Extracellular vesicles of the probiotic bacteria E. coli O83 activate innate immunity and prevent allergy in mice

BACKGROUND

E. coli O83 (Colinfant Newborn) is a Gram-negative (G-) probiotic bacterium used in the clinic. When administered orally, it reduces allergic sensitisation but not allergic asthma. Intranasal administration offers a non-invasive and convenient delivery method. This route bypasses the gastrointestinal tract and provides direct access to the airways, which are the target of asthma prevention. G- bacteria such as E. coli O83 release outer membrane vesicles (OMVs) to communicate with the environment. Here we investigate whether intranasally administered E. coli O83 OMVs (EcO83-OMVs) can reduce allergic airway inflammation in mice.

METHODS

EcO83-OMVs were isolated by ultracentrifugation and characterised their number, morphology (shape and size), composition (proteins and lipopolysaccharide; LPS), recognition by innate receptors (using transfected HEK293 cells) and immunomodulatory potential (in naïve splenocytes and bone marrow-derived dendritic cells; BMDCs). Their allergy-preventive effect was investigated in a mouse model of ovalbumin-induced allergic airway inflammation.

RESULTS

EcO83-OMVs are spherical nanoparticles with a size of about 110 nm. They contain LPS and protein cargo. We identified a total of 1120 proteins, 136 of which were enriched in OMVs compared to parent bacteria. Proteins from the flagellum dominated. OMVs activated the pattern recognition receptors TLR2/4/5 as well as NOD1 and NOD2. EcO83-OMVs induced the production of pro- and anti-inflammatory cytokines in splenocytes and BMDCs. Intranasal administration of EcO83-OMVs inhibited airway hyperresponsiveness, and decreased airway eosinophilia, Th2 cytokine production and mucus secretion.

CONCLUSIONS

We demonstrate for the first time that intranasally administered OMVs from probiotic G- bacteria have an anti-allergic effect. Our study highlights the advantages of OMVs as a safe platform for the prophylactic treatment of allergy. Video Abstract.

Polymyxin B inhibits pro-inflammatory effects of E. coli outer membrane vesicles whilst increasing immune cell uptake and clearance

Polymyxin B (PMB) is a peptide based antibiotic that binds the lipid A moiety of lipopolysaccharide (LPS) with a resultant bactericidal effect. The interaction of PMB with LPS presented on outer membrane vesicles (OMVs) is not fully known, however, a sacrificial role of OMVs in protecting bacterial cells by sequestering PMB has been described. Here we assess the ability of PMB to neutralize the immune-stimulatory properties of OMVs whilst modulating the uptake of OMVs in human immune cells. We show for the first time that PMB increases immune cell uptake of Escherichia coli derived OMVs whilst inhibiting TNF and IL-1β production. Therefore, we present a potential new role for PMB in the neutralization of OMVs via LPS masking and increased immune cell uptake.

Special considerations for studies of extracellular vesicles from parasitic helminths: A community-led roadmap to increase rigour and reproducibility

Over the last decade, research interest in defining how extracellular vesicles (EVs) shape cross-species communication has grown rapidly. Parasitic helminths, worm species found in the phyla Nematoda and Platyhelminthes, are well-recognised manipulators of host immune function and physiology. Emerging evidence supports a role for helminth-derived EVs in these processes and highlights EVs as an important participant in cross-phylum communication. While the mammalian EV field is guided by a community-agreed framework for studying EVs derived from model organisms or cell systems [e.g., Minimal Information for Studies of Extracellular Vesicles (MISEV)], the helminth community requires a supplementary set of principles due to the additional challenges that accompany working with such divergent organisms. These challenges include, but are not limited to, generating sufficient quantities of EVs for descriptive or functional studies, defining pan-helminth EV markers, genetically modifying these organisms, and identifying rigorous methodologies for in vitro and in vivo studies. Here, we outline best practices for those investigating the biology of helminth-derived EVs to complement the MISEV guidelines. We summarise community-agreed standards for studying EVs derived from this broad set of non-model organisms, raise awareness of issues associated with helminth EVs and provide future perspectives for how progress in the field will be achieved.

Longevity of Trichuris trichiura infection in the human host

In this research, we present evidence-based data for the longevity of Trichuris trichiura on a healthy volunteer who had ingested eggs of T. trichiura. Hence, T. trichiura lives in a human host for at least 6 years and 5 months. Concurrently, this study highlighted consideration for returning travellers and migrants.

Helminths and COVID-19 susceptibility, disease progression and vaccination efficacy

Almost 2 years into the coronavirus disease 2019 (COVID-19) pandemic, it remains to be determined how helminths interact with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We discuss how helminths may alter susceptibility to infection, COVID-19 pathology, and the efficiency of vaccines by combined analysis of available COVID-19 data and previous investigations of the effect of helminths in viral infections.

Fluorescent Labeling of Helminth Extracellular Vesicles Using an In Vivo Whole Organism Approach

In the last two decades, extracellular vesicles (EVs) from the three domains of life, Archaea, Bacteria and Eukaryotes, have gained increasing scientific attention. As such, the role of EVs in host-pathogen communication and immune modulation are being intensely investigated. Pivotal to EV research is the determination of how and where EVs are taken up by recipient cells and organs in vivo, which requires suitable tracking strategies including labelling. Labelling of EVs is often performed post-isolation which increases risks of non-specific labelling and the introduction of labelling artefacts. Here we exploited the inability of helminths to de novo synthesise fatty acids to enable labelling of EVs by whole organism uptake of fluorescent lipid analogues and the subsequent incorporation in EVs. We showed uptake of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(lissamine rhodamine B sulfonyl) (DOPE-Rho) in Anisakis spp. and Trichuris suis larvae. EVs isolated from the supernatant of Anisakis spp. labelled with DOPE-Rho were characterised to assess the effects of labelling on size, structure and fluorescence of EVs. Fluorescent EVs were successfully taken up by the human macrophage cell line THP-1. This study, therefore, presents a novel staining method that can be utilized by the EV field in parasitology and potentially across multiple species.

