Short-Term Outcomes and Patient Perceptions after Paramedic Non-Transport during the COVID-19 Pandemic.

BACKGROUND: EMS frequently encounter patients who decline transport, yet there are little data to inform the safety of patient and/or paramedic-initiated assess, treat, and refer (ATR) protocols. We determined patient decision-making and short-term outcomes after non-transport by EMS during the COVID-19 pandemic. METHODS: This was a prospective, observational study of a random sample of patients evaluated and not transported by EMS from August 2020 to March 2021. From the EMS database, we randomly selected a daily sample of adult patients with disposition of ATR. We excluded patients dispositioned against medical advice (AMA) and those in police custody. Investigators contacted patients by phone to administer a standardized survey regarding decision-making, symptom progression, follow-up care, and satisfaction with non-transport decision. We also determined the proportion of patients who re-contacted 9-1-1 within 72 h, and unexpected deaths within 72 h using coroner data. Descriptive statistics were calculated. RESULTS: Of 4613 non-transported patients, 3330 (72%) patients for whom the disposition was ATR were included. Patients were 46% male with a median age of 49 (inter-quartile range (IQR) 31-67). Median vital signs measurements fell within the normal range. Investigators successfully contacted 584/3330 patients (18%). The most common reason for failure was lack of accurate phone number. The most common reasons patients reported for not going to the ED on initial encounter were: felt reassured after the paramedic assessment (151/584, 26%), medical complaint resolved (113/584, 19%), paramedic suggested transport was not required (73/584, 13%), concern for COVID-19 exposure (57/584, 10%), and initial concern was not medical (46/584, 8%). Ninety-five percent (552/584) were satisfied with the non-transport decision and 49% (284/584) had sought follow-up care. The majority (501/584, 86%) reported equal, improved, or resolved symptoms, while 80 patients (13%) reported worse symptoms, of whom (64/80, 80%) remained satisfied with the non-transport decision. Overall, there were 154 of 3330 (4.6%) 9-1-1 recontacts within 72 h. Based on coroner data, three unexpected deaths (0.09%) occurred within 72 h of the initial EMS calls. CONCLUSION: Paramedic disposition by ATR protocols resulted in a low rate of 9-1-1 recontact. Unexpected deaths were extremely rare. Patient satisfaction with the non-transport decision was high.

Using tele-ultrasound to teach medical students: A randomised control equivalence study.

Objectives: Undergraduate ultrasound education is becoming increasingly important, but its expansion is limited by time, space and the availability of trained faculty. In order to validate an alternative and more accessible teaching model, our aim was to assess whether combining teleguidance and peer-assisted learning to teach ultrasound is as effective as traditional in-person methods. Methods: Peer instructors taught 47 second-year medical students ocular ultrasound via either teleguidance or traditional in-person methods. Proficiency was assessed using a multiple-choice knowledge test and objective structured clinical examination (OSCE). Confidence, overall experience, and experience with a peer instructor were measured using a 5-point Likert scale. Two one-sided t-tests were used to measure equivalency between the two groups. The null hypothesis that the two groups were not different was rejected when P < 0.05. Results: The teleguidance group performed as well as the traditional in-person group in terms of knowledge change, confidence change, OSCE time and OSCE score (p = 0.011, p = 0.006, p = 0.005 and  = 0.004, respectively, indicating the two groups are statistically equivalent). The teleguidance group rated the experience highly overall (4.06/5), but less than the traditional group (4.47/5; P = 0.448, indicating statistical difference). Peer instruction was rated 4.35/5 overall. Conclusion: Peer-instructed teleguidance was equivalent to in-person instruction with respect to knowledge change, confidence gain and OSCE performance in basic ocular ultrasound.

Ultrasound detected increase in optic disk height to identify elevated intracranial pressure: a systematic review.

