The importance of lymphotoxin (LT) betaR (LTbetaR) as a regulator of lymphoid organogenesis is well established, but its role in host defense has yet to be fully defined. In this study, we report that mice deficient in LTbetaR signaling were highly susceptible to infection with murine CMV (MCMV) and early during infection exhibited a catastrophic loss of T and B lymphocytes, although the majority of lymphocytes were themselves not directly infected. Moreover, bone marrow chimeras revealed that lymphocyte survival required LTalpha expression by hemopoietic cells, independent of developmental defects in lymphoid tissue, whereas LTbetaR expression by both stromal and hemopoietic cells was needed to prevent apoptosis. The induction of IFN-beta was also severely impaired in MCMV-infected LTalpha(-/-) mice, but immunotherapy with an agonist LTbetaR Ab restored IFN-beta levels, prevented lymphocyte death, and enhanced the survival of these mice. IFN-alphabetaR(-/-) mice were also found to exhibit profound lymphocyte death during MCMV infection, thus providing a potential mechanistic link between type 1 IFN induction and lymphocyte survival through a LTalphabeta-dependent pathway important for MCMV host defense.

Variant Creutzfeldt-Jakob disease and scrapie are typically initiated by extracerebral exposure to prions, and exhibit early prion accumulation in germinal centers. Follicular dendritic cells (FDCs), whose development and maintenance in germinal centers depends on tumor necrosis factor (TNF) and lymphotoxin (LT) signaling, are thought to be indispensable for extraneural prion pathogenesis. Here, we administered prions intraperitoneally to mice deficient for TNF and LT signaling components. LT alpha(-/-), LT beta(-/-), LT betaR(-/-), and LT alpha(-/-) x TNFalpha(-/-) mice resisted infection and contained no infectivity in spleens and lymph nodes (when present). However, TNFR1(-/-), TNFR2(-/-), and some TNFalpha(-/-) mice developed scrapie similarly to wild-type mice. High prion titers were detected in lymph nodes, but not spleens, of TNFR1(-/-) and TNF alpha(-/-) mice despite absence of FDCs and germinal centers. Transfer of TNFR1(-/-) fetal liver cells into lethally irradiated Prnp(0/0) mice restored infectivity mainly in lymph nodes. Prion protein (PrP) colocalized with a minority of macrophages in tumor necrosis factor receptor (TNFR) 1(-/-) lymph nodes. Therefore, prion pathogenesis can be restricted to lymphoreticular subcompartments, and mature follicular dendritic cells are dispensable for this process. Macrophage subsets are plausible candidates for lymphoreticular prion pathogenesis and neuroinvasion in the absence of FDCs, and may represent a novel target for postexposure prophylaxis.

In addition to a high aerobic fitness, the ability to buffer hydrogen ions (H+) may also be important for repeated-sprint ability (RSA). We therefore investigated the relationship between muscle buffer capacity (betamin vivo and betamin vitro) and RSA. Thirty-four untrained females [mean (SD): age 19 (1) years, maximum oxygen uptake (VO2peak) 42.3 (7.1) ml x kg(-1) x min(-1)] completed a graded exercise test (GXT), followed by a RSA cycle test (five 6-s sprints, every 30 s). Capillary blood was sampled during the GXT and before and after the RSA test to determine blood pH (pHb) and lactate concentration ([La-]b). Muscle biopsies were taken before (n=34) and after (n=23) the RSA test to determine muscle lactate concentration ([La-]i), hydrogen ion concentration ([H+]i) pHi, betamin vivo and betamin vitro. There were significant correlations between work decrement (%) and betamin vivo (r=-0.72, P<0.05), VO2peak (r=-0.62, P<0.05), lactate threshold (LT) (r=-0.56, P<0.05) and changes in [H+]i (r=0.41, P<0.05). There were however, no significant correlations between work decrement and betamin vitro, or changes in [La-]i, or [La-]b. There were also no significant correlations between total work (J x kg(-1)) during the RSA test and betamin vitro, betamin vivo, or changes in [La-]i, pHi, [La-]b, or pHb. There were significant correlations between total work (J x kg(-1)) and both VO2peak (r=0.60, P<0.05) and LT(r=0.54, P<0.05). These results support previous research, identifying a relationship between RSA and aerobic fitness. This study is the first to identify a relationship between betamin vivo and RSA. This suggests that the ability to buffer H+ may be important for maintaining performance during brief, repeated sprints.

