Core protocol for the adaptive Platform Trial In COVID-19 Vaccine priming and BOOsting (PICOBOO)

BACKGROUND

The need for coronavirus 2019 (COVID-19) vaccination in different age groups and populations is a subject of great uncertainty and an ongoing global debate. Critical knowledge gaps regarding COVID-19 vaccination include the duration of protection offered by different priming and booster vaccination regimens in different populations, including homologous or heterologous schedules; how vaccination impacts key elements of the immune system; how this is modified by prior or subsequent exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and future variants; and how immune responses correlate with protection against infection and disease, including antibodies and effector and T cell central memory.

METHODS

The Platform Trial In COVID-19 priming and BOOsting (PICOBOO) is a multi-site, multi-arm, Bayesian, adaptive, randomised controlled platform trial. PICOBOO will expeditiously generate and translate high-quality evidence of the immunogenicity, reactogenicity and cross-protection of different COVID-19 priming and booster vaccination strategies against SARS-CoV-2 and its variants/subvariants, specific to the Australian context. While the platform is designed to be vaccine agnostic, participants will be randomised to one of three vaccines at trial commencement, including Pfizer's Comirnaty, Moderna's Spikevax or Novavax's Nuvaxovid COVID-19 vaccine. The protocol structure specifying PICOBOO is modular and hierarchical. Here, we describe the Core Protocol, which outlines the trial processes applicable to all study participants included in the platform trial.

DISCUSSION

PICOBOO is the first adaptive platform trial evaluating different COVID-19 priming and booster vaccination strategies in Australia, and one of the few established internationally, that is designed to generate high-quality evidence to inform immunisation practice and policy. The modular, hierarchical protocol structure is intended to standardise outcomes, endpoints, data collection and other study processes for nested substudies included in the trial platform and to minimise duplication. It is anticipated that this flexible trial structure will enable investigators to respond with agility to new research questions as they arise, such as the utility of new vaccines (such as bivalent, or SARS-CoV-2 variant-specific vaccines) as they become available for use.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry ACTRN12622000238774. Registered on 10 February 2022.

Immunocompromised children and young people are at no increased risk of severe COVID-19

OBJECTIVES

We aimed to prospectively describe the incidence and clinical spectrum of SARS-CoV-2 infection in immunocompromised paediatric patients in the UK.

METHODS

From March 2020 to 2021 weekly questionnaires were sent to immunocompromised paediatric patients or their parents. Information, including symptom presentation and SARS-CoV-2 PCR test results, was collected from 1527 participants from 46 hospitals. Cross-sectional serology was investigated in February and March 2021.

RESULTS

Until the end of September 2020, no cases were reported. From September 28th 2020 to March 2021 a total of 38 PCR-detected SARS-CoV-2 infections were reported. Of these, four children were admitted to hospital but none had acute severe COVID-19. Increasing age in association with immunodeficiency increased reporting of SARS-CoV-2 infection. Worsening of fever, cough, and sore throat were associated with participants reporting SARS-CoV-2 infection. Serology data included 452 unvaccinated participants. In those reporting prior positive SARS-CoV-2 PCR, there were detectable antibodies in 9 of 18 (50%). In those with no prior report of infection, antibodies were detected in 32 of 434 (7•4%).

CONCLUSIONS

This study shows SARS-CoV-2 infections have occurred in immunocompromised children and young people with no increased risk of severe disease. No children died.

Improving paediatric antimicrobial stewardship in hospital-based settings: why, where and how?

Background

Antimicrobial resistance (AMR) is being recognized as a priority by healthcare organizations across the world. However, many children are managed on IV antimicrobials in hospital with very little consideration of antimicrobial stewardship issues.

Objectives

A nurse-led paediatric ambulatory outpatient parenteral antimicrobial therapy (OPAT) service, managing children with common infections being ambulated on short courses of IV antimicrobials, was introduced within Southampton Children’s Hospital in January 2018. We evaluated the impact of this service in terms of the quality of antimicrobial prescribing and timing of ambulation in children presenting with common infections.

Methods

All cases managed within the service were reviewed in two separate 2 month time periods: prior to introduction of the service (September–October 2016) and then prospectively after its introduction (September–October 2018).

