IMAGING BASILAR SKULL FRACTURES IN THE HORSE: A REVIEW

Due to the complex nature of the anatomy of the equine head, superimposition of numerous structures, and poor soft tissue differentiation, radiography may be of limited value in the diagnosis of basilar skull fractures. However, in many horses radiographic changes such as soft tissue opacification of the guttural pouch region, irregular bone margination at the sphenoccipital line, attenuation of the nasopharynx, ventral displacement of the dorsal pharyngeal wall and the presence of irregularly shaped bone fragments in the region of the guttural pouches are suggestive of a fracture of the skull base. These findings in conjunction with physical examination findings and historical information may lead to a presumptive diagnosis of a fracture. When available and when the patient will accommodate the equipment, computed tomography may give a definitive diagnosis owing to its superior resolution and differentiation of soft tissue structures.     

Ultrasound-guided erector spinae plane block in horses: a cadaver study

ObjectivesTo describe dye distribution and spinal nerve involvement after a simulated erector spinae plane (ESP) block performed on fresh equine cadavers.Study designExperimental cadaver study.AnimalsA group of 11 adult equine cadavers.MethodsThe spinal region surrounding the sixteenth thoracic vertebra (Th16) of one cadaver was removed and underwent magnetic resonance imaging. In 10 adult equine cadavers [body weight, 549 ± 58 kg (mean ± standard deviation)], 0.2 mL kg^–1 of a 50:1 2% lidocaine/dye solution was injected bilaterally (n = 20 injections) into the fascial plane between the transverse process of Th16 and the erector spinae muscles. An in-plane ultrasound-guided technique with a convex transducer was used to guide injection. Dissection was performed immediately following injection. The craniocaudal and lateral extent of dye distribution was measured (cm) and the number of vertebral bodies involved were counted (n = 20). Abdominal and thoracic cavities as well as the epidural space were also examined for presence of dye (yes/no) (n = 20). Further dissection was performed to evaluate if staining of the dorsal and ventral rami of the spinal nerves and sympathetic chain occurred (n = 14).ResultsThe thoracolumbar fascia was stained in 17/20 (85%) injections and three injections terminated intramuscularly. Multisegmental staining of the dorsal rami was observed in the 14 injections in which staining was evaluated. Ventral rami staining was observed in 3/14 injections where staining was evaluated. Epidural migration was observed in 4/20 (20%) injections. No evidence of dye was found in the thoracic and abdominal cavities or on the sympathetic chain.Conclusions and clinical relevanceThe ESP block may prove beneficial to desensitize structures innervated by the dorsal rami of the thoracic spinal nerves. Further investigation is necessary to evaluate complications caused by epidural contamination.     

The evolution of modern eukaryotic phytoplankton

The community structure and ecological function of contemporary marine ecosystems are critically dependent on eukaryotic phytoplankton. Although numerically inferior to cyanobacteria, these organisms are responsible for the majority of the flux of organic matter to higher trophic levels and the ocean interior. Photosynthetic eukaryotes evolved more than 1.5 billion years ago in the Proterozoic oceans. However, it was not until the Mesozoic Era (251 to 65 million years ago) that the three principal phytoplankton clades that would come to dominate the modern seas rose to ecological prominence. In contrast to their pioneering predecessors, the dinoflagellates, coccolithophores, and diatoms all contain plastids derived from an ancestral red alga by secondary symbiosis. Here we examine the geological, geochemical, and biological processes that contributed to the rise of these three, distantly related, phytoplankton groups.     

Participation of lectins in crustacean immune system

Several lectins have been found in crustaceans, and it has been suggested that they play roles in cell signalling, cell–cell interaction, protein synthesis and pathogen recognition. These functions are performed through their specificity for carbohydrates. This review analyses the carbohydrate specificity, tissue distribution and participation in the immune responses of lectins in crustaceans. Furthermore, we explore some data showing that lectin expression seems to be stimulated by pathogens, favouring crustacean survival.     

In Vitro Polymerization of Wheat Glutenin Subunits with Inorganic Oxidizing Agents. I. Comparison of Single‐Step and Stepwise Oxidations of High Molecular Weight Glutenin Subunits

High molecular weight glutenin subunits (HMW‐GS) were isolated from wheat flour and polymerized in vitro at pH 3.0 with different oxidizing agents (KBrO₃, KIO₃, H₂O₂). An oxidation protocol with single addition of oxidant (single‐step oxidation) was compared with a set‐up in which the oxidant was added in multiple steps (stepwise oxidation). Changes in size distribution were evaluated with size‐exclusion HPLC, multilayer SDS‐PAGE, and flow‐field flow fractionation (flow‐FFF). Flow‐FFF is particularly suitable for measuring changes in glutenin size in the very high size ranges. In order of increasing sizes of the resulting polymers, the different oxidizing agents could be ranked as KBrO₃ < KIO₃ < H₂O₂. However, none of the oxidation conditions allowed for a complete polymerization of HMW‐GS. Interestingly, it was found that high concentrations of KIO₃ negatively affect the degree of polymerization. A similar observation was not made with KBrO₃ or H₂O₂. SDS‐PAGE showed that y‐type HMW‐GS particularly failed to incorporate in glutenin polymers. Simultaneously, these HMW‐GS displayed higher mobilities on SDS‐PAGE that can be ascribed to the formation of intrachain SS bonds. Possible explanations for the incomplete polymerization of HMW‐GS are given.