Marsh migration and beyond: A scalable framework to assess tidal wetland resilience and support strategic management

Tidal wetlands are critical but highly threatened ecosystems that provide vital services. Efficient stewardship of tidal wetlands requires robust comparative assessments of different marshes to understand their resilience to stressors, particularly in the face of relative sea level rise. Existing assessment frameworks aim to address tidal marsh resilience, but many are either too localized or too general, and few directly translate resilience evaluations to recommendations for management strategies. In response to the deficiencies in existing frameworks, we identified a set of metrics that influence overall marsh resilience that can be assessed at any spatial scale. We then developed a new comprehensive assessment framework to rank relative marsh resilience using these metrics, which are nested within three categories. We represent resilience as the sum of results across the three metric categories: current condition, adaptive capacity, and vulnerability. Users of this framework can add scores from each category to generate a total resilience score to compare across marshes or take the score from each category and refer to recommended management actions we developed based on expert elicitation for each combination of category results. We then applied the framework across the contiguous United States using publicly available data, and summarized results at multiple spatial scales, from regions to coastal states to National Estuarine Research Reserves to finer scale marsh units, to demonstrate the framework's value across these scales. Our national analysis allowed for comparison of tidal marsh resilience across geographies, which is valuable for determining where to prioritize management actions for desired future marsh conditions. In combination, the assessment framework and recommended management actions function as a broadly applicable decision-support tool that will enable resource managers to evaluate tidal marshes and select appropriate strategies for conservation, restoration, and other stewardship goals.

Use of historical isoscapes to develop an estuarine nutrient baseline

Coastal eutrophication is a prevalent threat to the healthy functioning of ecosystems globally. While degraded water quality can be detected by monitoring oxygen, nutrient concentrations, and algal abundance, establishing regulatory guidelines is complicated by a lack of baseline data (e.g., pre-Anthropocene). We use historical carbon and nitrogen isoscapes over ~300 years from sediment cores to reconstruct spatial and temporal changes in nutrient dynamics for a central California estuary, Elkhorn Slough, where development and agriculture dramatically enhanced nutrient inputs over the past century. We found strong contrasts between current sediment stable isotopes and those from the recent past, demonstrating shifts exceeding those in previously studied eutrophic estuaries and substantial increases in nutrient inputs. Comparisons of contemporary with historical isoscapes also revealed that nitrogen sources shifted from a historical marine-terrestrial gradient with higher δ15N near the inlet to amplified denitrification at the head and mouth of the modern estuary driven by increased N inputs. Geospatial analysis of historical data suggests that an increase in fertilizer application - rather than population growth or increases in the extent of cultivated land - is chiefly responsible for increasing nutrient loads during the 20th century. This study demonstrates the ability of isotopic and stoichiometric maps to provide important perspectives on long-term shifts and spatial patterns of nutrients that can be used to improve management of nutrient pollution.

Mapping oysters on the Pacific coast of North America: A coast-wide collaboration to inform enhanced conservation

To conserve coastal foundation species, it is essential to understand patterns of distribution and abundance and how they change over time. We synthesized oyster distribution data across the west coast of North America to develop conservation strategies for the native Olympia oyster (Ostrea lurida), and to characterize populations of the non-native Pacific oyster (Magallana gigas). We designed a user-friendly portal for data entry into ArcGIS Online and collected oyster records from unpublished data submitted by oyster experts and from the published literature. We used the resulting 2,000+ records to examine spatial and temporal patterns and made an interactive web-based map publicly available. Comparing records from pre-2000 vs. post-2000, we found that O. lurida significantly decreased in abundance and distribution, while M. gigas increased significantly. Currently the distribution and abundance of the two species are fairly similar, despite one species being endemic to this region since the Pleistocene, and the other a new introduction. We mapped the networks of sites occupied by oysters based on estimates of larval dispersal distance, and found that these networks were larger in Canada, Washington, and southern California than in other regions. We recommend restoration to enhance O. lurida, particularly within small networks, and to increase abundance where it declined. We also recommend restoring natural biogenic beds on mudflats and sandflats especially in the southern range, where native oysters are currently found most often on riprap and other anthropogenic structures. This project can serve as a model for collaborative mapping projects that inform conservation strategies for imperiled species or habitats.

