Effectiveness of a Mental Health Chatbot for People With Chronic Diseases: Randomized Controlled Trial.

BACKGROUND: People with chronic diseases tend to experience more mental health issues than their peers without these health conditions. Mental health chatbots offer a potential source of mental health support for people with chronic diseases. OBJECTIVE: The aim of this study was to determine whether a mental health chatbot can improve mental health in people with chronic diseases. We focused on 2 chronic diseases in particular: arthritis and diabetes. METHODS: Individuals with arthritis or diabetes were recruited using various web-based methods. Participants were randomly assigned to 1 of 2 groups. Those in the treatment group used a mental health chatbot app (Wysa [Wysa Inc]) over a period of 4 weeks. Those in the control group received no intervention. Participants completed measures of depression (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder Scale-7), and stress (Perceived Stress Scale-10) at baseline, with follow-up testing 2 and 4 weeks later. Participants in the treatment group completed feedback questions on their experiences with the app at the final assessment point. RESULTS: A total of 68 participants (n=47, 69% women; mean age 42.87, SD 11.27 years) were included in the analysis. Participants were divided evenly between the treatment and control groups. Those in the treatment group reported decreases in depression (P<.001) and anxiety (P<.001) severity over the study period. No such changes were found among participants in the control group. No changes in stress were reported by participants in either group. Participants with arthritis reported higher levels of depression (P=.004) and anxiety (P=.004) severity than participants with diabetes over the course of the study, as well as higher levels of stress (P=.01); otherwise, patterns of results were similar across these health conditions. In response to the feedback questions, participants in the treatment group said that they liked many of the functions and features of the app, the general design of the app, and the user experience. They also disliked some aspects of the app, with most of these reports focusing on the chatbot's conversational abilities. CONCLUSIONS: The results of this study suggest that mental health chatbots can be an effective source of mental health support for people with chronic diseases such as arthritis and diabetes. Although cost-effective and accessible, these programs have limitations and may not be well suited for all individuals. TRIAL REGISTRATION: ClinicalTrials.gov NCT04620668; https://www.clinicaltrials.gov/study/NCT04620668.

Obtaining Consent for Research on Risky Behaviours Among Adolescents in Canada: A Scoping Review.

This scoping review explores current practices for obtaining consent in research on risky behaviours among adolescents in Canada. The JBI methodology for scoping reviews was used. The database search was conducted in August 2021 and updated in November 2022. Papers published in 2010 or later were included. Extracted data included study characteristics, sample characteristics, and consent procedures. The review included 83 reports covering 57 studies. Nearly 60% of studies relied on adolescent self-consent for participation. Adolescent self-consent was more common than parental/guardian consent for studies using in-person research methods, older adolescent groups, and particularly vulnerable populations. Parental/guardian consent was more common for studies using younger age groups and general population samples. Adolescent self-consent was more common than parental/guardian consent for most risky behaviours covered by this review. These results provide insight into current consent practices in this area and offer guidance to researchers and institutional review boards in Canada.

Depiction of conversational agents as health professionals: a scoping review.

