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Introduction: Visualization of the intact microvascular network in skeletal muscle requires labeling the entire network in whole mount preparations where muscle fibre length can be set to near optimal but the tools to do this are not clear., Methods: We intravascularly injected CD-1 mice with different fluorescently labelled lectins (fluorescent isolectin GS-IB4 (ISO), wheat germ agglutinin (WGA), lycopersicon esculentum (tomato) (LYCO) or FITC-labelled gel. Soleus, extensor digitorum longus, diaphragm, gluteus maximus and cremaster muscles were excised, pinned at optimal sarcomere length and viewed using fluorescence microscopy., Results: WGA and LYCO were the effective at labeling the entire vascular network with WGA labeling capillaries more bright. ISO labelled the arteriolar vasculature and early segments of the capillaries but not the full length of the capillaries or the venular network. FITC-labelled gel was effective at labelling the microvascular network but not all small vessels were consistently labelled. The pattern of staining for each labelling method was similar across all muscle fibre-types tested., Conclusions: WGA was optimal for perfusion labeling and visualization of the intact microvascular network in whole mount skeletal muscle preparations and can be used in combination with ISO to distinguish the arteriolar and venous sides of the network., (The Author(s). Published by S. Karger AG, Basel.)

Objective: We hypothesized that CO 2 and H + stimulate capillaries and arterioles to produce local and conducted vasodilations required to coordinate the distribution of blood flow to contracting skeletal muscle fibers., Methods: CO 2 and H + independently and in combination were applied to 2A arterioles (first branch order from the 1A feed arteriole) and capillaries of the in situ, blood-perfused hamster cremaster muscle. The resulting local and conducted vasodilations were measured., Results: H + (pH: 7.2-6.6) and CO 2 (5% and 10%) applied to the vascular network induced 2A arteriolar vasodilations, while 15% CO 2 produced vasoconstriction. Localized application of H + produced 2A arteriolar vasodilation, while 15% CO 2 resulted in a variable response. Simultaneous application of CO 2 and H + did not result in the predicted additive effects. Application of CO 2 and H + alone or combined on arterioles or capillaries did not induce a conducted response., Conclusions: CO 2 and H + produce arteriolar vasodilation but, critically, cannot stimulate the spread of vasodilation throughout the network, thus limiting their ability to coordinating blood flow to contracting skeletal muscle fibers. Given their potential for interaction, the importance of CO 2 and H + may lie in their ability to modify the effects of other vasodilators., (© 2018 John Wiley & Sons Ltd.)

Lactococcus species are counted among a large and closely related group of environmental streptococci and streptococci-like bacteria that include bovine mastitis pathogenic Streptococcus, Enterococcus, and Aerococcus species. Phenotypic and biochemical identification methods can be inaccurate and unreliable for species within this group, particularly for Lactococcus spp. As a result, the incidence of Lactococcus spp. on the farm may have been historically underreported and consequently little is known about the clinical importance of this genus as a mastitis pathogen. We used molecular genetic identification methods to accurately differentiate 60 environmental streptococci and streptococci-like bacteria isolated from cows with high somatic cell count and chronic intramammary infection (IMI; >2 somatic cell scores above 4) among 5 geographically distinct farms in New York and Minnesota that exhibited an observed increase in IMI. These isolates were phenotypically identified as Streptococcus uberis and Streptococcus spp. Genetic methods identified 42 isolates (70%) as Lactococcus lactis ssp. lactis, including all 10 isolates originally phenotypically identified as Streptococcus uberis. Antibiotic inhibition testing of all Lc. lactis ssp. lactis showed that 7 isolates were resistant to tetracycline. In the present study, a predominance of Lc. lactis ssp. lactis was identified in association with chronic, clinical bovine IMI among all 5 farms and characterized antimicrobial resistance for treatment therapies. Routine use by mastitis testing labs of molecular identification methods for environmental streptococci and streptococci-like bacteria can further define the role and prevalence of Lc. lactis ssp. lactis in association with bovine IMI and may lead to more targeted therapies., (Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Atrioventricular (AV) canal defects comprise a rare category of congenital heart disease associated with abnormal development of the endocardial cushions. These anomalies include a broad spectrum of lesions involving the atrial septum primum, the inlet portion of the ventricular septum, and the atrioventricular valves. In severe cases heart failure may result. The present report describes cardiopulmonary findings in a six-week-old, female Thoroughbred foal with persistent tachypnea and tachycardia since birth. Clinical, echocardiographic, cardiac catheterization, and pathologic findings were compatible with complete AV canal defect with bi-directional shunting, congestive heart failure, and pulmonary hypertension. Gross cardiac pathologic findings included a large atrioventricular septal defect, a common atriovalvular orifice, five atrioventricular leaflets, with two free-floating bridging leaflets. Histopathologic lesions in the lung included hypertrophy of the pulmonary arteriolar walls due to thickening of the tunica media. This represents a well documented case of complete endocardial cushion defect with anomalous development of the atrioventricular valves and resultant pulmonary hypertension and heart failure.

Transesophageal echocardiography (TEE) enhances our ability to see the patent ductus arteriosus in the dog. The improved visualization may potentially improve our ability to perform transcatheter coil embolization in patients that are more likely to have a successful outcome. This report uses still and video images to detail the specifics of coil embolization as performed with the assistance of TEE and compares the images with those of angiography, surgery and postmortem examination.