Burrowing crabs and physical factors hasten marsh recovery at panne edges

Salt marsh loss is projected to increase as sea-level rise accelerates with global climate change. Salt marsh loss occurs along both lateral creek and channel edges and in the marsh interior, when pannes expand and coalesce. Often, edge loss is attributed to erosive processes whereas dieback in the marsh interior is linked to excessive inundation or deposition of wrack, but remains poorly understood. We conducted a two-year field investigation in a central California estuary to identify key factors associated with panne contraction or expansion. Our study explored how an abundant burrowing crab, shown to have strong negative effects on marsh biomass near creek edges, affects panne dynamics. We also explored which physical panne attributes best predicted their dynamics. To our knowledge, ours is the first study of panne dynamics in a California marsh, despite how ubiquitous pannes are as a feature of marshes in the region and how often extensive marsh dieback occurs via panne expansion. Overall, we found that pannes contracted during the study period, but with variable rates of marsh recovery across pannes. Our model incorporating both physical and biological factors explained 86% of the variation in panne contraction. The model revealed a positive effect of crab activity, sediment accretion, and a composite of depth and elevation on panne contraction, and a negative effect of panne size and distance to nearest panne. The positive crab effects detected in pannes contrast with negative effects we detected near creek edges in a previous study, highlighting the context-dependence of top-down and bioturbation effects in marshes. As global change continues and the magnitude and frequency of disturbances increases, understanding the dynamics of marsh loss in the marsh interior as well as creek banks will be critical for the management of these coastal habitats.

Rapid enhancement of multiple ecosystem services following the restoration of a coastal foundation species

The global decline of marine foundation species (kelp forests, mangroves, salt marshes, and seagrasses) has contributed to the degradation of the coastal zone and threatens the loss of critical ecosystem services and functions. Restoration of marine foundation species has had variable success, especially for seagrasses, where a majority of restoration efforts have failed. While most seagrass restorations track structural attributes over time, rarely do restorations assess the suite of ecological functions that may be affected by restoration. Here we report on the results of two small-scale experimental seagrass restoration efforts in a central California estuary where we transplanted 117 0.25-m² plots (2,340 shoots) of the seagrass species Zostera marina. We quantified restoration success relative to persistent reference beds, and in comparison to unrestored, unvegetated areas. Within three years, our restored plots expanded ~8,500%, from a total initial area of 29 to 2,513 m² . The restored beds rapidly began to resemble the reference beds in (1) seagrass structural attributes (canopy height, shoot density, biomass), (2) ecological functions (macrofaunal species richness and abundance, epifaunal species richness, nursery function), and (3) biogeochemical functions (modulation of water quality). We also developed a multifunctionality index to assess cumulative functional performance, which revealed restored plots are intermediate between reference and unvegetated habitats, illustrating how rapidly multiple functions recovered over a short time period. Our comprehensive study is one of few published studies to quantify how seagrass restoration can enhance both biological and biogeochemical functions. Our study serves as a model for quantifying ecosystem services associated with the restoration of a foundation species and demonstrates the potential for rapid functional recovery that can be achieved through targeted restoration of fast-growing foundation species under suitable conditions.

Conservation aquaculture as a tool for imperiled marine species: Evaluation of opportunities and risks for Olympia oysters, Ostrea lurida

Conservation aquaculture is becoming an important tool to support the recovery of declining marine species and meet human needs. However, this tool comes with risks as well as rewards, which must be assessed to guide aquaculture activities and recovery efforts. Olympia oysters (Ostrea lurida) provide key ecosystem functions and services along the west coast of North America, but populations have declined to the point of local extinction in some estuaries. Here, we present a species-level, range-wide approach to strategically planning the use of aquaculture to promote recovery of Olympia oysters. We identified 12 benefits of culturing Olympia oysters, including identifying climate-resilient phenotypes that add diversity to growers’ portfolios. We also identified 11 key risks, including potential negative ecological and genetic consequences associated with the transfer of hatchery-raised oysters into wild populations. Informed by these trade-offs, we identified ten priority estuaries where aquaculture is most likely to benefit Olympia oyster recovery. The two highest scoring estuaries have isolated populations with extreme recruitment limitation—issues that can be addressed via aquaculture if hatchery capacity is expanded in priority areas. By integrating social criteria, we evaluated which project types would likely meet the goals of local stakeholders in each estuary. Community restoration was most broadly suited to the priority areas, with limited commercial aquaculture and no current community harvest of the species, although this is a future stakeholder goal. The framework we developed to evaluate aquaculture as a tool to support species recovery is transferable to other systems and species globally; we provide a guide to prioritizing local knowledge and developing recommendations for implementation by using transparent criteria. Our collaborative process engaging diverse stakeholders including managers, scientists, Indigenous Tribal representatives, and shellfish growers can be used elsewhere to seek win-win opportunities to expand conservation aquaculture where benefits are maximized for both people and imperiled species.

