Lectins As Effective Tools in the Study of the Biliary Network and the Parenchymal Architecture of the Zebrafish (Danio rerio) Liver

Lectins are carbohydrate-binding proteins with specific affinity to glycoconjugates expressed in various tissues. Lectins are of substantial utility as research, histochemical, and diagnostic tools in mammalian systems. Reactivity of 12 commonly used plant-based lectins was studied in zebrafish liver. Four lectins, tomato lectin (TL), wheat germ agglutinin, concanavalin A, and Jacalin showed strong reactivity to hepatic parenchymal structures. Importantly, TL reacted to glycoconjugates within segments of the larval and adult intrahepatic biliary network, from canaliculi to bile ducts. We provide evidence that lectins can serve as important histochemical tools to investigate the structural and functional characteristics of the zebrafish liver.

322 Snapshot Re-Audit of Implant Checks in SWLEOC Theatres

Introduction

Never events represent a huge cost burden to the NHS due to litigation. One such event occurred at a high-volume orthopaedic unit involving the wrong implant being inserted into a patient. An extensive investigation was undertaken which highlighted a combination of human error in the implant checking process and implant storage system. As a result, local guidance was developed to ensure a ‘prosthetic pause’ was performed prior to implant opening.

Method

An audit of implant checking practices was performed. The first cycle involved 14 cases observed over two weeks and the second involved 16 cases over five weeks. The checks were deemed compliant if the operating surgeon read aloud the implant details to the team, the scrub nurse did the same and both happened prior to implants being opened.

Results

The initial audit had 8 of 14 cases complying with local guidance. Following the addition of laminated copies of the guidance to all theatres, the guidance being re-distributed to staff and targeted education of the scrub team this improved to 13 of 16 cases.

Conclusions

Targeted interventions and the introduction of a ‘prosthetic pause’ resulted in an improvement in compliance with implant checks and reduces the risk of further never events.

Influence of season and pituitary pars intermedia dysfunction on hair cortisol concentration in horses

Hair cortisol has been demonstrated to reflect hypothalamic-pituitary-adrenal axis activity (including Cushing's disease and stress) in several species. We hypothesized that hair cortisol concentrations are increased in horses with pituitary pars intermedia dysfunction (PPID) compared with healthy adult horses and that this difference is magnified in the fall, when circulating adrenocorticotropin (ACTH) is generally the highest. Cortisol from hair collected using clippers with a #40 blade from the neck was compared between PPID horses and control horses over several months in the fall (August-December) and 1 mo in spring (May). Cortisol from hair at several sampling sites (neck, jugular furrow, sternum, and submandibular) were compared between PPID (n = 6) and control (n = 8) horses in May. Relationships between hair cortisol and ACTH were assessed in the fall. Hair cortisol when measured by weight was higher in PPID vs control horses in October and November (P ≤ 0.01) but not December (P = 0.15), May (P > 0.7), or August-September (P = 0.18). When normalized for hair length, hair cortisol was higher in PPID vs control horses in November (P = 0.0006), but not October or December (P ≥ 0.06). Hair cortisol concentrations did not differ between PPID and control horses from any collection site in May (P > 0.7). There were no consistent relationships between ACTH and hair cortisol concentrations in October, November, or December (P ≥ 0.05). These findings suggest that PPID horses have increased hair cortisol accumulation in the fall compared with control horses. Additional work is needed to clarify whether assessing cortisol per weight or per hair length is most relevant in the horse.

Normotopic and heterotopic cortical representations of mystacial vibrissae in rats with subcortical band heterotopia

The tish rat is a neurological mutant exhibiting bilateral cortical heterotopia similar to those found in certain epileptic patients. Previous work has shown that thalamocortical fibers originating in the ventroposteromedial nucleus, which in normal animals segregate as 'barrel' representations for individual whiskers, terminate in both normotopic and heterotopic areas of the tish cortex (Schottler et al., 1998). Thalamocortical innervation terminates as barrels in layer IV and diffusely in layer VI of the normotopic area. Discrete patches of terminals are also observed in the underlying heterotopic area suggesting that representations of individual vibrissa may be present in the heterotopic somatosensory areas. The present study examines this issue by investigating the organization of the vibrissal somatosensory system in the tish cortex. Staining for cytochrome oxidase or Nissl substance reveals a normal complement of vibrissal barrels in the normotopic area of the tish cortex. Dense patches of cytochrome oxidase staining are also found in the underlying lateral portions of the heterotopic area (i.e. the same area that is innervated by the ventroposteromedial nucleus). Injections of retrograde tracers into vibrissal areas of either the normotopic or heterotopic area produce topographically organized labeling of neurons restricted to one or a small number of barreloids within the ventroposteromedial nucleus of the thalamus. Physical stimulation of a single whisker (D3 or E3) elicits enhanced uptake of [(14)C]2-deoxyglucose in restricted zones of both the normotopic and heterotopic areas, demonstrating that single whisker stimulation can increase functional activity in both normotopic and heterotopic neurons. These findings indicate that the barrels are intact in the normotopic area and are most consistent with the hypothesis that at least some of the individual vibrissae are 'dually' represented in normotopic and heterotopic positions in the primary somatosensory areas of the tish cortex.