Results

A total of 96% of IV antibiotic management decisions at 48 h were deemed appropriate in 2018, compared with 75% in 2016. A total of 64% of patients were ambulated on IV antibiotics at some point during their treatment course in 2018, compared with 19% in 2016. However, a significant proportion of antimicrobial decisions made at the point of presentation to hospital remained suboptimal in 2018.

Conclusions

Children are commonly managed with IV antibiotics in hospital. We demonstrate marked improvements in appropriate antimicrobial use through the introduction of a nurse-led ambulatory OPAT service. In addition, such a service can promote a greater proportion of children being ambulated from hospital, freeing up valuable inpatient beds and potentially delivering cost savings that can be used to fund such services.

Clinical efficacy of a next-generation sequencing gene panel for primary immunodeficiency diagnostics

Primary immunodeficiencies (PIDs) are rare monogenic inborn errors of immunity that result in impairment of functions of the human immune system. PIDs have a broad phenotype with increased morbidity and mortality, and treatment choices are often complex. With increased accessibility of next-generation sequencing (NGS), the rate of discovery of genetic causes for PID has increased exponentially. Identification of an underlying monogenic diagnosis provides important clinical benefits for patients with the potential to alter treatments, facilitate genetic counselling, and pre-implantation diagnostics. We investigated a NGS PID panel of 242 genes within clinical care across a range of PID phenotypes. We also evaluated Phenomizer to predict causal genes from human phenotype ontology (HPO) terms. Twenty-seven participants were recruited, and a total of 15 reportable variants were identified in 48% (13/27) of the participants. The panel results had implications for treatment in 37% (10/27) of participants. Phenomizer identified the genes harbouring variants from HPO terms in 33% (9/27) of participants. This study shows the clinical efficacy that genetic testing has in the care of PID. However, it also highlights some of the disadvantages of gene panels in the rapidly moving field of PID genomics and current challenges in HPO term assignment for PID.

Co-infection as a confounder for the role of Clostridium difficile infection in children with diarrhoea: a summary of the literature

Although Clostridium difficile is a major cause of antibiotic-associated diarrhoea in adults, the incidence and severity of C. difficile infection (CDI) in children is unclear. One complicating factor in assessing the role of CDI in children is the possibility of co-infection with other gastrointestinal pathogens. In this review, we summarise the literature concerning C. difficile co-infections in young children, in an attempt to discuss the rate of co-infections and their potential role in the severity of CDI clinical presentation. We identified 31 studies where co-infections were analysed, comprising 1,718 patients with positive C. difficile tests. The pooled percentage of reported co-infections was 20.7% (range 0-100%). Viral co-infections were most commonly reported (46%), with bacteria and parasites accounting for 14.9% and 0.01% of cases, respectively. However, the panel of co-infections tested for varied considerably among studies and 38% of stated co-infections did not have a pathogen reported. Substantial variation in how and when tests for gastrointestinal co-infections are carried out, small sample sizes and a lack of clear CDI case definitions preclude meaningful conclusions on the true rate of co-infections in this patient population. This review suggests that co-infections may be common in children with diarrhoea who tested positive for C. difficile. Given a lack of CDI case definitions, especially in young children under the age of 5 years, a broad panel of pathogens should be tested for to exclude other microbiological causes. However, the summarised poor quality of the available literature on this subject highlights a need for further studies.

Evaluation of swabbing methods for estimating the prevalence of bacterial carriage in the upper respiratory tract: a cross sectional study

OBJECTIVES

Bacterial carriage in the upper respiratory tract is usually asymptomatic but can lead to respiratory tract infection (RTI), meningitis and septicaemia. We aimed to provide a baseline measure of Streptococcus pneumoniae, Moraxella catarrhalis, Pseudomonas aeruginosa, Staphylococcus aureus, Haemophilus influenzae and Neisseria meningitidis carriage within the community. Self-swabbing and healthcare professional (HCP) swabbing were compared.

DESIGN

Cross-sectional study.

SETTING

Individuals registered at 20 general practitioner practices within the Wessex Primary Care Research Network South West, UK.

PARTICIPANTS

10,448 individuals were invited to participate; 5394 within a self-swabbing group and 5054 within a HCP swabbing group. Self-swabbing invitees included 2405 individuals aged 0-4 years and 3349 individuals aged ≥5 years. HCP swabbing invitees included 1908 individuals aged 0-4 years and 3146 individuals aged ≥5 years.

