FEASIBILITY OF CONTRAST‐ENHANCED ULTRASOUND‐GUIDED BIOPSY OF SENTINEL LYMPH NODES IN DOGS

Our goal was to develop and validate a technique to identify the sentinel lymph nodes of the mammary glands of healthy dogs with contrast‐enhanced ultrasound, and evaluate the feasibility of obtaining representative samples of a sentinel lymph node under ultrasound guidance using a new biopsy device. Three healthy intact female adult hounds were anesthetized and each received an injection of octafluoropropane‐filled lipid microspheres and a separate subcutaneous injection of methylene blue dye around a mammary gland. Ultrasound was then used to follow the contrast agent through the lymphatic channel to the sentinel lymph node. Lymph node biopsy was performed under ultrasound guidance, followed by an excisional biopsy of the lymph nodes and a regional mastectomy procedure. Excised tissues were submitted for histopathologic examination and evaluated as to whether they were representative of the node. The ultrasound contrast agent was easily visualized with ultrasound leading up to the sentinel lymph nodes. Eight normal lymph nodes (two inguinal, one axillary in two dogs; two inguinal in one dog) were identified and biopsied. Lymphoid tissue was obtained from all biopsy specimens. Samples from four of eight lymph nodes contained both cortical and medullary lymphoid tissue. Contrast‐enhanced ultrasound can be successfully used to image and guide minimally invasive biopsy of the normal sentinel lymph nodes draining the mammary glands in healthy dogs. Further work is needed to evaluate whether this technique may be applicable in patients with breast cancer or other conditions warranting evaluation of sentinel lymph nodes in animals.     

Metastasis of osteosarcoma to the bladder in a Finnish harrier: a case report

Osteosarcoma has not been previously reported to have metastasized to the urinary bladder in the dog. Here such a case is reported; the diagnosis was based on clinical, radiological, scintigraphic and histological verification of the primary and metastatic tumours.     

Vascular and Morphologic Changes in Canine Femora after Uncemented Hip Arthroplasty

The effects on femoral remodeling of medullary reaming and insertion of a porous endopros-thesis in uncemented hip arthroplasty (UHA) were measured. A unilateral hip hemiarthroplasty (HA) was performed in 12 dogs, with six dogs receiving full-sized and six dogs receiving undersized femoral endoprostheses. A prosthetic head and neck, or acetabular cup, was not implanted. A control group of six dogs underwent femoral head and neck excision (FHNE) only. All dogs were killed 4 weeks after the surgical procedure. Porosity, vascularity, and bone formation were quantified in each femur of the dogs that had been operated on and in each femur of two unoperated dogs. Full-sized did not differ from undersized HA bones in vascularity, porosity, or bone formation. Femurs in which hemiarthroplasties had been performed (full-sized and undersized) had a three-fold increase in porosity, vascularity, and bone formation compared to the contralateral and the FHNE femurs. Changes in porosity and vascularity were greatest (p < .05) at the metaphyseal level and in the medial and caudal quadrants. There was a strong correlation (R² 0.77 to 0.93, and p − .0001) between the increase in porosity and vascularity. These results support the hypothesis that medullary reaming followed by uncemented prosthetic stem implantation contribute to remodeling of the proximal portion of the femur after UHA.     

A Large Frontonasal Bone Flap for Sinus Surgery in the Horse

A large frontonasal bone flap was created to treat diseases of the paranasal sinuses in 14 horses. The bone flap was made as wide as possible within the confines of the nasolacrimal duct so the floor of the frontal sinus and the dorsal and ventral conchae could be opened. These openings exposed the nasal passages, maxillary sinuses, and ventral conchal sinus thereby facilitating removal of diffuse and localized lesions from these sites. Diseases treated were ethmoid hematomas (4 horses), sinus cysts (5 horses), cryptococcal granuloma, osteoma, hemangiosarcoma, pus in the ventral conchal sinus, and periapical infection of a second molar. Four horses were euthanatized during or after surgery, one because of postsurgical pleuritis and pneumonia (horse with osteoma) and three because of their primary problems (cryptococcal granuloma, hemangiosarcoma, pus in the ventral conchal sinus). Skin suture abscesses that responded to treatment developed in four horses. Ten horses returned to their intended uses, the sinus flaps healed without blemish, and the original problems did not recur. The frontonasal flap technique provided greater access to all paranasal sinuses than methods described previously.     