OBJECTIVE: The purpose of this scoping review was to examine the depiction of conversational agents as health professionals. We identified the professional characteristics that are used with these depictions and determined the prevalence of these characteristics among conversational agents that are used for health care. INTRODUCTION: The depiction of conversational agents as health professionals has implications for both the users and the developers of these programs. For this reason, it is important to know more about these depictions and how they are implemented in practical settings. INCLUSION CRITERIA: This review included scholarly literature on conversational agents that are used for health care. It focused on conversational agents designed for patients and health seekers, not health professionals or trainees. Conversational agents that address physical and/or mental health care were considered, as were programs that promote healthy behaviors. METHODS: This review was conducted in accordance with JBI methodology for scoping reviews. The databases searched included MEDLINE (PubMed), Embase, CINAHL with Full Text (EBSCOhost), Scopus, Web of Science, ACM Guide to Computing Literature (Association for Computing Machinery Digital Library), and IEEE Xplore (IEEE). The main database search was conducted in June 2021, and an updated search was conducted in January 2022. Extracted data included characteristics of the report, basic characteristics of the conversational agent, and professional characteristics of the conversational agent. Extracted data were summarized using descriptive statistics. Results are presented in a narrative summary and accompanying tables. RESULTS: A total of 38 health-related conversational agents were identified across 41 reports. Six of these conversational agents (15.8%) had professional characteristics. Four conversational agents (10.5%) had a professional appearance in which they displayed the clothing and accessories of health professionals and appeared in professional settings. One conversational agent (2.6%) had a professional title (Dr), and 4 conversational agents (10.5%) were described as having professional roles. Professional characteristics were more common among embodied vs disembodied conversational agents. CONCLUSIONS: The results of this review show that the depiction of conversational agents as health professionals is not particularly common, although it does occur. More discussion is needed on the potential ethical and legal issues surrounding the depiction of conversational agents as health professionals. Future research should examine the impact of these depictions, as well as people's attitudes toward them, to better inform recommendations for practice.

Patient navigation programs for people with dementia, their caregivers, and members of the care team: a scoping review.

OBJECTIVE: The main objective of this review was to map the literature on the characteristics of patient navigation programs for people with dementia, their caregivers, and members of the care team across all settings. The secondary objective was to map the literature on the barriers and facilitators for implementing and delivering such patient navigation programs. INTRODUCTION: People with dementia have individualized needs that change according to the stage of their condition. They often face fragmented and uncoordinated care when seeking support to address these needs. Patient navigation may be one way to help people with dementia access better care. Patient navigation is a model of care that aims to guide people through the health care system, matching their unmet needs to appropriate resources, services, and programs. Organizing the available information on this topic will present a clearer picture of how patient navigation programs work. INCLUSION CRITERIA: This review focused on the characteristics of patient navigation programs for people living with dementia, their caregivers, and the members of the care team. It excluded programs not explicitly focused on dementia. It included patient navigation across all settings, delivered in all formats, and administered by all types of navigators if the programs aligned with this review's definition of patient navigation. This review excluded case management programs. METHODS: This review was conducted in accordance with JBI methodology for scoping reviews. MEDLINE, CINAHL, APA PsycINFO, Embase, and ProQuest Nursing and Allied Health databases were searched for published full-text articles. A gray literature search was also conducted. Two independent reviewers screened articles for relevance against the inclusion criteria. The results are presented in a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram, and the extracted data are presented narratively and in tabular format. RESULTS: Thirty-nine articles describing 20 programs were included in this review. The majority of these articles were published between 2015 and 2020, and based out of the United States. The types of sources included randomized controlled trials, quasi-experimental studies, and qualitative exploratory studies, among others. All programs provided some form of referral or linkage to other services or resources. Most dementia navigation programs included an interdisciplinary team, and most programs were community-based. There was no consistent patient navigator title or standard delivery method. Commonly reported barriers to implementing and delivering these programs were navigator burnout and a lack of coordination between stakeholders. Commonly reported facilitators were collaboration, communication, and formal partnerships between key stakeholders, as well as accessible and flexible program delivery models. CONCLUSIONS: This review demonstrates variety and flexibility in the types of services patient navigation programs provided, as well as in the modes of service delivery and in navigator title. This information may be useful for individuals and organizations looking to implement their own programs in the future. It also provides a framework for future systematic reviews that seek to evaluate the effectiveness or efficacy of dementia navigation programs.

Hospital-based patient navigation programmes for patients who experience injury-related trauma and their caregivers: a scoping review protocol.