RESULTS

1574 (15.1%) individuals participated, 1260 (23.4%, 95% CI 22.3% to 24.5%) undertaking self-swabbing and 314 (6.2%, 95% CI 5.5% to 6.9%) undertaking HCP-led swabbing. Participation was lower in young children and more deprived practice locations. Swab positivity rates were 34.8% (95% CI 32.2% to 37.4%) for self-taken nose swabs (NS), 19% (95% CI 16.8% to 21.2%) for self-taken whole mouth swabs (WMS), 25.2% (95% CI 20.4% to 30%) for nasopharyngeal swabs (NPS) and 33.4% (95% CI 28.2% to 38.6%) for HCP-taken WMS. Carriage rates of S. aureus were highest in NS (21.3%). S. pneumoniae carriage was highest in NS (11%) and NPS (7.4%). M. catarrhalis carriage was highest in HCP-taken WMS (28.8%). H. influenzae and P. aeruginosa carriage were similar between swab types. N. meningitidis was not detected in any swab. Age and recent RTI affected carriage of S. pneumoniae and H. influenzae. Participant costs were lower for self-swabbing (£41.21) versus HCP swabbing (£69.66).

CONCLUSIONS

Higher participation and lower costs of self-swabbing as well as sensitivity of self-swabbing favour this method for use in large population-based respiratory carriage studies.

Experience with pneumococcal polysaccharide conjugate vaccine (conjugated to CRM197 carrier protein) in children and adults

Streptococcus pneumoniae-related infections are a major cause of morbidity and mortality in people of all ages worldwide. Pneumococcal vaccine development started in 1911 with a whole cell vaccine and more recently multivalent plain polysaccharide and polysaccharide conjugate vaccines have been developed. The recent vaccines rely on capsular polysaccharide antigens to induce serotype-specific immune responses. We summarize here the presentations on pneumococcal polysaccharide conjugate vaccine (conjugated to CRM197 carrier protein) given during the integrated symposium organized and funded by Pfizer International Operations during the 22nd European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) 31 March to 3 April 2012, London, UK. A dramatic reduction in the incidence of invasive pneumococcal diseases (IPD) due to vaccine serotypes (VST-IPD) has been reported since the introduction of a hepta-valent pneumococcal conjugate vaccine (PCV7). An indirect (herd) effect has been demonstrated to be associated with PCV7 infant vaccination programmes, with many studies reporting reductions in VST-IPD in populations that are not eligible for PCV7 vaccination. Since 2010, a 13-valent pneumococcal conjugate vaccine (PCV13) has been introduced into national immunization programmes and results from early surveillance suggest that this vaccine also has an impact on the serotypes unique to PCV13, as well as continuing to protect against the PCV7 serotypes. Data from a passive surveillance system in Europe in 2009, for instance, showed that the highest incidence of IPD remains in those aged >65 years and in children <5 years. PCV13 has now been licensed for vaccination of adults >50 years based on safety and immunogenicity data; an efficacy trial is being conducted. Regardless of previous pneumococcal vaccination status, if the use of 23-valent polysaccharide is considered appropriate, it is recommended to give PCV13 first. Novel immunization strategies remain the only practical means to reduce significantly the remaining global mortality and morbidity due to S. pneumoniae in adults.

Sampling methods for the study of pneumococcal carriage: a systematic review

Streptococcus pneumoniae is an important pathogen worldwide. Accurate sampling of S. pneumoniae carriage is central to surveillance studies before and following conjugate vaccination programmes to combat pneumococcal disease. Any bias introduced during sampling will affect downstream recovery and typing. Many variables exist for the method of collection and initial processing, which can make inter-laboratory or international comparisons of data complex. In February 2003, a World Health Organisation working group published a standard method for the detection of pneumococcal carriage for vaccine trials to reduce or eliminate variability. We sought to describe the variables associated with the sampling of S. pneumoniae from collection to storage in the context of the methods recommended by the WHO and those used in pneumococcal carriage studies since its publication. A search of published literature in the online PubMed database was performed on the 1st June 2012, to identify published studies that collected pneumococcal carriage isolates, conducted after the publication of the WHO standard method. After undertaking a systematic analysis of the literature, we show that a number of differences in pneumococcal sampling protocol continue to exist between studies since the WHO publication. The majority of studies sample from the nasopharynx, but the choice of swab and swab transport media is more variable between studies. At present there is insufficient experimental data that supports the optimal sensitivity of any standard method. This may have contributed to incomplete adoption of the primary stages of the WHO detection protocol, alongside pragmatic or logistical issues associated with study design. Consequently studies may not provide a true estimate of pneumococcal carriage. Optimal sampling of carriage could lead to improvements in downstream analysis and the evaluation of pneumococcal vaccine impact and extrapolation to pneumococcal disease control therefore further in depth comparisons would be of value.