Acute Gastrointestinal Disease in 27 New World Camelids: Clinical and Surgical Findings

Objective—To describe clinical and surgical findings from New World camelids with acute gastrointestinal disease.
Study Design—Retrospective study.
Animal Population—20 llamas and 7 alpacas.
Methods—Camelids were grouped based on surgical lesions. Clinical and surgical findings were compared between groups and between surviving and nonsurviving camelids.
Results—Twelve of 27 initial celiotomies and 3 of 4 repeat celiotomies were successful. Death occurred from euthanasia during surgery (nine camelids), peritonitis or sepsis (five), aspiration pneumonia (one), and respiratory distress (one). Survival was lowest after celiotomy for proximal obstruction (3 of 10 camelids), ruptured viscus (0 of 4), and necrotizing enteritis (0 of 2) and highest after celiotomy for distal obstruction (10 of 13) and septic peritonitis without ruptured viscus (2 of 2). Before surgery, camelids with proximal obstruction had significantly lower ( P < .05) serum chloride concentrations (median, 97 mEq/L) than those with distal obstruction (median, 109 mEq/L) or ruptured viscus (median, 117 mEq/L). Serum bicarbonate concentration also was highest (median, 34.6 mEq/L) and often greater than 28 mEq/L in camelids with proximal obstruction. Camelids with distal obstruction had significantly lower ( P < .05) nucleated cell counts in peritoneal fluid (median, 700 cells/μL) than those with ruptured viscus (median, 20,600 cells/μL) or septic peritonitis (median, 88,300 cells/μL).
Conclusions—Camelids with proximal obstruction often had hypochloremic metabolic alkalosis. Camelids with distal obstruction had less metabolic derangement and tissue compromise and a higher survival rate.
Clinical Relevance—Awareness of the characteristics of the various types of acute gastrointestinal disease in camelids will augment veterinarians' ability to diagnose and treat these disorders.     

Closed One-Stage Functional End-to-End Jejunojejunostomy in Horses With Use of Linear Stapling Equipment

Objective—To use gastrointestinal linear stapling instrumentation to perform a closed one-stage functional end-to-end jejunojejunostomy in adult horses as an alternative to a stapled side-to-side jejunojejunostomy.
Study Design—Clinical outcome, anatomic and histological architecture, and anastomotic dimensions were determined at 2, 4, 8, 16, and 24 weeks postoperatively. Animals or Sample Population—18 adult horses.
Methods—The anastomosis and peritoneal cavity were inspected for adhesions. The diameter and circumference of the anastomosis and jejunum oral and aboral to the anastomosis were determined from digitized contrast radiographs and linear measurements. Healing of anastomotic sites was evaluated histologically.
Results—Three horses were euthantized in the immediate postoperative period. In the 15 surviving horses, there were no peritoneal adhesions or distortion of the anastomoses and stomas remodeled in an end-to-end fashion. The mean anastomotic staple line (7.48 cm) and mucosa (6.89 cm) diameters were significantly ( P < .05) larger than the mean jejunal diameter oral (6.03 cm) and aboral (6.01 cm) to the anastomosis. The mean anastomotic luminal circumference (13.61 cm) was significantly ( P < .01) larger than the mean oral (11.43 cm) and aboral (11.12 cm) jejunal circumference. Histologically, there was adequate mucosal and muscularis mucosae reapposition with a moderate degree of fibrosis and inflammation.
Conclusions —Closed one-stage functional end-to-end jejunojejunostomy resulted in an acceptable functional anastomosis.
Clinical Relevance —This technique appears to be an acceptable alternative to linearly stapled, side-to-side jejunojejunostomies performed in horses.     