Top-down and sideways: Herbivory and cross-ecosystem connectivity shape restoration success at the salt marsh-upland ecotone

Wetland restoration provides remarkable opportunities to understand vegetation dynamics and to inform success of future projects through rigorous restoration experiments. Salt marsh restoration typically focuses on physical factors such as sediment dynamics and elevation. Despite many demonstrations of strong top-down effects on salt marshes, the potential for consumers to affect salt marsh restoration projects has rarely been quantified. Recently, major restoration projects at the Elkhorn Slough National Estuarine Research Reserve in central California, USA provided an opportunity to examine how herbivory influences restoration success. We quantified the strength of consumer effects by comparing caged to uncaged plantings, and compared effects among plant species and sites. We used camera traps to detect which herbivores were most common and how their abundance varied spatially. Beyond characterizing consumer effects, we also tested management strategies for reducing negative effects of herbivory at the restoration sites, including caging, mowing, and acoustic playbacks of predator sounds. We found extremely strong consumer effects at sites with extensive stands of exotic forbs upland of the high marsh; uncaged restoration plants suffered heavy herbivory and high mortality, while most caged plants survived. Brush rabbits (Sylvilagus bachmani) were by far the most frequent consumers of these high marsh plants. Our work thus provides the first evidence of mammal consumers affecting salt marsh restoration success. Mowing of tall exotic forb cover adjacent to the marsh at one restoration site greatly reduced consumption, and nearly all monitored plantings survived at a second restoration site where construction had temporarily eliminated upland cover. Playbacks of predator sounds did not significantly affect restoration plantings, but restoration efforts in marsh communities vulnerable to terrestrial herbivory may benefit from concurrent restoration of predator communities in the upland habitats surrounding the marsh. A landscape approach is thus critical for recognizing linkages between terrestrial and marine vegetation.

Species recovery and recolonization of past habitats: lessons for science and conservation from sea otters in estuaries

Recovering species are often limited to much smaller areas than they historically occupied. Conservation planning for the recovering species is often based on this limited range, which may simply be an artifact of where the surviving population persisted. Southern sea otters (Enhydra lutris nereis) were hunted nearly to extinction but recovered from a small remnant population on a remote stretch of the California outer coast, where most of their recovery has occurred. However, studies of recently-recolonized estuaries have revealed that estuaries can provide southern sea otters with high quality habitats featuring shallow waters, high production and ample food, limited predators, and protected haul-out opportunities. Moreover, sea otters can have strong effects on estuarine ecosystems, fostering seagrass resilience through their consumption of invertebrate prey. Using a combination of literature reviews, population modeling, and prey surveys we explored the former estuarine habitats outside the current southern sea otter range to determine if these estuarine habitats can support healthy sea otter populations. We found the majority of studies and conservation efforts have focused on populations in exposed, rocky coastal habitats. Yet historical evidence indicates that sea otters were also formerly ubiquitous in estuaries. Our habitat-specific population growth model for California's largest estuary-San Francisco Bay-determined that it alone can support about 6,600 sea otters, more than double the 2018 California population. Prey surveys in estuaries currently with (Elkhorn Slough and Morro Bay) and without (San Francisco Bay and Drakes Estero) sea otters indicated that the availability of prey, especially crabs, is sufficient to support healthy sea otter populations. Combining historical evidence with our results, we show that conservation practitioners could consider former estuarine habitats as targets for sea otter and ecosystem restoration. This study reveals the importance of understanding how recovering species interact with all the ecosystems they historically occupied, both for improved conservation of the recovering species and for successful restoration of ecosystem functions and processes.