Unique glycan and lipid composition of helminth-derived extracellular vesicles may reveal novel roles in host-parasite interactions

Although the study of helminth-derived extracellular vesicles (EVs) is in its infancy, proteomic studies of EVs from representatives of nematodes, cestodes and trematodes have identified homologs of mammalian EV proteins including components of the endosomal sorting complexes required for transport and heat-shock proteins, suggesting conservation of pathways of EV biogenesis and cargo loading between helminths and their hosts. However, parasitic helminth biology is unique and this is likely reflected in helminth EV composition and biological activity. This opinion article highlights two exceptional studies that identified EVs released by Heligmosomoides polygyrus and Fasciola hepatica which display differential lipid and glycan composition, respectively, when compared with EVs derived from mammalian cells. Furthermore, we discuss the potential implications of helminth EV lipid and glycan composition upon helminth infection and host pathology. Future studies, focusing on the unique composition and functional properties of helminth EVs, may prove crucial to the understanding of host-parasite communication.

AB0972 DEVELOPMENT OF THE PARENT VERSION OF THE JUVENILE ARTHRITIS DISEASE ACTIVITY SCORE CUT-OFFS FOR MODERATE AND HIGH DISEASE ACTIVITY STATES IN JUVENILE IDIOPATHIC ARTHRITIS IN A LARGE MULTINATIONAL PATIENT SAMPLE

Background:

Measurement of disease activity level is of pivotal importance in the care of patients with juvenile idiopathic arthritis (JIA). According to the most recent requirements, both, parent’s and children’s perception should be taken into account while evaluating the disease course and assessing effectiveness of therapy. Therefore, a new disease activity evaluation tool, based only on parent assessment of the outcome, is under development and named Parent Juvenile Arthritis Disease Activity Score (parJADAS) [1].

Objectives:

The aim of this study is to develop the parJADAS cut-off values of moderate disease activity (MDA) and high disease activity (HDA) in JIA patients.

Methods:

The parJADAS (score range 0-40) is the sum of 4 values: 1) parent’s assessment of disease activity on a 21-numbered circle 0-10 VAS; 2) assessment of pain intensity on a 21-numbered circle 0-10 VAS; 3) proxy assessment of joint disease up to a maximum of 10 joints; 4) assessment of morning stiffness (MS) on a Likert scale, ranging from no MS (0 points) to > 2 hours of MS (10 points). The study dataset is composed of 2,412 patients with JIA, seen in 3389 visits with parJADAS available, enrolled in the the multinational registry PharmaChild, assessing the long-term safety of treatment of children with JIA. At each visit, subjects were subjectively rated as being in inactive disease, low disease activity, MDA, or HDA by the attending physician. For each patient, only one visit per disease state was retained.

To identify the cut-offs the following methods were implemented: 1) Mapping: the 25thpercentile value of the parJADAS in patients having MDA or HDA, respectively, was calculated; 2) Youden Index: Youden Index (J) identifies the maximum potential effectiveness of the biomarker through the receiver operating characteristic (ROC) curve analysis; 3) Max agreement: The analysis of agreement was based on kappa statistics, which assesses the agreement beyond chance between 2 dichotomous ratings. The first rating was obtained using all possible parJADAS values as hypothetical test criteria; to obtain the second rating, the categorical ratings of each attending physician were dichotomized and were coded as 0 or 1.

Results:

Preliminary cut-off values for parJADAS with sensitivity and specificity are presented in the table.

25th centileYouden IndexKappaMeanSensitivitySpecificityAUCMDA659773.482.00.853HDA14.81118.51571.287.60.892

Conclusion:

Tentative cut-off values for classifying the states of MDA and HAD using parJADAS were calculated. The obtained values will be tested in the validation analysis. Once validated the cut-offs are ideally suited to identify subjects at risk of disease flare when remotely monitored with the parJADAS.

References:

[1]Ridella F., et al. Ann Rheum Dis, volume 78, supplement 2, year 2019, page A1434.

Acknowledgments:

We wish to thank all researchers and patients participating in the PharmaChild registry

Disclosure of Interests:

Ilia Avrusin: None declared, Roberta Naddei: None declared, Francesca Ridella: None declared, Giedre Januskeviciute: None declared, Mikhail Kostik: None declared, Ben Whitehead: None declared, Romina Gallizzi: None declared, Elzbieta Smolewska: None declared, Serena Pastore: None declared, Philip Hashkes: None declared, Joost F. Swart: None declared, Nicolino Ruperto Grant/research support from: Bristol-Myers Squibb, Eli Lily, F Hoffmann-La Roche, GlaxoSmithKline, Janssen, Novartis, Pfizer, Sobi (paid to institution), Consultant of: Ablynx, AbbVie, AstraZeneca-Medimmune, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Eli Lily, EMD Serono, GlaxoSmithKline, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, Sanofi, Servier, Sinergie, Sobi, Takeda, Speakers bureau: Ablynx, AbbVie, AstraZeneca-Medimmune, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Eli Lily, EMD Serono, GlaxoSmithKline, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, Sanofi, Servier, Sinergie, Sobi, Takeda, Angelo Ravelli: None declared, Alessandro Consolaro Grant/research support from: Pfizer Inc., AlfaSigma, Speakers bureau: AbbVie

Criteria for Elective Admission to the Paediatric Intensive Care Unit following Adenotonsillectomy for Severe Obstructive Sleep Apnoea

During the period 1997 to 2002, 42 children were electively admitted to the Paediatric Intensive Care Unit at the John Hunter Children's Hospital following adenotonsillectomy for severe obstructive sleep apnoea. Forty children had a preoperative sleep study, of which 33 were complete polysomnograms. Of the 42 children admitted, 35 required no intervention while seven (17%) required an additional intervention beyond supplemental oxygen. Our criteria for elective admission to Paediatric Intensive Care following adenotonsillectomy for severe obstructive sleep apnoea are presented.

Ultrasound as a Visual Feedback Aid for the Hearing-Impaired

Ultrasound was explored as a visual feedback aid to assist in improving the speech of the deaf and hard of hearing. A mechanical sector real-time scanner produced images of the volunteer's tongue while a speech pathologist provided therapeutic intervention. Pre and postarticulation tests were administered to evaluate change in speech.

