Cardiac troponin I in canine patients with lymphoma and osteosarcoma receiving doxorubicin: comparison with clinical heart disease in a retrospective analysis

The cumulative cardiotoxicity that occurs as a result of doxorubicin chemotherapy is irreversible and can affect both quality and quantity of life for the cancer patient. Cardiac troponin I (cTnI) is a sensitive and specific marker of cardiomyocyte death. The purpose of this retrospective study was to evaluate serum concentrations of cTnI in dogs with lymphoma or osteosarcoma given doxorubicin chemotherapy, and with known cardiac outcome, based on a minimum assessment by physical examination and thoracic radiography. Serum samples were also available for cTnI measurement from seven healthy dogs given intracoronary doxorubicin. Serial serum samples obtained before, during and after doxorubicin chemotherapy showed increased cTnI concentrations in some clinical patients following chemotherapy (P = 0.0083 compared to baseline), but this did not correlate with clinical signs of cardiomyopathy. In dogs that subsequently developed cardiomyopathy however, serum cTnI concentrations were elevated before clinical signs became evident (confirmed with echocardiography).     

Performance of Pacific White Shrimp,Litopenaeus vannamei,Reared in Zero‐Exchange Tank Systems Exposed to Different Light Sources and Intensities

The development of biofloc production technology has generated significant commercial and research interest directed toward the inland culture of Pacific white shrimp, Litopenaeus vannamei. Most work to date has been conducted in greenhouses, where photoautotrophic organisms are significant contributors to system functionality. In more temperate locations, operations in insulated buildings would reduce heating costs. This experiment was designed to evaluate the effect of light on shrimp cultured in intensive biofloc systems. A 92‐d experiment was conducted in 3.8‐m³ tanks. There were five light treatments: (1) natural sunlight (SUN) as a control (midday: 718 lx); (2) one metal halide light (MHL) (1074 lx); (3) one fluorescent light (1FL) (214 lx); (4) two fluorescent lights (2FL) (428 lx); and (5) three fluorescent lights (3FL) (642 lx). Artificial light treatments operated on a 12:12 daily cycle. There were three replicate tanks per treatment and each was separated by black plastic to prevent light transmission between replicates. Each tank was stocked at 465 shrimp/m² of tank bottom (initial mean weight = 0.4 g). Light treatment had a significant (P≤ 0.05) impact on average individual weight, survival, harvest yield (kg/m²), and feed conversion ratio (FCR). Harvest yield and survival among shrimp in the SUN, MHL, and 1FL treatments were not significantly different. However, there was an inverse linear relationship (P≤ 0.05; R² = 0.76) between the number of fluorescent fixtures and survival, which was related to greater concentrations of filamentous bacteria as the intensity of fluorescent light increased, causing gill fouling. Natural light and MHL did not result in high concentrations of filamentous bacteria. These results indicate that natural light, metal halide lighting, and/or relatively low levels of fluorescent lighting are suitable for indoor production of Pacific white shrimp in biofloc systems. Light spectrum and intensity can affect bacterial community structure, which has a profound effect on shrimp survival and production.     

Pulsed Doppler assessment of left ventricular diastolic function in normal and cardiomyopathic cats.

Left ventricular (LV) diastolic function was evaluated in 16 cats with primary hypertrophic cardiomyopathy (HCM) using pulsed Doppler (PD) assessment of transmitral flow and isovolumic relaxation time. Data obtained was compared to data from 12 healthy, adult, research cats. Compared to normal cats, the HCM group showed significantly (p value less than 0.05) reduced early LV inflow velocities (mean +/- standard error [SE], peak velocity of 0.70+/-0.04 m/s versus 0.54+/-0.04 m/s and integrated velocity of 0.48+/-0.08 m/s versus 0.37+/-0.03 m/s); a reduced rate of deceleration of early inflow (mean+/-SE, -12.0+/-1.0 m/s2 versus -5.1+/-1.1 m/s2); prolonged isovolumic relaxation time (mean +/- SE, 45.7+/-3.3 ms versus 76.0+/-3.1 ms); and increased atrial systolic flow velocities (mean +/- SE, peak velocity of 0.29+/-0.04 m/s versus 0.48+/-0.04 m/s and integrated velocity of 0.21+/-0.03 m/s versus 0.34+/-0.03 m/s). The results suggest that PD provides a noninvasive method of identifying and quantifying functional diastolic impairment in cats with HCM.     

