Activation of the lectin pathway of complement by cardiopulmonary bypass contributes to the development of systemic inflammatory response syndrome after paediatric cardiac surgery.

The systemic inflammatory response is a challenge in the management of paediatric patients undergoing cardiac surgery. Although multi-factorial, a contribution by the lectin pathway of complement activation has been postulated. We therefore investigated the changes in serum levels of mannose binding lectin (MBL) and activities of MBL-MBL-associated serine protease (MASP)-1 and MBL-MASP-2 complexes immediately before and during surgery, throughout the first postoperative day and at discharge from the hospital. These changes were analysed in relation to postoperative complications. Blood samples were obtained from 185 children with congenital heart disease undergoing surgical correction with the use of cardiopulmonary bypass: preoperatively (MBL-1), 15 min after initiation of cardiopulmonary bypass (CPB) (MBL-E), 30 min (MBL-2), 4 h (MBL-3), 12 h (MBL-4) and 24 h (MBL-5) post-CPB and at discharge from hospital (MBL-K). Alterations in serum MBL levels were calculated as a ratio of its serum level at subsequent time-points (MBL-2, -3, -4, -5) to the preoperative (MBL-1) value. Decreases in MBL and MBL-MASP complexes were observed in all samples, correlating with a decrease in C4 and increase in C4a, confirming activation of the lectin pathway. Changes in MBL levels between children with an uncomplicated postoperative course and those suffering from infection or low cardiac output syndrome did not differ significantly, but significant differences were observed between the SIRS and non-SIRS groups. Paediatric cardiac surgery with the use of cardiopulmonary bypass activates the complement system via the lectin pathway and the latter contributes to the development of the post-bypass systemic inflammatory response.

Stereological studies on germ cell mitochondria of rat during spermatogenesis and spermiogenesis.

The following stereological parameters of mitochondria were calculated in rat germ cells during the spermatogenesis: volume density of matrix, outer compartment, outer membrane and inner membrane, surface density of outer membrane and inner membrane. They were the basis to calculate the partition coefficient of matrix and partition coefficient of outer compartment. The matrix volume demonstrated a decreasing in mitochondria of germ cells during spermatogenesis. The relative volume of outer compartment was calculated with the intracristal spaces and revealed increasing from spermatogonia to spermatids. The partition coefficient for the matrix significantly decreased. Our observations suggest that transformation of mitochondrial configuration during spermatogenesis and spermiogenesis is the expression of intensive metabolic processes and activity of membrane transport in germ cells.

Determination of hydrogen/deuterium ratio with neutron measurements on MAST.

On MAST, compressional Alfvén eigenmodes can be destabilized by the presence of a sufficiently large population of energetic particles in the plasma. This dependence was studied in a series of very similar discharges in which increasing amounts of hydrogen were puffed into a deuterium plasma. A simple method to estimate the isotopic ratio nH/nD using neutron emission measurements is here described. The inferred isotopic ratio ranged from 0.0 to 0.6 and no experimental indication of changes in radial profile of nH/nD were observed. These findings are confirmed by TRANSP/NUBEAM simulations of the neutron emission.

Conceptual design of a neutron camera for MAST Upgrade.

This paper presents two different conceptual designs of neutron cameras for Mega Ampere Spherical Tokamak (MAST) Upgrade. The first one consists of two horizontal cameras, one equatorial and one vertically down-shifted by 65 cm. The second design, viewing the plasma in a poloidal section, also consists of two cameras, one radial and the other one with a diagonal view. Design parameters for the different cameras were selected on the basis of neutron transport calculations and on a set of target measurement requirements taking into account the predicted neutron emissivities in the different MAST Upgrade operating scenarios. Based on a comparison of the cameras' profile resolving power, the horizontal cameras are suggested as the best option.

Investigating fusion plasma instabilities in the Mega Amp Spherical Tokamak using mega electron volt proton emissions (invited).

The proton detector (PD) measures 3 MeV proton yield distributions from deuterium-deuterium fusion reactions within the Mega Amp Spherical Tokamak (MAST). The PD's compact four-channel system of collimated and individually oriented silicon detectors probes different regions of the plasma, detecting protons (with gyro radii large enough to be unconfined) leaving the plasma on curved trajectories during neutral beam injection. From first PD data obtained during plasma operation in 2013, proton production rates (up to several hundred kHz and 1 ms time resolution) during sawtooth events were compared to the corresponding MAST neutron camera data. Fitted proton emission profiles in the poloidal plane demonstrate the capabilities of this new system.

Freeze-fracture studies on mitochondrial membranes of spermatocytes.

Separation of the two-folded lamina of the mitochondrial cristae occurs in mitochondria of spermatocytes and spermatids. Freeze-fracture exposes large areas of the inner and outer halves of the inner membrane. The surface of the outer half of the inner membrane is concave, with small numbers of intramembranous particles (IMPs). Its distinctive feature is the presence of protruding particles surrounding a pit. On the inner half of the inner membrane, there are large numbers of densely-packed, irregularly-distributed IMPs, among which regular pits are seen. Morphometric analysis and reconstructions suggest that these structures are "channels" in the mitochondrial membrane with an internal diameter of approximately 18 nm. It is uncertain whether such mitochondrial structures are confined to the spermatocyte or whether they may also occur in other cells.