Protective efficacy of short-term infection with Necator americanus hookworm larvae in healthy volunteers in the Netherlands: a single-centre, placebo-controlled, randomised, controlled, phase 1 trial.

BACKGROUND: Vaccine development against hookworm is hampered by the absence of the development of protective immunity in populations repeatedly exposed to hookworm, limiting identification of mechanisms of protective immunity and new vaccine targets. Immunisation with attenuated larvae has proven effective in dogs and partial immunity has been achieved using an irradiated larvae model in healthy volunteers. We aimed to investigate the protective efficacy of immunisation with short-term larval infection against hookworm challenge. METHODS: We did a single-centre, placebo-controlled, randomised, controlled, phase 1 trial at Leiden University Medical Center (Leiden, Netherlands). Healthy volunteers (aged 18-45 years) were recruited using advertisements on social media and in publicly accessible areas. Volunteers were randomly assigned (2:1) to receive three short-term infections with 50 infectious Necator americanus third-stage filariform larvae (50L3) or placebo. Infection was abrogated with a 3-day course of albendazole 400 mg, 2 weeks after each exposure. Subsequently all volunteers were challenged with two doses of 50L3 at a 2-week interval. The primary endpoint was egg load (geometric mean per g faeces) measured weekly between weeks 12 and 16 after first challenge, assessed in the per-protocol population, which included all randomly assigned volunteers with available data on egg counts at week 12-16 after challenge. This study is registered with ClinicalTrials.gov, NCT03702530. FINDINGS: Between Nov 8 and Dec 14, 2018, 26 volunteers were screened, of whom 23 enrolled in the trial. The first immunisation was conducted on Dec 18, 2018. 23 volunteers were randomly assigned (15 to the intervention group and eight to the placebo group). Egg load after challenge was lower in the intervention group than the placebo group (geometric mean 571 eggs per g [range 372-992] vs 873 eggs per g [268-1484]); however, this difference was not statistically significant (p=0·10). Five volunteers in the intervention group developed a severe skin rash, which was associated with 40% reduction in egg counts after challenge (geometric mean 742 eggs per g [range 268-1484] vs 441 eggs per g [range 380-520] after challenge; p=0·0025) and associated with higher peak IgG1 titres. INTERPRETATION: To our knowledge, this is the first study to describe a protective effect of short-term exposure to hookworm larvae and show an association with skin response, eosinophilic response, and IgG1. These findings could inform future hookworm vaccine development. FUNDING: Dioraphte Foundation.

Combinatorial multimer staining and spectral flow cytometry facilitate quantification and characterization of polysaccharide-specific B cell immunity.

Bacterial capsular polysaccharides are important vaccine immunogens. However, the study of polysaccharide-specific immune responses has been hindered by technical restrictions. Here, we developed and validated a high-throughput method to analyse antigen-specific B cells using combinatorial staining with fluorescently-labelled capsular polysaccharide multimers. Concurrent staining of 25 cellular markers further enables the in-depth characterization of polysaccharide-specific cells. We used this assay to simultaneously analyse 14 Streptococcus pneumoniae or 5 Streptococcus agalactiae serotype-specific B cell populations. The phenotype of polysaccharide-specific B cells was associated with serotype specificity, vaccination history and donor population. For example, we observed a link between non-class switched (IgM+) memory B cells and vaccine-inefficient S. pneumoniae serotypes 1 and 3. Moreover, B cells had increased activation in donors from South Africa, which has high-incidence of S. agalactiae invasive disease, compared to Dutch donors. This assay allows for the characterization of heterogeneity in B cell immunity that may underlie immunization efficacy.

Synthesis and evaluation of 3'-[18F]fluorothymidine-5'-squaryl as a bioisostere of 3'-[18F]fluorothymidine-5'-monophosphate.