Pattern and scale: evaluating generalities in crab distributions and marsh dynamics from small plots to a national scale

The generality of ecological patterns depends inextricably on the scale at which they are examined. We investigated patterns of crab distribution and the relationship between crabs and vegetation in salt marshes at multiple scales. By using consistent monitoring protocols across 15 U.S. National Estuarine Research Reserves, we were able to synthesize patterns from the scale of quadrats to the entire marsh landscape to regional and national scales. Some generalities emerged across marshes from our overall models, and these are useful for informing broad coastal management policy. We found that crab burrow distribution within a marsh could be predicted by marsh elevation, distance to creek and soil compressibility. While these physical factors also affected marsh vegetation cover, we did not find a strong or consistent overall effect of crabs at a broad scale in our multivariate model, though regressions conducted separately for each site revealed that crab burrows were negatively correlated with vegetation cover at 4 out of 15 sites. This contrasts with recent smaller-scale studies and meta-analyses synthesizing such studies that detected strong negative effects of crabs on marshes, likely because we sampled across the entire marsh landscape, while targeted studies are typically limited to low-lying areas near creeks, where crab burrow densities are highest. Our results suggest that sea-level rise generally poses a bigger threat to marshes than crabs, but there will likely be interactions between these physical and biological factors. Beyond these generalities across marshes, we detected some regional differences in crab community composition, richness, and abundance. However, we found striking differences among sites within regions, and within sites, in terms of crab abundance and relationships to marsh integrity. Although generalities are broadly useful, our findings indicate that local managers cannot rely on data from other nearby systems, but rather need local information for developing salt marsh management strategies.

What Is the Minimal Competency for a Clinical Ethics Consult Simulation? Setting a Standard for Use of the Assessing Clinical Ethics Skills (ACES) Tool

Background: The field of clinical ethics is examining ways of determining competency. The Assessing Clinical Ethics Skills (ACES) tool offers a new approach that identifies a range of skills necessary in the conduct of clinical ethics consultation and provides a consistent framework for evaluating these skills. Through a training website, users learn to apply the ACES tool to clinical ethics consultants (CECs) in simulated ethics consultation videos. The aim is to recognize competent and incompetent clinical ethics consultation skills by watching and evaluating a videotaped CEC performance. We report how we set a criterion cut score (i.e., minimally acceptable score) for judging the ability of users of the ACES tool to evaluate simulated CEC performances. Methods: A modified Angoff standard-setting procedure was used to establish the cut score for an end-of-life case included on the ACES training website. The standard-setting committee viewed the Futility Case and estimated the probability that a minimally competent CEC would correctly answer each item on the ACES tool. The committee further adjusted these estimates by reviewing data from 31 pilot users of the Futility Case before determining the cut score. Results: Averaging over all 31 items, the proposed proportion correct score for minimal competency was 80%, corresponding to a cut score that is between 24 and 25 points out of 31 possible points. The standard-setting committee subsequently set the minimal competency cut score to 24 points. Conclusions: The cut score for the ACES tool identifies the number of correct responses a user of the ACES tool training website must attain to "pass" and reach minimal competency in recognizing competent and incompetent skills of the CECs in the simulated ethics consultation videos. The application of the cut score to live training of CECs and other areas of practice requires further investigation.

Timing of stressors alters interactive effects on a coastal foundation species

The effects of climate-driven stressors on organismal performance and ecosystem functioning have been investigated across many systems; however, manipulative experiments generally apply stressors as constant and simultaneous treatments, rather than accurately reflecting temporal patterns in the natural environment. Here, we assessed the effects of temporal patterns of high aerial temperature and low salinity on survival of Olympia oysters (Ostrea lurida), a foundation species of conservation and restoration concern. As single stressors, low salinity (5 and 10 psu) and the highest air temperature (40°C) resulted in oyster mortality of 55.8, 11.3, and 23.5%, respectively. When applied on the same day, low salinity and high air temperature had synergistic negative effects that increased oyster mortality. This was true even for stressor levels that were relatively mild when applied alone (10 psu and 35°C). However, recovery times of two or four weeks between stressors eliminated the synergistic effects. Given that most natural systems threatened by climate change are subject to multiple stressors that vary in the timing of their occurrence, our results suggest that it is important to examine temporal variation of stressors in order to more accurately understand the possible biological responses to global change.