Safety and immunogenicity of AS03B adjuvanted split virion versus non-adjuvanted whole virion H1N1 influenza vaccine in UK children aged 6 months-12 years: open label, randomised, parallel group, multicentre study

OBJECTIVES

To compare the safety, reactogenicity, and immunogenicity of an adjuvanted split virion H1N1 vaccine and a non-adjuvanted whole virion vaccine used in the pandemic immunisation programme in the United Kingdom.

DESIGN

Open label, randomised, parallel group, phase II study.

SETTING

Five UK centres (Oxford, Southampton, Bristol, Exeter, and London).

PARTICIPANTS

Children aged 6 months to less than 13 years for whom a parent or guardian had provided written informed consent and who were able to comply with study procedures were eligible. Those with laboratory confirmed pandemic H1N1 influenza or clinically diagnosed disease meriting antiviral treatment, allergy to egg or any other vaccine components, or coagulation defects, or who were severely immunocompromised or had recently received blood products were excluded. Children were grouped by age: 6 months-<3 years (younger group) and 3-<13 years (older group). Recruitment was by media advertising and direct mailing. Recruitment visits were attended by 949 participants, of whom 943 were enrolled and 937 included in the per protocol analysis.

INTERVENTIONS

Participants were randomised 1:1 to receive AS03(B) (tocopherol based oil in water emulsion) adjuvanted split virion vaccine derived from egg culture or non-adjuvanted whole virion vaccine derived from cell culture. Both were given as two doses 21 days apart. Reactogenicity data were collected for one week after immunisation by diary card. Serum samples were collected at baseline and after the second dose.

MAIN OUTCOME MEASURES

Primary reactogenicity end points were frequency and severity of fever, tenderness, swelling, and erythema after vaccination. Immunogenicity was measured by microneutralisation and haemagglutination inhibition assays. The primary immunogenicity objective was a comparison between vaccines of the percentage of participants showing seroconversion by the microneutralisation assay (fourfold rise to a titre of >or=1:40 from before vaccination to three weeks after the second dose).

RESULTS

Seroconversion rates were higher after the adjuvanted split virion vaccine than after the whole virion vaccine, most notably in the youngest children (163 of 166 participants with paired serum samples (98.2%, 95% confidence interval 94.8% to 99.6%) v 157 of 196 (80.1%, 73.8% to 85.5%), P<0.001) in children under 3 years and 226 of 228 (99.1%, 96.9% to 99.9%) v 95.9%, 92.4% to 98.1%, P=0.03) in those over 3 years). The adjuvanted split virion vaccine was more reactogenic than the whole virion vaccine, with more frequent systemic reactions and severe local reactions in children aged over 5 years after dose one (13 (7.2%, 3.9% to 12%) v 2 (1.1%, 0.1% to 3.9%), P<0.001) and dose two (15 (8.5%, 4.8% to 13.7%) v 2 (1.1%, 0.1% to 4.1%), P<0.002) and after dose two in those under 5 years (15 (5.9%, 3.3% to 9.6%) v 0 (0.0%, 0% to 1.4%), P<0.001). Dose two of the adjuvanted split virion vaccine was more reactogenic than dose one, especially for fever >or=38 masculineC in those aged under 5 (24 (8.9%, 5.8% to 12.9%) v 57 (22.4%, 17.5% to 28.1%), P<0.001).

CONCLUSIONS

In this first direct comparison of an AS03(B) adjuvanted split virion versus whole virion non-adjuvanted H1N1 vaccine, the adjuvanted vaccine, while more reactogenic, was more immunogenic and, importantly, achieved high seroconversion rates in children aged less than 3 years. This indicates the potential for improved immunogenicity of influenza vaccines in this age group.

