Assessment of Epithelial Lining Fluid Partitioning of Systemically Administered Monoclonal Antibodies in Rats

For systemically administered monoclonal antibodies (mAbs) with pharmacological targets in the epithelial lining fluid (ELF), information on the partitioning of mAb between plasma and ELF is instrumental for dose predictions. Bronchoalveolar lavage (BAL) combined with measurements of urea as indicator of sample dilution is often used to estimate ELF concentrations of a drug. However, unbalanced extraction of mAb and urea could potentially lead to a systematic bias in the back-calculated ELF concentration. In the present study 0.5, 1, or 4 mL phosphate-buffered saline was instilled to lungs of rats to obtain lavage samples after systemic dosing of mAb and tool small molecule (n≥4/group). Furthermore, extraction of urea, mAb and the small molecule was assessed by repeatedly lavaging the lung (n = 4). There was no statistically significant difference in the calculated partitioning into ELF between the evaluated instillation volumes. Repeated BAL demonstrated that urea and the small molecule were extracted from other sources than the ELF. In contrast, there was limited to none in-flow of mAb into the lavage fluid. The unbalanced extraction of urea and mAb could theoretically result in underestimated ELF concentrations and the calculated partitioning of 0.17±0.062 might therefore constitute a lower boundary for the true partitioning.

Storing keV negative ions for an hour: the lifetime of the metastable ^(2)P((1/2)^(o)) level in ^(32)S^(-)

We use a novel electrostatic ion storage ring to measure the radiative lifetime of the upper level in the 3p^{5} ^{2}P_{1/2}^{o}→3p^{5} ^{2}P_{3/2}^{o} spontaneous radiative decay in ^{32}S^{-} to be 503±54  sec. This is by orders of magnitude the longest lifetime ever measured in a negatively charged ion. Cryogenic cooling of the storage ring gives a residual-gas pressure of a few times 10^{-14} mbar at 13 K and storage of 10 keV sulfur anions for more than an hour. Our experimental results differ by 1.3σ from the only available theoretical prediction [P. Andersson et al., Phys. Rev. A 73, 032705 (2006)].

First storage of ion beams in the Double Electrostatic Ion-Ring Experiment: DESIREE

We report on the first storage of ion beams in the Double ElectroStatic Ion Ring ExpEriment, DESIREE, at Stockholm University. We have produced beams of atomic carbon anions and small carbon anion molecules (C(n)(-), n = 1, 2, 3, 4) in a sputter ion source. The ion beams were accelerated to 10 keV kinetic energy and stored in an electrostatic ion storage ring enclosed in a vacuum chamber at 13 K. For 10 keV C2 (-) molecular anions we measure the residual-gas limited beam storage lifetime to be 448 s ± 18 s with two independent detector systems. Using the measured storage lifetimes we estimate that the residual gas pressure is in the 10(-14) mbar range. When high current ion beams are injected, the number of stored particles does not follow a single exponential decay law as would be expected for stored particles lost solely due to electron detachment in collision with the residual-gas. Instead, we observe a faster initial decay rate, which we ascribe to the effect of the space charge of the ion beam on the storage capacity.

Inflammatory cytokines in gastric fluid at birth and the development of bronchopulmonary dysplasia

AIM

To assess whether the levels of inflammatory and anti-inflammatory proteins in gastric fluid of premature infants shortly after birth are associated with the development of bronchopulmonary dysplasia (BPD).

METHODS

Gastric fluid retrieved within 1 h of birth of premature infants (gestational age <29 weeks) was analysed for interleukin (IL)-8, growth-related oncogene (Gro)-α, epithelial cell-derived neutrophil-activating peptide (ENA)-78, IL-1β and Clara cell secretory protein with ELISA.

RESULTS

Of 51 enrolled infants, 86% had BPD. Of these, 54% had mild BPD, 30% had moderate BPD and 16% had severe BPD. Clinical chorioamnionitis was associated with high levels of IL-8, Gro-α, Epithelial cell-derived neutrophil-activating peptide-78 (ENA-78) and IL-1β in gastric fluid. Gastric fluid levels of IL-8, Gro-α, ENA-78 and IL-1β were higher in infants with moderate or severe BPD than in those with no or mild BPD. Ligation of the patent ductus arteriosus was associated with the development of moderate or severe BPD. These associations were no longer significant after adjustment for gestational age.

CONCLUSION

The levels of inflammatory mediators in gastric fluid samples retrieved soon after birth from intubated or nonintubated infants can be used to assess the infants' perinatal exposure to inflammatory mediators and its association with neonatal outcome.

The double electrostatic ion ring experiment: a unique cryogenic electrostatic storage ring for merged ion-beams studies

We describe the design of a novel type of storage device currently under construction at Stockholm University, Sweden, using purely electrostatic focussing and deflection elements, in which ion beams of opposite charges are confined under extreme high vacuum cryogenic conditions in separate "rings" and merged over a common straight section. The construction of this double electrostatic ion ring experiment uniquely allows for studies of interactions between cations and anions at low and well-defined internal temperatures and centre-of-mass collision energies down to about 10 K and 10 meV, respectively. Position sensitive multi-hit detector systems have been extensively tested and proven to work in cryogenic environments and these will be used to measure correlations between reaction products in, for example, electron-transfer processes. The technical advantages of using purely electrostatic ion storage devices over magnetic ones are many, but the most relevant are: electrostatic elements which are more compact and easier to construct; remanent fields, hysteresis, and eddy-currents, which are of concern in magnetic devices, are no longer relevant; and electrical fields required to control the orbit of the ions are not only much easier to create and control than the corresponding magnetic fields, they also set no upper mass limit on the ions that can be stored. These technical differences are a boon to new areas of fundamental experimental research, not only in atomic and molecular physics but also in the boundaries of these fields with chemistry and biology. For examples, studies of interactions with internally cold molecular ions will be particular useful for applications in astrophysics, while studies of solvated ionic clusters will be of relevance to aeronomy and biology.