Coast-wide recruitment dynamics of Olympia oysters reveal limited synchrony and multiple predictors of failure

Recruitment of new propagules into a population can be a critical determinant of adult density. We examined recruitment dynamics in the Olympia oyster (Ostrea lurida), a species occurring almost entirely in estuaries. We investigated spatial scales of interannual synchrony across 37 sites in eight estuaries along 2,500 km of Pacific North American coastline, predicting that high vs. low recruitment years would coincide among neighboring estuaries due to shared exposure to regional oceanographic factors. Such synchrony in recruitment has been found for many marine species and some migratory estuarine species, but has never been examined across estuaries in a species that can complete its entire life cycle within the same estuary. To inform ongoing restoration efforts for Olympia oysters, which have declined in abundance in many estuaries, we also investigated predictors of recruitment failure. We found striking contrasts in absolute recruitment rate and frequency of recruitment failure among sites, estuaries, and years. Although we found a positive relationship between upwelling and recruitment, there was little evidence of synchrony in recruitment among estuaries along the coast, and only limited synchrony of sites within estuaries, suggesting recruitment rates are affected more strongly by local dynamics within estuaries than by regional oceanographic factors operating at scales encompassing multiple estuaries. This highlights the importance of local wetland and watershed management for the demography of oysters, and perhaps other species that can complete their entire life cycle within estuaries. Estuaries with more homogeneous environmental conditions had greater synchrony among sites, and this led to the potential for estuary-wide failure when all sites had no recruitment in the same year. Environmental heterogeneity within estuaries may thus buffer against estuary-wide recruitment failure, analogous to the portfolio effect for diversity. Recruitment failure was correlated with lower summer water temperature, higher winter salinity, and shorter residence time: all indicators of stronger marine influence on estuaries. Recruitment failure was also more common in estuaries with limited networks of nearby adult oysters. Large existing oyster networks are thus of high conservation value, while estuaries that lack them would benefit from restoration efforts to increase the extent and connectivity of sites supporting oysters.

Trophic cascades on the edge: fostering seagrass resilience via a novel pathway

Despite widespread degradation, some coastal ecosystems display remarkable resilience. For seagrasses, a century-old paradigm has implicated macroalgal blooms stimulated by anthropogenic nutrient, loading as a primary driver of seagrass decline, yet relatively little attention has been given to drivers of seagrass resilience. In Elkhorn Slough, CA, an estuarine system characterized by extreme anthropogenic nutrient loading and macroalgal (Ulva spp.) blooms, seagrass (Zostera marina) beds have recovered concurrent with colonization of the estuary by top predators, sea otters (Enhydra lutris). Here, we follow up on the results of a previous experiment at the seagrass interior, showing how sea otters can generate a trophic cascade that promotes seagrass. We conducted an experiment and constructed structural equation models to determine how sea otters, through a trophic cascade, might affect the edge of seagrass beds where expansion occurs. We found that at the edge, sea otters promoted both seagrass and ephemeral macroalgae, with the latter contributing beneficial grazers to the seagrass. The surprising results that sea otters promote two potentially competing vegetation types, and a grazer assemblage at their boundary provides a mechanism by which seagrasses can expand in eutrophic environments, and contributes to a growing body of literature demonstrating that ephemeral macroalgae are not always negatively associated with seagrass. Our results highlight the potential for top predator recovery to enhance ecosystem resilience to anthropogenic alterations through several cascading mechanisms.