TRIAL REGISTRATION

Clinical trials.gov NCT00980850; ISRCTN89141709.

Identification of novel pneumolysin alleles from paediatric carriage isolates of Streptococcus pneumoniae

Pneumolysin (Ply) is a major virulence factor of Streptococcus pneumoniae and is produced by all known clinical isolates of pneumococci. Pneumolysin toxoids are being considered as vaccine candidates. We investigated the diversity of pneumolysin among 194 nasopharyngeal pneumococci characterized by serotyping and multilocus sequence typing (MLST). Eight Ply protein alleles were identified, four of which were novel. The 4 novel alleles varied at 10 different amino acid positions, from a total of 147, 3 of these substitutions have been previously reported in different combinations. The protein allele correlated closely with MLST. It is critical that the presence of pneumolysin variants is considered with regards to the potential use of Ply in future vaccine formulations, as variation in Ply amino acid sequence may influence the immunogenicity of vaccines based on the presence of an individual Ply allele.

Nonlinear refractive index of porcine cornea studied by z-scan and self-focusing during femtosecond laser processing

We have investigated the nonlinear refractive index of ex-vivo pig cornea by a combined approach using the standard z-scan technique on extracted corneas or corneal slices, as well as studying the deviations caused by self-focusing during femtosecond laser processing of the pig eyes. The experiments yield consistently an upper limit of 1.2 MW for the critical power of self-focusing in porcine cornea, and a value of 2 x 10(-19) m(2)/W for its nonlinear refractive index. We also demonstrate that due to this nonlinear refraction the cutting depth of typical fs-laser surgery processing in cornea may depend considerably, albeit in a well controllable way, on the laser parameters.

Human serum albumin (HSA) nanoparticles: Reproducibility of preparation process and kinetics of enzymatic degradation

Nanoparticles prepared from human serum albumin (HSA) are versatile carrier systems for drug delivery and can be prepared by an established desolvation process. A reproducible process with a low batch-to-batch variability is required for transfer from the lab to an industrial production. In the present study the batch-to-batch variability of the starting material HSA on the preparation of nanoparticles was investigated. HSA can build dimers and higher aggregates because of a free thiol group present in the molecule. Therefore, the quality of different HSA batches was analysed by size exclusion chromatography (SEC) and analytical ultracentrifugation (AUC). The amount of dimerised HSA detected by SEC did not affect particle preparation. Higher aggregates of the protein detected in two batches by AUC disturbed nanoparticle formation at pH values below 8.0. At pH 8.0 and above monodisperse particles between 200 and 300 nm could be prepared with all batches, with higher pH values leading to smaller particles. Besides human derived albumin a particle preparation was also feasible based on recombinant human serum albumin (rHSA). Under comparable preparation conditions monodisperse nanoparticles could be achieved and the same effects of protein aggregates on particle formation were observed. For nanoparticulate drug delivery systems the enzymatic degradation is a crucial parameter for the release of an embedded drug. For this reason, besides the particle preparation process, particle degradation in the presence of different enzymes was studied. Under acidic conditions HSA as well as rHSA nanoparticles could be digested by pepsin and cathepsin B. At neutral pH trypsin, proteinase K, and protease were suitable for particle degradation. It could be shown that the kinetics of particle degradation was dependent on the degree of particle stabilisation. Therefore, the degree of particle stabilisation will influence drug release after cellular accumulation of HSA nanoparticles.

Haplotypic diversity in human CEACAM genes: effects on susceptibility to meningococcal disease

