Recent studies have reported that patients with von Willebrand disease treated perioperatively with a von Willebrand factor (VWF)/factor VIII (FVIII) concentrate with a ratio of 2.4:1 (Humate ...P/Haemate P) often present with VWF and/or FVIII levels outside of prespecified target levels necessary to prevent bleeding. Pharmacokinetic (PK)-guided dosing may resolve this problem. As clinical guidelines increasingly recommend aiming for certain target levels of both VWF and FVIII, application of an integrated population PK model describing both VWF activity (VWF:Act) and FVIII levels may improve dosing and quality of care. In total, 695 VWF:Act and 894 FVIII level measurements from 118 patients (174 surgeries) who were treated perioperatively with the VWF/FVIII concentrate were used to develop this population PK model using nonlinear mixed-effects modeling. VWF:Act and FVIII levels were analyzed simultaneously using a turnover model. The protective effect of VWF:Act on FVIII clearance was described with an inhibitory maximum effect function. An average perioperative VWF:Act level of 1.23 IU/mL decreased FVIII clearance from 460 mL/h to 264 mL/h, and increased FVIII half-life from 6.6 to 11.4 hours. Clearly, in the presence of VWF, FVIII clearance decreased with a concomitant increase of FVIII half-life, clarifying the higher FVIII levels observed after repetitive dosing with this concentrate. VWF:Act and FVIII levels during perioperative treatment were described adequately by this newly developed integrated population PK model. Clinical application of this model may facilitate more accurate targeting of VWF:Act and FVIII levels during perioperative treatment with this specific VWF/FVIII concentrate (Humate P/Haemate P).
•The developed population PK model could adequately describe the interaction between VWF and FVIII in perioperative patients with VWD.•Presence of VWF decreases FVIII clearance, clarifying FVIII accumulation over time as observed after multiple VWF/FVIII concentrate doses.
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Autophagy is a cellular process through which toxic aggregates, pathogens, and damaged organelles are disposed of and essential metabolites recycled. This study challenges the belief that a core ...autophagy protein is indispensable.
A validated in vitro model of the large intestine (TIM‐2), set up with human or pig faeces, was used to evaluate the impact of potentially probiotic Lactobacillus amylovorus DSM 16698, administered ...alone (i), in the presence of prebiotic galactooligosaccharides (GOS) (ii), and co‐administered with probiotic Bifidobacterium animalis ssp. lactis Bb‐12 (Bb‐12) (iii) on GOS degradation, microbial growth (L. amylovorus, lactobacilli, bifidobacteria and total bacteria) and metabolite production. High performance anion exchange chromatography revealed that GOS degradation was more pronounced in TIM‐2 inoculated with pig faeces than with human faeces. Denaturing gradient gel electrophoresis profiling of PCR‐amplified 16S rRNA genes detected a more complex Lactobacillus spp. community in pig faecal material than in human faecal inoculum. According to 16S rRNA gene‐targeted qPCR, GOS stimulated the growth of lactobacilli and bifidobacteria in faecal material from both materials. The cumulative production of short chain fatty acids and ammonia was higher (P < 0.05) for pig than for human faeces. However, lactate accumulation was higher (P < 0.05) in the human model and increased after co‐administration with GOS and Bb‐12. This study reinforced the notion that differences in microbiota composition between target host organisms need to be considered when animal data are extrapolated to human, as is often done with pre‐ and probiotic intervention studies.
The Cnr (Colourless non-ripening) tomato (Lycopersicon esculentum Mill.) mutant has an aberrant fruit-ripening phenotype in which fruit do not soften and have reduced cell adhesion between pericarp ...cells. Cell walls from Cnr fruit were analysed in order to assess the possible contribution of pectic polysaccharides to the non-softening and altered cell adhesion phenotype. Cell wall material (CWM) and solubilised fractions of mature green and red ripe fruit were analysed by chemical, enzymatic and immunochemical techniques. No major differences in CWM sugar composition were detected although differences were found in the solubility and composition of the pectic polysaccharides extracted from the CWM at both stages of development. In comparison with the wild type, the ripening-associated solubilisation of homogalacturonan-rich pectic polysaccharides was reduced in Cnr. The proportion of carbohydrate that was chelator-soluble was 50% less in Cnr cell walls at both the mature green and red ripe stages. Chelator-soluble material from ripe-stage Cnr was more susceptible to endo-polygalacturonase degradation than the corresponding material from wild-type fruit. In addition, cell walls from Cnr fruit contained larger amounts of galactosyl- and arabinosyl-containing polysaccharides that were tightly bound in the cell wall and could only be extracted with 4 M KOH, or remained in the insoluble residue. The complexity of the cell wall alterations that occur during fruit ripening and the significance of different extractable polymer pools from cell walls are discussed in relation to the Cnr phenotype.
