Caudal vena cava point-of-care ultrasound in dogs with degenerative mitral valve disease without clinically important right heart disease.

OBJECTIVES: Caudal vena cava (CVC) diameter and collapsibility index (CVCD and CVCCI) have been used to assess intravascular volume status (IVS). Maladaptations with progressive degenerative mitral valve disease (DMVD) lead to hypervolemia. We hypothesised that stages of DMVD will affect ultrasonographic CVC variables in dogs without clinically important right heart disease. ANIMALS, MATERIALS AND METHODS: This retrospective study included 79 dogs with DMVD presented to the cardiology department between January 2017 and 2019. Subxiphoid views were used to obtain CVC cineloops. By visual inspection, CVC was subjectively scored as flat, normal or fat. Maximal and minimal CVCD were measured and indexed to aortic diameter (CVCD-max/Ao and CVCD-min/Ao); CVCCI was calculated as (CVCD-max-CVCD-min)/CVCD-max. Fisher's exact and Kruskal-Wallis tests were used to compare CVC variables. RESULTS: Subjective assessment was associated with American College of Veterinary Internal Medicine (ACVIM) stages (P < 0.001). The proportion of fat CVC was greater in stages C and D. In stage D, CVCD-max/Ao was larger compared with stages B1, B2 and C (P = 0.002, P = 0.002 and P = 0.035, respectively). In stages C and D, CVCD-min/Ao was larger compared with B1 (P = 0.016 and P = 0.001) and B2 (P = 0.002 and P < 0.001. In stages C and D, CVCCI was less than stage B1 (P = 0.016 and P = 0.044) and B2 (P = 0.001 and P = 0.010). CONCLUSIONS: In dogs with DMVD without clinically important right heart disease, CVC variables differ across ACVIM stage. Subjective and objective CVC variables may be used to predict hypervolemia.

[Impact of prematurity on the optic nerve]. / Impact de la prématurité sur l'aspect morphologique et tomographique du nerf optique.

INTRODUCTION: Thanks to the progress made in the past few years in pediatric intensive care as well as the increased survival of preterm infants, the consequences of premature birth are increasingly well documented. With regard to ophthalmologic complications, retinopathy of prematurity is well described, but the optic nerve may also be affected. The goal of this study is to compare the optic nerves of preterm infants as a function of their gestational period with a control group of the same age. MATERIALS AND METHODS: We conducted a case-control study pairing a full-term infant with each preterm infant. Inclusion criteria were: any child from 5- to 10-years-old, separated into three sub-groups according to their degree of prematurity. Variables were: cup/disc ratio, ocular biometry, intraocular pressure and RNFL thickness. RESULTS: Thirty-seven preterm infants and 37 controls were included in the study. The mean age at the time of inclusion was 7.05 years for the preterm group and 7.19 years for the control group. No significant difference was observed in axial length or spherical equivalent (P=0.31 and P=0.98, respectively). No significant difference was observed in pachymetry or intraocular pressure (P=0.28 and P=0.22, respectively). We observed a significant increase of 0.1 in the cup/disc ratio of the preterm group compared to the control group (P<0.05). The preterm group cup/disc ratio was 0.36 versus 0.27 for the control group. No significant difference was observed in the 7 quadrants of RNFL between the two groups. However, when comparing infants born before 28 weeks gestation with the control group, we observed a mean decrease of 14.5 microns in the superior temporal sector (P=0.04), a 9 micron decrease in the global thickness G (P=0.03) and a 12.7 micron decrease in the nasal sector (P=0.01). CONCLUSIONS: In the case of the studied children (aged 5 to 10), the reduced RNFL fiber thickness is a phenomenon dependent essentially on the stage of prematurity. It would be useful to follow these preterm populations over the long term and to compare them to a matched control group to be able to obtain functional results.

Exercise-induced laryngeal obstruction: From clinical examination to continuous laryngoscopy during exercise.