Adhesion between the opacity-associated adhesin (Opa) proteins of Neisseria meningitidis and human carcino-embryonic antigen cell adhesion molecule (CEACAM) proteins is an important stage in the pathogenesis of meningococcal disease, a globally important bacterial infection. Most disease is caused by a small number of meningococcal genotypes known as hyperinvasive lineages. As these are also carried asymptomatically, acquisition of them alone cannot explain why only some hosts develop meningococcal disease. Our aim was to determine whether genetic diversity in CEACAM is associated with susceptibility to meningococcal disease. Frequency distributions of alleles, genotypes and haplotypes were compared in four CEACAM genes in 384 case samples and 190 controls. Linkage disequilibrium among polymorphic sites, haplotype structures and relationships were also analysed. A number of polymorphisms were observed in CEACAM genes but the diversity of CEACAM1, to which most Opa proteins bind, was lower, and a small number of high-frequency haplotypes were detected. Dose-dependent associations of three CEACAM haplotypes with meningococcal disease were observed, with the effect of carrying these haplotypes amplified in homozygous individuals. Two haplotypes were protective while one haplotype in CEACAM6 was associated with a twofold increase in disease susceptibility. These data imply that human CEACAM may be one determinant of human susceptibility to meningococcal disease.

Pathophysiology of meningococcal meningitis and septicaemia

Neisseria meningitidis is remarkable for the diversity of interactions that the bacterium has with the human host, ranging from asymptomatic nasopharyngeal colonisation affecting virtually all members of the population; through focal infections of the meninges, joints, or eye; to the devastating and often fatal syndrome of meningococcal septic shock and purpura fulminans.

Severe meningococcal disease is characterized by early neutrophil but not platelet activation and increased formation and consumption of platelet-neutrophil complexes

Approximately 25% of polymorphonuclear leukocytes (PMNL) circulate in heterotypic complexes with one or more activated platelets. These platelet-neutrophil complexes (PNC) require platelet CD62P expression for their formation and represent activated subpopulations of both cell types. In this study, we have investigated the presence, time course, and mechanisms of PNC formation in 32 cases of severe pediatric meningococcal disease (MD) requiring intensive care. There were marked early increases in PMNL CD11b/CD18 expression and activation, and reduced CD62L expression compared with intensive care unit control cases. Minimal platelet expression of the active form of alphaIIbbeta3 (GpIIb/IIIa) was seen. PNC were reduced on presentation and fell to very low levels after 24 h. Immunostaining of skin biopsies demonstrated that PNC appear outside the circulation in MD. In vitro studies of anticoagulated whole blood inoculated with Neisseria meningitidis supported these clinical findings with marked increases in PMNL CD11b/CD18 expression and activation but no detectable changes in platelet-activated alphaIIbbeta3 or CD62P expression. In vitro PMNL activation with N. meningitidis (or other agonists) potentiated the formation of PNC in response to platelet activation with adenine diphosphate. Therefore, in severe MD, PMNL activation is likely to promote PNC formation, and we suggest that the reduced levels of PNC seen in established MD reflect rapid loss of PNC from the circulation rather than reduced formation.

Analysis of pathogen-host cell interactions in purpura fulminans: expression of capsule, type IV pili, and PorA by Neisseria meningitidis in vivo

The pattern of meningococcal surface structure expression in different microenvironments following bloodstream invasion in vivo is not known. We used immunohistochemistry to determine the expression of capsule, type IV pili, and PorA by meningococci residing in the skin lesions of children with purpura fulminans. All the skin biopsy samples showed evidence of thrombosis and, frequently, a perivascular inflammatory cell infiltrate consisting of neutrophils (elastase positive) and monocytes/macrophages (CD68 positive). Modified Gram staining revealed 20 to over 100 gram-negative diplococci in each 4-microm-thick section, usually grouped into microcolonies. Immunoperoxidase staining demonstrated that the invading meningococci expressed PorA, capsule, and type IV pilin. Expression of these antigens was not restricted to any particular environment and was found in association with meningococci located in leukocytes, small blood vessels, and the dermal interstitium. Confocal laser scanning microscopy demonstrated coexpression of pilin and capsule by numerous microcolonies. However, there was some discordance in capsule and pilin expression within the microcolonies, suggesting phase variation. The strategy employed in this study will be helpful in investigating invasive bacterial diseases where antigenic and phase variation has a significant impact on virulence and on vaccine design.

Dysfunction of endothelial protein C activation in severe meningococcal sepsis

BACKGROUND

Impairment of the protein C anticoagulation pathway is critical to the thrombosis associated with sepsis and to the development of purpura fulminans in meningococcemia. We studied the expression of thrombomodulin and the endothelial protein C receptor in the dermal microvasculature of children with severe meningococcemia and purpuric or petechial lesions.