INTRODUCTION: Patients who experience injury-related trauma tend to have complex care needs and often require support from many different care providers. Many patients experience gaps in care while in the hospital and during transitions in care. Providing access to integrated care can improve outcomes for these patients. Patient navigation is one approach to improving the integration of care and proactively supporting patients and their caregivers as they navigate the healthcare system. The objective of this scoping review is to map the literature on the characteristics and impact of hospital-based patient navigation programmes that support patients who experience injury-related trauma and their caregivers. METHODS AND ANALYSIS: This review will be conducted in accordance with Joanna Briggs Institute methodology for scoping reviews. The review will include primary research studies, unpublished studies and evaluation reports related to patient navigation programmes for injury-related trauma in hospital settings. The databases to be searched will include CINAHL (EBSCO), EMBASE (Elsevier), ProQuest Nursing & Allied Health, PsycINFO (EBSCO) and MEDLINE (Ovid). Two independent reviewers will screen articles for relevance against the inclusion criteria. Results will be presented in a Preferred Reporting Items for Systematic Reviews and Meta-analyses for Scoping Reviews (PRISMA-ScR) flow diagram and follow the PRISMA-ScR checklist. The extracted data will be presented both tabularly and narratively. ETHICS AND DISSEMINATION: Ethics approval is not required, as the scoping review will synthesise information from publicly available material. To disseminate the findings of this review, the authors will submit the results for publication in a medical or health sciences journal, present at relevant conferences and use other knowledge translation strategies to reach diverse stakeholders (eg, host webinars, share infographics).

An Attachment Perspective on Favorite Media Figures.

Anxiously attached individuals tend to report stronger parasocial relationships with their favorite media figures than people with other attachment orientations. Researchers have suggested that these individuals may be inclined to see their favorite media figures as safe and secure attachment figures. The purpose of the current study was to evaluate this possibility by assessing the qualities of people's favorite media figures, particularly within a television context. A sample of 200 online participants filled out an attachment measure, reported their favorite television figure, and rated several aspects of the television figure's personality. It was expected that anxiously attached individuals would be drawn to figures that are high in warmth, emotional stability, and sensitivity. Instead, results showed that these individuals preferred figures with greater anxious and insecure characteristics. These results suggest that anxiously attached individuals may not see their favorite media figures as safe and secure attachment figures as previously theorized. Exploratory analyses failed to show significant effects for the second attachment dimension, attachment avoidance, or for the interaction between anxiety and avoidance.

Professional representation of conversational agents for health care: a scoping review protocol.

OBJECTIVE: The purpose of this scoping review is to examine the professional representation of conversational agents that are used for health care. Professional characteristics associated with these agents will be identified, and the prevalence of these characteristics will be determined. INTRODUCTION: Conversational agents that are used for health care lack the qualifications and capabilities of real health professionals, but this fact may not be clear to some patients and health seekers. This problem may be exacerbated when conversational agents are described as health professionals or are given professional titles or appearances. To date, the professional representation of conversational agents that are used for health care has received little attention in the literature. INCLUSION CRITERIA: This review will include scholarly publications on conversational agents that are used for health care, particularly descriptive/developmental case studies and intervention/evaluation studies. This review will consider conversational agents designed for patients and health seekers, but not health professionals or trainees. Agents addressing physical and/or mental health will be considered. METHODS: This review will be conducted in accordance with JBI methodology for scoping reviews. The databases to be searched will include MEDLINE (PubMed), Embase (Elsevier), CINAHL with Full Text (EBSCO), Scopus (Elsevier), Web of Science (Clarivate), ACM Guide to Computing Literature (ACM Digital Library), and IEEE Xplore (IEEE). The extracted data will include study characteristics, basic characteristics of the conversational agent, and characteristics relating to the professional representation of the conversational agent. The extracted data will be presented in tabular format and summarized using frequency analysis. These results will be accompanied by a narrative summary.

Patient navigation programs for people with dementia, their caregivers, and members of their care team: a scoping review protocol.