The squaryl moiety has emerged as an important phosphate bioisostere with reportedly greater cell permeability. It has been used in the synthesis of several therapeutic drug molecules including nucleoside and nucleotide analogues but is yet to be evaluated in the context of positron emission tomography (PET) imaging. We have designed, synthesised and evaluated 3'-[18F]fluorothymidine-5'-squaryl ([18F]SqFLT) as a bioisostere to 3'-[18F]fluorothymidine-5'-monophosphate ([18F]FLTMP) for imaging thymidylate kinase (TMPK) activity. The overall radiochemical yield (RCY) was 6.7 ± 2.5% and radiochemical purity (RCP) was >90%. Biological evaluation in vitro showed low tracer uptake (<0.3% ID mg-1) but significantly discriminated between wildtype HCT116 and CRISPR/Cas9 generated TMPK knockdown HCT116shTMPK-. Evaluation of [18F]SqFLT in HCT116 and HCT116shTMPK- xenograft mouse models showed statistically significant differences in tumour uptake, but lacked an effective tissue retention mechanism, making the radiotracer in its current form unsuitable for PET imaging of proliferation.

Genetics and Crime: Integrating New Genomic Discoveries Into Psychological Research About Antisocial Behavior.

Drawing on psychological and sociological theories of crime causation, we tested the hypothesis that genetic risk for low educational attainment (assessed via a genome-wide polygenic score) is associated with criminal offending. We further tested hypotheses of how polygenic risk relates to the development of antisocial behavior from childhood through adulthood. Across the Dunedin and Environmental Risk (E-Risk) birth cohorts of individuals growing up 20 years and 20,000 kilometers apart, education polygenic scores predicted risk of a criminal record with modest effects. Polygenic risk manifested during primary schooling in lower cognitive abilities, lower self-control, academic difficulties, and truancy, and it was associated with a life-course-persistent pattern of antisocial behavior that onsets in childhood and persists into adulthood. Crime is central in the nature-nurture debate, and findings reported here demonstrate how molecular-genetic discoveries can be incorporated into established theories of antisocial behavior. They also suggest that improving school experiences might prevent genetic influences on crime from unfolding.

Hormonal Smartphone Diagnostics.

Mobile point-of-care diagnostics are paramount for the provision of healthcare. Hormonal diagnostics are powerful tools to monitor timely changes in human physiology. Hormone concentrations in serum directly correlate with urine excretions with minor time delays. Therefore, rapid tests for hormones in urine have been widely used for decades as means of early diagnostics, particularly in lateral flow immunoassay formats. However, the challenge of reading and interpreting these binary tests remains. Here we present a method for utilizing mobile technologies to quantitatively read and interpret hormonal test strips. The method demonstrates the detection of a urinary by-product of progesterone, pregnanediol glucuronide (PdG), and its relation to ovulation and the fertility cycle.

Comparison of Immune Responses in Pigs Infected with Chinese Highly Pathogenic PRRS Virus Strain HV and North American Strain NADC-20.

INTRODUCTION: Chinese HP-PRRSV characterized by high morbidity and mortality of all ages of pigs emerged since 2006 in China. The immune response of HP-PRRSV was never compared with conventional low pathogenic PRRSV strain. OBJECTIVE: In this study, we compared the immune responses elicited by a Chinese HP-PRRSV strain HV and a North American RRSV strain NADC20 infections. RESULT: Pigs infected with NADC-20 showed significantly higher Ab titers than HV-PRRSV infected pigs at 9 DPI. Infection with HV-PRRSV induced a significantly higher levels of TNF-α and IL-10 in both sera and lung tissues and higher IFN-α and IFN-γ in the serum. Flow cytometry analysis showed that HV-PRRSV infected pigs generated significantly higher frequencies of NK cells in the peripheral blood and Th/memory, CTLs, and T-reg cells in the lung as compared with NADC-20 infected pigs. CONCLUSION: This study demonstrates that different immunity profiles were elicited by HV-PRRSV and NADC-20, and these differences may contribute to the distinct pathogenesis of HV-PRRSV and NADC-20.