BACKGROUND: Elevated intracranial pressure (eICP) is a serious medical emergency that requires prompt identification and monitoring. The current gold standards of eICP detection require patient transportation, radiation, and can be invasive. Ocular ultrasound has emerged as a rapid, non-invasive, bedside tool to measure correlates of eICP. This systematic review seeks to explore the utility of ultrasound detected optic disc elevation (ODE) as an ultrasonographic finding of eICP and to study its sensitivity and specificity as a marker of eICP. METHODS: This systematic review followed the preferred reporting items for systematic reviews and meta-analyses guidelines. We systematically searched PubMed, EMBASE, and Cochrane Central for English articles published before April 2023; yielding 1,919 total citations. After eliminating duplicates, and screening the records, we identified 29 articles that addressed ultrasonographically detected ODE. RESULTS: The 29 articles included a total of 1249 adult and pediatric participants. In patients with papilledema, the mean ODE ranged between 0.6 mm and 1.2 mm. Proposed cutoff values for ODE ranged between 0.3 mm and 1 mm. The majority of studies reported a sensitivity between 70 and 90%, and specificity ranged from 69 to 100%, with a majority of studies reporting a specificity of 100%. CONCLUSIONS: ODE and ultrasonographic characteristics of the optic disc may aid in differentiating papilledema from other conditions. Further research on ODE elevation and its correlation with other ultrasonographic signs is warranted as a means to increase the diagnostic accuracy of ultrasound in the setting of eICP.

Evolution of male pregnancy associated with remodeling of canonical vertebrate immunity in seahorses and pipefishes.

A fundamental problem for the evolution of pregnancy, the most specialized form of parental investment among vertebrates, is the rejection of the nonself-embryo. Mammals achieve immunological tolerance by down-regulating both major histocompatibility complex pathways (MHC I and II). Although pregnancy has evolved multiple times independently among vertebrates, knowledge of associated immune system adjustments is restricted to mammals. All of them (except monotremata) display full internal pregnancy, making evolutionary reconstructions within the class mammalia meaningless. Here, we study the seahorse and pipefish family (syngnathids) that have evolved male pregnancy across a gradient from external oviparity to internal gestation. We assess how immunological tolerance is achieved by reconstruction of the immune gene repertoire in a comprehensive sample of 12 seahorse and pipefish genomes along the "male pregnancy" gradient together with expression patterns of key immune and pregnancy genes in reproductive tissues. We found that the evolution of pregnancy coincided with a modification of the adaptive immune system. Divergent genomic rearrangements of the MHC II pathway among fully pregnant species were identified in both genera of the syngnathids: The pipefishes (Syngnathus) displayed loss of several genes of the MHC II pathway while seahorses (Hippocampus) featured a highly divergent invariant chain (CD74). Our findings suggest that a trade-off between immunological tolerance and embryo rejection accompanied the evolution of unique male pregnancy. That pipefishes survive in an ocean of microbes without one arm of the adaptive immune defense suggests a high degree of immunological flexibility among vertebrates, which may advance our understanding of immune-deficiency diseases.

Blunt Trauma Abdominal and Pelvic Computed Tomography Has Low Yield for Injuries in More Than One Anatomic Region.

INTRODUCTION: Most trauma centers order abdominal and pelvic computed tomography (CT) as an automatically paired CT for adult blunt trauma evaluation. However, excessive CT utilization adds risks of excessive exposure to ionizing radiation, the need to work up incidental findings (leading to unnecessary and invasive tests), and greater costs. Examining a cohort of adult blunt trauma patients that received paired abdominal and pelvic (A/P) CT, we sought to determine the diagnostic yield of clinically significant injuries (CSI) in the following: 1) the abdomen alone; 2) the pelvis alone; 3) the lumbosacral spine alone; and 4) more than one of these anatomic regions concomitantly. METHODS: In this retrospective study, we reviewed the imaging and hospital course of a consecutive sample of blunt trauma activation patients older than 14 years of age who received paired A/P CT during their blunt trauma assessments at an urban Level I trauma center from April through October 2014. Categorization of CSI was determined according to an a priori, expert panel-derived classification scheme. RESULTS: The median age of the 689 patients who had A/P CT was 48 years old; 68.1% were male; 64.0% were admitted, and hospital mortality was 3.6%. CSI yields were as follows: abdomen 2.2% (95% confidence interval [CI] [1.3-3.6%]); pelvis 2.9% (95% CI [1.9-4.4%]); lumbosacral spine 0.6% (95% CI [0.2-1.5%]); both abdomen and pelvis 0.3% (95% CI [0.1-1.1%]); both the abdomen and lumbosacral spine 0.6% (0.2-1.5%); both the pelvis and lumbosacral spine 0.1% (0.0-0.8%); all three regions - abdomen, pelvis and lumbosacral spine - 0.1% (0.0-0.8%). CONCLUSION: Automatic pairing of A/P CT has very low diagnostic yield for CSI in both the abdomen and pelvis. These data suggest a role for selective CT imaging protocols that image these regions individually instead of automatically as a pair.

