultaneous perineal ultrasound. RESULTS: This study shows that compliance of the supporting structures remains relatively constant during pregnancy and returns to normal values 6 months after childbirth. Hysteresis, however, showed an increase after childbirth, persisting at least until 6 months post partum. CONCLUSIONS: Vaginal delivery may stretch and or load beyond the physiological properties of the pelvic floor tissue and in this way may lead to irreversible changes in tissue properties which play an important role in the urethral support continence mechanism.

A guinea pig model of acute and chronic asthma using permanently instrumented and unrestrained animals.

To investigate mechanisms underlying allergen-induced asthmatic reactions, airway hyperresponsiveness and remodeling, we have developed a guinea pig model of acute and chronic asthma using unanesthetized, unrestrained animals. To measure airway function, ovalbumin (IgE)-sensitized animals are permanently instrumented with a balloon-catheter, which is implanted inside the pleural cavity and exposed at the neck of the animal. Via an external cannula, the balloon-catheter is connected to a pressure transducer, an amplifier, an A/D converter and a computer system, enabling on-line measurement of pleural pressure (P(pl))-closely correlating with airway resistance-for prolonged periods of time. Using aerosol inhalations, the method has been successfully applied to measure ovalbumin-induced early and late asthmatic reactions and airway hyperresponsiveness. Because airway function can be monitored repeatedly, intra-individual comparisons of airway responses (e.g., to study drug effects) are feasible. Moreover, this model is suitable to investigate chronic asthma and airway remodeling, which occurs after repeated allergen challenges. The protocol for establishing this model takes about 4 weeks.

The value of ventilation scintigraphy after single lung transplantation.

BACKGROUND: A decrease in forced expiratory volume in 1 second (FEV(1)) as a diagnostic criterion for bronchiolitis obliterans syndrome (BOS) after single lung transplantation may be influenced significantly by the presence of the native lung. To quantify and to discriminate between the relative contribution of graft and native lung to the FEV(1), we retrospectively investigated the diagnostic value of combined FEV(1) measurements and ventilation scintigraphy in pulmonary dysfunction after single lung transplantation in 11 recipients with pulmonary vascular disease, 3 with obstructive lung disease, and 3 with restrictive lung disease. METHODS: We assessed function of the native lung and the graft, and subsequently calculated an adjusted grading of BOS by correcting routine FEV(1) measurements using linear interpolation of bi-annual lung ventilation scans. RESULTS: The contribution of the native lung to the total FEV(1) was slight (median, 9%) in recipients with obstructive disease compared with recipients with vascular (38%) or restrictive lung diseases (27%). Adjusted BOS grading was not useful in patients with obstructive disease. In the other patient groups, the onset of adjusted BOS Grade 1 and standard BOS Grade 1 was at a median of 220 days (range, 127-1146 days) and 836 days (184-3065 days), respectively. CONCLUSION: Ventilation scintigraphy is a useful adjunct in the (early) diagnosis of BOS in recipients of single lung transplants who have vascular and restrictive lung diseases.

Bronchiolar airflow impairment after lung transplantation: an early and common manifestation.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) is the major limitation to long-term survival after lung transplantation (LT). In this study we investigate the extent and frequency of airflow limitation after LT and its value for the diagnosis of BOS. METHODS: Flow-volume measurements were analyzed retrospectively in 36 recipients of a bilateral LT, with a median follow-up of 32.9 months. The prevalence and onset of a decline of FEV(1), FEF(25), FEF(50), FEF(75) and MMEF(75/25) were evaluated and subsequently related to the occurrence of Grade 1 BOS. RESULTS: Grade 1 BOS was diagnosed in 16 recipients at a median of 218 (range 88 to 1,007) days after LT. A persistent and significant decrease in FEV(1), FEF(25), FEF(50), FEF(75) and MMEF(75/25) was observed in 23, 24, 30, 32 and 29 patients, respectively. In those patients developing BOS during follow-up this decrease was determined at 147 (55 to 657), 130 (78 to 932), 110 (21 to 573), 103 (32 to 657) and 121 (32 to 657) days after LT (p < 0.0005), respectively. The respective predictive values of these parameters for the occurrence of Grade 1 BOS (within 120 days) were 88%, 60%, 50%, 35% and 41%. CONCLUSION: Bronchiolar dysfunction is a common and early finding after LT. The decrease of FEV(1) in BOS is often preceded by a decrease of bronchial airflow. Airflow markers may be used as an early warning sign for the development of BOS, although their predictive values are moderate.