The diagnosis of exercise-induced laryngeal obstruction (EILO) should be suspected when exercise triggers inspiratory stridor. EILO is common in adolescent populations and has a significant impact on sports. Identification of laryngeal obstruction during continuous laryngoscopy during exercise (CLE) is the gold standard diagnostic tool for this disorder, which is not widely known in France. The challenge faced by otolaryngologists is to identify, among patients referred by pulmonologists or sports physicians, those with exercise-induced inspiratory symptoms or poorly controlled exercise-induced asthma, in whom a diagnosis of EILO is strongly suspected. Laryngoscopy at rest may reveal a laryngeal, glottic or supraglottic abnormality predictive of obstruction at increased inspiratory airflow. When pulmonary function tests are normal or in the case of failure of treatment of exercise-induced asthma, the otolaryngologist must complete the examination by a CLE test to confirm the diagnosis of EILO and identify the site of obstruction. This examination is well tolerated, minimally invasive and allows identification of the site of airflow obstruction, allowing specific conservative or surgical treatment. This technical note describes in detail clinical examination and CLE testing in patients with suspected EILO.

A priori selection of the regularization parameters in emission tomography by Fourier synthesis.

This paper describes how the stability of the inverse problem underlying emission tomography can be measured and controlled in clinical settings. We show how the Lanczos approximation provides a way to regularize a certain class of iterative reconstruction algorithms through a given level of noise or resolution in the slices and for a given acquisition protocol. Moreover, we show how the same Lanczos approximation can be used to decide when the iterative reconstruction algorithm actually converges for a given machine precision. These ideas are illustrated by means of reconstructions of simulated and actual emission datasets.

Antibacterial effects of chitosan powder: mechanisms of action.

Chitosan, the deacetylated derivative of chitin, is a natural D-glucosamine polymer that can be extracted from the shells of seafood such as prawns crabs and lobsters. It can be used as a flocculent, plant disease resistant promoter, anti-cancer agent, wound healing promotion agent and antimicrobial agent. The aim of this paper is the study of the interaction between chitosan powder and various kinds of pathogen microorganisms potentially present in water. First of all, physico-chemical characterisations of chitin and chitosan powder were performed. The deacetylation yields were 35%, 60% and 80 +/- 10%. The experimental studies focused on the measurements of the mortality constant rate for various bacterial strains, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus saprophyticus. An explanation of the antibacterial mechanisms is proposed involving the cell wall disruption due to free amino groups present in chitosan.

Drug/lactose co-micronization by jet milling to improve aerosolization properties of a powder for inhalation.

The aim of this work was to formulate a powder for inhalation with fusafungine, a drug substance initially highly cohesive. The classical approach based on micronization by jet milling to prepare respirable drug particles and then blending with a carrier was first applied. A fractional factorial experimental design was implemented to screen six formulation parameters. The effect of drug/lactose co-micronization on aerosolization was then evaluated. In vitro deposition studies were performed with the twin stage glass impinger and the inhaler Spinhaler. Micronization did not induce DSC-detectable amorphization and gave a highly cohesive, poor flowable powder with a theoretical aerodynamic diameter of 5 microm. The powder was then blended with coarse lactose and optionally fine lactose. Unfortunately, the respirable fraction could not be optimized and remained below 10%. On the other hand, a co-micronized powder drug/fine lactose 50:50 gave a respirable fraction of 16%. Following blending with a carrier, the respirable fraction and the emitted dose fraction reached 23% and 69%, respectively. The use of a fine lactose grade for co-micronization was essential. In conclusion, this study demonstrated that co-micronization with a fine lactose is an efficient and simple strategy to formulate a powder for inhalation with enhanced aerosolization properties, especially for highly cohesive drug substance.

Chemical nucleation for CVD diamond growth.

A new nucleation method to form diamond by chemically pretreating silicon (111) surfaces is reported. The nucleation consists of binding covalently 2,2-divinyladamantane molecules on the silicon substrate. Then low-pressure diamond growth was performed for 2 h via microwave plasma CVD in a tubular deposition system. The resulting diamond layers presented a good cristallinity and the Raman spectra showed a single very sharp peak at 1331 cm(-1), indicating high-quality diamonds.