Petrous Face Meningiomas: Classification, Clinical Syndromes, and Surgical Outcomes.

BACKGROUND: Petrous face meningiomas (PFMs) are challenging tumors because of their proximity to the cranial nerves, brainstem, and critical vasculature. The objective of this study is to present surgical outcomes and support an anatomic classification for PFM based on clinical presentation. METHODS: A retrospective chart review was performed, and 51 PFMs were identified. Tumors were classified by location along the petrous face into anterior, middle, and posterior. Presentation and outcomes were analyzed with logistic regression. RESULTS: The median follow-up was 31.6 months. Tumors were World Health Organization grade I (n = 50), with 1 World Health Organization grade II tumor. Location was anterior (22%), middle (14%), posterior (53%), and overlapping (12%). Median tumor diameter was 3.0 cm (range, 0.8-6.2 cm). Anterior location was associated with facial pain/numbness on presentation (P < 0.0001), middle location with hearing loss/vestibular dysfunction (P = 0.0035), and posterior with hydrocephalus (P = 0.0190), headache (P = 0.0039), and vertigo (P = 0.0265). Extent of resection was gross total (63%), near total (14%), and subtotal (25%). The observed radiographic recurrence rate was 15%. Mean progression-free survival after diagnosis was 9.1 years with 2-year, 5-year, and 10-year progression-free survival of 91.8%, 78.6%, and 62.9%, respectively. The complication rate was 27%. Age, location, and approach were not associated with complications. CONCLUSIONS: PFMs present with distinct clinical syndromes based on their location along the petrous face: anterior with trigeminal symptoms, middle with auditory/vestibular symptoms, and posterior with symptoms of mass effect/hydrocephalous. Surgical resection is associated with excellent long-term survival and a low rate of recurrence, which can be managed with radiotherapy.

Low Yield of Clinically Significant Injury With Head-To-Pelvis Computed Tomography in Blunt Trauma Evaluation.

BACKGROUND: Many trauma centers have adopted routine head-to-pelvis computed tomography (CT) imaging for the evaluation of adults with blunt trauma. OBJECTIVE: We sought to determine the yields of detecting clinically significant injuries (CSIs) with CT in >1 anatomic region. METHODS: We conducted this observational cohort study of all trauma activation patients >14 years of age who received CT imaging during blunt trauma evaluation at a Level 1 trauma center from April to October 2014. Expert panels determined the clinical significance of head, neck, chest, abdomen, and pelvis injuries seen on CT. We calculated yields of CSI, defined as the number of patients with CSI divided by the total number of patients who underwent CT imaging. The 3 specified anatomic regions considered were head/neck, chest, and abdomen/pelvis. RESULTS: The median age of 1236 patients who had CT was 48 years; 69% were male; 51.2% were admitted; and hospital mortality was 4.4%. Yields of CSI with 95% confidence intervals (CIs) were: head/neck region injury 11.3% (9.6-13.3%); chest region injury only 7.9% (6.0-10.4%); abdomen/pelvis region injury only 5.1% (3.7-7.0%); both head/neck and chest CSI 2.8% (1.7-4.5%); both head/neck and abdomen/pelvis CSI 1.6% (0.9-2.9%); and both chest and abdomen/pelvis CSI 1.1% (0.5-2.4%). The yield of CSI in all 3 anatomic regions with head-to-pelvis CT was 0.6% (0.2-1.7%), and 76.7% (68.8-83.1%) of CSIs occurred in isolation. CONCLUSIONS: During multiple anatomic region CT imagng for adult blunt trauma evaluation, the yield for CSI in >1 region is low. In low-risk populations, selective CT imaging of anatomic regions (instead of reflexive head-to-pelvis CT imaging) may be more appropriate.

Comparative transcriptomics of stickleback immune gene responses upon infection by two helminth parasites, Diplostomum pseudospathaceum and Schistocephalus solidus.