OBJECTIVE: The objective of this review is to map the literature on the characteristics, barriers, and faciliators of patient navigation programs for people with dementia, their caregivers, and/or members of their care team across all settings. INTRODUCTION: Patient navigation refers to a model of care that helps guide people through the health care system, matching their unmet needs to appropriate resources, services, and programs. Patient navigation may be beneficial to people with dementia because this is a population that frequently faces fragmented and uncoordinated care and has individualized care needs. INCLUSION CRITERIA: This review will focus on patient navigation programs for people living with dementia, their caregivers, and/or members of their care team, while excluding programs that do not explicitly focus on dementia. It will include patient navigation across all settings, delivered in all formats, and administered by all types of navigators, as long as the program is aligned with this article's definition of patient navigation, while excluding case management. METHODS: This review will be conducted in accordance with JBI methodology for scoping reviews. The MEDLINE, CINAHL, PsycINFO, Embase, and ProQuest Nursing and Allied Health databases will be searched for published articles. Two independent reviewers will screen articles for relevance against the inclusion criteria. The results will be presented in a Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews flow diagram, and the extracted data will be presented in both tabular and narrative format.

Canadian guidelines on the management of colorectal peritoneal metastases.

Modern management of colorectal cancer (crc) with peritoneal metastasis (pm) is based on a combination of cytoreductive surgery (crs), systemic chemotherapy, and hyperthermic intraperitoneal chemotherapy (hipec). Although the role of hipec has recently been questioned with respect to results from the prodige 7 trial, the role and benefit of a complete crs were confirmed, as observed with a 41-month gain in median survival in that study, and 15% of patients remaining disease-free at 5 years. Still, crc with pm is associated with a poor prognosis, and good patient selection is essential. Many questions about the optimal management approach for such patients remain, but all patients with pm from crc should be referred to, or discussed with, a pm surgical oncologist, because cure is possible. The objective of the present guideline is to offer a practical approach to the management of pm from crc and to reflect on the new practice standards set by recent publications on the topic.

Tyrosine kinase inhibitors significantly improved survival outcomes in patients with metastatic gastrointestinal stromal tumour: a multi-institutional cohort study.

Background: The real-world impact of tyrosine kinase inhibitors (tkis) in clinical practice for gastrointestinal stromal tumour (gist) has not been extensively reported. We sought to assess how outcomes have changed over the eras and to evaluate the effect of access to imatinib and sunitinib on survival in patients with unresectable or metastatic gist in British Columbia. Methods: Patients with metastatic or unresectable gist were allocated to one of three eras: pre-2002, 2002-2007, and post-2007 based on treatment availability (pre-imatinib, post-imatinib, and post-sunitinib). Overall survival (os) and progression-free survival (pfs) were compared between eras. Univariate and multivariate analyses were performed to determine the effects of tumour, patient, and treatment characteristics on survival outcomes. Results: Of 657 patients diagnosed with gist throughout British Columbia during 1996-2016, 196 had metastatic disease: 23 in the pre-imatinib era, 67 in the post-imatinib era, and 106 in the post-sunitinib era. A significant increase in os, by 53.6 months (p = 0.0007), and pfs, by 29.1 months (p = 0.044), was observed after the introduction of imatinib. The introduction of sunitinib did not significantly affect os or pfs. Conclusions: Implementation of tkis has drastically improved survival outcomes for patients with metastatic gist by up to 4.55 years in the real-world setting. Our study demonstrates that implementation of tkis in clinical practice has outperformed their benefit predicted in clinical trials.

A physiological assessment of patient pain during surgery with wide-awake local anesthesia.

PURPOSE: Patients receiving surgery with wide-awake local anesthesia typically report little or no intraoperative pain. However, self-report assessments of pain are susceptible to bias. In the present study, patient self-report ratings were supplemented with objective physiological measures of electrodermal activity. METHODS: Fifteen patients receiving forefoot surgery using wide-awake local anesthesia were recruited. Pain ratings and skin conductance responses were acquired during the initial anesthetic injection (into unanesthetized tissue), during a follow-up anesthetic injection (into anesthetized tissue), and during five intraoperative procedures. RESULTS: The highest ratings of self-reported pain coincided with the initial anesthetic injection, and pain ratings were similarly low at all remaining measurement points. Fourteen patients reported no pain beyond the initial injection, whereas one patient reported minimal pain during two intraoperative procedures. Skin conductance data were consistent with pain ratings such that responses to the initial injection were significantly larger than responses at any subsequent measurement point. CONCLUSION: These results provide further evidence that patients experience little or no pain during surgery with wide-awake local anesthesia.