<A<em>b</em>stractText>The aim of this study was to determine whether the Joint European Societies guidelines on secondary cardiovascular prevention are followed in everyday practice.</A<em>b</em>stractText><A<em>b</em>stractText>A cross-sectional ESC-EORP survey (EUROASPIRE V) at 131 centres in 81 regions in 27 countries.</A<em>b</em>stractText><A<em>b</em>stractText>Patients (&<em>lt</em>;80 years old) with verified coronary artery events or interventions were interviewed and examined ≥6 months later.</A<em>b</em>stractText><p><div>(<em>b</em>)RESULTS</<em>b</em>)</div>A total of 8261 patients (females 26%) were interviewed. Nineteen per cent smoked and 55% of them were persistent smokers, 38% were o<em>b</em>ese (<em>b</em>ody mass index ≥30 kg/m²), 59% were centrally o<em>b</em>ese (waist circumference: men ≥102 cm; women ≥88 cm) while 66% were physically active &<em>lt</em>;30 min 5 times/week. Forty-two per cent had a <em>b</em>lood pressure ≥140/90 mmHg (≥140/85 if dia<em>b</em>etic), 71% had low-density lipoprotein cholesterol ≥1.8 mmol/L (≥70 mg/dL) and 29% reported having dia<em>b</em>etes. Cardioprotective medication was: anti-platelets 93%, <em>beta</em>-<em>b</em>lockers 81%, angiotensin-converting enzyme inhi<em>b</em>itors/angiotensin receptor <em>b</em>lockers 75% and statins 80%.</p><A<em>b</em>stractText>A large majority of coronary patients have unhea<em>lt</em>hy lifestyles in terms of smoking, diet and sedentary <em>b</em>ehaviour, which adversely impacts major cardiovascular risk factors. A majority did not achieve their <em>b</em>lood pressure, low-density lipoprotein cholesterol and glucose targets. Cardiovascular prevention requires modern preventive cardiology programmes delivered <em>b</em>y interdisciplinary teams of hea<em>lt</em>hcare professionals addressing all aspects of lifestyle and risk factor management, in order to reduce the risk of recurrent cardiovascular events.</A<em>b</em>stractText>

Objectives: Our objective was to review the literature on the inferred duration of the infectious period of COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, and provide an overview of the variation depending on the methodological approach.

Design: Rapid scoping review. Literature review with fixed search terms, up to 1 April 2020. Central tendency and variation of the parameter estimates for infectious period in (A) asymptomatic and (B) symptomatic cases from (1) virological studies (repeated testing), (2) tracing studies and (3) modelling studies were gathered. Narrative review of viral dynamics.

Information sources: Search strategies developed and the following searched: PubMed, Google Scholar, MedRxiv and BioRxiv. Additionally, the Health Information Quality Authority (Ireland) viral load synthesis was used, which screened literature from PubMed, Embase, ScienceDirect, NHS evidence, Cochrane, medRxiv and bioRxiv, and HRB open databases.

Results: There was substantial variation in the estimates, and how infectious period was inferred. One study provided approximate median infectious period for asymptomatic cases of 6.5-9.5 days. Median presymptomatic infectious period across studies varied over <1-4 days. Estimated mean time from symptom onset to two negative RT-PCR tests was 13.4 days (95% CI 10.9 to 15.8) but was shorter when studies included children or less severe cases. Estimated mean duration from symptom onset to hospital discharge or death (potential maximal infectious period) was 18.1 days (95% CI 15.1 to 21.0); time to discharge was on average 4 days shorter than time to death. Viral dynamic data and model infectious parameters were often shorter than repeated diagnostic data.

Conclusions: There are limitations of inferring infectiousness from repeated diagnosis, viral loads and viral replication data alone and also potential patient recall bias relevant to estimating exposure and symptom onset times. Despite this, available data provide a preliminary evidence base to inform models of central tendency for key parameters and variation for exploring parameter space and sensitivity analysis.

Keywords: epidemiology; infectious diseases; public health; virology.

<A<em>b</em>stractText>To study the national prevalence of 10 developmental disa<em>b</em>ilities in US children aged 3 to 17 years and explore changes over time <em>b</em>y associated demographic and socioeconomic characteristics, using the National Hea<em>lt</em>h Interview Survey.</A<em>b</em>stractText><A<em>b</em>stractText>Data come from the 2009 to 2017 National Hea<em>lt</em>h Interview Survey, a nationally representative survey of the civilian noninstitutionalized population. Parents reported physician or other hea<em>lt</em>h care professional diagnoses of attention-deficit/hyperactivity disorder; autism spectrum disorder; <em>b</em>lindness; cere<em>b</em>ral palsy; moderate to profound hearing loss; learning disa<em>b</em>ility; intellectual disa<em>b</em>ility; seizures; stuttering or stammering; and other developmental delays. Weighted percentages for each of the selected developmental disa<em>b</em>ilities and any developmental disa<em>b</em>ility were calculated and stratified <em>b</em>y demographic and socioeconomic characteristics.</A<em>b</em>stractText><p><div>(<em>b</em>)RESULTS</<em>b</em>)</div>From 2009 to 2011 and 2015 to 2017, there were overall significant increases in the prevalence of any developmental disa<em>b</em>ility (16.2%-17.8%, <i>P</i> &<em>lt</em>; .001), attention-deficit/hyperactivity disorder (8.5%-9.5%, <i>P</i> &<em>lt</em>; .01), autism spectrum disorder (1.1%-2.5%, <i>P</i> &<em>lt</em>; .001), and intellectual disa<em>b</em>ility (0.9%-1.2%, <i>P</i> &<em>lt</em>; .05), <em>b</em>ut a significant decrease for any other developmental delay (4.7%-4.1%, <i>P</i> &<em>lt</em>; .05). The prevalence of any developmental disa<em>b</em>ility increased among <em>b</em>oys, older children, non-Hispanic white and Hispanic children, children with private insurance only, children with <em>b</em>irth weight ≥2500 g, and children living in ur<em>b</em>an areas and with less-educated mothers.</p><A<em>b</em>stractText>The prevalence of developmental disa<em>b</em>ility among US children aged 3 to 17 years increased <em>b</em>etween 2009 and 2017. Changes <em>b</em>y demographic and socioeconomic su<em>b</em>groups may <em>b</em>e related to improvements in awareness and access to hea<em>lt</em>h care.</A<em>b</em>stractText>

