We report demographic, clinical, and imaging data on 92 patients with osteochondral lesions of the talus collected in one center between 1981 and 1992. All patients reported pain as their primary symptom. Ninety-four percent of the patients reported pain with activity. Physical examination was unhelpful. Using newer imaging techniques (bone scan and computed tomography) and with increased awareness, we have observed a sevenfold increase in the diagnostic frequency of osteochondral lesions of the talus between the years 1981 to 1986 and 1987 to 1992. Bone scan is an excellent screening tool for patients with chronic ankle pain and has 99% sensitivity in depicting osteochondral lesions. Computed tomography demonstrated a previously unclassified lesion, the radiolucent defect, which accounts for 77% of the lesions in this series. We have therefore modified the Berndt and Harty classification system, basing it on radiographic appearance (principally computed tomography) and adding the radiolucent lesion. Fifty-eight patients were treated surgically. Anterior and midtalar lesions are now approached arthroscopically. Surgical treatment of the radiolucent lesion, consisting of curettage and drilling, gives 42% excellent and 32% good results. Pain relief often occurs within months of surgery, but healing of the lesion requires years, and some may persist indefinitely.

We studied the lungs of seven patients of various ages who had Down's syndrome, to determine whether they had abnormalities in pulmonary development. Six of the seven had hypoplastic lungs. Five had congenital heart disease, but pulmonary hypoplasia was of equal severity, irrespective of the presence or absence or the type of congenital heart disease. Three other patients with congenital heart disease but without Down's syndrome had lungs that were equally diminished in volume. However, these lungs lacked the structural abnormalities seen in Down's syndrome, which consisted of a diminished number of alveoli in relation to acini and enlarged alveoli and alveolar ducts. The patients with Down's syndrome also had a smaller total number of alveoli and a smaller alveolar surface area. We speculate that the smaller alveolar surface area is accompanied by loss of capillary surface area, which is responsible for the aggravation of pulmonary hypertension in Down's syndrome.

ABSTRACr The radial alveolar count method of Emery and Mithal has been re-evaluated on 76 normal postnatal lungs. Results of reproducibility assessments suggest that each observer should establish normal control values when beginning with the method, and should subsequently use control cases to maintain strict reproducibility. The use of 10 fields per case was found to be inadequate to obtain satisfactory reproducibility, even for a single observer. Prior inflation of the lungs significantly increased the radial counts, and this factor may help to explain the large discrepancy between the results of this study and that of Emery and Mithal. The radial counts correlated well with the chronological age of the child (r = +0*76; p < 0.001).Alveolarisation of the acinus occurs primarily between birth and 2 years; significant but slower growth is seen up to 8 years, after which the results plateau, suggesting that alveolarisation is complete. The radial count method appears to provide a relatively simple and reasonably satisfactory assessment of alveolar development, as originally proposed by Emery and Mithal.There is a wide variation in estimations by different observers of the number of alveoli in the human lung at a particular age and of the time at which alveolar multiplication ceases. These discrepancies have been attributed to several causes'-different methods of preparation of the lungs for analysis; variation in results between different observers when the same sections are examined; difficulty in recognition of alveoli; and the small number of cases from which current data have been derived. Additional theoretical limitations are imposed by the alveolar shape constant (a3) that study were made from a respiratory bronchiole to the edge of the acinus. A respiratory bronchiole was defined as a bronchiole lined by epithelium in one part of the wall. From the centre of such a bronchiole a perpendicular was dropped to the edge of the acinus (connective tissue septum or pleura), and the number of alveoli cut by this line was then counted. Ten such counts were made from each of 309 cases and the mean for each case was estimated. Results were expressed as average figures in different age groups, and an increase in the radial alveolar count throughout the whole of childhood was documented. By the use of this method of choosing bronchioles adequate reproducibility of results was said to have been achieved.Although the information derived by this method differs from (and is less than) that obtained by conventional alveolar counting, the technique has obvious merits. Large numbers of cases may be rapidly examined. It is claimed that the method overcomes

Major ecological realignments are already occurring in response to climate change. To be successful, conservation strategies now need to account for geographical patterns in traits sensitive to climate change, as well as climate threats to species-level diversity. As part of an effort to provide such information, we conducted a climate vulnerability assessment that included all anadromous Pacific salmon and steelhead ( Oncorhynchus spp.) population units listed under the U.S. Endangered Species Act. Using an expert-based scoring system, we ranked 20 attributes for the 28 listed units and 5 additional units. Attributes captured biological sensitivity, or the strength of linkages between each listing unit and the present climate; climate exposure, or the magnitude of projected change in local environmental conditions; and adaptive capacity, or the ability to modify phenotypes to cope with new climatic conditions. Each listing unit was then assigned one of four vulnerability categories. Units ranked most vulnerable overall were Chinook ( O . tshawytscha ) in the California Central Valley, coho ( O . kisutch ) in California and southern Oregon, sockeye ( O . nerka ) in the Snake River Basin, and spring-run Chinook in the interior Columbia and Willamette River Basins. We identified units with similar vulnerability profiles using a hierarchical cluster analysis. Life history characteristics, especially freshwater and estuary residence times, interplayed with gradations in exposure from south to north and from coastal to interior regions to generate landscape-level patterns within each species. Nearly all listing units faced high exposures to projected increases in stream temperature, sea surface temperature, and ocean acidification, but other aspects of exposure peaked in particular regions. Anthropogenic factors, especially migration barriers, habitat degradation, and hatchery influence, have reduced the adaptive capacity of most steelhead and salmon populations. Enhancing adaptive capacity is essential to mitigate for the increasing threat of climate change. Collectively, these results provide a framework to support recovery planning that considers climate impacts on the majority of West Coast anadromous salmonids.