Qualitative aspects of patient pain during surgery with wide-awake local anesthesia.

PURPOSE: Studies assessing intraoperative pain during surgery with wide-awake local anesthesia typically use a unidimensional pain scale, which provides a limited view of the pain experience. The present paper describes two studies that assessed qualitative aspects of intraoperative pain using a multidimensional pain measure. METHODS: The first study was a retrospective survey of 24 patients who received a variety of foot and ankle procedures under wide-awake local anesthesia. Patients completed a copy of the Short-Form McGill Pain Questionnaire (SF-MPQ) through the mail an average of six months following surgery. The second study was a prospective assessment of 40 patients receiving forefoot procedures under the same anesthesia. Patients completed a copy of the SF-MPQ directly after the surgery. RESULTS: Patients in the first study selected an average of 1.17 pain descriptors (SD = 3.02) on the SF-MPQ, whereas patients in the second study selected an average of 1.90 pain descriptors (SD = 1.82). In general, both studies found that sensory descriptors of pain (e.g., sharp, shooting, tender) were more common than affective descriptors. However, mean intensity ratings were low for all descriptors. CONCLUSION: The results of these studies provide a more comprehensive understanding of the patient experience during surgery with wide-awake local anesthesia.

A prospective comparison of wide-awake local anesthesia and general anesthesia for forefoot surgery.

BACKGROUND: A recent case series suggested that surgery with wide-awake local anesthesia is tolerated well by most foot and ankle patients. However, patients were assessed retrospectively and there was no comparison group to show the relative efficacy of this approach. The present study was conducted to address these concerns. METHODS: Perioperative pain and anxiety were assessed in 40 patients receiving forefoot surgery using either wide-awake local anesthesia or general anesthesia. Ratings were collected on the day of surgery using 11-point (0-10) numerical rating scales. RESULTS: Patients in the two anesthesia groups reported no differences in preoperative pain (p=0.500) or anxiety (p=0.820). Patients who received wide-awake local anesthesia reported lower levels of postoperative pain (p<0.001) and anxiety (p<0.001) than patients who received general anesthesia. They also reported little pain (M=0.17, SD=0.32) or anxiety (M=1.33, SD=1.74) during the operation. CONCLUSIONS: Results indicate that surgery with wide-awake local anesthesia is tolerated well by most patients, and that it may have some benefit compared to surgery with general anesthesia.

Wide-awake foot and ankle surgery: A retrospective analysis.

BACKGROUND: The "wide-awake" approach to foot and ankle surgery is characterized by a surgeon-administered mixture of local anesthetic and epinephrine. No tourniquet, sedation, or general anesthesia are required for surgery. This paper describes a retrospective survey of the initial patients to undergo wide-awake foot and ankle surgery at our center. METHODS: Thirty former wide-awake patients were surveyed about their perioperative anxiety, pain, and satisfaction. RESULTS: Twenty-seven of 30 patients (90%) completed the survey. Patients received a variety of forefoot, hindfoot, and lower leg procedures. In general, they reported a decrease in anxiety over the course of the perioperative period (p=0.005). Pain fell from the preoperative to the intraoperative period, then rose to preoperative levels during recovery (p<0.001). Most patients said that the surgery was better than expected (83%); would choose wide-awake surgery for a subsequent procedure (87%); and would recommend wide-awake surgery to someone who required surgery (88%). CONCLUSIONS: Results indicate that the wide-awake approach to foot and ankle surgery causes little discomfort to patients who receive many common procedures. The removal of hindfoot hardware under local anesthesia is contraindicated.