CD8+ islet cell-specific CTL lines and clones were established from lymphocytes infiltrating the pancreatic islets of acutely diabetic nonobese diabetic (NOD) mice from two subcolonies (NOD/Yn and NOD/Lt). CTL from NOD/Yn mice were predominantly cytotoxic against H-2b+ islet cells and to a lesser extent against H-2d+ islet cells. On the other hand, CTL from NOD/Lt mice were cytotoxic against H-2d+ but not against H-2b+ islet cells. Three of four CTL clones derived from NOD/Yn mice were H-2Db restricted, whereas two of two CTL clones derived from NOD/Lt mice were H-2Kd restricted. However, all of the H-2Kd restricted T cell clones expressed the same TCR, regardless of the NOD subcolony from which they were derived, compatible with a restricted repertoire. When two representative CTL clones were transferred into irradiated young NOD mice, neither induced insulitis or diabetes. However, transfer of these clones, together with CD4(+)-rich NOD splenocytes depleted of CD8+ T cells, caused severe insulitis and diabetes. When recipient NOD mice were treated with anti-CD4 mAbs, none of the mice developed insulitis or diabetes. Most of the irradiated NOD mice that received CD8-depleted splenocytes alone did not become diabetic. Through these studies we show that CTL clones can destroy pancreatic beta-cells as final effectors but that these clones require signals from CD4+ T cells to effect beta-cell damage.

Tumor necrosis factor (TNF)-related cytokines regulate cell death and survival and provide strong selective pressures for viruses, such as cytomegalovirus (CMV), to evolve counterstrategies in order to persist in immune-competent hosts. Signaling by the lymphotoxin (LT)-beta receptor or TNF receptor-1, but not Fas or TRAIL receptors, inhibits the cytopathicity and replication of human CMV by a nonapoptotic, reversible process that requires nuclear factor kappa B (NF-kappa B)-dependent induction of interferon-beta (IFN-beta). Efficient induction of IFN-beta requires virus infection and LT signaling, demonstrating the need for both host and viral factors in the curtailment of viral replication without cellular elimination. LT alpha-deficient mice and LT beta R-Fc transgenic mice were profoundly susceptible to murine CMV infection. Together, these results reveal an essential and conserved role for LTs in establishing host defense to CMV.

Aspirin-intolerant asthma (AIA), a distinct clinical syndrome affecting about 10% of adult asthmatics, appears to be unusually dependent on cysteine leukotriene (cys-LT) overproduction by pulmonary eosinophils. The gene coding for leukotriene (LT) C(4) synthase (LTC(4)S), the enzyme controlling cys-LT biosynthesis, exists as two common alleles distinguished by an A to C transversion at a site 444 nucleotides upstream of the translation start. We tested the hypothesis that this single nucleotide polymorphism (SNP) affects binding of transcription factors and influences the transcription rate, predisposing to AIA. Gel shift assay studies revealed that the (-444)C allele, conferring an activator protein-2 binding sequence, is an additional target for a transcription factor of histone H4 consensus. Introduction of the H4TF-2 decoy oligonucleotide into LTC(4)S-positive, differentiated HL-60 cells decreased accumulation of LTC(4) to 68%. Transfection of COS-7 with promoter construct increased expression of beta-galactosidase reporter for the (-444)C variant. The (-444)C allelic frequency was significantly higher in AIA patients (n = 76) as compared with matched aspirin-tolerant asthmatics (n = 110) and healthy controls (n = 75). Patients with AIA had also upregulated LTC(4)S messenger RNA expression in peripheral blood eosinophils. An inhaled provocation test with lysine-aspirin led to an increase in urinary output of LTE(4), which reached statistical significance only in carriers of the (-444)C allele. Our results suggest that a transcription factor, present in dividing and bone marrow resident progenitors of eosinophils, triggers LTC(4)S transcription in carriers of a common (-444)C allele due to binding with the histone H4 promoter element of the gene. Genetic predisposition to cys-LT pathway upregulation, a hallmark of AIA, can be related to overactive expression of the LTC(4)S (-444)C allele.

Pathogenic strains of Bacillus anthracis produce two potent toxins, lethal toxin (LT), a metalloprotease that cleaves mitogen-activated protein kinase kinases, and oedema toxin (ET), a calcium/calmodulin-dependent adenylate cyclase. Emerging evidence indicates a role for both toxins in suppressing the initiation of both innate and adaptive immune responses, which are essential to keep the infection under control. Here we show that LT and ET inhibit chemotaxis of T-cells and macrophages by subverting signalling by both CXC and CC chemokine receptors. The data highlight a novel strategy of immunosuppression by B. anthracis based on inhibition of immune cell homing.