Immune systems of vertebrates are much more diverse than previously thought, in particular at the base of the vertebrate clade. RNA-seq was used to describe in detail the transcriptomic response of stickleback hosts to infection by two helminth parasites, the trematode Diplostomum pseudospathaceum (2 genotypes plus a genotype mix) and the cestode Schistocephalus solidus. Based on a global transcription profiling, we present immune genes that are active during chronic or multiple repeated infection. We found that the transcription profiles of D. pseudospathaceum genotypes were as divergent as those of the two parasite species. When comparing the host immune response, only 5 immune genes were consistently upregulated upon infection by both species. These genes indicated a role for enhanced toll like receptor (TLR) activity (CTSK, CYP27B1) and an associated positive regulation of macrophages (CYP27B1, THBS1) for general helminth defense. We interpret the largely differentiated gene expression response among parasite species as general redundancy of the vertebrate immune system, which was also visible in genotype-specific responses among the different D. pseudospathaceum infections. The present study provides the first evidence that IL4-mediated activation of T-helper lymphocyte cells is also important in anti-helminthic immune responses of teleost fish.

Toward clinical genomics in everyday medicine: perspectives and recommendations.

Precision or personalized medicine through clinical genome and exome sequencing has been described by some as a revolution that could transform healthcare delivery, yet it is currently used in only a small fraction of patients, principally for the diagnosis of suspected Mendelian conditions and for targeting cancer treatments. Given the burden of illness in our society, it is of interest to ask how clinical genome and exome sequencing can be constructively integrated more broadly into the routine practice of medicine for the betterment of public health. In November 2014, 46 experts from academia, industry, policy and patient advocacy gathered in a conference sponsored by Illumina, Inc. to discuss this question, share viewpoints and propose recommendations. This perspective summarizes that work and identifies some of the obstacles and opportunities that must be considered in translating advances in genomics more widely into the practice of medicine.

How Generalizable Are the Results From Trials of Direct Antiviral Agents to People Coinfected With HIV/HCV in the Real World?

BACKGROUND: Direct-acting antivirals (DAAs) against hepatitis C virus (HCV) have been described as revolutionary. However, it remains uncertain how effective these drugs will be for individuals coinfected with human immunodeficiency virus (HIV)-HCV. Bridging this gap between efficacy and effectiveness requires a focus on the generalizability of clinical trials. METHODS: Generalizability of DAA trials was assessed by applying the eligibility criteria from 5 efficacy trials: NCT01479868, PHOTON-1 (NCT01667731), TURQUOISE-I (NCT01939197), ION-4 (NCT02073656), and ALLY-2 (NCT02032888) that evaluated simeprevir; sofosbuvir; ombitasvir, paritaprevir/ritonavir/dasabuvir; sofosbuvir/ledipasvir; and daclatasvir/sofosbuvir, respectively, to the Canadian Coinfection Cohort, representing approximately 23% of the total coinfected population in care in Canada. RESULTS: Of 874 active participants, 70% had chronic HCV, of whom 410, 26, 94, and 11 had genotypes 1, 2, 3, and 4, respectively. After applying trial eligibility criteria, only 5.9% (24/410) would have been eligible for enrollment in the simeprevir trial, 9.8% (52/530) in PHOTON-1, 6.3% (26/410) in TURQUOISE-I, and 8.1% (34/421) in ION-4. The ALLY-2 study was more inclusive; 43% (233/541) of the cohort would have been eligible. The most exclusive eligibility criteria across all trials with the exception of ALLY-2 were restriction to specific antiretroviral therapies (63%-79%) and active illicit drug use (53%-55%). CONCLUSIONS: DAA trial results may have limited generalizability, since the majority of coinfected individuals were not eligible to participate. Exclusions appeared to be related to improving treatment outcomes by not including those at higher risk of poor adherence and reinfection--individuals for whom real-world data are urgently needed.

Immunity comes first: the effect of parasite genotypes on adaptive immunity and immunization in three-spined sticklebacks.

