Clinical assessment of a chemosensitivity assay as a treatment planning tool for dogs with cancer

This study evaluated the clinical utility of a commercially available chemosensitivity assay. In the first part of the study, tumor tissues from dogs with various malignancies were tested, and the dogs were treated with a mitoxantrone/cyclophosphamide combination protocol. Tumor response was evaluated and compared to the predicted response. Assay results were not a significant predictor of clinical response to chemotherapy or of survival time. In the second part of the study, assay results were used to direct therapy in dogs with refractory lymphoma. There was no significant correlation (p equals 0.323) between predicted response and case outcome.     

A Screening for the Occurrence of Autoreactive Antibodies in Sera of Pregnant and Non-pregnant Bitches

Sera of healthy pregnant (group I, n = 11) and non-pregnant (group II, n = 11) bitches were screened for autoantibodies (AAb). In both groups, blood samples were drawn every fifth day between days 5 and 55 after mating. Serum was analysed via indirect immunofluorescence (IIF) with the Canine ANA HEp-2 Screening Kit. In all animals, anticytoplasmic AAb were detected. Utilizing primate-heart substrate slides AAb against contractile proteins of the cytoplasm could be observed. The predominating fluorescence pattern in pregnant animals resembled above all desmin, which was proven via Western blot. The sera were then pre-incubated with tropomyosin, actin, vimentin, vinculin and keratin solutions, and assessed on HEp-2 slides and on human and canine fibroblasts as well. The latter substrate was used to verify whether the detected Ab were in fact AAb. Utilizing tropomyosin, revealed elimination of the cytoplasmic fluorescences on all three substrates. It is therefore assumed, that in sera of healthy dogs, AAb against contractile structure proteins of the cytoplasm are present regularly. The majority of pregnant bitches presented with higher end-point titres (EPT), than to be found in non-pregnant dogs. AAb against desmin played the key role in those patterns. In addition, sera were screened for thyroid specific AAb, namely thyroglobulin, thyroid peroxidase (TPO), T3 and T4, and for AAb against insulin by ELISA or Western blot (TPO). Only in two of the pregnant bitches a weak positive reaction (1:100) for T3-AAb was detected.     

Ostertagiasis in calves. II. infection parameters and body weight gains following housing

The performance of six groups of six calves each from a previous field experiment was followed from the beginning of housing until turning out seven months later. When housed the groups harboured different levels of infection with Ostertagia ostertagi and had corresponding weight and gain reductions. The most heavily infected groups improved rapidly following housing. Elevated serum pepsinogen levels decreased markedly, and approached normal values at eight weeks. Differences in serum pepsinogen levels between groups diminished considerably, but remained significant over the entire stabling period. The serum albumin level was low in the most seriously affected animals at the time of housing, but normal levels were restored within the first twelve weeks. In general, the number of parasite eggs in the faeces of the animals decreased, but there was considerable fluctuation. Apart from a single sampling date, no significant difference in egg per gram (EPG) could be demonstrated between the experimental groups during the stabling period.The calves were fed according to their age. The live weight differences between most and least affected groups diminished from 64 kg at the time of housing to 37 kg at the end of the stabling period. The reduction took place particularly during the first four weeks of housing.Considering both the grazing and stabling periods, it appeared that anthelmintic treatment twice during the period had no effect on the final live weight, whereas remeated treatments at three-week intervals resulted in an increase of 24 kg. Similarly, moving the animals to a clean pasture in mid-July resulted in an increase of 39 kg at the end of the stabling period when compared to calves which were not moved. Treatment of moved animals did not result in further body weight gain after seven months of housing.No significant correlation was found between parasite EPG of faeces and growth rate during the stabling period. However, a positive correlation was found between serum pepsinogen during the first eight weeks of housing and the weight gain over the entire stabling period. This was in contrast to the correlation experienced during the grazing period.     