Ultrasound as a visual feedback aid may be potentially useful for improving articulation problems for some hearing-impaired speakers. Further research with this population needs to be carried out to explore the practicality of using ultrasound as a visual feedback aid and to gather quantitative data on the long-term effects of learning.

This study has demonstrated that typical real-time sector ultrasound scanners, of the type found in the field today, can be modified to produce useful images of the human tongue during speech production. It is yet unknown what specific type of scanner as well as frequency range is best suited for tongue placement imaging.

Tumour exosomes display differential mechanical and complement activation properties dependent on malignant state: implications in endothelial leakiness

Background

Exosomes have been implicated in tumour progression and metastatic spread. Little is known of the effect of mechanical and innate immune interactions of malignant cell-derived exosomes on endothelial integrity, which may relate to increased extravasation of circulating tumour cells and, therefore, increased metastatic spread.

Methods

Exosomes isolated from non-malignant immortalized HCV-29 and isogenic malignant non-metastatic T24 and malignant metastatic FL3 bladder cells were characterized by nanoparticle tracking analysis and quantitative nanomechanical mapping atomic force microscopy (QNM AFM) to determine size and nanomechanical properties. Effect of HCV-29, T24 and FL3 exosomes on human umbilical vein endothelial cell (HUVEC) monolayer integrity was determined by transendothelial electrical resistance (TEER) measurements and transport was determined by flow cytometry. Complement activation studies in human serum of malignant and non-malignant cell-derived exosomes were performed.

Results

FL3, T24 and HCV-29 cells produced exosomes at similar concentration per cell (6.64, 6.61 and 6.46×10⁴ exosomes per cell for FL3, T24 and HCV-29 cells, respectively) and of similar size (120.2 nm for FL3, 127.6 nm for T24 and 117.9 nm for HCV-29, respectively). T24 and FL3 cell-derived exosomes exhibited a markedly reduced stiffness, 95 MPa and 280 MPa, respectively, compared with 1,527 MPa with non-malignant HCV-29 cell-derived exosomes determined by QNM AFM. FL3 and T24 exosomes induced endothelial disruption as measured by a decrease in TEER in HUVEC monolayers, whereas no effect was observed for HCV-29 derived exosomes. FL3 and T24 exosomes traffic more readily (11.6 and 21.4% of applied exosomes, respectively) across HUVEC monolayers than HCV-29 derived exosomes (7.2% of applied exosomes). Malignant cell-derived exosomes activated complement through calcium-sensitive pathways in a concentration-dependent manner.

Conclusions

Malignant (metastatic and non-metastatic) cell line exosomes display a markedly reduced stiffness and adhesion but an increased complement activation compared to non-malignant cell line exosomes, which may explain the observed increased endothelial monolayer disruption and transendothelial transport of these vesicles.

Comparative analysis of discrete exosome fractions obtained by differential centrifugation

Background

Cells release a mixture of extracellular vesicles, amongst these exosomes, that differ in size, density and composition. The standard isolation method for exosomes is centrifugation of fluid samples, typically at 100,000×g or above. Knowledge of the effect of discrete ultracentrifugation speeds on the purification from different cell types, however, is limited.

Methods

We examined the effect of applying differential centrifugation g-forces ranging from 33,000×g to 200,000×g on exosome yield and purity, using 2 unrelated human cell lines, embryonic kidney HEK293 cells and bladder carcinoma FL3 cells. The fractions were evaluated by nanoparticle tracking analysis (NTA), total protein quantification and immunoblotting for CD81, TSG101, syntenin, VDAC1 and calreticulin.

Results

NTA revealed the lowest background particle count in Dulbecco's Modified Eagle's Medium media devoid of phenol red and cleared by 200,000×g overnight centrifugation. The centrifugation tube fill level impacted the sedimentation efficacy. Comparative analysis by NTA, protein quantification, and detection of exosomal and contamination markers identified differences in vesicle size, concentration and composition of the obtained fractions. In addition, HEK293 and FL3 vesicles displayed marked differences in sedimentation characteristics. Exosomes were pelleted already at 33,000×g, a g-force which also removed most contaminating microsomes. Optimal vesicle-to-protein yield was obtained at 67,000×g for HEK293 cells but 100,000×g for FL3 cells. Relative expression of exosomal markers (TSG101, CD81, syntenin) suggested presence of exosome subpopulations with variable sedimentation characteristics.

Conclusions

Specific g-force/k factor usage during differential centrifugation greatly influences the purity and yield of exosomes. The vesicle sedimentation profile differed between the 2 cell lines.

Quantitative proteomics of fractionated membrane and lumen exosome proteins from isogenic metastatic and nonmetastatic bladder cancer cells reveal differential expression of EMT factors

Cancer cells secrete soluble factors and various extracellular vesicles, including exosomes, into their tissue microenvironment. The secretion of exosomes is speculated to facilitate local invasion and metastatic spread. Here, we used an in vivo metastasis model of human bladder carcinoma cell line T24 without metastatic capacity and its two isogenic derivate cell lines SLT4 and FL3, which form metastases in the lungs and liver of mice, respectively. Cultivation in CLAD1000 bioreactors rather than conventional culture flasks resulted in a 13- to 16-fold increased exosome yield and facilitated quantitative proteomics of fractionated exosomes. Exosomes from T24, SLT4, and FL3 cells were partitioned into membrane and luminal fractions and changes in protein abundance related to the gain of metastatic capacity were identified by quantitative iTRAQ proteomics. We identified several proteins linked to epithelial-mesenchymal transition, including increased abundance of vimentin and hepatoma-derived growth factor in the membrane, and casein kinase II α and annexin A2 in the lumen of exosomes, respectively, from metastatic cells. The change in exosome protein abundance correlated little, although significant for FL3 versus T24, with changes in cellular mRNA expression. Our proteomic approach may help identification of proteins in the membrane and lumen of exosomes potentially involved in the metastatic process.