METHODS

We assessed the integrity of the endothelium and the expression of thrombomodulin and the endothelial protein C receptor in biopsy specimens of purpuric lesions from 21 children with meningococcal sepsis (median age, 41 months), as compared with control skin-biopsy specimens.

RESULTS

The expression of endothelial thrombomodulin and of the endothelial protein C receptor was lower in the patients with meningococcal sepsis than in the controls, both in vessels with thrombosis and in vessels without thrombosis. On electron microscopical examination, the endothelial cells were generally intact in both thrombosed and nonthrombosed vessels. Plasma thrombomodulin levels in the children with meningococcal sepsis (median, 6.4 ng per liter) were higher than those in the controls (median, 3.6 ng per liter; P=0.002). Plasma levels, protein C antigen, protein S antigen, and antithrombin antigen were lower than those in the controls. In two patients treated with unactivated protein C concentrate, activated protein C was undetectable at the time of admission, and plasma levels remained low.

CONCLUSIONS

In severe meningococcal sepsis, protein C activation is impaired, a finding consistent with down-regulation of the endothelial thrombomodulin-endothelial protein C receptor pathway.

Coagulation in severe sepsis: a central role for thrombomodulin and activated protein C

OBJECTIVES

To review the mechanisms that cause coagulation abnormalities in sepsis, focusing on the interaction between the vascular endothelium and the circulating coagulation factors, particularly the role of the protein C pathway and thrombomodulin.

DATA SOURCES/STUDY SELECTION

Published research abstracts and review articles on the experimental and clinical investigation of the pathophysiology of disseminated intravascular coagulation in sepsis.

DATA EXTRACTION AND SYNTHESIS

The data provide increasing evidence that the coagulopathy seen in sepsis is a result of a complex imbalance of pro- and anticoagulant pathways. Whereas previous research has largely studied events in the plasma, it is now apparent that reactions on cell surfaces such as the vascular endothelium are important in the control of the regulatory pathways.

CONCLUSIONS

The plasma components of the protein C pathway are down-regulated in sepsis. Decreased thrombomodulin expression may cause defective function of the endothelial component of this pathway in septic patients. Treatments must be designed to overcome any functional defect.

Molecular cloning and characterization of a human metalloprotease disintegrin--a novel marker for dendritic cell differentiation

The 1alpha,25-dihydroxyvitamin D(3) (1,25- [OH](2)VD(3)) modulates the differentiation of monocytic cell lines and monocytes (MOs) in vitro. Up to now several target genes of 1,25(OH)(2)VD(3) have been described in monocytic cell lines; however, little is known about target genes in primary MOs. With the Differential Display technique, we found a transcript up-regulated by 1,25(OH)(2)VD(3) in short-term cultured human blood MOs, which we called MADDAM (metalloprotease and disintegrin dendritic antigen marker; EMBL/GenBank/DDBJ accession no. Y13786). Northern blot analysis confirmed this result and revealed a signal of MADDAM messenger RNA (mRNA) at about 7.5 kilobases (kb). Long-term culture (more than 20 hours) of MOs during macrophage (MAC) differentiation led to a rapid and complete down-regulation of MADDAM expression. In contrast, MADDAM expression was maintained in MOs differentiated along the dendritic cell (DC) pathway and induced in CD34(+)-derived DCs. In addition, in situ hybridization revealed signals of MADDAM mRNA in follicles of human lymph nodes and MADDAM mRNA was detected in freshly isolated human blood-DCs by reverse transcription-polymerase chain reaction (RT-PCR). By means of a database search, we found that MADDAM is a member of the ADAM (a metalloprotease and disintegrin) family, the human homologue to murine meltrin-beta (ADAM 19). From these data, we conclude that MADDAM is an important marker for the differentiation and characterization of DCs and the distinction between MACs and DCs. (Blood. 2000;96:732-739)

Disseminated intravascular coagulation and purpura fulminans secondary to infection

Infection is one of the commonest causes of disseminated intravascular coagulation (DIC). DIC is a complex disorder that results from an imbalance of the pro- and anticoagulant regulatory pathways. This chapter will explain the cellular and molecular basis of the disorder and consider the rationale behind current and experimental treatment strategies.