Invasion of infectious agents through mucosal surfaces can be prevented by use of the common mucosal immune system (CMIS), which interconnects inductive tissues, including Peyer's patches (PPs) and nasopharyngeal-associated lymphoreticular tissue (NALT), and effector tissues of the intestinal and respiratory tracts. In order for the CMIS to induce maximal protective mucosal immunity, co-administration of mucosal adjuvant has been shown to be essential. When vaccine antigen is administered together with mucosal adjuvant, antigen-specific T-helper (Th) 1 and Th2 cells, cytotoxic T lymphocytes (CTLs) and IgA B cell responses are effectively induced by oral or nasal routes via the CMIS. In the early stages of induction of mucosal immune response, the uptake of orally or nasally administered antigens is achieved through a unique set of antigen-sampling cells, M cells located in follicle-associated epithelium (FAE) of inductive sites. After successful uptake, the antigens are immediately processed and presented by the underlying dendritic cells (DCs). Elucidation of the molecular/cellular characteristics of M cells and mucosal DCs will greatly facilitate the design of a new generation of effective mucosal adjuvants and of a vaccine delivery vehicle that maximises the use of the CMIS. Our recent efforts at mucosal vaccine development have focused on nasal administration of vaccine antigen together with nontoxic mutant-based or cytokine-/chemokine-based adjuvant for the induction of the protective immunity. To this end, a chimeric form of a nontoxic adjuvant combining the merits of mutant cholera toxin A subunit (mCT-A) and heat labile toxin B subunit (LT-B) was created as the second generation of detoxified toxin-based mucosal adjuvant. When a vaccine antigen was coexpressed together with an immune stimulatory/delivery molecule in crop seed, this edible vaccine is not only effective but also extremely practical in that it can be produced in huge quantities and preserved and shipped over long distances at room temperature without altering the quality of the vaccine. Because such qualities would greatly facilitate global vaccination, this new generation edible vaccines with a built-in adjuvant and/or M cell-targeted edible vaccine promises to be a powerful weapon for combating infectious diseases and bioterrorism.

<A<em>b</em>stractText>Lipoprotein(a) levels are genetically determined and, when elevated, are a risk factor for cardiovascular disease and aortic stenosis. There are no approved pharmacologic therapies to lower lipoprotein(a) levels.</A<em>b</em>stractText><p><div>(<em>b</em>)METHODS</<em>b</em>)</div>We conducted a randomized, dou<em>b</em>le-<em>b</em>lind, place<em>b</em>o-controlled, dose-ranging trial involving 286 patients with esta<em>b</em>lished cardiovascular disease and screening lipoprotein(a) levels of at least 60 mg per deciliter (150 nmol per liter). Patients received the hepatocyte-directed antisense oligonucleotide AKCEA-APO(a)-L<su<em>b</em>)Rx</su<em>b</em>), referred to here as APO(a)-L<su<em>b</em>)Rx</su<em>b</em>) (20, 40, or 60 mg every 4 weeks; 20 mg every 2 weeks; or 20 mg every week), or saline place<em>b</em>o su<em>b</em>cutaneously for 6 to 12 months. The lipoprotein(a) level was measured with an isoform-independent assay. The primary end point was the percent change in lipoprotein(a) level from <em>b</em>aseline to month 6 of exposure (week 25 in the groups that received monthly doses and week 27 in the groups that received more frequent doses).</p><p><div>(<em>b</em>)RESULTS</<em>b</em>)</div>The median <em>b</em>aseline lipoprotein(a) levels in the six groups ranged from 204.5 to 246.6 nmol per liter. Administration of APO(a)-L<su<em>b</em>)Rx</su<em>b</em>) resu<em>lt</em>ed in dose-dependent decreases in lipoprotein(a) levels, with mean percent decreases of 35% at a dose of 20 mg every 4 weeks, 56% at 40 mg every 4 weeks, 58% at 20 mg every 2 weeks, 72% at 60 mg every 4 weeks, and 80% at 20 mg every week, as compared with 6% with place<em>b</em>o (P values for the comparison with place<em>b</em>o ranged from 0.003 to &<em>lt</em>;0.001). There were no significant differences <em>b</em>etween any APO(a)-L<su<em>b</em>)Rx</su<em>b</em>) dose and place<em>b</em>o with respect to platelet counts, liver and renal measures, or influenza-like symptoms. The most common adverse events were injection-site reactions.</p><p><div>(<em>b</em>)CONCLUSIONS</<em>b</em>)</div>APO(a)-L<su<em>b</em>)Rx</su<em>b</em>) reduced lipoprotein(a) levels in a dose-dependent manner in patients who had elevated lipoprotein(a) levels and esta<em>b</em>lished cardiovascular disease. (Funded <em>b</em>y Akcea Therapeutics; ClinicalTrials.gov num<em>b</em>er, NCT03070782.).</p>