Prospective study of antenatally diagnosed congenital cystic adenomatoid malformations

PURPOSE

Congenital cystic adenomatoid malformations (CCAMs) are increasingly diagnosed in recent years due to the routine usage of antenatal ultrasound. The aim of this study was to present the natural course and outcome of antenatally diagnosed cystic lung diseases, which were prospectively studied.

METHODS

Between the period June 2004 and June 2010, 25 fetuses with suspected CCAMs were seen in a single tertiary maternal fetal unit. One child was excluded as the fetal MRI suggested congenital diaphragmatic hernia. Data were prospectively entered into a database including antenatal and postnatal findings which were then analyzed.

RESULTS

Mean gestational age at the time of diagnosis was 20.8 weeks (range 17-29). Fetal interventions included amnioreduction (n = 2) and fetal thoracocentesis (n = 3) in one child. The mean gestational age at delivery was 38.5 weeks (range 31.6-40.6). None of the mothers underwent termination of pregnancy or spontaneous abortion. All patients underwent postnatal radiological assessment. Of the 24 cases, 5 children were symptomatic in the immediate neonatal period and 19 were asymptomatic. Anatomical surgical resection was undertaken in all symptomatic cases. There was one death in this group due to severe pre-existing pulmonary hypoplasia. Among the 19 asymptomatic cases, 5 children were managed conservatively as the lesions were not significant and the remaining 14 (73%) underwent surgical resection. The mean age at surgery was 11.1 months (range 3.3-34 months). Postnatal pathology confirmed CCAM in all operated cases, except one who had pulmonary sequestration.

CONCLUSION

Antenatally diagnosed CCAMs have an excellent prognosis except in children with a large lesion and associated with lung hypoplasia. Postnatal investigations are required in all cases to confirm the diagnosis. Symptomatic CCAMs require immediate surgery in the neonatal period with a good outcome. Asymptomatic CCAMs can be safely operated between 9 and 12 months of age.

Surveillance programme for important equine infectious respiratory pathogens in the USA

The prevalence and epidemiology of important viral (equine influenza virus [EIV], equine herpesvirus type 1 [EHV-1] and EHV-4) and bacterial (Streptococcus equi subspecies equi) respiratory pathogens shed by horses presented to equine veterinarians with upper respiratory tract signs and/or acute febrile neurological disease were studied. Veterinarians from throughout the USA were enrolled in a surveillance programme and were asked to collect blood and nasal secretions from equine cases with acute infectious upper respiratory tract disease and/or acute onset of neurological disease. A questionnaire was used to collect information pertaining to each case and its clinical signs. Samples were tested by real-time PCR for the presence of EHV-1, EHV-4, EIV and S equi subspecies equi. A total of 761 horses, mules and donkeys were enrolled in the surveillance programme over a 24-month study period. In total, 201 (26.4 per cent) index cases tested PCR-positive for one or more of the four pathogens. The highest detection rate was for EHV-4 (82 cases), followed by EIV (60 cases), S equi subspecies equi (49 cases) and EHV-1 (23 cases). There were 15 horses with double infections and one horse with a triple infection. The detection rate by PCR for the different pathogens varied with season and with the age, breed, sex and use of the animal.

A phase I, open-label study of the safety and pharmacokinetics (PK) of pazopanib (P) and lapatinib (L) administered concurrently

3088

Background: P is a potent tyrosine kinase inhibitor of VEGF-R1, -R2, and R3, PDGF-α/β, and c-Kit. L is a potent inhibitor of ErbB1 and ErbB2 tyrosine kinases. Several lines of evidence support combined inhibition of VEGFR and Erb in the treatment of malignancies. Methods: Patients (pts) with solid tumors received P and L daily. Safety, limited PK, biomarkers, and clinical activity were evaluated. Dose escalation occurred in cohorts of 3–6 pts based on DLT. Results: Thirty-three pts received L/P doses of 750/250 (n=4), 750/500 (n=6), 1000/250 (n=3), 1000/400 (n=2), 1000/500 (n=4), 1250/250 (n=6), 1250/400 (n=5) and 1500/200 (n=3) mg once daily (qd). Preliminary mean plasma P concentrations 24 h after administration (C24) on Day 22 were ∼19 μg/mL and 23 μg/mL after administration of 250 mg and 500 mg, respectively. These values are similar to mean C24 values observed after administration of 800 mg P alone (23.1 μg/mL). Plasma L concentrations at 750 - 1500 mg qd were similar to those observed after monotherapy. The most frequent AE’s were diarrhea (Grade (G)1 n=10, G2 n=2, G3 n=3), fatigue (G1: n=7, G2 n=5, G4 n=1), nausea (G1 n=9, G2 n=2), anorexia (G1 n=8, G2 n=3), vomiting (G1 n=9), hair depigmentation (n=7), rash (G1 n=6, G2 n=1) and abdominal cramps (G1 n=3, G2 n=2, G3 n=1). Prolonged disease stabilization of > 16 wks (median 21.5 wks) occurred in 10 pts (RCC n=3, CRC n=3, GIST n=1, mesothelioma n=1, adenocarcinoma GE junction n=1, aggressive fibromatosis n=1). 3 pts (renal cancer n=2, and giant cell tumor of the bone n=1) demonstrated tumor shrinkage of < 30% (i.e. SD by RECIST). Conclusions: Concurrent administration of pazopanib and lapatinib was generally well tolerated. Coadministration of lapatinib may alter the PK of pazopanib.