Biodiversity effects and rates of spread of nonnative eucalypt woodlands in central California

Woodlands comprised of planted, nonnative trees are increasing in extent globally, while native woodlands continue to decline due to human activities. The ecological impacts of planted woodlands may include changes to the communities of understory plants and animals found among these nonnative trees relative to native woodlands, as well as invasion of adjacent habitat areas through spread beyond the originally planted areas. Eucalypts (Eucalyptus spp.) are among the most widely planted trees worldwide, and are very common in California, USA. The goals of our investigation were to compare the biological communities of nonnative eucalypt woodlands to native oak woodlands in coastal central California, and to examine whether planted eucalypt groves have increased in size over the past decades. We assessed site and habitat attributes and characterized biological communities using understory plant, ground-dwelling arthropod, amphibian, and bird communities as indicators. Degree of difference between native and nonnative woodlands depended on the indicator used. Eucalypts had significantly greater canopy height and cover, and significantly lower cover by perennial plants and species richness of arthropods than oaks. Community composition of arthropods also differed significantly between eucalypts and oaks. Eucalypts had marginally significantly deeper litter depth, lower abundance of native plants with ranges limited to western North America, and lower abundance of amphibians. In contrast to these differences, eucalypt and oak groves had very similar bird community composition, species richness, and abundance. We found no evidence of "invasional meltdown," documenting similar abundance and richness of nonnatives in eucalypt vs. oak woodlands. Our time-series analysis revealed that planted eucalypt groves increased 271% in size, on average, over six decades, invading adjacent areas. Our results inform science-based management of California woodlands, revealing that while bird communities would probably not be affected by restoration of eucalypt to oak woodlands, such a restoration project would not only stop the spread of eucalypts into adjacent habitats but would also enhance cover by western North American native plants and perennials, enhance amphibian abundance, and increase arthropod richness.

Testing local and global stressor impacts on a coastal foundation species using an ecologically realistic framework

Despite the abundance of literature on organismal responses to multiple environmental stressors, most studies have not matched the timing of experimental manipulations with the temporal pattern of stressors in nature. We test the interactive effects of diel-cycling hypoxia with both warming and decreased salinities using ecologically realistic exposures. Surprisingly, we found no evidence of negative synergistic effects on Olympia oyster growth; rather, we found only additive and opposing effects of hypoxia (detrimental) and warming (beneficial). We suspect that diel-cycling provided a temporal refuge that allowed physiological compensation. We also tested for latent effects of warming and hypoxia to low-salinity tolerance using a seasonal delay between stressor events. However, we did not find a latent effect, rather a threshold survival response to low salinity that was independent of early life-history exposure to warming or hypoxia. The absence of synergism is likely the result of stressor treatments that mirror the natural timing of environmental stressors. We provide environmental context for laboratory experimental data by examining field time series environmental data from four North American west coast estuaries and find heterogeneous environmental signals that characterize each estuary, suggesting that the potential stressor exposure to oysters will drastically differ over moderate spatial scales. This heterogeneity implies that efforts to conserve and restore oysters will require an adaptive approach that incorporates knowledge of local conditions. We conclude that studies of multiple environmental stressors can be greatly improved by integrating ecologically realistic exposure and timing of stressors found in nature with organismal life-history traits.

Food refusal and dysphagia in older people with dementia: ethical and practical issues

Food refusal poses difficulties for nurses and care staff and can place older patients with dementia at risk of undernutrition. The dangers of and reasons for food refusal in these patients are explored and the fundamental ethical and legal issues raised in caring for these patients are examined. Practical guidance and solutions are offered through dietetics and speech and language therapy with the aim of helping nurses and care staff, as well as professional carers in palliative care, and explore ways of critically examining and coping with these dilemmas.

Mammalian microsporidiosis

The phylum Microspora contains a diverse group of single-celled, obligate intracellular protozoa sharing a unique organelle, the polar filament, and parasitizing a wide variety of invertebrate and vertebrate animals, including insects, fish, birds, and mammals. Encephalitozoon cuniculi is the classic microsporidial parasite of mammals, and encephalitozoonosis in rabbits and rodents has been and continues to be recognized as a confounding variable in animal-based biomedical research. Although contemporary research colonies are screened for infection with this parasite, E. cuniculi remains a cause of morbidity and mortality in pet and conventionally raised rabbits. In addition, E. cuniculi is a potential pathogen of immature domestic dogs and farm-raised foxes. The recent discovery and identification of Encephalitozoon intestinalis, Encephalitozoon hellem, and Enterocytozoon bieneusi, in addition to E. cuniculi, as opportunistic pathogens of humans have renewed interest in the Microspora. Veterinary pathologists, trained in the comparative anatomy of multiple animal species and infectious disease processes, are in a unique position to contribute to the diagnosis and knowledge of the pathogenesis of these parasitic diseases. This review article covers the life cycle, ultrastructure, and biology of mammalian microsporaidia and the clinical disease and lesions seen in laboratory and domestic animals, particularly as they relate to Encephalitozoon species. Human microsporidial disease and animal models of human infection are also addressed. Often thought of as rabbit pathogens of historical importance, E. cuniculi and the related mammalian microsporidia are emerging as significant opportunistic pathogens of immunocompromised individuals.

