Impact of bull age, sperm processing, and microclimatic conditions on the viability and DNA integrity of cryopreserved bovine sperm.

Context Seasonal microclimatic fluctuations can cause changes in sperm quality even in dairy bulls bred under temperate climate. These changes can vary between sires of different age and affect sperm freezability. Aims We aimed to evaluate the modulating effect of bull age and equilibration time before freezing on the seasonal pattern of sperm viability and DNA integrity post-thaw. Methods In the frame of systematic sperm quality control, we assessed the integrity of sperm plasma membrane and acrosome (PMAI) in 15,496 cryopreserved bovine batches, and the percentage of sperm with high DNA fragmentation index (%DFI) after 0h and 3h incubation at 38°C post-thaw (3h) in 3422 batches. Semen was equilibrated for 24h before freezing if collected on Monday or Wednesday and 72h if produced on Friday. We investigated the effect of season, bull age, equilibration, and temperature-humidity index (THI) on the day of semen collection on sperm traits using mixed-effects linear models. Key results PMAI and %DFI (0h and 3h) deteriorated with increasing THI. The effect of THI on %DFI was detected with a 30-day time lag. Seasonal fluctuations of sperm quality were similar between young, mature, and older sires. Prolonged equilibration did not affect PMAI but was linked to elevated %DFI (3h) in summer. Conclusions Extending equilibration from 24 to 72h is compatible with commercial standards of bovine sperm quality post-thaw; however, it could interfere with the seasonal pattern of the latter. Implications Systematic monitoring of bovine sperm quality enables the prompt detection of stress factors related to microclimate and semen processing.

Does marking as sterile mean really sterile? Stenotrophomonas maltophilia outbreak caused by a blood-gas injector containing liquid heparin.

An outbreak investigation was initiated after detecting an increase in the number of patients with Stenotrophomonas maltophilia bloodstream infections (SM-BSIs) througout the hospital. S. maltophilia was isolated from the cultures of blood-gas injectors containing liquid heparin. The incidence density of SM-BSIs decreased significantly after prohibiting the use of those injectors.

Synthesis and characterisation of two novel proton transfer compounds and their inhibition studies on carbonic anhydrase isoenzymes.

Two novel proton transfer compounds were prepared between 2,4-dichloro-5-sulphamoylbenzoic acid (lasamide) (Hsba) and ethylenediamine (en), namely ethane-1,2-diaminium 2,4-dichloro-5-sulphamoylbenzoate (1), and also between Hsba and 2-amino-3-methylpyridine (2-amino-3-picoline) (amp), namely 2-amino-3-methylpyridinium 2,4-dichloro-5-sulphamoylbenzoate (2). All these were characterised by elemental, spectral (IR and UV-vis), thermal analyses, and single crystal X-ray diffraction studies. Compounds 1 and 2 crystallised in the P-1 and P21/c space groups, respectively. Intermolecular non-covalent interactions, such as ion pairing, hydrogen bonding, and π-π stacking were observed for these ionic compounds. The free ligands Hsba, en and amp, the products 1 and 2, and acetazolamide (AAZ) as the control compound, were also evaluated for their in vitro inhibitor effects on the human carbonic anhydrase isoenzymes (hCA I and hCA II) purified from erythrocyte cells by affinity chromatography for their hydratase and esterase activities. The half maximal inhibitory concentration (IC(50)) values for products 1 and 2 with respect to hydratase activity are 0.15 and 0.32 µM for hCA I and 0.06 and 0.15 µM for hCA II, respectively. The IC(50) values of the same inhibitors for esterase activity are 0.13 and 0.8 µM for hCA I and 0.14 and 0.1 µM for hCA II, respectively. In relation to esterase activities, the inhibition equilibrium constants (Ki) were also determined and found to be 0.137 and 0.99 µM on hCA I and 0.157 and 0.075 µM on hCA II for 1 and 2, respectively. The comparison of the inhibition studies of the newly synthesised compounds 1 and 2 to the parent compounds Hsba and amp and also to AAZ indicated that 1 and 2 have an effective inhibitory activity on hCA I and II, and might be used as potential inhibitors.