Histologic and Immunohistochemical Characterization of Pheochromocytomas in 20 Clouded Leopards ( Neofelis nebulosa).

Clouded leopards in North American zoological institutions have a high frequency of pheochromocytomas and were identified in 32 of 70 (45%) animals necropsied. Archival sections of adrenal gland from 20 adult clouded leopards with unilateral or bilateral pheochromocytomas collected between 1984 and 2011 were examined by light microscopy and immunohistochemistry, and case demographics were reviewed. Affected leopards were older than 10 years of age (mean, 16 years; range, 11-19 years), and males were overrepresented (12 males, 8 females). Pedigree analysis yielded no evidence for heritability. Five clouded leopards had bilateral neoplasms. Pheochromocytoma was the cause of death due to invasion of the caudal vena cava and fatal hemorrhage in 4 cases. Most pheochromocytomas were well-demarcated, nodular, and expansile masses composed of cords and packets of neoplastic polygonal cells. Five pheochromocytomas had vascular invasion, of which 4 resulted in hemorrhage that was the cause of death. One of the latter pheochromocytomas also had pulmonary metastasis. Ultrastructurally, neoplastic cells had cytoplasmic structures consistent with both norepinephrine- and epinephrine-containing granules. In all cases, neoplasms were immunohistochemically positive for chromogranin A, protein gene product 9.5, and synaptophysin. A subset of neoplasms evaluated by tissue microarray were positive for met-enkephalin and ß-endorphin and negative for melan-A. Histologically, 7 of 20 (35%) clouded leopards with pheochromocytomas had retinal detachment, retinal degeneration, or intramyocardial muscular arteriosclerosis, suggestive of hypertension. Pheochromocytomas can cause mortality and may be a source of clinically significant hypertension in clouded leopards. These neoplasms share similar histologic, immunohistochemical, and ultrastructural characteristics with those of other species.

Temperature effects on polygraph detection of concealed information.

Thermoregulatory influences on electrodermal and cardiovascular activity may interfere with the detection of concealed information using a polygraph. This possibility was assessed by means of a mock terrorism scenario. Seventy-two participants were assigned to either a guilty or an innocent role. They were given a polygraph test at one of three ambient temperatures: 10°C, 22°C, or 34°C. Among guilty participants, electrodermal and cardiovascular measures were least effective at 10°C. Electrodermal results were optimal at 22°C, whereas cardiovascular results were optimal at 34°C. Among innocent participants, the effectiveness of these same measures was not affected by ambient temperature. Temperature had no significant impact on respiration results within the guilty or the innocent groups. Taken together, these findings have implications for those who use polygraphs in uncontrolled testing environments.

Cognitive and emotional reactions to questions in the Comparison Question Test.

The effect of situational factors on perceptions of items on the polygraph Comparison Question Test (CQT) was assessed. In an initial experiment, 86 students (30 men, 56 women; M age = 20.3 yr., SD = 4.0) imagined one of eight scenarios that varied by guilt or innocence, the commission of a real crime or mock crime, and interrogation by a police officer or a professor. They then rated generic CQT questions for importance and emotional concern. All participants rated crime-relevant questions as being more important than past-crime comparison questions. "Guilty" participants also rated these questions as being more emotionally concerning, but "innocent" participants showed no differences in their ratings of concern for the two question types. Interrogator or crime type did not affect the general pattern of responding. A second experiment involving 80 students (21 men, 58 women, 1 non-specified; M age = 22.5 yr., SD = 7.3) replaced the generic CQT questions with content-specific questions developed by the participant. Those imagining guilt showed no differencesin their ratings of relevant and comparison questions, whereas those imagining innocence rated comparison questions as more concerning. Again, interrogator type and crime type had little effect on results. Overall these findings indicated distinctions in cognitive and emotional appraisal for CQT questions, with the nature of emotional concern dependent on guilt/innocence status and the personal relevance of comparison questions. Evidence suggests that the CQT is robust to other situational factors, such as crime type and interrogator type.