<A<em>b</em>stractText>Complete and timely tissue genotyping is challenging, leading to significant num<em>b</em>ers of patients with newly diagnosed metastatic non-small cell lung cancer (mNSCLC) <em>b</em>eing undergenotyped for all eight genomic <em>b</em>iomarkers recommended <em>b</em>y professional guidelines. We aimed to demonstrate noninferiority of comprehensive cell-free DNA (cfDNA) relative to physician discretion standard-of-care (SOC) tissue genotyping to identify guideline-recommended <em>b</em>iomarkers in patients with mNSCLC.</A<em>b</em>stractText><A<em>b</em>stractText>Prospectively enrolled patients with previously untreated mNSCLC undergoing physician discretion SOC tissue genotyping su<em>b</em>mitted a pretreatment <em>b</em>lood sample for comprehensive cfDNA analysis (Guardant360).</A<em>b</em>stractText><p><div>(<em>b</em>)RESULTS</<em>b</em>)</div>Among 282 patients, physician discretion SOC tissue genotyping identified a guideline-recommended <em>b</em>iomarker in 60 patients versus 77 cfDNA identified patients (21.3% vs. 27.3%; <i>P</i> &<em>lt</em>; 0.0001 for noninferiority). In tissue-positive patients, the <em>b</em>iomarker was identified alone (12/60) or concordant with cfDNA (48/60), an 80% cfDNA clinical sensitivity for any guideline-recommended <em>b</em>iomarker. For FDA-approved targets (<i>EGFR, ALK, ROS1, BRAF</i>) concordance was >98.2% with 100% positive predictive value for cfDNA versus tissue (34/34 <i>EGFR-, ALK-,</i> or <i>BRAF</i>-positive patients). Utilizing cfDNA, in addition to tissue, increased detection <em>b</em>y 48%, from 60 to 89 patients, including those with negative, not assessed, or insufficient tissue resu<em>lt</em>s. cfDNA median turnaround time was significantly faster than tissue (9 vs. 15 days; <i>P</i> &<em>lt</em>; 0.0001). Guideline-complete genotyping was significantly more likely (268 vs. 51; <i>P</i> &<em>lt</em>; 0.0001).</p><p><div>(<em>b</em>)CONCLUSIONS</<em>b</em>)</div>In the largest cfDNA study in previously untreated mNSCLC, a validated comprehensive cfDNA test identifies guideline-recommended <em>b</em>iomarkers at a rate at least as high as SOC tissue genotyping, with high tissue concordance, more rapidly and completely than tissue-<em>b</em>ased genotyping.<i>See related commentary <em>b</em>y Meador and Oxnard, p. 4583</i>.</p>

Intranasal immunization of mice with a chimeric VP6 protein and the mucosal adjuvant Escherichia coli heat labile toxin LT(R192G) induces nearly complete protection against murine rotavirus (strain EDIM [epizootic diarrhea of infant mice virus]) shedding for at least 1 year. The aim of this study was to identify the protective lymphocytes elicited by this new vaccine candidate. Immunization of mouse strains lacking one or more lymphocyte populations revealed that protection was dependent on alphabeta T cells but mice lacking gammadelta T cells and B cells remained fully protected. Furthermore, depletion of CD8 T cells in immunized B-cell-deficient mice before challenge resulted in no loss of protection, while depletion of CD4 T cells caused complete loss of protection. Therefore, alphabeta CD4 T cells appeared to be the only lymphocytes required for protection. As confirmation, purified splenic T cells from immunized mice were intraperitoneally injected into Rag-2 mice chronically infected with EDIM. Transfer of 2 x 10(6) CD8 T cells had no effect on shedding, while transfer of 2 x 10(5) CD4 T cells fully resolved shedding in 7 days. Interestingly, transfer of naive splenic CD4 T cells also resolved shedding but more time and cells were required. Together, these results establish CD4 T cells as effectors of protection against rotavirus after intranasal immunization of mice with VP6 and LT(R192G).

We investigated the ability of Salmonella typhimurium vaccines to deliver heterologous antigens to the systemic and secretory immune systems of the mouse, while retaining their immunogenicity against salmonellosis. S. typhimurium SL3261, an avirulent aroA mutant, or SL3261 carrying plasmid pBRD026, a pBR322 derivative encoding the gene for Escherichia coli LT-B were used to immunize BALB/c mice orally. Both immunizing strains invaded the mononuclear phagocyte system of the mice, grew slowly until approximately day 14 post-infection, and then were rapidly cleared. No salmonellae were detected in livers, spleens, mesenteric lymph nodes or Peyer's patches by day 42. Mice immunized with either strain and challenged orally with the virulent parent strain, SL1344, several weeks after clearing the immunizing organism, were protected against the lethal S. typhimurium infection. Mice infected with SL3261 (pBRD026) developed substantial levels of IgG and IgA anti-LT-B antibodies 14 days post-infection in both serum and gut samples. The sera neutralized the effects of LT in an in vitro Vero cell assay. Thus, aroA mutants of S. typhimurium can deliver a heterologous antigen from a different enteric pathogen to the murine systemic and secretory immune systems without altering their efficacy against salmonellosis.

BACKGROUND

Patients with more frequent exacerbations of chronic obstructive pulmonary disease (COPD) may have increased bronchial inflammation. Airway inflammation was measured in patients who had been thoroughly investigated with full pulmonary function testing, thoracic HRCT scanning, and sputum microbiology to examine further the relationship between exacerbation frequency and bronchial inflammation.

