Broncho-alveolar lavage fluid recovery correlates with airway neutrophilia in lung transplant patients

SummaryBroncho-alveolar lavage (BAL) is important to assess airway inflammation. There is debate about the volume instilled, but the variation of BAL fluid recovery (BFR) has received little attention. We investigated the association between BFR and rejection/infection status after lung transplantation (LTx).We combined clinical findings, FEV1, transbronchial biopsies and BAL analysis (BFR, interleukin-8 (IL8), cell counts, microbiology) of 115 samples/LTx patients. The patients were divided into 4 groups: stable (subdivided in colonized and non-colonized), acute rejection (AR), Bronchiolitis Obliterans Syndrome (BOS) and infection.BFR was significantly lower in AR, BOS and infection, and correlated with the severity of AR and BOS. A 10ml decrease of BFR was associated with a FEV1 decrease of 4.4% and a %neutrophils and IL8 increase of 9.6% and 9.7pg/ml, respectively. Colonized stable patients had no significant differences in airway inflammation, FEV1 and BFR compared to the non-colonized stable patients.We conclude that a low BFR is an indicator of lung rejection or infection. BFR variation is related to airway obstruction and neutrophilic inflammation, which can cause an increased compliance of the airway wall, making it more collapsible. Airway colonization in stable patients had no effect on airway inflammatory parameters, BFR and FEV1

Detection of literacy problems in the educational domain of adult second language learners

Background Our society is characterized by a large diversity of languages. A vast number of inhabitants of Belgium start learning Dutch when they’re already adults. Because dyslexia occurs throughout all languages, this population might also exhibit literacy problems. However, the detection of the problems with second language learners is more complex. There’ s a need for suitable tests with adapted norm scores to detect limited literacy of adult second language learners of Dutch. Method A group of 88 adult second language learners following an intensive Dutch course (4x3h/ week) at the same instructional level (CEFR start B1) performed a standardized Dutch word reading test at three difficulty levels. The number of words read and those correctly read within three minutes was calculated and the influence of different background factors was analyzed. Moreover, a qualitative analysis of the results and error patterns is presently performed. Results Although a higher number of errors occurred in the reading tasks, the number of words read and those correctly read at the different reading levels followed a normal distribution. The educational background level and the number of years the test subjects had been living in Belgium had a significant influence on the scores of the reading test, mainly at the lowest reading level. Conclusion The measured standardized word reading test with adapted norm scores seems to be suitable as a first indication of the need for a larger diagnostic assessment. A combination of reading speed and accuracy for multisyllable words give the most reliable results.status: publishe

The Leuven experience with a dichotomy in Bronchiolitis Obliterans Syndrome (BOS) after lung transplantation revealed by azithromycin

BOS is the most important cause of late mortality after LTx. Until 5 years ago, the prevalence was around 30% and 50%, 3 and 5 years after LTx. Introduction of azithromycin (AZI) improved the FEV1 in 40% of BOS patients. AZI treatment may explain why in our center, the BOS prevalence at 3 years has decreased from 30% to 15% compared to the ISHLT registry. Opposed to the current belief about BOS, we hypothesize a dichotomy within BOS: Neutrophilic Reversible Allograft Dysfunction (NRAD) and fibropoliferative BOS (fBOS; table 1). This dichotomy is based on the discrepancy in AZI response and observations within our center consisting of clinical, biochemical and cellular (BAL) analysis

The mode of death in the non-heart-beating donor has an impact on lung graft quality

