Genetic disorders of GH action pathway.

While insensitivity to GH (GHI) is characterized by low IGF-I levels, normal or elevated GH levels, and lack of IGF-I response to GH treatment, IGF-I resistance is characterized by elevated IGF-I levels with normal/high GH levels. Several genetic defects are responsible for impairment of GH and IGF-I actions resulting in short stature that could affect intrauterine growth or be present in the postnatal period. The genetic defects affecting GH and/or IGF-I action can be divided into five different groups: GH insensitivity by defects affecting the GH receptor (GHR), the intracellular GH signaling pathway (STAT5B, STAT3, IKBKB, IL2RG, PIK3R1), the synthesis of insulin-like growth factors (IGF1, IGF2), the transport/bioavailability of IGFs (IGFALS, PAPPA2), and defects affecting IGF-I sensitivity (IGF1R).

Development of self-administered versions of modified baseline and transition dyspnea indexes in COPD.

In this study we developed self-administered versions of modified baseline and transition dyspnea indexes and compared the scores obtained by this method with the mean value obtained by two trained interviewers. Twenty-five patients (14 males/11 females) with chronic obstructive disease who had a chief complaint of "breathlessness" were tested. Age was 66+/-11 years; forced expiratory volume in one second was 48+/-23% predicted.

Responsiveness of continuous ratings of dyspnea during exercise in patients with COPD.

Purpose: To examine the responsiveness of a new computerized method for patients to provide continuous ratings of dyspnea during exercise in patients with chronic obstructive pulmonary disease (COPD).

Methods: In this randomized, double-blind study the effects of an inhaled bronchodilator (BD), albuterol/ipratropium bromide solution, were compared with normal saline (NS) in 30 patients with COPD (age, 66+/-9 yr; forced expiratory volume in 1 s, 48+/-14% pred). At visit 1, patients were familiarized with the cycle ergometer and computer, monitor, and mouse system to provide continuous ratings of dyspnea during exercise.

Comparison of continuous and discrete measurements of dyspnea during exercise in patients with COPD and normal subjects.

Study Objectives: The objectives of this study were as follows: (1) to compare results of the discrete and the continuous methods for measuring breathlessness; (2) to examine test-retest reliability; (3) and to test the hypothesis that patients with COPD have higher slopes and lower x-intercepts and absolute thresholds for power production, oxygen consumption (O(2)), and minute ventilation as independent variables and breathlessness ratings as the dependent variable, as compared with healthy subjects.

Design: Visit 1 (familiarization) and visit 2 and visit 3 (2 days apart) with randomized assignment of the discrete and continuous methods for subjects rating breathlessness during cycle ergometry.

Setting: Cardiopulmonary exercise laboratory in a university medical center.

Evaluation of dyspnea in the elderly.

The word "dyspnea" encompasses many different features. It can be considered to be a sensation, a symptom, or an illness. From a practical perspective many physicians and nurses use dyspnea to refer to difficult or labored breathing or an uncomfortable awareness of breathing.