There is a growing tendency to estimate energy requirements by means of the assessment of resting energy expenditure (REE) by indirect calorimetry. In this study a computerized open-circuit ...ventilated hood system is described that was constructed for assessing REE in a clinical setting. Measurement error of the device, tested by ethanol combustion was +2% for VO2 and VCO2 and less than 1% for respiratory quotient. To assess the within-patient variability of REE measurements performed in a daily clinical routine, we studied the following aspects of the measurements in several groups of patients with chronic obstructive pulmonary disease: (1) reproducibility, (2) the influence of routine physical activities before the measurement, (3) measurement duration, and (4) difference between measurements using a ventilated hood or a mouthpiece. Reproducibility of measurements with a 2-month interval in 12 weight-stable patients was good (1415 +/- 128 and 1398 +/- 138 kcal/day). Variations due to limited activities and different measurement durations (between 10 and 30 minutes) were not significant. Variations between measurements with a mouthpiece and ventilated hood were larger in patients than in healthy control subjects, but for both groups no systematic difference was established. REE can be assessed reliably by short-term measurements with a ventilated hood in stable chronic obstructive pulmonary disease patients on an outpatient basis, provided a short rest is taken before the measurement.
The kinetics of cellulose hydrolysis by commercially available Cellubrix were described mathematically, with Avicel and wheat straw as substrates. It was demonstrated that hydrolysis could be ...described by three reactions: direct glucose formation and indirect glucose formation via cellobiose. Hydrolysis did not involve any soluble oligomers apart from low amounts of cellobiose. Phenomena included in the mathematical model were substrate limitation, adsorption of enzyme onto substrate, glucose inhibition, temperature dependency of reaction rates, and thermal enzyme inactivation. In addition, substrate heterogeneity was described by a recalcitrance constant. Model parameters refer to both enzyme characteristics and substrate-specific characteristics.
Quantitative model development was carried out on the basis of Avicel hydrolysis. In order to describe wheat straw hydrolysis, wheat straw specific parameter values were measured. Updating the pertinent parameters for wheat straw yielded a satisfactory description of wheat straw hydrolysis, thus underlining the generic potential of the model.
Background:
Inherited platelet disorders (IPDs) are disorders consisting of thrombocytopenia, thromobocytopathy or a combination of these. Diagnosis is often hampered by the lack of specificity and ...correct validation of current hematological assays. In addition, these disorders exhibit a genetic heterogeneity with over 50 genes involved.
Aims:
This study evaluates an upfront diagnostic strategy using whole‐exome sequencing (WES) with a targeted analysis of a panel of 145 genes involved in thrombosis and hemostasis in patients suspected for an IPD.
Methods:
Sixty‐Six patients suspicious for an IPD were subjected to WES, followed by targeted analysis of 145 genes (besides platelet genes also genes involved in coagulation and venous thrombosis embolism are analyzed). Variants were classified according to the five‐tier (class 1 to class 5) scheme.
Results:
Fourteen patients (21%) harbored (likely) pathogenic variants that explained the clinical spectrum in these patients. Genes affected in these patients were GP9, MYH9 (2 cases), NBEAL2, P2RY12, RUNX1 (3 cases), SLFN14 and VWF (2 cases), all these genes are involved in thrombocytopenia or thromobocytopathy. In the disorders with an autosomal recessive mode of inheritance either the mutation was homozygous (GP9 and P2RY12), or compound heterozygous (NBEAL2). Additionally, 2 patients with a mutation in the THPO gene and 1 patient with a mutation in SEPRINC1 were observed, both genes are known to be involved in venous thrombosis.
In 4 (6%) other patients only one heterozygous (likely) pathogenic variant of an autosomal recessive disease gene was observed. In 12 patients (18%) a variant of unknown significance (VUS/class 3) was observed. Further segregation studies within the family and functional studies are required to fully solve these cases.
Summary/Conclusion:
We found that WES is a powerful tool in genetically diagnosing patients with IPD.
BACKGROUND
The aim of this study was to test the hypothesis that the chronic inflammatory process present in chronic obstructive pulmonary disease (COPD) is due to a defective endogenous ...anti-inflammatory mechanism.
METHODS
Systemic levels of the anti-inflammatory mediators soluble interleukin 1 receptor II (sIL-1RII), soluble tumour necrosis factor receptor p55 (sTNF-R55) and sTNF-R75, and of C reactive protein (CRP) and lipopolysaccharide binding protein (LBP) were analysed in 55 patients with stable COPD (median forced expiratory volume in one second (FEV
1
) 34% predicted (range 15–78)) and compared with levels in 23 control subjects. In addition, changes in these mediators were studied in 13 patients with COPD (median FEV
1
34% predicted (range 19–51)) during the first 7 days in hospital with an exacerbation of the disease.
RESULTS
Patients with stable COPD were characterised by a systemic inflammatory process indicated by an increased leucocyte count (7.2 (4.7–16.4)
v
4.8 (3.5–8.3) × 10
9
/l), raised levels of CRP (11.8 (1.1–75.0)
v
4.1 (0.6–75.0) μg/ml) and LBP (45.6 (8.1–200.0)
v
27.9 (14.1–71.5) μg/ml), and moderate increases in both sTNF-Rs. In contrast, the sIL-1RII level did not differ between patients and controls (4.53 (2.09–7.60)
v
4.63 (3.80–5.93) ng/ml). During treatment of disease exacerbations, systemic levels of both CRP (at day 3) and LBP (at day 7) were significantly reduced compared with day 1, whereas sIL-1RII levels increased.
CONCLUSIONS
These data suggest an imbalance in systemic levels of pro- and anti-inflammatory mediators in patients with stable COPD. The increase in the anti-inflammatory mediator sIL-1RII during treatment of exacerbations may contribute to the clinical improvement.
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