Characterization of a novel oil-in-water emulsion adjuvant for swine influenza virus and Mycoplasma hyopneumoniae vaccines.

Vaccines consisting of subunit or inactivated bacteria/virus and potent adjuvants are widely used to control and prevent infectious diseases. Because inactivated and subunit antigens are often less antigenic than live microbes, a growing need exists for the development of new and improved vaccine adjuvants that can elicit rapid and long-lasting immunity. Here we describe the development and characterization of a novel oil-in-water emulsion, OW-14. OW-14 contains low-cost plant-based emulsifiers and was added to antigen at a ratio of 1:3 with simple hand mixing. OW-14 was stable for prolonged periods of time at temperatures ranging from 4 to 40°C and could be sterilized by autoclaving. Our results showed that OW-14 adjuvanted inactivated swine influenza viruses (SIV; H3N2 and H1N1) and Mycoplasma hyopneumoniae (M. hyo) vaccines could be safely administered to piglets in two doses, three weeks apart. Injection sites were monitored and no adverse reactions were observed. Vaccinated pigs developed high and prolonged antibody titers to both SIV and M. hyo. Interestingly, antibody titers were either comparable or greater than those produced by commercially available FluSure (SIV) or RespiSure (M. hyo) vaccines. We also found that OW-14 can induce high antibody responses in pigs that were vaccinated with a decreased antigen dose. This study provides direct evidence that we have developed an easy-to-use and low-cost emulsion that can act as a powerful adjuvant in two common types of swine vaccines.

Post-traumatic syringomyelia refractory to surgical intervention: a series of cases on recurrent syringomyelia.

OBJECTIVE: The objective of this study was to analyze a series of traumatic spinal cord injury (SCI) patients with a diagnosis of syrinx who had recurrence of symptomatic syrinx following surgical intervention. DESIGN: This is a patient series. SETTING: The study was conducted in an acute inpatient rehabilitation facility. PARTICIPANTS: Participants included patients (N=6) with post-traumatic syringomyelia (PTS) who had recurrent syrinx despite surgical repair. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The main outcome measures were time period between injury and clinical manifestations of syringomyelia, time to recurrence and presenting symptoms. RESULTS: Among the six patients, there is great variability between time of the initial SCI and the development of syrinx. In terms of time periods between diagnosis of syrinx and recurrence of syrinx, there is also some variability (ranging from 6 to 936 weeks). The median length of time to recurrence was 104 weeks. In all cases, the presenting symptom was ultimately weakness, and in most cases it was associated with rising sensory deficits. Notably, all patients were male, aged 31-55 years, had suffered diffuse traumatic SCI and four of six patients lost the ability to ambulate because of syrinx formation. CONCLUSIONS: This series suggests that there may be risk factors for developing post-traumatic syringomyelia. We question whether there is a relationship between American Spinal Injury Association Impairment Scale grade and recurrence of PTS. We need to look closely at these patients to see whether there are modifiable risk factors that may minimize their chance of developing PTS. Once these are identified, there may be a role in routine screening of all patients and particularly those who may be at an increased risk for PTS to avoid loss of ambulatory function.

Comparison of host immune responses to homologous and heterologous type II porcine reproductive and respiratory syndrome virus (PRRSV) challenge in vaccinated and unvaccinated pigs.

Porcine reproductive and respiratory syndrome (PRRS) is a high-consequence animal disease with current vaccines providing limited protection from infection due to the high degree of genetic variation of field PRRS virus. Therefore, understanding host immune responses elicited by different PRRSV strains will facilitate the development of more effective vaccines. Using IngelVac modified live PRRSV vaccine (MLV), its parental strain VR-2332, and the heterologous KS-06-72109 strain (a Kansas isolate of PRRSV), we compared immune responses induced by vaccination and/or PRRSV infection. Our results showed that MLV can provide complete protection from homologous virus (VR-2332) and partial protection from heterologous (KS-06) challenge. The protection was associated with the levels of PRRSV neutralizing antibodies at the time of challenge, with vaccinated pigs having higher titers to VR-2332 compared to KS-06 strain. Challenge strain did not alter the cytokine expression profiles in the serum of vaccinated pigs or subpopulations of T cells. However, higher frequencies of IFN-γ-secreting PBMCs were generated from pigs challenged with heterologous PRRSV in a recall response when PBMCs were re-stimulated with PRRSV. Thus, this study indicates that serum neutralizing antibody titers are associated with PRRSV vaccination-induced protection against homologous and heterologous challenge.