Type I immune-mediated polyarthritis in dogs: 39 cases (1997-2002)

OBJECTIVE: To determine clinical signs, laboratory findings, relationship to vaccination, and response to treatment for type I immune-mediated polyarthritis (IMPA) in dogs. DESIGN: Retrospective study. ANIMALS: 39 dogs PROCEDURE: Clinical records and radiographic reports from 3 university referral hospitals were reviewed. Clinical signs, laboratory and investigative findings, relationship to vaccination, and response to treatment were evaluated. RESULTS: Clinical signs and initial laboratory and clinical investigative findings were frequently abnormal but were nonspecific and not associated with likelihood of recovery. Time of vaccination was not associated with onset of disease. Chemotherapeutic immunosuppression resulted in complete cure in 56% of dogs. Continuous medication was required in 18% (7/39) of dogs, relapses were treated successfully in 13% (5/39) of dogs, and 15% (6/39) of dogs died or were euthanatized as a result of disease. CONCLUSIONS AND CLINICAL RELEVANCE: The possible involvement of vaccination in type I IMPA was not made clear from this study because of the small population size. Signalment, clinical signs, and results of diagnostic tests other than multiple synovial fluid analyses were generally nonspecific. Most dogs with type I IMPA responded to initial immunosuppressive treatment, but 31% (12/39) of dogs relapsed, required further treatment, or both.     

Self-Assembled Metal Colloid Monolayers: An Approach to SERS Substrates

The self-assembly of monodisperse gold and silver colloid particles into monolayers on polymer-coated substrates yields macroscopic surfaces that are highly active for surface-enhanced Raman scattering (SERS). Particles are bound to the substrate through multiple bonds between the colloidal metal and functional groups on the polymer such as cyanide (CN), amine (NH(2)), and thiol (SH). Surface evolution, which can be followed in real time by ultraviolet-visible spectroscopy and SERS, can be controlled to yield high reproducibility on both the nanometer and the centimeter scales. On conducting substrates, colloid monolayers are electrochemically addressable and behave like a collection of closely spaced microelectrodes. These favorable properties and the ease of monolayer construction suggest a widespread use for metal colloid-based substrates.     

Evaluation of Stocking Density during Second‐Year Growth of Largemouth Bass,Micropterus salmoides,Raised Indoors in a Recirculating Aquaculture System

Largemouth bass (LMB), Micropterus salmoides, are a highly desirable food fish especially among Asian populations in large cities throughout North America. The primary production method for food‐size LMB (>500 g) has been outdoor ponds that require two growing seasons (18 mo). Indoor, controlled‐environment production using recirculating aquaculture system (RAS) technologies could potentially reduce the growout period by maintaining ideal temperatures year‐round. Researchers conducted a 26‐wk study to evaluate optimal stocking densities for growout of second‐year LMB to food‐fish size in an indoor RAS. LMB fingerlings (112.0 ± 38.0 g) were randomly stocked into nine 900‐L tanks to achieve densities of 30, 60, or 120 fish/m³ with three replicate tanks per density. The RAS consisted of a 3000‐L sump, ¼ hp pump, bead filter for solids removal, mixed‐moving‐bed biofilter for nitrification, and a 400‐watt ultraviolet light for sterilization. Fish were fed a commercially available floating diet (45% protein and 16% lipid) once daily to apparent satiation. At harvest, all fish were counted, individually weighed, and measured. Total biomass densities significantly increased (P ≤ 0.05) with stocking rate achieving 6.2, 13.2, and 22.9 kg/m³ for fish stocked at 20, 60, and 120 fish/m³, respectively. The stocking densities evaluated had no significant impact (P > 0.05) on survival, average harvest weight, or feed conversion ratio which averaged 92.9 ± 5.8%, 294.5 ± 21.1 g, and 1.8 ± 0.3, respectively. After approximately 6 mo of culture, LMB did not attain target weights of >500 g. Observed competition among fish likely resulted in large size variability and overall poor growth compared to second‐year growth in ponds. Additional research is needed to better assess the suitability of LMB for culture in RAS.     

Clinical usefulness of cardiac event recording in dogs and cats examined because of syncope, episodic collapse, or intermittent weakness: 60 cases (1997-1999)

OBJECTIVE: To determine the clinical usefulness of cardiac event recording in evaluating dogs and cats with unexplained syncope, episodic collapse, or intermittent weakness. DESIGN: Retrospective study. ANIMALS: 58 dogs and 2 cats. PROCEDURE: Medical records and electrocardiographic rhythm strips obtained by cardiac event recordings were reviewed. Cardiac rhythm data from the event recordings were classified as diagnostic or nondiagnostic. Diagnostic yield was calculated by dividing the number of animals for which cardiac event recording was diagnostic by the total number of animals undergoing cardiac event recording. RESULTS: For 51 animals, cardiac event recording was classified as diagnostic; therefore, overall diagnostic yield was 85%. Diagnostic yield was lower for animals without underlying structural heart disease (75.5%) than for animals with structural heart disease (95.6%). A specific arrhythmia was identified as the cause of clinical signs in 18 of the 51 (35%) animals for which cardiac event recording was diagnostic. Cardiac arrhythmia was definitively excluded as the cause of clinical signs in the remaining 33 (65%) animals in which cardiac event recording was diagnostic. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that cardiac event recording had a high diagnostic yield in dogs and cats examined because of unexplained syncope, episodic collapse, or transient weakness and ataxia, regardless of whether animals did or did not have an underlying structural heart disease. Diagnostic yield of cardiac event recording was higher than that reported previously for Holter monitoring.