METHODS

Airway inflammation (spontaneous sputum sol phase myeloperoxidase (MPO), elastase, leukotriene (LT)B(4), interleukin (IL)-8, secretory leukoprotenase inhibitor (SLPI), protein leakage) and serum levels of C reactive protein (CRP) were compared in 40 patients with stable, smoking related COPD, divided into those with frequent >> or =3/year) or infrequent (< or =2/year) exacerbations according to the number of primary care consultations during the preceding year. The comparisons were repeated after excluding eight otherwise clinically indistinguishable patients who had tubular bronchiectasis on the HRCT scan.

RESULTS

Patients with frequent (n=12) and infrequent (n=28) exacerbations were indistinguishable in terms of their clinical, pulmonary function, and sputum characteristics, CRP concentrations, and all of their bronchial inflammatory parameters (p>0.05). The patients without evidence of tubular bronchiectasis (n=32) were equally well matched but the sputum concentrations of SLPI were significantly lower in the frequent exacerbators (n=8) in this subset analysis (p<0.05).

CONCLUSIONS

There are several clinical features that directly influence bronchial inflammation in COPD. When these were carefully controlled for, patients with more frequent reported exacerbations had lower sputum concentrations of SLPI. This important antiproteinase is also known to possess antibacterial and antiviral activity. Further studies are required into the nature of recurrent exacerbations and, in particular, the regulation and role of SLPI in affected individuals.

OBJECTIVE

This study was performed to compare the 2-nitroimidazole derivatives [124I]IAZA, [18F]FAZA and well known [18F]FMISO in visualization of tumor hypoxia in a mouse model of human cancer using small animal PET.

METHODS

PET imaging of female Balb/c nude mice bearing A431 tumors on a Phillips Mosaic small animal PET scanner was performed 3 h p.i. for all three tracers. Mice injected with [124I]IAZA were scanned again after 24 h and 48 h. In addition to the mice breathing air, in the case of [18F]FAZA and [124I]IAZA a second group of mice for each tracer was kept in an atmosphere of carbogen gas (5% of CO2 + 95 % of O2; from 1 h before to 3 h after injection) to evaluate the oxygenation dependency on uptake (all experiments n = 4). After the final PET scan animals were sacrificed and biodistribution was studied.

RESULTS

Mice injected with [18F]FAZA displayed significantly higher tumor-to background (T/B) ratios (5.19 +/- 0.73) compared to those injected with [18F]FMISO (3.98 +/- 0.66; P $lt; 0.05) or [124I]IAZA (2.06 +/- 0.26; P $lt; 0.001) 3 h p.i. Carbogen breathing mice showed lower ratios ([18F]FAZA: 4.06 +/- 0.59; [124I]IAZA: 2.02 +/- 0.36). The T/B ratios increased for [124I]IAZA with time (24 h: 3.83 +/- 0.61; 48 h: 4.20 +/- 0.80), but after these late time points the absolute whole body activity was very low, as could be seen from the biodistribution data (< 0.1 %ID/g for each investigated organ) and ratios were still lower than for [18F]FAZA 3 h p.i. Due to de-iodination uptake in thyroid was high. Biodistribution data were in good agreement with the PET results.

CONCLUSIONS

[18F]FAZA showed superior biokinetics compared to [18F]FMISO and [124I]IAZA in this study. Imaging at later time points that are not possible with the short lived 18F labeled tracers resulted in no advantage for [124I]IAZA, i. e. tumor to normal tissue ratios could not be improved.

Previous clinical studies have demonstrated the feasibility of using edible transgenic plants to deliver protective antigens as new oral vaccines. Transgenic corn is particularly attractive for this purpose since the recombinant antigen is stable and homogeneous, and corn can be formulated in several edible forms without destroying the cloned antigen. Transgenic corn expressing 1 mg of LT-B of Escherichia coli without buffer was fed to adult volunteers in three doses, each consisting of 2.1 g of plant material. Seven (78%) of nine volunteers developed rises in both serum IgG anti-LT and numbers of specific antibody secreting cells after vaccination. Four (44%) of nine volunteers also developed stool IgA. Transgenic plants represent a new vector for oral vaccine antigens.

The anthrax toxins lethal toxin (LT) and edema toxin (ET) are essential virulence factors produced by Bacillus anthracis. These toxins act during two distinct phases of anthrax infection. During the first, prodromal phase, which is often asymptomatic, anthrax toxins act on cells of the immune system to help the pathogen establish infection. Then, during the rapidly progressing (or fulminant) stage of the disease bacteria disseminate via a hematological route to various target tissues and organs, which are typically highly vascularized. As bacteria proliferate in the bloodstream, LT and ET begin to accumulate rapidly reaching a critical threshold level that will cause death even when the bacterial proliferation is curtailed by antibiotics. During this final phase of infection the toxins cause an increase in vascular permeability and a decrease in function of target organs including the heart, spleen, kidney, adrenal gland, and brain. In this review, we examine the various biological effects of anthrax toxins, focusing on the fulminant stage of the disease and on mechanisms by which the two toxins may collaborate to cause cardiovascular collapse. We discuss normal mechanisms involved in maintaining vascular integrity and based on recent studies indicating that LT and ET cooperatively inhibit membrane trafficking to cell-cell junctions we explore several potential mechanisms by which the toxins may achieve their lethal effects. We also summarize the effects of other potential virulence factors secreted by B. anthracis and consider the role of toxic factors in the evolutionarily recent emergence of this devastating disease.