Adaptive immunity in vertebrates can confer increased resistance against invading pathogens upon re-infection. But how specific parasite genotypes affect the temporal transition from innate to adaptive immunity under continual exposure to parasites is poorly understood. Here, we investigated the effects of homologous and heterologous exposures of genetically distinct parasite lineages of the eye fluke Diplostomum pseudospathaceum on gene expression patterns of adaptive immunity in sticklebacks (Gasterosteus aculeatus). Observable differences in gene expression were largely attributable to final exposures while there was no transcription pattern characteristic for a general response to repeated infections with D. pseudospathaceum. None of the final exposure treatments was able to erase the distinct expression patterns resulting from a heterologous pre-exposed fish. Interestingly, heterologous final exposures showed similarities between different treatment groups subjected to homologous pre-exposure. The observed pattern was supported by parasite infection rates and suggests that host immunization was optimized towards an adaptive immune response that favored effectiveness against parasite diversity over specificity.

Specific gene expression responses to parasite genotypes reveal redundancy of innate immunity in vertebrates.

Vertebrate innate immunity is the first line of defense against an invading pathogen and has long been assumed to be largely unspecific with respect to parasite/pathogen species. However, recent phenotypic evidence suggests that immunogenetic variation, i.e. allelic variability in genes associated with the immune system, results in host-parasite genotype-by-genotype interactions and thus specific innate immune responses. Immunogenetic variation is common in all vertebrate taxa and this reflects an effective immunological function in complex environments. However, the underlying variability in host gene expression patterns as response of innate immunity to within-species genetic diversity of macroparasites in vertebrates is unknown. We hypothesized that intra-specific variation among parasite genotypes must be reflected in host gene expression patterns. Here we used high-throughput RNA-sequencing to examine the effect of parasite genotypes on gene expression patterns of a vertebrate host, the three-spined stickleback (Gasterosteus aculeatus). By infecting naïve fish with distinct trematode genotypes of the species Diplostomum pseudospathaceum we show that gene activity of innate immunity in three-spined sticklebacks depended on the identity of an infecting macroparasite genotype. In addition to a suite of genes indicative for a general response against the trematode we also find parasite-strain specific gene expression, in particular in the complement system genes, despite similar infection rates of single clone treatments. The observed discrepancy between infection rates and gene expression indicates the presence of alternative pathways which execute similar functions. This suggests that the innate immune system can induce redundant responses specific to parasite genotypes.

High level antibody avidity is achieved in HIV-seropositive recipients of an inactivated split adjuvanted (AS03A) influenza vaccine.

PURPOSE: More severe influenza disease and poor vaccine immunogenicity is reported in HIV-infected patients. We measured antibody avidity after influenza vaccination in HIV patients to assess vaccine efficacy. METHODS: Two dosing strategies (Group1: single dose, n = 28. Group2: single dose plus booster, n = 36) with an AS03A-adjuvanted H1N12009 pandemic influenza vaccine (Arepanrix, GSK) were assessed in HIV patients. Serum hemagglutination inhibition (HAI) titers and antibody avidity reported as an avidity index (AI) were measured at days 21 and 42 and at 6 months. RESULTS: Baseline HIV parameters were similar among all participants. Eighteen participants had measurable baseline HAI titers. In these subjects, AI was at ~9 at baseline and was not significantly increased by one or two vaccine doses. In those without detectable baseline antibodies, immunization induced modest antibody titers [Group1 HAI, 61 (26-144); Group2 HAI, 46 (28-76)] with high AI after one dose at day 21 [Group1 AI, 8.8 (7.3-10.7); Group2 AI, 8.9 (7.8-10.1)]. A second dose of vaccine generated significantly higher HAI titers at day 42 [Group1 HAI, 41 (18-90); Group2 HAI, 92 (64-132)] and persisted to 6 months [Group1 HAI, 9 (6-13); Group2 HAI, 19 (13-30)]. All subjects who produced detectable HAI titers after vaccination generated high antibody avidity (AI, 9-10), which persisted up to 6 months. CONCLUSION: In participants initially seronegative, two doses of vaccine enabled a greater percentage of subjects to respond to the vaccine and elicited higher HAI titers. All subjects who produced detectable HAI titers also rapidly generated high AI in the short and long term. We demonstrate that high avidity antibodies can be achieved after vaccination and support a two-dose immunization strategy for HIV-positive subjects.

Patterns and correlates of cannabis use among individuals with HIV/AIDS in Maritime Canada.