A national trainee advisory network: a proposal

Trainees should have a well-defined and consistent communication conduit to the authorities involved with their training. It is important that trainees are involved in the evolution of structured training programmes and for training authorities to receive feedback from individuals in each specialty. This paper proposes a structure for trainee representation on regional and national training authorities to facilitate an advisory network.

[For an updated acupuncture]

The author proposes an acupuncture which is characterized by its complete break with the ancient chinese physiopathology and its concepts of "acupuncture points" (in the old sense of the term) of "meridians", "energies", "ying-yang" etc.. This process of renewal of the practice and the theory has been coined "contemporary acupuncture". Its originality stands out in comparison with most teachings of acupuncture which have remained faithful to traditional acupuncture. Contemporary acupuncture creates bridges between acupunture and classical medicine. It offers simple therapeutic gestures to general practitioners. Acupuncture acts, from a clinical point of view, particularly through the following forms of action: a) a relaxing action on striated muscle; b) an anti-inflammatory action on the ligaments; c) an antidepressant and anxiolytic action.

Heart transplantation in patients with Marfan's syndrome: a survey of attitudes and results

Our institution performed an orthotopic heart transplantation in a patient with Marfan's syndrome. The immediate postoperative course was complicated with ultimate discharge; however, this patient died within 1 year as a result of an aortic dissection. On the basis of our experience, we surveyed all heart transplant centers listed with the North American Transplant Coordinator Organization for other patients with Marfan's syndrome who had been referred for transplantation. Nearly one third of responding centers evaluated a total of 30 patients with Marfan's syndrome. Of these, only 13 were formally listed for a donor organ and 11 underwent heart transplantation with an operative mortality of 9.1% (n = 1). Posttransplantation morbidity was significant and includes a 40% (n = 4) incidence of thoracic aorta dissection (one fatal) in operative survivors. There were three other non-dissection-related late deaths for an overall survival of 54.4% after a mean follow-up of 33.0 months. In this shared experience, it appears that the known vascular complications of Marfan's syndrome may diminish the anticipated results after heart transplantation. The reluctance to place these patients on heart transplant donor waiting lists can be justified.

DSM-III-R disorders in Vietnamese refugees. Prevalence and correlates

This study's purpose was a) to determine the prevalence of DSM-III-R disorders in newly arrived ethnic Vietnamese and ethnic Chinese refugees from Vietnam and b) to determine the correlates of DSM-III-R disorders. A Vietnamese-speaking psychiatrist administered translated sections of the Structured Clinical Interview for DSM-III-R to 201 Vietnamese new arrivals undergoing mandatory health screening. Overall, 18.4% had one or more current disorders: 8.5% had adjustment disorder and 5.5% had major depression. Ethnic Vietnamese, compared with ethnic Chinese, had significantly (p < .05) higher rates of current posttraumatic stress disorder and generalized anxiety disorder. Ethnic differences in psychopathology were largely explained by the fact that ethnic Vietnamese refugees had experienced more traumatic events and separation from family. After adjusting for ethnicity, refugees who reported traumatic events, refugees who were married, and veterans were significantly (p < .05) more likely to have one or more psychiatric disorders.

Depression in Southeast Asian refugees

Depressive illness is common among Southeast Asian refugees. Classic vegetative symptoms seem to cross cultural boundaries and have been found in all ethnic groups studied. A migration history is important for eliciting information about the flight experience and the current living situation. Symptomatic treatment, combined with an abbreviated form of psychotherapy, is effective for many patients.

Improved enzyme-linked immunosorbent assay for aflatoxin B1 in agricultural commodities

An improved enzyme-linked immunosorbent assay (ELISA) for aflatoxin B1 in cornmeal and peanut butter was developed. Aflatoxin B1 in cornmeal and peanut butter samples was extracted with 70% methanol in water containing 1% dimethylformamide diluted with assay buffer to a final concentration of 7.0% methanol, and directly subjected to an ELISA procedure that took less than 1 h for quantitative analysis and less than 30 min for screening tests. Analytical recoveries for 5-100 ppb B1 added to the cornmeal and peanut butter were 91 and 95.4%, respectively. The interwell and interassay coefficient of variation was 10% or less at the 20 ppb level and above. Agreement for B1 levels in more than 30 naturally contaminated corn, mixed feed, and peanut butter samples was excellent between the ELISA data and the data obtained from different independent laboratories using TLC or other analytical methods.