[Table: see text]

Exercise tolerance in children with cystic fibrosis undergoing lung transplantation assessment

The aim of this study was to compare the 6-min walk test against the recently developed 3-min step test, as measures of exercise tolerance in children with moderate to severe cystic fibrosis (CF) lung disease referred for lung transplantation assessment. Twenty-eight children with CF (16 girls, 12 boys), with a mean age of 13.7 yrs (range 7.2-17.8 yrs) and mean forced expiratory volume in one second of 34% predicted (range 17%-67%) were recruited. All subjects performed both the 6-min walk and 3-min step-tests. Outcome measures were maximum rise in heart rate (HR), and maximum fall in arterial oxygen saturation (Sa,O2). There was no significant difference in resting HR or Sa,O2 prior to starting the two tests. Both step and walk tests produced significant rises in median HR (from 114-149 min(-1), p<0.0005, and 119-138 min(-1), p<0.0005, respectively) and significant falls in Sa,O2 (both from 94-92%, p<0.0005). The step test produced a significantly greater percentage rise in HR (30% versus 18%, p<0.0005) and a significantly greater percentage fall in Sa,O2 (4% versus 2%, p=0.002). Bland-Altman analysis gave wide 95% limits of agreement (10.7-29.3% for rise in HR, -2.14.6% for fall in Sa,O2). The step test was well tolerated. The 3-min step test produced a greater fall in Sa,O2 and a greater rise in HR than the 6-min walk test in children with moderate to severe CF lung disease. It may be of value when assessing a child's suitability for lung transplantation.

Paediatric incidence of acute rejection and obliterative bronchiolitis: a comparison with adults

Obliterative bronchiolitis (OB) continues to be a major cause of morbidity and mortality following heart-lung transplantation. We compared the incidence of death from obliterative bronchiolitis in 19 children and 72 adults following heart-lung transplantation at our institutes. The incidence of death from OB at 2 years was 38% for children compared with 17% for adults, this difference was significant (Cox-Mantel Z value = 2.243, P < 0.05). The frequency of acute lung rejection and persistent lung rejection, previously described as risk factors for OB in adults, were significantly more common in children, P = 0.004 and P = 0.001, respectively. Average forced expiratory volume in 1 s was lower in children than in adults for each 3-month period after transplantation (P < 0.001). In conclusion, identified risk factors for the development of OB were more common, and the risk of death from OB was greater in children than in adults following heart-lung transplantation.

The effect of prelung transplant clinical status on post-transplant survival of children with cystic fibrosis

The aim of this study was to determine whether transplanting paediatric cystic fibrosis (CF) patients later in the course of their disease was detrimental to their post-transplant survival. Data was collected from 51 children with CF undergoing lung or heart-lung transplantation May 1988-March 1999. The following risk factors were tested by Cox proportional hazards modelling: age at transplant; sex; donor/recipient sex mismatch; donor/recipient cytomegalovirus (CMV) mismatch; cold and warm graft ischaemic times; and donor age. Pretransplant forced expiratory volume in one second (FEV1), minimum oxygen saturation obtained during 12 min walk (Sa,O2min), and a survival probability score (SP) calculated from FEV1, age adjusted resting heart rate, age, sex, blood haemoglobin (Hb), and serum albumin were then added to the model. None of the risk factors were significantly correlated with death during the study period. No evidence that clinical status prior to transplant has any effect upon the post-transplant survival of children with cystic fibrosis was found.

A model for predicting life expectancy of children with cystic fibrosis

In this study the authors aimed to produce a model for predicting the life expectancy of children with severe cystic fibrosis (CF) lung disease. The survival of 181 children with severe CF lung disease referred for transplantation assessment 1988-1998 (mean age 11.5 yrs, median survival without transplant 1.9 yrs from date of assessment) were studied. Proportional hazards modelling was used to identify assessment measurements that are of value in predicting longevity. The resultant model included low height predicted forced expiratory volume in one second (FEV1), low minimum oxygen saturation (Sa,O2min) during a 12-min walk, high age adjusted resting heart rate, young age, female sex, low plasma albumin, and low blood haemoglobin as predictors for poor prognosis. Extrapolation from the model suggests that a 12-yr old male child with an FEV1 of 30% pred and a Sa,O2min of 85% has a 44% risk of death within 2 yrs (95% confidence interval (CI) 35-54%), whilst a female child with the same measurements has a 63% risk of death (95% CI 52-73%) within the same period. The model produced may be of value in predicting the life expectancy of children with severe cystic fibrosis lung disease and in optimizing the timing of lung transplantation.

An investigation of the oral status and reported oral care of children with heart and heart-lung transplants

AIM

To investigate the oral health status and oral microflora of children who have received heart and heart-lung transplants. Parental knowledge and current practice of oral health procedures by the child were also investigated.

SAMPLE AND METHOD

Thirty-five children attending the Cardio-Thoracic Transplant Unit, Great Ormond Street Hospital for Children were included. Measurements were compared with children matched by age and gender attending the trauma clinic at the Department of Paediatric Dentistry, Eastman Dental Hospital. Teeth were examined for the presence or absence of caries or enamel defects. Plaque deposition, gingivitis, gingival bleeding and gingival enlargement were measured and a swab was taken to look at the oral microbial flora. A questionnaire was used to assess parental knowledge of dental health procedures and the current practice of these.

RESULTS

There were no significant differences between transplant and control children in caries experience, plaque or gingivitis. Children with heart or heart-lung transplants had significantly greater numbers of enamel defects and more gingival enlargement than control children, children in the heart transplant group had significantly more gingival bleeding. There was little difference in the dental knowledge and reported behaviour of the transplant group compared to the control group.

CONCLUSION

The dental needs of heart and heart-lung transplant patients treated at the Great Ormond Street Hospital for Children were similar to those of the control group in this study, however further improvement could be made in educating parents and children on the importance of caries prevention and good oral hygiene.

Lung transplantation and life extension in children with cystic fibrosis

BACKGROUND

Lung transplantation has been available as therapy for end-stage lung disease since the early 1980s, but survival after transplantation remains poor, with continued controversy as to the survival benefit from the procedure. We examined the effect of lung or heart-lung transplantation on the survival of a cohort of children with cystic fibrosis and severe lung disease.

METHODS

Between May, 1988, and May, 1998, 124 children with cystic fibrosis were accepted for lung transplantation. 47 received transplants, 68 died while they awaited organs, and nine remained on the active waiting list. We constructed a proportional-hazards model that used variables of prognostic significance in this population. By including transplant status as a time-dependent covariate, we were able to calculate a hazard ratio for transplantation. Date of entry into the study was the date when children were added to the list for transplantation, and measurements were taken at this time. Children were accepted for transplantation if they had a life expectancy of 2 years or less, a poor quality of life, and no contraindications to transplantation.