微量Bradford法测定提纯禽结核菌素蛋白含量

研究用96孔微量板Bradford法测定提纯禽结核菌素蛋白含量。通过不同浓度的待测禽结核菌素与考马斯亮蓝G-250溶液混合后，在595nm光波下测定各孔样品的OD值。微量Bradford法检测禽结核菌素的线性范围是50—1000μg／mL，相关系数为0．999，最低定量限为50μg／mL。试验用3支禽结核菌素国际参照品，分别配制成125、250、500μg／mL三种不同浓度，每支每种浓度测定4次，计算实际测得的蛋白质浓度。结果显示，批内相对标准偏差为1．6％～4．4％；批间相对标准偏差0．7％-2．2％。研究结果表明微量Bradford法可作为测定禽结核菌素蛋白含量的一种方法。     

Validation of two-dimensional kinematic analysis of walk and sit-to-stand motions in dogs

OBJECTIVE: To assess the intra- and interobserver repeatability of 2-dimensional (2-D) kinematic analysis of walk and sit-to-stand motions in dogs. ANIMALS: 10 healthy adult Labrador Retrievers. PROCEDURES: 10 dogs were filmed during walk and sit-to-stand motions. Five trials were recorded for each dog, 3 of which were digitized. Two observers manually marked 15 landmarks on each frame during the motions of interest for these 3 trials. Each observer repeated the procedure approximately 1 week later. The 2-D joint angles were calculated. Intra- and interobserver coefficients of multiple correlations (CMCs) were calculated for each joint angle-time history. RESULTS: Intraobserver repeatability, assessed as the mean CMCs of 12 joint angle measurements made for 10 dogs by 2 observers, was good or excellent in 23 of 24 (96%) mean CMCs of the joints measured. Interobserver variation, assessed by comparing CMCs of measurements made by 2 observers on 10 dogs on 2 days, was good or excellent in 161 of 240 (67%) CMCs of joints measured. CONCLUSIONS AND CLINICAL RELEVANCE: Intraobserver repeatability of 2-D kinematic measurements made on digitized videotapes was excellent. Interobserver repeatability of these measurements was acceptable.     

Does 2-ketogluconate chelate calcium in the pH range 2.4 TO 6.4?

The dissolution of synthetic hydroxyapatite was studied as a function of pH in the presence of 10 mM 2-ketogluconate, acetate, citrate, and EDTA. In the pH range 5.7–7.7, the relative effectiveness for the dissolution of hydroxyapatite increased in the order 2-ketogluconate ? g acetate < citrate < EDTA. The dissociation constants for gluconic acid (pK_a = 3.41 at μ = 0.2, 25°C) and 2-ketogluconic acid (pK_a = 2.66, at μ = 0.2, 25°C) were measured potentiometrically and used to determine the 1:1 stability constant for the corresponding calcium complexes. The observed calcium-stability constant for the gluconate ion (log K₁₁ = 1.19 at μ = 0.2, 25°C) is in accord with an earlier determination made under similar conditions, however, the calcium stability constant for the 2-ketogluconate ion, which has not previously been reported was found to be less than or equal to the experimental error in the determination (log K₁₁ < 0 at μ = 0.2, 25°C). The negligible value for the calcium stability constant for 2-ketogluconate, confirms the dissolution observations and refutes previous qualitative assumptions in the literature suggesting that 2-ketogluconic acid is an effective chelating agent for calcium ions. It was concluded that 2-ketogluconic, the major acid component of wheat-seedling rhizosphere products is one of the strongest monobasic carboxylic acids and as such acts as a readily available source of hydrogen ions for the dissolution of hydroxyapatite. This dissolution does not involve chelation of calcium ions.     

