When to suspect and how to diagnose pulmonary lymphangioleiomyomatosis

Abstract The objective of this study was to present clinical and radiological data of eight women with histologically proven lymphangioleiomyomatosis (LAM) diagnosed between 1984 and 1994, and to suggest a diagnostic strategy when LAM is suspected. A review of case reports, including results of biopsies, lung function and radiological procedures was undertaken. The mean age of the women at start of symptoms was 36 years, and the mean age at time of diagnosis 42 years. The most frequent presenting complaint was dyspnea, either in conjunction with pneumothorax (3), chylothorax (2) or on exertion (2). All patients had airflow limitation and markedly reduced gas transfer. Five patients had 16 episodes of pneumothorax. In seven patients multiple cysts were observed on the surface of the lung during thoracotomy while computerized tomography (CT) scans revealed numerous cysts evenly distributed throughout the lung parenchyma. The procedures that confirmed the diagnosis included transbronchial lung biopsy (4), open lung biopsy (2), thoracoscopy (1), thoracotomy (3) and autopsy (1). Three specimens had to be revised before the histological diagnosis was confirmed. It was concluded that the important clues to a diagnosis of LAM are recurrent episodes of pneumothoraces in fertile women, progressive air-flow limitation, markedly reduced gas transfer and characteristic findings on thoracic CT scans. A specific request to the pathologist to stain lung tissue specimens for smooth muscle cells is mandatory.     

Biodiversity and infrastructure interact to drive tourism to and within Costa Rica

Nature-based tourism has potential to sustain biodiversity and economic development, yet the degree to which biodiversity drives tourism patterns, especially relative to infrastructure, is poorly understood. Here, we examine relationships between different types of biodiversity and different types of tourism in Costa Rica to address three questions. First, what is the contribution of species richness in explaining patterns of tourism in protected areas and country-wide in Costa Rica? Second, how similar are the patterns for birdwatching tourism compared to those of overall tourism? Third, where in the country is biodiversity contributing more than other factors to birdwatching tourism and to overall tourism? We integrated environmental data and species occurrence records to build species distribution models for 66 species of amphibians, reptiles, and mammals, and for 699 bird species. We used built infrastructure variables (hotel density and distance to roads), protected area size, distance to protected areas, and distance to water as covariates to evaluate the relative importance of biodiversity in predicting birdwatching tourism (via eBird checklists) and overall tourism (via Flickr photographs) within Costa Rica. We found that while the role of infrastructure is larger than any other variable, it alone is not sufficient to explain birdwatching and tourism patterns. Including biodiversity adds predictive power and alters spatial patterns of predicted tourism. Our results suggest that investments in infrastructure must be paired with successful biodiversity conservation for tourism to generate the economic revenue that countries like Costa Rica derive from it, now and into the future.