FINDINGS

After 1 year, 35 (74%) children were still alive; after 5 years 12 (33%) children were alive. The univariate hazard ratio for transplantation was 0.41 (95% CI 0.23-0.74; p=0.003). Transplantation remained significantly associated with survival after correction for differences in age, sex, height-corrected forced expiratory volume in 1 s, minimum oxygen saturation during a 12 min walk, haemoglobin concentration, albumin concentration, and age-corrected resting heart rate (hazard ratio 0.31 [0.13-0.72]; p=0.007).

INTERPRETATION

If centres follow our criteria for accepting patients for transplantation, and achieve similar survival after transplantation, they could expect a survival benefit for their patients in line with our results.

Heart or heart-lung transplantation: psychosocial outcome

The psychosocial outcome of 23 heart and 21 heart-lung transplant recipients, aged 5-17 yrs, was determined and compared with the psychosocial outcome of a group of 46 children and adolescents who underwent conventional cardiac surgery. Preoperatively, and 12 months post-operatively, the patients' physical health status, mental state (ICD-9) and level of psychosocial functioning (GAF scale, DSM-IIIR) were assessed. There was an improvement in physical health in all groups. Preoperatively, psychiatric disorder, including anxiety and phobic states, depression and adjustment reaction, was noted in 6/23 (26%) children assessed for heart transplantation, 6/21 (28.5%) children assessed for heart-lung transplantation, and 12/46 (26%) children undergoing conventional cardiac surgery. The prevalence of psychiatric disorder remained in the transplant group but decreased in the non-transplant comparison group (6.5%). Improvement in overall levels of psychosocial functioning were found in all groups, but over 40% of all the participants were still functioning below normal levels. In summary, children with end-stage cardio-respiratory disease benefit physically and psychologically from heart or heart-lung transplantation treatment but there is a need for systematic psychosocial support both before and after transplantation.

The EH1 domain of Eps15 is structurally classified as a member of the S100 subclass of EF-hand-containing proteins

The Eps15 homology (EH) domain is a protein-protein interaction module that binds to proteins containing the asparagine-proline-phenylalanine (NPF) or tryptophan/phenylalanine-tryptophan (W/FW) motif. EH domain-containing proteins serve important roles in signaling and processes connected to transport, protein sorting, and organization of subcellular structure. Here, we report the solution structure of the apo form of the EH1 domain of mouse Eps15, as determined by high-resolution multidimensional heteronuclear NMR spectroscopy. The polypeptide folds into six alpha-helices and a short antiparallel beta-sheet. Additionally, it contains a long, structured, topologically unique C-terminal loop. Helices 2-5 form two EF-hand motifs. Structural similarity and Ca(2+) binding properties lead to classification of the EH1 domain as a member of the S100 subclass of EF-hand-containing proteins, albeit with a unique set of interhelical angles. Binding studies using an eight-residue NPF-containing peptide derived from RAB, the cellular cofactor of the HIV Rev protein, show a hydrophobic peptide-binding pocket formed by conserved tryptophan and leucine residues.

Paranoid psychosis in an 11-year-old boy following cardiac transplantation

This is the first reported case of psychotic illness following pediatric cardiac transplantation. The case highlights diagnostic issues, and indicates a need for monitoring the psychological effects of cardiac transplantation in children.

Incomplete adherence after pediatric heart and heart-lung transplantation

BACKGROUND

Poor adherence to treatment after organ transplantation is life threatening. Clinical experience indicates that failure to adhere to the medical regimen after pediatric heart or heart-lung transplantation is more common than might be anticipated. This is the first empirical study of adherence in this population.

METHODS

The subjects were 53 children and adolescents (mean age 10.3 years) who underwent transplantation and were followed up for 12 months after transplantation. At each attendance blood levels of cyclosporine were measured and medical diaries checked. For children who had undergone heart-lung transplantation, serial measures of respiratory function were obtained, both at home and in the laboratory. Levels of adherence to the immunosuppressive therapy and completion of the medical diary were determined on the basis of prior operational definitions.

RESULTS

Satisfactory adherence to medication and satisfactory completion of the diaries were found in 37 children (70%). Satisfactory adherence to medication but unsatisfactory completion of the diaries were found in 11 children (21%). There was poor adherence to medication in 5 other children (9%) regardless of whether the diary was satisfactorily completed. Independent variables associated with poor adherence to medication were heart-lung as opposed to heart transplantation, one-parent or blended families, and family adjustment.

CONCLUSION

Nearly one third of the sample showed unsatisfactory adherence to the treatment regimen. This relatively high prevalence indicates the importance of close monitoring of adherence. The identification of family characteristics as risk factors indicates a need for more intensive psychoeducational family counseling in the 12 months after transplantation.

Effect of fingerspelling task on temporal characteristics and perceived naturalness of speech in simultaneous communication

This study investigated the effect of fingerspelling task length on temporal characteristics and perceived naturalness of speech produced during simultaneous communication. Stimulus words at four levels of fingerspelling task length were embedded in a sentence that was spoken and produced with simultaneous communication. Five temporal measures were calculated from acoustic recordings, and perceived speech naturalness was rated by a panel of listeners using a 9-point scale. Results indicated significant differences in temporal measures and naturalness ratings between the speech and simultaneous communication conditions and among levels of fingerspelling task length. Speech produced during simultaneous communication was rated as less natural and demonstrated increased interword interval, diphthong, word, and sentence durations. Regression analysis indicated significant correlations between temporal measures and perceived speech naturalness, and analysis of variance showed significant increases in segmental and interword interval durations and perceived speech unnaturalness as fingerspelling task length increased. These results are discussed in relation to previous findings regarding production and perception characteristics of speech that is altered in temporal parameters by a variety of conditions.

