There are conflicting reports concerning the effects of aging on mechanical properties of the human respiratory system (1-4). The present study was undertaken to collect additional information pertaining to the relationships between normal aging and lung mechanics. Besides the mechanics measurements, data are reported for lung volumes, intrapulmonary gas mixing, and ventilatory capacity. METHODSNineteen subjects over 60 years old were selected who a) were free from complaints referable to cardiac, pulmonary, or neuromuscular systems; b) had normal physical examinations; and c) demonstrated normal chest roentgenograms and electrocardiograms. These men constitute group I subjects. Similar criteria were applied in selection of 13 men under 40 who comprised group II. Eight older men and six of the younger were cigarette smokers. Physical characteristics of the two groups are shown in Table I.Spirograms were recorded with a 13.5 L Collins 1 spirometer from which all valves had been removed. A closed-circuit, constant-volume, helium (He) -dilution method was used to measure the functional residual capacity (FRC) in seated subjects. Lung compartments and their ratios were calculated. Intrapulmonary distribution of inspired gas was evaluated by the N2 singlebreath test (5).The dynamic lung compliance (Cdyn) was determined by the methods of Mead and Whittenberger (6).Mouth-esophageal pressure gradients were detected by a differential pressure transducer.2 The signal was amplified and displayed on the horizontal axis of a cathoderay oscilloscope a (CRO). Flow rates were measured

This study contributes to establish a first picture in the Chilean mestizo population about the frequencies of these variants, which could act as single or complementary risk factors to trigger CVD. The obtained allele frequencies show great differences in relation to other South American populations.

Coronary angioplasty in Chile is performed mostly for the treatment of acute coronary syndromes. Stents are the most frequently used devices. The high success, low mortality and complications observed are comparable to North American registries.

I. A comparative study has been made of a population genetically homogeneous 2. Individuals were 'marked' with common serologic major genes. 3. The predominant strength of the environmental factors was demonstrated by the observation that when maintaining the genetic factor constant, hypertension appeared in the more advanced ('acculturated') Lowland populations.4. The absence of hypertension was confirmed in Highland isolated primitive peoples.5. Blood pressure correlation between relatives varied significantly with changing ecosystems.6. The predominant strength of heredity was nevertheless demonstrated by the fact that in acculturated populations the genetic component of variance was found to be greater than the environmental one, and the dominant component accounted for nearly half the genetic variance.7. Hypertension appears in the Lowlands to be exclusively associated with some specific genotypes of the Rhesus and MN systems.8. The determination of blood pressure may be controlled by few major genes operating in given ecosystems under the permissiveness of environmental agents. living in two adjacent but strongly different ecosystems.

Balloon pulmonary angioplasty for the treatment of chronic thromboembolic pulmonary hypertension Background: Balloon pulmonary angioplasty (BPA) is a therapeutic alternative for patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). Aim: To report the initial experience with the "refined BPA technique" with the use of intravascular images. Patients and Methods: Between June 2015 and June 2016 we selected fourteen patients with CTEPH who were considered candidates for BPA. Lesions targeted for treatment were further analyzed using intravascular imaging with optical frequency domain imaging (OFDI). We report the immediate hemodynamic results and four weeks of follow-up of the first eight patients of this series. Results: We performed 16 BPA in eight patients aged 61 ± 14 years (88% women). Mean pulmonary artery pressure (PAPm) was 48.6 ± 5.8 mmHg. Success was achieved in seven patients (88%). A mean of 2.3 segments per patient were intervened in 11 sessions (1.6 sessions/ patient). Only one patient developed lung reperfusion injury. No mortality was associated with the procedure. After the last BPA session, PAPm decreased to 37.4 ± 8.6 mmHg (p=0.