Consequences of concurrent Ascaridia galli and Escherichia coli infections in chickens

   

The principal aim of this study was to evaluate dissociative anaesthesia for castration of colts during field conditions. Three dissociative anaesthetic protocols were evaluated during castration of colts in an animal hospital. The protocol considered to be the most suitable was thereafter evaluated during castration of colts under field conditions. Respiratory and haemodynamic parameters and the response to surgery were determined during anaesthesia. All horses breathed air spontaneously during anaesthesia. Under hospital conditions 26 colts were randomised to receive one of three anaesthetic protocols: Romifidine and tiletamine-zolazepam (RZ); acepromazine, romifidine and tiletamine-zolazepam (ARZ); or acepromazine, romifidine, butorphanol and tiletamine-zolazepam (ARBZ). The surgeon was blinded to the anaesthetic protocol used and decided whether supplemental anaesthesia was needed to complete surgery. Under field conditions 31 colts were castrated during anaesthesia with the ARBZ protocol. All inductions, anaesthesia and recoveries were calm and without excitation under both hospital and field conditions. Surgery was performed within 5–20 minutes after the horses had assumed lateral recumbency during both hospital and field castrations. Under hospital conditions some horses needed supplemental anaesthesia with all three anaesthetic protocols to complete surgery. Interestingly, none of the horses castrated with protocol ARBZ under field conditions needed additional anaesthesia. Cardiorespiratory changes were within acceptable limits in these clinically healthy colts.     

Microbial signaling and systems biology

A report of the symposium on Signaling and Systems Biology held during the Society for General Microbiology Spring Meeting, 29-30 March 2010, Edinburgh, UK.     

Circadian Variations in the Number of Actively Secreting Sebaceous Follicles and Androgen Circadian Rhythms

Sebum excretion has been shown to demonstrate a circadian rhythm using a gravimetric method (cigarette paper). With the newly introduced method of Sebutape, we confirmed this periodicity and showed that the elevation in sebum excretion is correlated with an increase in the number of secreting follicles. We found, furthermore, that the number of secreting follicles on the forehead showed a distinct and statistically significant circadian rhythmicity, in contrast to those of the chest, which remained almost constant. The quantification in plasma levels of cortisol, melatonin, δ-4-androstenedione, dehydroepiandrosterone sulphate, and free testosterone showed no correlation with sebum excretion at either site. These observations suggest that local factors are involved in control of sebum secretion.     

Developmental Expression of Nicein Adhesion Protein (Laminin-5) Subunits Suggests Multiple Morphogenic Roles

Nicein/kalinin (laminin-5) is a heterotrimeric laminin-like adhesion protein, which is secreted at the basement membrane of subsets of epithelia and is involved in the etiology of junctional epidermolysis bullosa, a severe human blistering disease characterized by disadhesion of epidermis from dermis.

cDNA clones encoding the three chains of mouse nicein and antibodies specific to each polypeptide were used to examine the expression of the protein in the developing mouse embryo from 10.5 day post coitum to 7 days after birth. At various stages of development, co-expression of the three chains of nicein was observed in amnion, skin, and in epithelia of respiratory, urinary and digestive systems. High level expression of nicein was seen in enamel-secreting ameloblasts in developing teeth. Cell-specific distribution of nicein was also detected in other specialized tissues representative of the three primary embryonic germ layers with prominent secretory or protective functions. Differential and focal expression of nicein subunits was observed in the choroid plexus and the floor plate of the neural tube. Messenger for the heavy chain of nicein was detected in the floor plate, where mouse s-laminin messengers were also found. This suggests that nicein genes may play a role in the migration and polarization of motor neurons in the developing spinal cord.     

Study of permeation and blocker binding in TMEM16A calcium-activated chloride channels

We studied the effects of mutations of positively charged amino acid residues in the pore of X. tropicalis TMEM16A calcium-activated chloride channels: K613E, K628E, K630E; R646E and R761E. The activation and deactivation kinetics were not affected, and only K613E showed a lower current density. K628E and R761E affect anion selectivity without affecting Na⁺ permeation, whereas K613E, R646E and the double mutant K613E + R646E affect anion selectivity and permeability to Na⁺. Furthermore, altered blockade by the chloride channel blockers anthracene-9-carboxylic acid (A-9-C), 4, 4''-Diisothiocyano-2,2''-stilbenedisulfonic acid (DIDS) and T16inh-A01 was observed. These results suggest the existence of 2 binding sites for anions within the pore at electrical distances of 0.3 and 0.5. These sites are also relevant for anion permeation and blockade.