BACKGROUND: The prevalence of cannabis use in HIV-infected individuals is high and its long-term effects are unclear. METHODS: The prevalence, perceived benefits and consequences, and predictors of cannabis use were studied using a cross-sectional survey in two immunodeficiency clinics in Maritime Canada. RESULTS: Current cannabis use was identified in 38.5% (87 of 226) of participants. Almost all cannabis users (85 of 87 [97.7%]) acknowledged its use for recreational purposes, with 21.8% (19 of 87) reporting medicinal cannabis use. The majority of patients enrolled in the present study reported mild or no symptoms related to HIV (n=179). Overall, 80.5% (70 of 87) of the cannabis-using participants reported a symptom-relieving benefit, mostly for relief of stress, anorexia or pain. Participants consumed a mean (± SD) of 18.3±21.1 g of cannabis per month and spent an average of $105.15±109.87 on cannabis per month. Cannabis use was associated with rural residence, lower income level, driving under the influence of a substance, and consumption of ecstasy and tobacco. Income level, ecstasy use and tobacco use were retained as significant predictors in regression modelling. Cannabis use was not associated with adverse psychological outcomes. DISCUSSION: Prolonged previous cannabis consumption and the substantial overlap between recreational and medicinal cannabis use highlight the challenges in obtaining a tenable definition of medicinal cannabis therapy.

HISTORIQUE: La prévalence de consommation de cannabis est élevée chez les personnes infectées par le VIH, mais on n'en connaît pas les effets à long terme. MÉTHODOLOGIE: Les chercheurs ont étudié la prévalence, les avantages perçus et les conséquences et prédicteurs de consommation de cannabis au moyen d'un sondage transversal mené dans deux cliniques d'immunodéficience des Maritimes, au Canada. RÉSULTATS: Les chercheurs ont constaté une consommation courante de cannabis chez 38,5 % des participants (87 sur 226). Presque tous les consommateurs de cannabis (85 sur 87 [97,7 %]) admettaient en prendre pour des fins récréatives, et 21,8 % (19 sur 87) indiquaient en prendre pour des fins médicinales. La majorité des patients qui participaient à la présente étude a déclaré des symptômes du VIH légers, sinon inexistants (n=179). Dans l'ensemble, 80,5 % des participants consommateurs de cannabis (70 sur 87) ont affirmé remarquer un soulagement des symptômes, particulièrement le stress, l'anorexie ou la douleur. Les participants consommaient en moyenne 18,3±21,1 g de cannabis par mois et dépensaient en moyenne 105,15±109,87 $ par mois pour se le procurer. La consommation de cannabis était liée à un logement en milieu rural, à un niveau de revenu plus bas, à la conduite sous l'influence d'une substance et à la consommation d'ecstasy et de tabac. Le niveau de revenu, la consommation d'ecstasy et la consommation de tabac étaient considérés comme des prédicteurs importants selon le modèle de régression. La consommation de cannabis ne s'associait pas à des résultats psychologiques indésirables. EXPOSÉ: Une consommation antérieure prolongée de cannabis et le chevauchement important entre la consommation de cannabis à des fins récréatives et médicinales font ressortir la difficulté d'obtenir une définition viable du traitement médicinal par le cannabis.

In vitro leukocyte response of three-spined sticklebacks (Gasterosteus aculeatus) to helminth parasite antigens.

Helminth parasites of teleost fish have evolved strategies to evade and manipulate the immune responses of their hosts. Responsiveness of fish host immunity to helminth antigens may therefore vary depending on the degree of host-parasite counter-adaptation. Generalist parasites, infective for a number of host species, might be unable to adapt optimally to the immune system of a certain host species, while specialist parasites might display high levels of adaptation to a particular host species. The degree of adaptations may further differ between sympatric and allopatric host-parasite combinations. Here, we test these hypotheses by in vitro exposure of head kidney leukocytes from three-spined sticklebacks (Gasterosteus aculeatus) to antigens from parasites with a broad fish host range (Diplostomum pseudospathaceum, Triaenophorus nodulosus), a specific fish parasite of cyprinids (Ligula intestinalis) and parasites highly specific only to a single fish species as second intermediate host (Schistocephalus pungitii, which does not infect G. aculeatus, and Schistocephalus solidus, infecting G. aculeatus). In vitro responses of stickleback leukocytes to S. solidus antigens from six European populations, with S. solidus prevalence from <1% to 66% were tested in a fully crossed experimental design. Leukocyte cultures were analysed by means of flow cytometry and a chemiluminescence assay to quantify respiratory burst activity. We detected decreasing magnitudes of in vitro responses to antigens from generalist to specialist parasites and among specialists, from parasites that do not infect G. aculeatus to a G. aculeatus-infecting species. Generalist parasites seem to maintain their ability to infect different host species at the costs of relatively higher immunogenicity compared to specialist parasites. In a comparison of sympatric and allopatric combinations of stickleback leukocytes and antigens from S. solidus, magnitudes of in vitro responses were dependent on the prevalence of the parasite in the population of origin, rather than on sympatry. Antigens from Norwegian (prevalence 30-50%) and Spanish (40-66%) S. solidus induced generally higher in vitro responses compared to S. solidus from two German (<1%) populations. Likewise, leukocytes from stickleback populations with a high S. solidus prevalence showed higher in vitro responses to S. solidus antigens compared to populations with low S. solidus prevalence. This suggests a rather low degree of local adaptation in S. solidus populations, which might be due to high gene flow among populations because of their extremely mobile final hosts, fish-eating birds.