Objective: We hypothesised that the agonal phase prior to cardiac death may negatively influence the quality of the pulmonary graft recovered from non-heart-beating donors (NHBDs). Different modes of death were compared in an experimental model. Methods: Non-heparinised pigs were divided into three groups (n=6 per group). Animals in group I [FIB] were sacrificed by ventricular fibrillation resulting in immediate circulatory arrest. In group II [EXS], animals were exsanguinated (45+/-11min). In group III [HYP], hypoxic cardiac arrest (13+/-3min) was induced by disconnecting the animal from the ventilator. Blood samples were taken pre-mortem in HYP and EXS for measurement of catecholamine levels. After 1h of in situ warm ischaemia, unflushed lungs were explanted and stored for 3h (4 degrees C). Left lung performance was then tested during 60min in our ex vivo reperfusion model. Total protein concentration in bronchial lavage fluid was measured at the end of reperfusion. Results: Pre-mortem noradrenalin (mcgl(-1)) concentration (baseline: 0.03+/-0) increased to a higher level in HYP (50+/-8) vs EXS (15+/-3); p=0.0074. PO(2) (mmHg) at 60min of reperfusion was significantly worse in HYP compared to FIB (445+/-64 vs 621+/-25; p<0.05), but not to EXS (563+/-51). Pulmonary vascular resistance (dynesscm(-5)) was initially higher in EXS (p<0.001) and HYP (NS) vs FIB (15824+/-5052 and 8557+/-4933 vs 1482+/-61, respectively) but normalised thereafter. Wet-to-dry weight ratio was higher in HYP compared to FIB (5.2+/-0.3 vs 4.7+/-0.2, p=0.041), but not to EXS (4.9+/-0.2). Total protein (gl(-1)) concentration was higher, although not significant in HYP and EXS vs FIB (18+/-6 and 13+/-4 vs 4.5+/-1.3, respectively). Conclusion: Pre-mortem agonal phase in the NHBD induces a sympathetic storm leading to capillary leak with pulmonary oedema and reduced oxygenation upon reperfusion. Graft quality appears inferior in NHBD lungs when recovered in controlled (HYP) vs uncontrolled (EXS and FIB) setting.status: publishe

High-level expression, purification, and characterization of recombinant wheat xylanase inhibitor TAXI-I secreted by the yeast Pichia pastoris

Triticum aestivum xylanase inhibitor I (TAXI-I) is a wheat protein that inhibits microbial xylanases belonging to glycoside hydrolase family 11. In the present study, recombinant TAXI-I (rTAXI-I) was successfully produced by the methylotrophic yeast Pichia pastoris at high expression levels (approximately 75 mg/L). The rTAXI-I protein was purified from the P. pastoris culture medium using cation exchange and gel filtration chromatographic steps. rTAXI-I has an iso-electric point of at least 9.3 and a mass spectrometry molecular mass of 42,013 Da indicative of one N-linked glycosylation. The recombinant protein fold was confirmed by circular dichroism spectroscopy. Xylanase inhibition by rTAXI-I was optimal at 20-30 degrees C and at pH 5.0. rTAXI-I still showed xylanase inhibition activity at 30 degrees C after a 40 min pre-incubation step at temperatures between 4 and 70 degrees C and after 2 h pre-incubation at room temperature at a pH ranging from 3.0 to 12.0, respectively. All tested glycoside hydrolase family 11 xylanases were inhibited by rTAXI-I whereas those belonging to family 10 were not. Specific inhibition activities against family 11 Aspergillus niger and Bacillus subtilis xylanases were 3570 and 2940IU/mg protein, respectively. The obtained biochemical characteristics of rTAXI-I produced by P. pastoris (no proteolytical cleft) were similar to those of natural TAXI-I (mixture of proteolytically processed and non-processed forms) and non-glycosylated rTAXI-I expressed in Escherichia coli. The present results show that xylanase inhibition activity of TAXI-I is only affected to a limited degree by its glycosylation or proteolytic processing.status: publishe

Interfacing silicon photonics for CPO

We report the development of high-yield and scalable optical coupling interfaces for CPO. Two concepts are discussed, a polymer waveguide based optical redistribution layer, and a micro-lens based free-space coupling interface. We detail both design, fabrication, assembly and characterization results, and provide a discussion on the applicability for CPO