The Cytoscan (TM) model E-II, a new reflectance microscope for intravital microscopy: Comparison with the standard fluorescence method

The Cytoscan(TM) Model E-II (Cytometrics Inc., Philadelphia, Pa., USA) is a newly developed instrument which functions as an intravital microscope and is small and easily portable. Through the use of orthogonal polarization spectral (OPS) imaging, the Cytoscan Model E-II delivers images of the microcirculation which are comparable to those achieved with intravital fluorescence videomicroscopy (IFM), but without the use of fluorescent dyes. The purpose of this study was to validate the Cytoscan Model E-II instrument against IFM. The experiments were carried out on striated muscle in the dorsal skinfold chamber of the awake Syrian hamster. The following parameters were measured in identical regions of interest in the same animal under baseline conditions and 0.5 and 2 h after a 4-hour period of pressure-induced ischemia: arteriolar diameter, venular diameter and venular red blood cell velocity. Bland-Altman plots showed good agreement between the two techniques for venular red blood cell velocity. As expected, arteriolar and venular diameters as measured by the Cytoscan were on average 5 mum smaller than the values from IFM, since the Cytoscan measures the red blood cell column width and IFM measures luminal diameter. Thus, OPS imaging can be used to make valid measurements of microvascular diameter and red blood cell velocity in tissues. Copyright (C) 2000 S. Karger AG, Basel

Effects of NO synthase inhibitors on the synovial microcirculation in the mouse knee joint

Production of nitric oxide by the inducible NO synthase (iNOS) is known to be enhanced in chronic joint inflammation and osteoarthritis as well as aseptic loosening of joint prostheses. Initial studies yielded promising results after inhibition of the nitric oxide synthase (NOS). However, the effect of NOS inhibition has not been studied at the site of the primary function of NO, the microcirculation of the synovium in vivo. Using our recently developed model for the in vivo study of synovial microcirculation in the mouse knee joint, the effects of selective versus nonselective inhibition of iNOS were investigated by means of intravital fluorescence microscopy. After resection of the patella tendon, the synovial fatty tissue was exposed for intravital microscopy. Diameter of arterioles, functional capillary density (FCD), diameter of venules, venular red blood cell velocity and leukocyte-endothelial cell interaction were quantitatively analyzed before, and 10 and 60 min after intravenous injection of NOS inhibitors {[}selective iNOS inhibitor N-iminoethyl-L-lysine (L-NIL), and nonselective NOS inhibitor N-G-nitro-L-arginine methyl ester (L-NAME)]. Our results demonstrate that L-NAME causes a significant decrease in the arteriolar diameter and FCD associated with an increase in the leukocyte accumulation in the synovium in vivo. In contrast, L-NIL neither altered the microhemodynamics nor the leukocyte-endothelial cell interaction in the synovium, indicating its potential use for selective inhibition of iNOS in joint inflammation. Using our method, further studies will provide new insights into the unknown effect of NOS inhibition on the synovial microvasculature in inflammatory joint disease in vivo. Copyright (C) 1999 S. Karger AG, Basel

Determination of regional bone blood flow by means of fluorescent microspheres using an automated sample-processing procedure

The determination of regional blood flow utilizing fluorescent microspheres (FMs) is an established method for numerous organs. Recent progress, in particular the automation of sample processing, has further improved this method. However, the FM method (reference sample technique), which allows repetitive measurement of regional organ blood flow, has so far not been used for the determination of blood flow in bone. The aim of the present study was to establish FM for the quantification of regional bone blood flow (RBBF). Female, anesthetized New Zealand rabbits (n = 6) received left ventricular injections of different amounts of FM at six subsequent time points. In order to examine the precision of RBBF determination, two different FM species were injected simultaneously at the sixth injection. At the end of the experiments the femoral and tibial condyles of each hind limb were removed and the fluorescence intensity in the tissue samples was measured by an automated procedure. In an in vitro study we have shown that acid digestion of the crystalline matrix has no effect on the fluorescence characteristics of FM. The determination of the number of spheres per tissue sample revealed that depending on the tissue sample size up to 3 x 10(6) spheres/injection were necessary to obtain about 400 microspheres in the individual bone samples. RBBF values of the tibial and femoral condyles did not differ at various injection intervals. The tibial blood flow values varied between 6.6 +/- 1.1 and 8.5 +/- 1.4 ml/min/100 g and were significantly higher than those of the femur (4.3 +/- 1.1 to 6.0 +/- 1.8 ml/min/100 g). The bone blood flow values obtained by simultaneous injection of two FM species correlated significantly (r = 0.96, slope = 1.06, intercept = 0.05), the mean difference was 0.39 +/- 1.11 ml/min/100 g. Our data demonstrate that the measurement of RBBF by means of FM allows a valid determination of RBBF. Copyright (C) 2003 S. Karger AG, Basel