Intrathymic transplantation of syngeneic islets into adolescent NOD/Lt mice was performed to establish whether the thymus would serve as an immunoprivileged site for beta-cell engraftment, and whether this treatment would prevent the development of diabetes by eliciting tolerance to islet antigens. Intrathymic injection of cells from 200 NOD islets into 4-wk-old female NOD/Lt mice produced a significant reduction in the severity of insulitis at 24 wk of age. Furthermore, diabetes development was strongly suppressed (11% incidence) compared with controls (100% incidence). Both thymus histology and thymic insulin content revealed a rapid loss of the implanted beta-cells with < 1% remaining 1 wk posttransplantation. Despite the rapid loss of thymus-implanted islet cells, evidence for tolerance induction to islet cell antigens was obtained by adoptive transfer of splenic leukocytes from these mice into NOD-scid/scid recipients. After adoptive transfer of splenic leukocytes from 24-wk-old untreated prediabetic donors, 4 of 5 NOD-scid/scid recipients developed diabetes within 4 wk, and none of the recipients became diabetic after transfer of splenocytes from intrathymic islet-implanted donors. Intrathymic islet transplantation did not lead to reduction of sialitis in females with reduced severity of insulitis, indicating that the protective effect was tissue specific. This also was reflected in adoptive transfer experiments, because equal severity of sialitis was observed in NOD-scid/scid recipients of spleen cells from either islet transplanted or control NOD/Lt mice. In conclusion, the data suggest that intrathymic injection of islet cells prevents diabetes by stimulating immunological tolerance to beta-cells.

Migration of mast cells is essential for their recruitment within target tissues where they play an important role in innate and adaptive immune responses. These processes rely on the ability of mast cells to recognize appropriate chemotactic stimuli and react to them by a chemotactic response. Another level of intercellular communication is attained by production of chemoattractants by activated mast cells, which results in accumulation of mast cells and other hematopoietic cells at the sites of inflammation. Mast cells express numerous surface receptors for various ligands with properties of potent chemoattractants. They include the stem cell factor (SCF) recognized by c-Kit, antigen, which binds to immunoglobulin E (IgE) anchored to the high affinity IgE receptor (FcεRI), highly cytokinergic (HC) IgE recognized by FcεRI, lipid mediator sphingosine-1-phosphate (S1P), which binds to G protein-coupled receptors (GPCRs). Other large groups of chemoattractants are eicosanoids [prostaglandin E(2) and D(2), leukotriene (LT) B(4), LTD(4), and LTC(4), and others] and chemokines (CC, CXC, C, and CX3C), which also bind to various GPCRs. Further noteworthy chemoattractants are isoforms of transforming growth factor (TGF) ββ serine/threonine type I and II β receptors, adenosine, C1q, C3a, and C5a components of the complement, 5-hydroxytryptamine, neuroendocrine peptide catestatin, tumor necrosis factor-α, and others. Here we discuss the major types of chemoattractants recognized by mast cells, their target receptors, as well as signaling pathways they utilize. We also briefly deal with methods used for studies of mast cell chemotaxis and with ways of how these studies profited from the results obtained in other cellular systems.

<A<em>b</em>stractText>The significance of the liver-micro<em>b</em>iome axis has <em>b</em>een increasingly recognised as a major modulator of autoimmunity. The aim of this study was to take advantage of a large well-defined corticosteroids treatment-naïve group of patients with autoimmune hepatitis (AIH) to rigorously characterise gut dys<em>b</em>iosis compared with hea<em>lt</em>hy controls.</A<em>b</em>stractText><A<em>b</em>stractText>We performed a cross-sectional study of individuals with AIH (n=91) and matched hea<em>lt</em>hy controls (n=98) <em>b</em>y 16S rRNA gene sequencing. An independent cohort of 28 patients and 34 controls was analysed to validate the resu<em>lt</em>s. All the patients were collected <em>b</em>efore corticosteroids therapy.</A<em>b</em>stractText><p><div>(<em>b</em>)RESULTS</<em>b</em>)</div>The gut micro<em>b</em>iome of steroid treatment-naïve AIH was characterised with lower alpha-diversity (Shannon and o<em>b</em>served operational taxonomic units, <em>b</em>oth p&<em>lt</em>;0.01) and distinct overall micro<em>b</em>ial composition compared with hea<em>lt</em>hy controls (p=0.002). Depletion of o<em>b</em>ligate anaero<em>b</em>es and expansion of potential patho<em>b</em>ionts including <i>Veillonella</i> were associated with disease status. Of note, <i>Veillonella dispar</i>, the most strongly disease-associated taxa (p=8.85E-8), positively correlated with serum level of aspartate aminotransferase and liver inflammation. Furthermore, the com<em>b</em>ination of four patients with AIH-associated genera distinguished AIH from controls with an area under curves of approximately 0.8 in <em>b</em>oth exploration and validation cohorts. In addition, mu<em>lt</em>iple predicted functional modules were a<em>lt</em>ered in the AIH gut micro<em>b</em>iome, including lipopolysaccharide <em>b</em>iosynthesis as well as meta<em>b</em>olism of amino acids that can <em>b</em>e processed <em>b</em>y <em>b</em>acteria to produce immunomodulatory meta<em>b</em>olites.</p><A<em>b</em>stractText>Our study esta<em>b</em>lishes compositional and functional a<em>lt</em>erations of gut micro<em>b</em>iome in AIH and suggests the potential for using gut micro<em>b</em>iota as non-invasive <em>b</em>iomarkers to assess disease activity.</A<em>b</em>stractText>

OBJECTIVE

To evaluate the impact of dosimetry based on MAA SPECT/CT for the prediction of response, toxicity and survival, and for treatment planning in patients with hepatocellular carcinoma (HCC) treated with (90)Y-loaded glass microspheres (TheraSphere®).