Work-related health advice in primary care.

BACKGROUND: The dangers of long-term sickness absence and worklessness are well recognized. In the UK, the occupational health (OH) community was challenged to seek new partners to support health in working age people. A National Health Service OH service and Leicestershire general practice set up a pilot clinic to provide work-related health advice in primary care. AIMS: To recruit 100 patients to an OH clinic in general practice and record their demographic characteristics, diagnoses and occupational outcomes. METHODS: Pre-booked 30 min appointments for work-related health consultations in general practice were offered over 12 months. Consultations were recorded electronically and questionnaire feedback invited 3-6 months later. The main outcome was subjective reporting of benefit and workplace adjustments. RESULTS: Ninety-six patients attended OH appointments in general practice, 86 were in employment: 49 on sick leave at the time of their consultation and 10 were workless. Mental health and musculoskeletal problems accounted for the most common diagnoses. Following their consultation, 29% of patients reported workplace adjustments which were beneficial to them. None of the workless reported a return to employment. CONCLUSIONS: Patients will access work-related health advice in primary care. Extended OH consultations by general practitioners can achieve positive self-reported outcomes for patients in employment.

Comparison of restriction enzyme analysis versus pulsed-field gradient gel electrophoresis as a typing system for Torulopsis glabrata and Candida species other than C. albicans.

Candida species have recently emerged as important nosocomial pathogens. Because of the lack of a reliable system for detecting differences within the same species, little is known about the epidemiology of infection with Candida species. We describe a typing system for Torulopsis glabrata and the non-C. albicans Candida species that uses contour-clamped homogeneous electric field electrophoresis (CHEF), a version of pulsed-field gradient gel electrophoresis, and compared it with restriction enzyme analysis (REA) of genomic DNA. One hundred seventeen clinical isolates from 40 patients were evaluated. CHEF and REA were performed on each of the isolates, and the results of the two procedures were compared. The REA procedure revealed 8 different types of Candida lusitaniae, 20 of Torulopsis glabrata, 5 of Candida tropicalis, 3 of Candida parapsilosis, and 7 of Candida kefyr, whereas the CHEF method revealed 14 different types of C. lusitaniae, 16 of T. glabrata, 10 of C. tropicalis, 10 of C. parapsilosis, and 7 of C. kefyr. The CHEF technique yielded unique patterns of electrophoretic karyotypes that could be used to distinguish intraspecies variations. When compared with REA, CHEF demonstrated greater sensitivity in recognizing subtle strain-to-strain variations in most isolates and will be a useful epidemiologic tool for studying non-C. albicans Candida species and T. glabrata.

Comparison of restriction enzyme analysis and pulsed-field gradient gel electrophoresis as typing systems for Candida albicans.

Candida species are an important cause of infection in immunocompromised hosts and the leading cause of nosocomial fungal infections. Study of the epidemiology of Candida infection has been difficult because of lack of a reliable typing system. We describe a typing system utilizing contour-clamped homogeneous electric fields (CHEF), which is a modified version of pulsed-field gradient gel electrophoresis, and compared it with restriction enzyme analysis (REA) of genomic DNA. The study was done with 35 Candida albicans clinical isolates from separate patients. CHEF and REA were performed on each isolate, and the patterns were compared. The REA procedure revealed 17 strain types while the CHEF procedure was able to distinguish 23 strain types of C. albicans. The CHEF technique yields unique patterns of chromosomal bands that can be used to distinguish clinical isolates and demonstrates greater sensitivity than REA.