Ethical arguments for providing palliative care to non-cancer patients

Palliative care professionals have begun to address the issues surrounding the provision of palliative care to non-cancer patients. Yet the situation remains inconsistent and morally unjustifiable. The duty to provide care, non-maleficence, beneficence, protecting the patient's best interests and respecting patient autonomy are key responsibilities which palliative care professionals have for all their patients, regardless of their diagnosis. On the grounds of justice as fairness, equality and equity, the current inconsistencies in the provision of palliative care to non-cancer patients are unfair unequal and inequitable. Professionals can no longer ignore their moral responsibility to address these issues and change their practice to include the provision of care for dying patients regardless of their diagnoses.

Therapeutic efficacy of oral lactobacillus preparation for antibiotic-associated enteritis in guinea pigs

Enteritis is a potential complication of antimicrobial agent use, particularly in certain species of rodents. The organism most frequently implicated in this disease is Clostridium difficile. Anecdotal information suggests that administration of yogurt or other Lactobacillus-containing products in conjunction with antimicrobial agents will prevent or minimize the effects of antibiotic-associated enteritis. We wanted to determine whether a single subcutaneous injection of clindamycin phosphate could induce enteritis in guinea pigs and whether a commercial Lactobacillus preparation would ameliorate the clinical effects of antibiotic administration in these animals. Juvenile male guinea pigs were divided into three treatment groups. Group 1 guinea pigs (n=8) received a single saline injection followed by an oral Lactobacillus preparation twice daily; group 2 (n=8) received a single antibiotic injection followed by an oral Lactobacillus preparation twice daily; group 3 (n=8) received a single antibiotic injection. Attitude, body temperature, body weight, and feed and water consumption were recorded for each guinea pig 7 days prior to and after treatment. Fecal samples were collected and necropsies performed on each guinea pig at the time of euthanasia. C. difficile and other enteric pathogens were not isolated from any group before or after treatment, although some guinea pigs receiving the antibiotic developed enteritis. There were no significant clinical differences between guinea pigs receiving antibiotics with the oral Lactobacillus preparation, and those receiving antibiotics alone. The results of this study suggest that a single injection of clindamycin phosphate can induce enteritis in guinea pigs and that oral administration of a Lactobacillus-containing product is ineffective in preventing clinical disease in guinea pigs administered clindamycin phosphate.

Cis-lycopene is more bioavailable than trans-lycopene in vitro and in vivo in lymph-cannulated ferrets

Lycopene is the predominant carotenoid in tomatoes and tomato-based foods and is also a predominant carotenoid in human serum and tissues. Intake of lycopene-rich foods was recently associated with decreased risk for several chronic diseases. The observation that serum and tissue lycopene is more than 50% cis-lycopene, whereas tomatoes and tomato-based foods contain mainly all-trans-lycopene, has led to the hypothesis that cis-isomers of lycopene are more bioavailable. We tested this hypothesis both in vitro (study 1) and in vivo (study 2). In study 1, bile acid micelles containing crystalline lycopene were prepared. The crystalline lycopene used for these analyses was 54.4% cis-lycopene. The optically clear micelle preparation contained 75.9% cis-lycopene in repeated analyses. In study 2, mesenteric lymph duct cannulated ferrets were used to study the in vivo absorption of lycopene from LycoredTM (an ethyl acetate extract of tomatoes containing 5% lycopene by weight; of which 91% was all-trans lycopene). Before being anesthetized, male ferrets (n = 7) were dosed orally with 40 mg lycopene per kg body weight in soybean oil. Lymph secretions were collected, on ice, for 2 h. The residual stomach and small intestinal contents, mucosa lining, lymph secretion and serum were analyzed by HPLC. Whereas the dose, stomach and intestinal contents contained 6.2-17.5% cis-lycopene, the mesenteric lymph secretions contained significantly more, 77.4%, cis-lycopene (P < 0.01). These studies demonstrate that in ferrets, cis-isomers of lycopene are more bioavailable than trans-lycopene probably because cis-isomers are more soluble in bile acid micelles and may be preferentially incorporated into chylomicrons.