METHODS

TheraSphere® was administered to 71 patients with inoperable HCC. MAA SPECT/CT quantitative analysis was used for the calculation of the tumour dose (TD), healthy injected liver dose (HILD), and total injected liver dose. Response was evaluated at 3 months using EASL criteria. Time to progression (TTP) and overall survival (OS) were evaluated using the Kaplan-Meier method. Factors potentially associated with liver toxicity were combined to construct a liver toxicity score (LTS).

RESULTS

The response rate was 78.8%. Median TD were 342 Gy for responding lesions and 191 Gy for nonresponding lesions (p < 0.001). With a threshold TD of 205 Gy, MAA SPECT/CT predicted response with a sensitivity of 100% and overall accuracy of 90%. Based on TD and HILD, 17 patients underwent treatment intensification resulting in a good response rate (76.4%), without increased grade III liver toxicity. The median TTP and OS were 5.5 months (2-9.5 months) and 11.5 months (2-31 months), respectively, in patients with TD <205 Gy and 13 months (10-16 months) and 23.2 months (17.5-28.5 months), respectively, in those with TD >205 Gy (p = 0.0015 and not significant). Among patients with portal vein thrombosis (PVT) (n = 33), the median TTP and OS were 4.5 months (2-7 months) and 5 months (2-8 months), respectively, in patients with TD <205 Gy and 10 months (6-15.2 months) and 21.5 months (12-28.5 months), respectively, in those with TD >205 Gy (p = 0.039 and 0.005). The median OS was 24.5 months (18-28.5 months) in PVT patients with TD >205 Gy and good PVT targeting on MAA SPECT/CT. The LTS was able to detect severe liver toxicity (n = 6) with a sensitivity of 83% and overall accuracy of 97%.

CONCLUSIONS

Dosimetry based on MAA SPECT/CT was able to accurately predict response and survival in patients treated with glass microspheres. This method can be used to adapt the injected activity without increasing liver toxicity, thus defining a new concept of boosted selective internal radiation therapy (B-SIRT). This new concept and LTS enable fully personalized treatment planning with glass microspheres to be achieved.

(<em>b</em>)Background:</<em>b</em>) The lockdown and social distancing caused <em>b</em>y COVID-19 may influence common hea<em>lt</em>h <em>b</em>ehavior. The unprecedent worldwide confinement, in which Spain has <em>b</em>een one of the most affected-with severe rules governing confinement-may have changed physical activity (PA) and sedentary ha<em>b</em>its due to prolonged stays at home. (<em>b</em>)Purpose:</<em>b</em>) The aim of this study is to evaluate how self-reported PA and sedentary time (ST) have changed during confinement in the Spanish population. (<em>b</em>)Methods:</<em>b</em>) 3800 hea<em>lt</em>hy adu<em>lt</em>s (age 18-64 years) residing in Spain answered the international physical activity questionnaire short (IPAQ-S) twice <em>b</em>etween 23 March and 1 April (confinement). Data analysis was carried out taking into consideration meeting general PA recommendations <em>b</em>efore confinement, age and gender. (<em>b</em>)Resu<em>lt</em>s:</<em>b</em>) Self-reported PA decreased significantly during confinement in our sample. Vigorous physical activities (VPA) and walking time decreased <em>b</em>y 16.8% (<i>p</i> &<em>lt</em>; 0.001) and 58.2% (<i>p</i> &<em>lt</em>; 0.001), respectively, whereas ST increased <em>b</em>y 23.8% (<i>p</i> &<em>lt</em>; 0.001). The percent of people fulfilling the 75 min/week of VPA recommendation decreased <em>b</em>y 10.7% (<i>p</i> &<em>lt</em>; 0.001) while the percent of people who reached 150 min/week of moderate activity <em>b</em>arely changed (1.4%). The group that performed (<em>b</em>)the most</<em>b</em>) VPA <em>b</em>efore confinement showed the greatest decrease (30.5%, <i>p</i> &<em>lt</em>; 0.001). Men reduced time in VPA more than women (21% vs 9%, respectively) who even increased time in moderate PA <em>b</em>y 11% (<i>p</i> &<em>lt</em>; 0.05) and (<em>b</em>)reported</<em>b</em>) less increase in ST than men (35% vs 25.3%, respectively). (<em>b</em>)Conclusion:</<em>b</em>) The Spanish adu<em>lt</em> population, especially young people, students and very active men, decreased daily self-reported PA and increased ST during COVID-19 confinement.

Keywords: Covid-19; confinement; physical activity; sedentary behavior.