Residential Property Values and Community Right‐to‐Know Laws: Has the Toxics Release Inventory Had an Impact?

ABSTRACT This paper uses a cross‐sectional hedonic pricing model to investigate the relationship between the U.S. Environmental Protection Agency's (EPA) Toxics Release Inventory (TRI) data releases and the prices of single‐family residences within postal zip code areas situated in Omaha, Nebraska's Douglas County. The model employs demographic data from the 2000 Census, toxic chemical release data for the year 2000 from the EPA's TRI database, as well as other pollution variables for each of the zip code areas comprising Douglas County. The model also employs house‐specific data supplied by the Douglas County Assessor's Office on dwelling characteristics for homes sold in Douglas County in the year 2000. The findings indicate that, when controlling for relevant socioeconomic variables, TRI pollutant releases are significant determinants of residential housing values. The results should be of interest to anyone in the real estate industry, including tax assessors, appraisers, mortgage lenders, and property owners.     

Cities,Skills, and Inequality

ABSTRACT The surge in U.S. wage inequality over the past several decades is now commonly attributed to an increase in the returns paid to skill. Although theories differ with respect to why, specifically, this increase has come about, many agree that it is strongly tied to the increase in the relative supply of skilled (i.e., highly educated) workers in the U.S. labor market. A greater supply of skilled labor, for example, may have induced skill‐biased technological change or generated greater stratification of workers by skill across firms or jobs. Given that metropolitan areas in the U.S. have long possessed more educated populations than non‐metropolitan areas, these theories suggest that the rise in both the returns to skill and wage inequality should have been particularly pronounced in cities. Evidence from the U.S. Census over the period of 1950 to 1990 supports both implications.     

Is Alternative Agriculture a Viable Rural Development Strategy?

Alternative agriculture is promoted as a means of enhancing rural area jobs and income. This nontraditional agricultural activity is defined as: new crops or products to an area, industrial uses of agricultural products, value-enhancement activities, and urban agricultural activities. The potential for new agriculturally-related activities is summarized. The long-term rural economic and development potential, through new income and jobs, is assessed. Next, five case studies are provided to illustrate alternative agriculture successes, limited successes, and failures (Guayule, Jojoba, Muscadine grapes, market windows for fresh fruit and vegetables, and aquaculture). We conclude that alternative agriculture may be viable in select rural areas. However, total employment generation potential is too small and diffused to provide significant rural development impacts.     

MAJOR PATHWAYS FOR NITROGEN REMOVAL IN WASTE WATER STABILIZATION PONDS

A study on the factors influencing nitrogen removal in waste water stabilization ponds was undertaken in an eight-pond series in Werribee, Australia. Nitrogen species including Kjeldahl nitrogen, total ammonia nitrogen, nitrite and nitrate were monitored monthly from March 1993 to January 1994. At the same time, pH, temperature, chlorophylla content and dissolved oxygen were also recorded. Highest nitrogen removal occurred during the period with highest levels of chlorophylla content and dissolved oxygen, but the rate of nitrogen removal was not related to temperature and pH. Enhanced photosynthetic activities resulting from an increased phytoplankton abundance due to prolonged detention time caused an increase in dissolved oxygen, and created an optimum condition for nitrification to occur. In this process, ammonia was oxidized to nitrite and nitrate which were subsequently reduced to elemental nitrogen. Apart from nitrification-denitrification which was the major nitrogen removal pathway in the study system, algal uptake of ammonium, nitrate and nitrite as nutrient sources also contributed to the nitrogen removal. The role of phytoplankton and zooplankton in the treatment process in waste stabilization ponds was discussed.