Factors affecting antiretroviral pharmacokinetics in HIV-infected women with virologic suppression on combination antiretroviral therapy: a cross-sectional study.

BACKGROUND: Although some studies show higher antiretroviral concentrations in women compared to men, data are limited. We conducted a cross-sectional study of HIV-positive women to determine if protease inhibitor (PI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) C(min) and Cmax values were significantly different than historical general population (predominantly male) averages and to evaluate correlates of higher concentrations. METHODS: HIV-positive women with virologic suppression (viral load < 50copies/mL) on their first antiretroviral regimen were enrolled. Timed blood samples for C(min) and Cmax were drawn weekly for 3 weeks. The ratio of each individual's median C(min) and Cmax to the published population mean values for their PI or NNRTI was calculated and assessed using Wilcoxon sign-rank. Intra- and inter-patient variability of antiretroviral drug levels was assessed using coefficient of variation and intra-class correlation. Linear regression was used to identify correlates of the square root-transformed C(min) and Cmax ratios. RESULTS: Data from 82 women were analyzed. Their median age was 41 years (IQR=36-48) and duration of antiretrovirals was 20 months (IQR=9-45). Median antiretroviral C(min) and Cmax ratios were 1.21 (IQR=0.72-1.89, p=0.003) (highest ratios for nevirapine and lopinavir) and 0.82 (IQR=0.59-1.14, p=0.004), respectively. Nevirapine and efavirenz showed the least and unboosted atazanavir showed the most intra- and inter-patient variability. Higher CD4+ count correlated with higher C(min). No significant correlates for Cmax were found. CONCLUSIONS: Compared to historical control data, C(min) in the women enrolled was significantly higher whereas Cmax was significantly lower. Antiretroviral C(min) ratios were highly variable within and between participants. There were no clinically relevant correlates of drug concentrations. TRIAL REGISTRATION: NCT00433979.

Absence of major histocompatibility complex class II mediated immunity in pipefish, Syngnathus typhle: evidence from deep transcriptome sequencing.

The major histocompatibility complex (MHC)-mediated adaptive immune system is the hallmark of gnathostome immune defence. Recent work suggests that cod-like fishes (Gadidae) lack important components of the MHC class II mediated immunity. Here, we report a putative independent loss of functionality of this pathway in another species, the pipefish Syngnathus typhle, that belongs to a distantly related fish family (Syngnathidae). In a deep transcriptome sequencing approach comprising several independent normalized and non-normalized expressed sequence tag (EST) libraries with approximately 7.5 × 10(8) reads, sequenced with two next generation platforms (454 and Illumina), we were unable to identify MHC class IIα/ß genes as well as genes encoding associated receptors. Along with the recent findings in cod, our results suggest that immune systems of the Euteleosts may be more variable than previously assumed.

Genetic compatibilities, outcrossing rates and fitness consequences across life stages of the trematode Diplostomum pseudospathaceum.