Letter from the Editor

This issue of Human–Wildlife Interactions features a special section highlighting the urban coyote (Canis latrans). The special section is entitled “Cosmopolitan Coyotes,” not because coyotes are present in practically every metropolitan center, city, and town across North America, but more so because I just like using alliteration. In reality, coyotes are on the move, and more and more urban areas are providing them with suitable refugia. Many urban residents are in denial as to the cause, while still trying to get used to their new neighbors and their predatory habits

Special Topic: 50th Anniversary of the Wild Free-Roaming Horses and Burros Act of 1971

Human-Wildlife Interactions is interested in publishing papers that synthesize the management, policy, human dimensions, and biological science that have contributed or can contribute to achieving sustainable wild horse and burro (WHB) management in the United States and globally. In particular, we are interested in case studies of local community involvement in WHB management and policy, synthesis of the applications of fertility control in managing WHB populations, public knowledge and perceptions of WHBs and their management, and research evaluating the cost-effectiveness and efficiency of management options to achieve sustainable WHB management. We also encourage letters to the editor that share and describe local experiences in WHB management. The submission deadline for contributing a research article, case study, opinion, commentary, or other manuscript for this special issue is July 1, 2021

\u3cem\u3eCommentary\u3c/em\u3e Human-Wildlife Conflicts: Emerging Challenges and Opportunities

Wildlife management has been defined as the art and science of applying scientific knowledge and ecological principles to manage wildlife populations for human objectives. Historically, wildlife managers have sought to maintain or increase desirable wildlife species (e.g., game fi sh, birds, and mammals) to meet human food and recreational needs by directly manipulating their habitats or the populations themselves. However, many contemporary rural and urban environments are inhabited by much larger populations of wildlife than were present a century ago. As local wildlife populations increase, so can the damage caused by them. Additionally, because many rare species inhabit private lands, the potential exists for increased land-use regulatory conflicts. Thus, public concerns regarding negative experiences associated with overabundant and nuisance species of wildlife are increasing. If wildlife management is to grow as a profession, managers may need to change their traditional emphasis from that of managing to sustain or increase populations to one of mitigating conflicts. Increased agency emphasis on managing human–wildlife conflicts may afford wildlife management professionals a new forum to engage the widest range of stakeholders in conservation. To make this transition, wildlife managers will need better information about how and why human–wildlife conflicts occur, the magnitude and type of damage occurring, the techniques to manage challenges posed by locally overabundant or rare wildlife populations, and the communication strategies that can be implemented to more effectively involve the capacity of local governance in seeking viable solutions

Antibiotic Accumulation in an Outdoor Anaerobic Poultry Manure Lagoon

There is an increasing trend towards the concentration of poultry populations. With the increased popularity of confinement housing and the purchasing of the feed, less land is needed to raise and keep poultry. A serious problem arising from this change is that manure disposal is becoming increasingly difficult for owners of large poultry flocks. Lagoons have been used as a means of poultry waste disposal. This method of manure treatment is not new. The stabilization of waste in a lagoon is limited by the biological population which in turn is controlled by: nutrition, temperature, oxygen, and toxic materials. Oxytetracycline is a broad-spectrum antibiotic and is known to be excreted in quite large amounts by humans and chicks when administered orally. The quantity of oxytetracycline in the feed ration and in the feces was also assayed to determine the amount of antibiotic passing through the chicken and being deposited, initially in the lagoon

Berryman Institute Awards and Scholarships

Applications are being accepted for professional awards and undergraduate student scholarships provided by the Berryman Institute

Prophet

This is the letter from the editor-in-chief

Call for Papers

The vast majority of wildlife species provide a net benefit to society; thus, the problems that wildlife often create for humans are overshadowed by the many benefits they provide. However, the rapid expansion of global urban and rural development is increasing opportunities for wildlife to forage and become dependent on anthropogenic resources. This co-existence and subsequent dependency has contributed to increased human–wildlife conflicts, which can involve larger charismatic mega-fauna such as bears (Ursus spp.) to smaller microscopic species. Human–bear conflicts probably have occurred since humans first inhabited the planet. Although bears have substantial ecological, aesthetic, and economic value, bears using urban areas and the urban–rural interface are often perceived as being urban or not, with some individuals removed in the belief that dependency on anthropogenic resources is irreversible and can lead to increased human– wildlife conflict. For many bear populations, little is known about the degree of bear urbanization and its ecological mechanisms to guide the management of human–bear conflicts