An acute outbreak of teat lesions affecting 38% of a dairy herd in Northland

Extract

Teat lesions are common in dairy cattle in New Zealand. Most of the infectious cases are caused by pseudocowpox virus, but lesions similar to those caused by bovine herpesvirus (BHV)-2 have been described clinically and confirmed serologically in New Zealand (Horner and Raynel 1988). BHV-2 and BHV-4 cause an acute viral disease in cattle known as bovine herpes mammillitis or ulcerative mammillitis (Hillerton et al 2001). Presumptive cases have been reported in New Zealand based on the nature and distribution of lesions (Daniel 1970). The disease is probably endemic in New Zealand but is poorly documented and generally considered to be mild and sporadic. The main differential diagnosis is pseudocowpox, which is often also present in herds affected with bovine herpes mammillitis, and dual infections of individual cattle have been reported (Gibbs et al 1972). To my knowledge, neither BHV-2 nor BHV-4 have yet been isolated in New Zealand.     

Conservation genetics of evolutionary lineages of the endangered mountain yellow-legged frog, Rana muscosa (Amphibia: Ranidae), in southern California

Severe population declines led to the listing of southern California Rana muscosa (Ranidae) as endangered in 2002. Nine small populations inhabit watersheds in three isolated mountain ranges, the San Gabriel, San Bernardino and San Jacinto. One population from the Dark Canyon tributary in the San Jacinto Mountains has been used to establish a captive breeding population at the San Diego Zoo Institute for Conservation Research. Because these populations may still be declining, it is critical to gather information on how genetic variation is structured in these populations and what historical inter-population connectivity existed between populations. Additionally, it is not clear whether these populations are rapidly losing genetic diversity due to population bottlenecks. Using mitochondrial and microsatellite data, we examine patterns of genetic variation in southern California and one of the last remaining populations of R. muscosa in the southern Sierra Nevada. We find low levels of genetic variation within each population and evidence of genetic bottlenecks. Additionally, substantial population structure is evident, suggesting a high degree of historical isolation within and between mountain ranges. Based on estimates from a multi-population isolation with migration analysis, these populations diversified during glacial episodes of the Pleistocene, with little gene flow during population divergence. Our data demonstrate that unique evolutionary lineages of R. muscosa occupy each mountain range in southern California and should be managed separately. The captive breeding program at Dark Canyon is promising, although mitigating the loss of neutral genetic diversity relative to the natural population might require additional breeding frogs.     

Evaluation of satraplatin in dogs with spontaneously occurring malignant tumors

Background: Satraplatin is the 1st orally bioavailable platinum anticancer drug. Objective: Our objectives were to evaluate efficacy in vitro against a canine cancer cell line, to determine the maximally tolerated dose (MTD) of satraplatin in tumor‐bearing dogs, to identify the dose‐limiting and other toxicities in dogs, and to record pharmacokinetics (PK). Animals: Dogs with macro‐ or microscopic malignant neoplasia. Methods: D17 canine osteosarcoma cells first were evaluated in a clonogenic survival assay. Then, dogs with a diagnosis of malignant neoplasia were prospectively entered in standard 3 + 3 cohorts. Additional patients were entered at the MTD to assess efficacy. Total and free platinum (by ultrafiltrate) concentrations were determined with inductively coupled plasma mass spectroscopy. Results: Satraplatin inhibited clonogenic survival in vitro at clinically relevant and achievable concentrations. Twenty‐three dogs were treated, 14 with PK evaluation. The MTD was 35 mg/m²/d for 5 days, repeated every 3–4 weeks. Bioavailability was 41%. PK variables (mean ± SD) at the MTD included T_max 1.8 (± 0.7) hours, C_max 72 (± 26) ng/mL, area under concentration (AUC)_{0–24 h} 316 (± 63) h × ng/mL, and MRT 7 (± 1.3) hours. Higher AUC after the 5th versus the 1st dose suggested drug accumulation. Interestingly, platelets consistently reached nadir sooner than did neutrophils (day 14 versus 19). Myelosuppression was dose‐limiting and gastrointestinal toxicity was mild. Conclusions and Clinical Importance: Satraplatin was well tolerated in tumor‐bearing dogs, thus warranting further investigation in a phase II trial.