Measurement of (15)N- (1)H coupling constants in uniformly (15)N-labeled proteins: Application to the photoactive yellow protein

A modified HNHB experiment is presented that allows thedetermination of J(NH) coupling constants directly from the ratio ofcross-peak to diagonal-peak intensities. The experiment was applied to thephotoactive yellow protein (PYP) and yielded the magnitude of 117(3)J(NH(beta)) coupling constants. In addition, 29(3)J(NH(alpha(i-1))) coupling constantscould be measured, providing information about the backbone angle psi.These data, in conjunction with the magnitudes of the(3)J(H(N)H(alpha)) coupling constantsobtained from the HNHA spectrum, effectively discriminate the twopossibilities for the stereospecific assignment of theH(alpha) resonances in glycine residues. For all eight glycineresidues in PYP that were not subject to conformational averaging and hadnon-degenerate H(alpha) resonance frequencies, the J-couplingdata, together with limited NOE data, yielded the stereospecific assignmentof the H(alpha) resonances for these residues. In addition,reliable and precise phi,psi dihedral constraints were also derived forthese residues from the J-coupling data.

A 15n-filtered 2D 1H TOCSY experiment for assignment of aromatic ring resonances and selective identification of tyrosine ring resonances in proteins: Description and application to Photoactive Yellow Protein

A new method to selectively detect the ring resonances of the aromatic residues in 15N-labelled proteins is presented. The experiment consists of a 2D 1H TOCSY sequence withremoval of the amide signals via 15N-filtering. Experiments are acquired in the absence andpresence of water inversion; combining the two spectra allows selective observation of thetyrosine ring resonances and enables the identification of their delta andepsilon ring protons. The experiment is demonstrated on a 15N-labelled sample of Photoactive Yellow Protein and isshown to give good selectivity for tyrosine ring resonances under a wide range oftemperatures and pH values.

Psychosocial morbidity in children, and their families, awaiting heart or heart-lung transplantation

Awaiting heart or heart lung transplantation is a time of extreme stress for child and family, but there has been little evaluation of the psychosocial morbidity in this population. This preliminary study monitored changes in the mental health status of these children and their families. Fifty-one children considered suitable for transplantation and their families were assessed at the time of acceptance onto the waiting list and 6 months later. Twenty-five percent of the children had a psychiatric disorder, and 60% had a degree of impairment in psychosocial functioning. These high levels of morbidity indicate the need for a more comprehensive approach to treatment for this population.

Complexes formed between calmodulin and the antagonists J-8 and TFP in solution

The binding of the antagonists N-(8-aminooctyl)-5-iodonaphthalene-1-sulfonamide (J-8) and trifluoperazine (TFP) to intact calcium-saturated bovine calmodulin (CaM) and also of J-8 to the C-terminal domain (tr2c) has been investigated. Using a combination of NMR methods, including NOESY data, mobility measurements, and chemical shift and line-shape analysis, we show that the primary interaction between J-8 and tr2c is between the naphthalene ring of the antagonist and the hydrophobic pocket of the protein, similar to the binding of the hydrophobic side-chain residues of calmodulin target peptides. Comparison of the mobility of the drug, the intensity and pattern of intermolecular NOESY cross-peaks, and chemical shift changes shows that there is no significant change in the binding mode in J-8. CaM compared to J-8.tr2c, with one molecule binding to each domain. In particular, we find that the mobility of the aliphatic amino "tail" of J-8 remains highly mobile in both systems. This contrasts with the notion that the tail may bridge between the two domains to give a "globular" form of CaM. We also show that TFP induces very similar shift changes to J-8 and that the stoichiometry of the major binding event in all three cases is one drug molecule per domain. It also appears that secondary binding sites for the drug molecules are present in all three systems.

Voice onset time in speech produced during simultaneous communication

This study investigated speaking rate and voice onset time (VOT) in speech produced during simultaneous communication (SC) by speakers with normal hearing. Stimulus words initiated with voiced and voiceless plosives were embedded in a sentence that was spoken and produced with SC. VOT measures were calculated from acoustic recordings and results indicated significant differences between speech-only and SC conditions, with speech produced during SC demonstrating both slower speaking rate and increased VOT of voiceless consonants. VOTs produced during both SC and speech-only conditions followed English voicing rules and varied appropriately with place of articulation. The somewhat enlarged voicing contrast during SC was consistent with previous findings regarding the influence of rate changes on the temporal fine structure of speech (Miller, 1987) and was similar to the voicing contrast results reported for clear speech by Picheny, Durlach, and Braida (1986).

Cardiac transplantation in childhood cancer survivors in Great Britain

The aim of this study was to identify patients treated in Great Britain for childhood cancer and subsequently referred for cardiopulmonary transplantation in order to assess diagnosis, cancer treatment, management and outcome. Computerised record linkage between the National Registry of Childhood Tumours and the national transplant database held and maintained by the United Kingdom Transplant Support Service Authority (UKTSSA) was used to identify patients. Verification and clinical details were then obtained from the oncology and transplant centres. 16 patients were identified from the 31992 cases of childhood malignancy diagnosed in Britain since 1970. These comprised 13 heart transplants, 2 heart/lung transplants and 1 patient who died while on the heart transplantation waiting list. All 14 potential heart transplant patients had cardiomyopathy presumed secondary to anthracycline therapy. The original diagnoses were acute myeloblastic leukaemia (3), Wilms' tumour (4), rhabdomyosarcoma (2) and one each of five different solid tumours. Median age at diagnosis was 44 months (range 4-165 months). Median anthracycline dose was 413 mg/m2 (range 240-680 mg/m2). 13 of the 14 potential cardiac transplantation patients were more than 2 years from end of their cancer treatment before requiring transplantation and the transplantation was performed 2-126 months after onset of cardiac failure at a median age of 163 months. Five year actuarial survival from transplantation was 74%. There was no recurrence of the original malignancy in any of these patients. Both heart/lung patients died, 3 and 11 months after the transplant. These heart transplantation data suggest that, in Britain, survival compares favourably with that of patients whose heart transplant was required for other causes of cardiomyopathy. This indicates that patients successfully treated for childhood cancer should not be excluded from transplant programmes.