Myxoma virus induces apoptosis in cultured feline carcinoma cells.

There is growing interest in utilizing replicating oncolytic viruses as cancer therapeutics agents. The effectiveness of myxoma virus-induced oncolysis was evaluated in two feline cancer cell cultures. Although myxoma virus is a rabbit-specific pathogen, protein expression driven by myxoma virus and production of infectious viral particles were detected. Cell death occurred in primary feline cancer cells within 48 h of inoculation with myxoma virus. Future studies to determine if other feline neoplasms are susceptible to myxoma virus infection are warranted.

Effects of ophthalmic disease on concentrations of plasma fibrinogen and serum amyloid A in the horse.

REASONS FOR PERFORMING STUDY: There is little scientific information available about the ability of ocular disease to cause a systemic inflammatory response. Horses are frequently affected with ocular disease and ensuring their systemic health prior to performing vision saving surgery under anaesthesia is essential for the successful treatment of ophthalmic disease. HYPOTHESIS: Ocular disease will cause elevations in the concentration of the acute phase proteins fibrinogen and serum amyloid A in peripheral blood. METHODS: Whole blood and serum samples were obtained from 38 mature horses with ulcerative keratitis or uveitis and no evidence of systemic disease, 9 mature horses with no evidence of ocular or systemic disease (negative controls) and 10 mature horses with systemic inflammatory disease and no evidence of ocular disease (positive controls). Blood samples were assayed for concentrations of the acute phase proteins fibrinogen and serum amyloid A. RESULTS: Fibrinogen and serum amyloid A were significantly different in the positive control group compared to the negative control, corneal disease and uveitis groups (P<0.126). There was no significant difference between the negative control, corneal disease and uveitis groups (P<0.001). CONCLUSIONS: Ulcerative keratitis and anterior uveitis are not associated with elevated concentrations of the acute phase proteins fibrinogen and serum amyloid A in peripheral blood. POTENTIAL RELEVANCE: When the clinician is presented with a patient with ocular disease and elevated plasma fibrinogen or serum amyloid A concentrations, a nonocular inflammatory focus should be suspected.

Distance decay of similarity among parasite communities of three marine invertebrate hosts.

The similarity in species composition between two communities generally decays as a function of increasing distance between them. Parasite communities in vertebrate definitive hosts follow this pattern but the respective relationship in intermediate invertebrate hosts of parasites with complex life cycles is unknown. In intermediate hosts, parasite communities are affected not only by the varying vagility of their definitive hosts (dispersing infective propagules) but also by the necessary coincidence of all their hosts in environmentally suitable localities. As intermediate hosts often hardly move they do not contribute to parasite dispersal. Hence, their parasite assemblages may decrease faster in similarity with increasing distance than those in highly mobile vertebrate definitive hosts. We use published field survey data to investigate distance decay of similarity in trematode communities from three prominent coastal molluscs of the Eastern North-Atlantic: the gastropods Littorina littorea and Hydrobia ulvae, and the bivalve Cerastoderma edule. We found that the similarity of trematode communities in all three hosts decayed with distance, independently of local sampling effort, and whether or not the parasites used the mollusc as first or second intermediate host in their life cycle. In H. ulvae, the halving distance (i.e. the distance that halves the similarity from its initial similarity at 1 km distance) for the trematode species using birds as definitive hosts was approximately two to three times larger than for species using fish. The initial similarities (estimated at 1 km distance) among trematode communities were relatively higher, whereas mean halving distances were lower, compared to published values for parasite communities in vertebrate hosts. We conclude that the vagility of definitive hosts accounts for a high similarity at the local scale, while the strong decay of similarity across regions is a consequence of the low probability that all necessary hosts and suitable environmental conditions coincide on a large scale.