The tourism sector is well-poised to generate win–win approaches to biodiversity conservation and sustainable development given its nonextractive nature and its dependence on scenic beauty (1). However, for sustainable tourism to succeed as a strategy for biodiversity conservation, the role that biodiversity plays in driving tourism patterns needs to be better understood. On one hand, wildlife and nature motivate a significant portion of global tourism (2), and protected areas with higher species richness tend to attract more tourists and yield higher economic benefits (3). On the other hand, tourism hotspots also tend to occur in places where more human-built infrastructure (e.g., hotels, roads, and airports) enables access (4, 5). Studies have reached mixed conclusions on the relative importance of biodiversity and accessibility for tourism, and little is known about how they work in concert (6–11). Given the potential negative impacts of infrastructure on biodiversity conservation, their relative contributions to tourism deserves explicit study, particularly in developing countries where both biodiversity conservation and sustainable development are urgently needed (7, 12).Drivers of tourism patterns across landscapes have been explored through questionnaire surveys and structured interviews that ask tourists about their affinity for landscape features (13–15) and through spatial models that predict recreation using photographs (e.g., geographically weighted regression, MaxEnt) (16, 17). Recently, geo-tagged photographs and species lists shared on social media platforms have become popular tools for tourism-focused research (18–22). These studies, however, typically focus narrowly on the role of single taxa (22, 23) and landscape attributes without accounting for species diversity (14, 20), or they focus only on the role of infrastructure as a driver of tourism (5). Recent advances in satellite Earth observations make it possible to capture more of the ecosystem heterogeneity that can drive variability in species distributions, compared to more conventional modeling based on land cover (24–26). An integrated approach is needed, linking species richness of multiple taxa along with infrastructure variables, both modeled and mapped through high resolution Earth observations. Such an approach could be scaled up to larger regions and applied globally, helping to identify where biodiversity is playing a significant role in driving tourism, such that governments and the tourism sector can prioritize investments in biodiversity conservation.Here, we ask three questions in the iconic case of Costa Rica. First, what is the contribution of species richness (of vertebrate taxa) in explaining patterns of tourism in protected areas and also country-wide? Second, how similar are the patterns for birdwatching tourism compared to those of overall tourism? Third, where in the country is biodiversity contributing more than other factors to birdwatching tourism and to overall tourism? We predict that vertebrate species richness is more important for driving tourism in protected areas than in the rest of the country, because nature-seeking tourists often go to protected areas to find wildlife (3). We also expect that birdwatching tourism is predicted by richness of threatened and endemic bird species rather than total species richness, given birdwatchers’ preferences for rare birds (27). We predict a saturating relationship between species richness and tourism, because beyond a large number of species additional species are unlikely to contribute more to tourism (28). Finally, we predict that national-level tourism is better explained by infrastructure (such as roads and hotels) and distance to water than by biodiversity, because tourists going to Costa Rica often seek activities such as surfing and relaxing in beach resorts (29, 30). We predict nonlinear effects of proximity to roads and water, because a place is deemed inaccessible if it is further away from roads, and a beach tourist destination is also either close to water or not a destination at all. Access diminishes rapidly over a few miles (31).To answer our research questions, we analyze patterns of tourism at two different spatial scales. First, we analyze tourism patterns in protected areas only. Many protected areas provide reliable data on visitation rates and biodiversity tends to be higher inside than outside protected areas (29). However, given that they are often visited by tourists who are already interested in biodiversity, protected areas are not representative of all tourism patterns (30). Second, we evaluate the relative importance of biodiversity to all tourism across Costa Rica (excluding offshore islands). Investigating tourism across the whole nation may give a better understanding of how biodiversity contributes to tourism writ large and not only for tourists with a predisposition for finding wildlife. At both the protected area and national scales, we use a modified MaxEnt model that integrates species distribution models for 66 terrestrial vertebrate species (including amphibians, reptiles, and mammals) and 699 bird species, based on remotely sensed climate and habitat variables, with spatial patterns of infrastructure (hotel density and distance to roads) and distance to water. We measure tourism in two ways for both scales: using eBird checklists as a proxy for birdwatching (32), and using Flickr photographs as a proxy for all international and domestic tourism (19).Costa Rica is an ideal country to explore these questions because tourism represents 7% of the national gross domestic product and employs 3% of the working population directly and a further 9% indirectly (33). Approximately 70% of all international visitors to Costa Rica state that the wildlife, dramatic scenery, and opportunities for adventure sports are the main motivation for visiting the country (33, 34). However, the importance of biodiversity as a factor that influences tourism to, or domestically within, the country has not been evaluated (apart from very local studies) (35, 36). The Central Bank of Costa Rica is currently piloting a nature-based tourism account under the United Nations System of Environmental Economic Accounts (UN SEEA). The state of the art with this methodology is to attribute value to different ecosystems, which may vary widely in their biodiversity. Understanding the relationships between biodiversity and tourism in Costa Rica is a key step toward maintaining the vibrant ecotourism industry and can serve as an example for other biodiverse nations that often look to Costa Rica as a leader in sustainable development (37).     

Group specific component and susceptibility to HIV infection and progression to AIDS

The distribution of phenotypes of the group specific component (Gc) was examined in 85 AIDS patients and in 40 couples, each consisting of one HIV seropositive patient and one seronegative sexual partner. Phenotype and allele frequencies in these groups did not differ significantly from those in a Swedish control population. Our observations did not indicate any involvement of the Gc system in susceptibility to HIV infection or progression to AIDS.     

Allergic Reactions to Clopidogrel and Cross-Reactivity to Other Agents

Clopidogrel is a widely used antiplatelet agent, particularly after coronary stent implantation. About 1% of patients have allergic or hematologic adverse reactions to clopidogrel. This has important therapeutic implications, as premature discontinuation of clopidogrel is the strongest risk factor for stent thrombosis. Clopidogrel allergy most commonly manifests as a rash. It is important to distinguish this from other causes of rash occurring in patients who have had a recent coronary stent. Although antihistamines and short-term oral corticosteroids are effective in treating most clopidogrel hypersensitivity reactions, some persistent reactions may require discontinuation of clopidogrel. When discontinuation of clopidogrel is required, substitution with an alternative thienopyridine such as ticlopidine traditionally has been performed. However, a recent study suggests that there may be as high as a 27% risk of recurrence of non-life-threatening allergic reactions in such patients, which are usually similar to the allergic reactions that occurred with clopidogrel. No data are available regarding the frequency of cross-reactivity to prasugrel and ticagrelor; these may be potential therapeutic options in some patients.