Rabbit intestinal xenograft model for human Encephalitozoon infections in mice

BACKGROUND AND PURPOSE

The gastrointestinal tract is a common portal of entry for Encephalitozoon cuniculi, one of several microsporidial organisms emerging as opportunistic pathogens in immunocompromised humans. Although most human microsporidial pathogens can be propagated in vitro and in a variety of laboratory animals, an experimental animal system to specifically study intestinal uptake and systemic spread of these organisms does not exist.

METHODS

Paired segments of near-term fetal rabbit small intestine were implanted subcutaneously into 25 athymic nude or 10 severe combined immune deficient mice. Five weeks after surgery, 65 xenografts were inoculated intraluminally with E. cuniculi (n = 14), E. intestinalis (n = 27), E. hellem (n = 20), or RK-13 cells (n = 2), or were left uninoculated (n = 2).

RESULTS

Intestinal xenograft infection with E. cuniculi (n = 11), E. intestinalis (n = 17), and E. hellem (n = 18) was determined by light microscopy; control xenografts remained uninfected. Extraintestinal infection with E. cuniculi developed in host mouse brain, respiratory tract, spleen, salivary glands, and gastrointestinal tract (3 of 3 mice), and infection with E. intestinalis developed in the liver (8 of 15 mice).

CONCLUSION

Intestinal xenografts provide a unique, sterile, and biologically relevant animal model system for studying host enterocyte/parasite interactions, mechanisms of microsporidial pathogenicity, antimicrosporidial chemotherapeutic agents, and immune effector mechanisms. This model provides evidence for persistent graft infection with three Encephalitozoon spp., and for intestinal spread of E. cuniculi and E. intestinalis from infected enterocytes in immunoincompetent mice.

Sexual Modes in the Colonial Kamptozoan Genus Barentsia

Sexual mode in colonial animals is expressed at the zooid, colony, and genet level; all three must be characterized to understand sexuality in these animals. I carried out such an examination of the sexual mode of a colonial kamptozoan (entoproct), Barentsia hildegardae, at Friday Harbor, Washington. Calyces never contained both ovaries and testes, and colonies never contained both male and female calyces. Calyces and colonies (including replicate colonies from the same genet) monitored over two years did not change sex. These results suggest that B. hildegardae is comprehensively gonochoric. For comparison, I examined the sexual mode of five other species in the genus Barentsia. Barentsia benedeni, B. conferta, and B. ramosa also appear to be comprehensively gonochoric. Barentsia discreta is hermaphroditic at the colony level, with gonochoric calyces whose sex is environmentally determined, as noted by previous workers. Barentsia aggregata has simultaneously hermaphroditic calyces; this was reported by the authors who described it, but has escaped notice in subsequent reviews of kamptozoan biology. There are thus three contrasting modes of sex within the genus Barentsia. All three modes also occur in colonial cnidarians, and two of them are known in bryozoans, colonial hemichordates, and colonial urochordates. These disparate sexual modes may have evolved as adaptations to differing environmental conditions or population densities.

Fatal pulmonary hemorrhage after transbronchial lung biopsy through the fiberoptic bronchoscope

A case is reported in which transbronchial lung biopsy using the fiberoptic bronchoscope was complicated by massive, fatal hemorrhage. This previously unreported complication occurred despite normal prothrombin and partial thromboplastin times and platelets of 93,000. Pathological examination revealed that a very small (0.5-mm) vessel was the source of the bleeding. Although severe complications are undoubtedly rare, this report suggests that the transbronchial lung biopsy is not a totally benign procedure. Suggestions are made to prevent future similar occurrences in very ill patients or in patients with coagulative abnormalities or blood dyscrasias.