Pulmonary alveolar microlithiasis in childhood: diagnosis by transbronchial biopsy

A 7-year-old girl of Arabic origin by consanguineous parents presented with a miliary pattern on chest x-ray. Transbronchial lung biopsy revealed a histological diagnosis of pulmonary alveolar microlithiasis, a condition rarely described in childhood. This report highlights the clinical and radiological features, documents the transbronchial lung biopsy as a useful diagnostic procedure, and suggests a possible genetic etiology with autosomal recessive inheritance.

Ventricular expression and circulating levels of insulin-like growth factor I in heart transplant recipients

1. Insulin-like growth factor I is a major mediator of growth-promoting activities. We studied the ventricular insulin-like growth factor I gene expression at mRNA and peptide levels in 24 heart transplant recipients (14 children and 10 adults), using 'slot blot' hybridization with insulin-like growth factor I cDNA probe and a specific radioimmunoassay. 2. Ventricular insulin-like growth factor I mRNA was detected in all the cardiac transplant children but was below the limit of detection in the cardiac transplant adults. Ventricular insulin-like growth factor I levels were significantly higher in the transplant children [174 +/- 15 (SEM; range 39-950) pg/mg soluble protein] than in transplant adults [39 +/- 2 (range 14-85) pg/mg soluble protein, P < 0.01, n = 14]. Circulating levels of insulin-like growth factor I in the cardiac transplant children [164 +/- 10 (range 105-192) ng/ml] and adults [176 +/- 15 (range 126-244) ng/ml] were within normal ranges for children and adults. 3. These results suggest that the human heart is a site for insulin-like growth factor I production and provide support for an autocrine role for insulin-like growth factor I in the ventricle, despite cardiac denervation.

Evaluation of a training course on sexual counselling in a drug work setting

It has been repeatedly reported that while risks associated with the injecting behaviour of drug users has been reduced, no parallel changes have been made in sexual risk behaviour. Counselling advice to clients attending drug unit services has not focused sufficiently on the sexual behaviour of this client group. The present study evaluates the impact of a 4-day tailored training course on the counselling practices of two teams of drug workers at a London hospital. The course was designed following the experience and evaluation of a more general training course on sexual issues, and included information, group discussions, experiential learning and skills training. Results indicate that though there were no significant behavioural changes, some attitudinal changes have taken place; training appears to have increased the staff's awareness of the importance of sexual counselling and reduced the perceived difficulty of discussing certain specific sexual issues. The implications of single-agency training courses are discussed and recommendations are made for future training courses on the basis of the findings of this study.

Ventricular expression of brain natriuretic peptide gene following orthotopic cardiac transplantation in children--a three year follow up

OBJECTIVE

The aim was to examine ventricular brain natriuretic peptide (B-type natriuretic peptide, BNP) gene expression and to determine its relationship with ventricular BNP and circulating BNP levels in paediatric cardiac transplant recipients, over a three year period after transplantation.

METHODS

Total RNA extracted from endomyocardial right ventricular biopsy tissues (n = 26) of 13 cardiac transplant recipients (age range 5-17 years) and 10 normal hearts obtained at necropsy (age range 19-76 years) as controls was analysed by northern and slot blot hybridisations. Specific radioimmunoassay techniques were used to determine levels of BNP and atrial natriuretic peptide (A-type natriuretic peptide, ANP) in plasma (n = 26) and ventricular biopsy (n = 26) samples.

RESULTS

Ventricular BNP messenger ribonucleic acid (mRNA) levels from slot blot hybridisations in the transplanted heart [122(3) arbitrary units, range 97-143] were significantly higher (p < 0.01) than in the normal heart [63(5) arbitrary units, range 37-98]. Northern blot hybridisations confirmed this result and gave a major BNP mRNA transcript of approximately 900 nucleotides. There was no significant relationship between ventricular BNP mRNA levels and ventricular BNP (r = 0.15, p = 0.5, n = 26) or plasma BNP levels (r = 0.16, p = 0.4, n = 26). There was also no significant relationship between ventricular BNP mRNA levels and any of the haemodynamic variables, or immunosuppressive drugs. A ventricular ANP RNA transcript of approximately 900 nucleotides was detected in the transplanted heart but was below the limit of detection in the normal heart. For the long term study, increased levels of BNP and ANP in both plasma and ventricular samples were observed in the first year after transplantation, with a significant reduction (p < 0.01) in levels three years later.

CONCLUSIONS

Ventricular BNP gene expression is increased at the mRNA level after heart transplantation in children. Expression of both ventricular BNP mRNA and ANP mRNA in the transplanted heart may be an important response in the modulation of cardiac function after transplantation.

Incidence of obliterative bronchiolitis after heart-lung transplantation in children

Between June 1988 and February 1993, combined heart-lung transplantation was performed in 30 children and adolescents aged 3.6 to 18.6 years (mean, 12.2 years) at The Hospital for Sick Children in London. Original diagnoses included cystic fibrosis (n = 25), Eisenmenger's syndrome (n = 4), and chronic graft-versus-host disease of the lung (n = 1). Posttransplantation maintenance immunosuppression comprised a triple regimen, with methylprednisolone and antithymocyte globulin given perioperatively and for episodes of allograft rejection. Actuarial survival was 63% (95% confidence interval: 42%-78%) at 1 year and 48% (95% confidence interval: 27%-66%) at 3 years. Obliterative bronchiolitis has been diagnosed in 13 patients (43%). Actuarial freedom from obliterative bronchiolitis in survivors was 76%, 59%, and 37% at 12, 24, and 36 months after transplantation, respectively. Recipients in whom obliterative bronchiolitis developed within the first year (n = 6) had more episodes of pulmonary rejection during the first 6 months after transplantation (mean, 5.7 episodes per patient) than those in whom "premature" obliterative bronchiolitis did not develop (mean, 3.2 episodes per patient). Infection of the pulmonary allograft was implicated to a lesser extent in predisposing to obliterative bronchiolitis. At 2, 3, and 6 months, tracheal stenosis developed in three patients, all of whom died with obliterative bronchiolitis within 10 months of transplantation. Noncompliance with therapy was considered a contributory factor in producing obliterative bronchiolitis in four adolescent recipients. The high incidence of obliterative bronchiolitis observed in this pediatric cohort may have a multifactorial cause.