Many parasitic helminths exhibit mixed mating systems, and switches between self-fertilization and outcrossing may be influenced by environmental conditions and parasite demography. While inbreeding depression selects against the development of purely self-fertilizing populations, genetic compatibility may contribute to stabilizing mixed strategies. Here we study the effects of inbreeding and genetic compatibility on offspring fitness in the digenean trematode Diplostomum pseudospathaceum, a parasite with a three-host life cycle. Hatching rates and infection success in two intermediate hosts, the freshwater snail Lymnaea stagnalis and the three-spined stickleback, Gasterosteus aculeatus, were used as proxies for parasite fitness. Single trematode clones and combinations of two and three different clones were allowed to reproduce sexually using naïve herring gulls (Larus argentatus) as definitive hosts. The hatched larvae were used to assess the proportion of selfed and outcrossed miracidia by means of microsatellite genotyping. These results were matched with hatching rates and infection success of inbred and outcrossed trematodes in both intermediate hosts. Inbreeding effects were obscured by differences in clone performance. In addition, clones outcrossed to a lesser extent than expected in some experimental pairings, indicating the importance of genetic compatibility.

High-level immunogenicity is achieved vaccine with adjuvanted pandemic H1N1(2009) and improved with booster dosing in a randomized trial of HIV-infected adults.

BACKGROUND: More severe influenza disease and poor vaccine immunogenicity in HIV-infected patients necessitate improved immunization strategies to maximize vaccine efficacy. METHODS: A phase III, randomized trial was conducted at 4 Canadian sites. Two dosing strategies (standard dose vs standard dose plus booster on day 21) were assessed in HIV patients aged 20 to 59 years during the H1N1(2009) pandemic. A single antigen, inactivated split adjuvanted (AS03(A)) influenza vaccine (Arepanrix) was utilized. Serum hemagglutination inhibition (HAI) titres were assessed at days 21 and 42 and at month 6. RESULTS: 150 participants received at least one injection. Baseline parameters were similar between groups: 83% male, 85% on HAART, median CD4 = 519 cells/mm(3), 84% with HIV RNA < 50 copies/mL. At day 21, seroprotection (HAI ≥1:40) was achieved in 80% (95% CI, 70-89) of participants. Seroconversion occurred in 74% (63-85). Seroprotection and seroconversion were further improved in those randomized to booster dosing: day 42, 94% (85-98) versus 73% (60-83) (P < .01) and 86% (75-93) versus 66% (5-77) (P = .01). Seroprotec-tion was retained in 40% (28-54) of recipients at month 6 with trends toward greater retention of immunity in booster recipients. CONCLUSION: High-level immunogenicity was achieved with a single dose of this adjuvanted vaccine. Immunogenicity was further improved with booster dosing. Use of this adjuvanted vaccine and booster represent an important approach to increasing immunogenicity in this vaccine hypo-responsive population.

Immunogenicity is not improved by increased antigen dose or booster dosing of seasonal influenza vaccine in a randomized trial of HIV infected adults.

INTRODUCTION: The risk of poor vaccine immunogenicity and more severe influenza disease in HIV necessitate strategies to improve vaccine efficacy. METHODS: A randomized, multi-centered, controlled, vaccine trial with three parallel groups was conducted at 12 CIHR Canadian HIV Trials Network sites. Three dosing strategies were used in HIV infected adults (18 to 60 years): two standard doses over 28 days, two double doses over 28 days and a single standard dose of influenza vaccine, administered prior to the 2008 influenza season. A trivalent killed split non-adjuvanted influenza vaccine (Fluviral™) was used. Serum hemagglutinin inhibition (HAI) activity for the three influenza strains in the vaccine was measured to assess immunogenicity. RESULTS: 297 of 298 participants received at least one injection. Baseline CD4 (median 470 cells/µL) and HIV RNA (76% of patients with viral load <50 copies/mL) were similar between groups. 89% were on HAART. The overall immunogenicity of influenza vaccine across time points and the three influenza strains assessed was poor (Range HAI ≥ 40 =  31-58%). Double dose plus double dose booster slightly increased the proportion achieving HAI titre doubling from baseline for A/Brisbane and B/Florida at weeks 4, 8 and 20 compared to standard vaccine dose. Increased immunogenicity with increased antigen dose and booster dosing was most apparent in participants with unsuppressed HIV RNA at baseline. None of 8 serious adverse events were thought to be immunization-related. CONCLUSION: Even with increased antigen dose and booster dosing, non-adjuvanted influenza vaccine immunogenicity is poor in HIV infected individuals. Alternative influenza vaccines are required in this hyporesponsive population. TRIAL REGISTRATION: ClinicalTrials.gov NCT00764998.