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Summary: Sedation facilitates the ocular examination in horses. Alpha2‐adrenoceptor agonists are commonly used in equine practice. If the eye is painful, the combination of an α2‐adrenoceptor agonist and butorphanol provides a greater analgesic effect. Unfortunately, little is known about the effects of α2‐adrenoceptor agonists on equine Schirmer tear test I (STT I) values. The aim of the study was to assess the effects of intravenous romifidine, detomidine, detomidine combined with butorphanol, and xylazine on the STT I values in horses. Forty healthy client‐owned Italian saddle horses were enrolled. Horses received 0.04 mg/kg bwt of romifidine or 15 μg/kg bwt of detomidine or 10 μg/kg bwt of detomidine combined with 10 μg/kg bwt of butorphanol or 0.7 mg/kg bwt of xylazine intravenously. The Schirmer tear test strip was inserted into the lateral third side of the inferior conjunctival fornix for 1 min in each eye. The STT I measurements were performed before sedation and at 5, 15, 30, 60, 120 and 180 min after the administration of sedation. The data were analysed by ANOVA. Romifidine did not affect the STT I values. Detomidine significantly reduced the STT I values at 15 min (18.17 ± 0.97 mm/min). The combination of detomidine and butorphanol significantly reduced the STT I values at 30 and 60 min (17.44 ± 0.99, 15.81 ± 0.99 mm/min). Xylazine significantly increased the STT I values at 5, 15 and 30 min (25.17 ± 0.99, 26.72 ± 0.99, 28.07 ± 0.99 mm/min). The STT I values at 180 min were similar to those before sedation. These results suggest that the administration of xylazine or detomidine alone or combined with butorphanol is associated with significant changes in aqueous tear production, whereas romifidine does not affect the STT I values. Romifidine is therefore suitable for chemical restraint to measure tear production in horses. [ABSTRACT FROM AUTHOR]

SUMMARY A novel method to solve the minimum-time anti-swing motion planning problem for cranes based on the use of linear programming is proposed. It is shown that its solution can be obtained by solving a sequence of fixed-time maximum-range linear programming problems. A convergence proof is presented. A classical kinematical model for which the trolley acceleration is the control variable is used. The crane motion equations are discretized in time assuming that the control variable is piecewise constant. Inequality constraints on both trolley speed and acceleration are included to represent physical bounds associated to the electromechanical driving system. The load and the trolley are required to be at rest both at the initial and at the final times. The load cable length as a function of time is assumed given. The ease of both the formulation and the solution of the problem is in contrast with the traditional two-point boundary value problem associated to the Pontryagin's minimum principle. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented regarding the study on the prevalence of non-alcoholic steatohepatitis (NASH) and non-alcoholic fatty liver disease (NAFLD) in psoriatic patients.

Purpose: To evaluate peripapillary retinal nerve fibre layer (RNFL) thickness, measured by spectral-domain optical coherence tomography (SD-OCT), as a surrogate of visual function in a population of paediatric patients affected by optic pathway glioma (OPG) associated with neurofibromatosis type 1 (NF1)., Methods: A total of 38 paediatric patients (66 eyes) affected by MRI-proven OPG were included. Each patient underwent complete ophthalmological examination, including age-appropriate visual acuity (VA) assessment and RNFL analysis by SD-OCT. Visual acuity was classified as normal or pathologic using age-based normative data. Visual acuity was correlated to mean RNFL thickness of the whole peripapillary area and of each single analyzed sector (nasal, superior, temporal, inferior)., Results: Visual acuity was normal in 43 (65%) and pathologic in 23 (35%) eyes. Mean parapapillary RNFL thickness of each analyzed sector was significantly lower in eyes with abnormal VA (p < 0.05). The best balanced cut-off value of global RNFL thickness allowing to discriminate between eyes with normal and pathologic VA was 76.25 μm (91%, 76%, 67% and 94% of sensitivity, specificity, positive and negative predicting value, respectively). Considering best balanced cut-off values of other analyzed RNFL sectors, the superior (p = 0.0029) and the inferior (p = 0.0024) sectors reached the higher sensitivity (87% and 87%, respectively) and specificity (81% and 79%, respectively)., Conclusion: Retinal nerve fibre layer thickness is directly related to VA in children affected by NF1-related OPG, and should be considered as a potential surrogate marker of VA. Retinal nerve fibre layer thickness cut-off values can be used in paediatric patients to discriminate false-positive results obtained by VA measurement., (© 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Left ventricular assist device (LVAD) overpumping is associated with hemolysis, thrombus release, and tissue damage at the pump inlet. However, the impact of LVAD suction on pulmonary circulatory function remains unknown. We investigated LVAD suction as induced by pulmonary artery banding and overpumping in experimental animals and in a computer model. In six sheep, a rotary LVAD was implanted. Before inducing suction, partial support (40-60% of cardiac output) was established and characterized by measuring pressures and flows. In the animals, pulmonary artery occlusion (PAOC) elicited LVAD suction (left ventricular pressure was from -10 to -20 mm Hg) within 5-10 heartbeats. During suction, aortic pressure dropped to 50% and LVAD flow decreased significantly. After releasing the occlusion (20 s), the collapsed state persisted for another 20 s. A similar trend was obtained by simulating PAOC in the computer model. Additional simulations showed that pulmonary vascular resistance (PVR), volume status, and right ventricular (RV) contractility are exponentially related to the persistence of collapse after a suction event. Even modest increases in predisposing factors (elevated PVR, RV dysfunction, hypovolemia) caused sustained hemodynamic collapse lasting in excess of 15 min. Both in selected animals and the computer model, comparable suction-induced collapse was obtained by increasing LVAD speed by about 33%. Attempted compensation by simply decreasing speed was not effective, but temporarily shutting down the LVAD caused rapid reversal of collapse. In conclusion, rotary LVAD suction causes unfavorable conditions for effective unloading. The use of pump interventions appears a promising tool to detect suction and to avoid the associated hemodynamic depression.