Evaluation of cisplatin administered with piroxicam in dogs with transitional cell carcinoma of the urinary bladder

OBJECTIVE: To evaluate the antitumor activity and toxic effects of a conservative dose of cisplatin administered in combination with piroxicam to dogs with transitional cell carcinoma (TCC) of the urinary bladder. DESIGN: Clinical trial (nonrandomized, noncontrolled). ANIMALS: 14 client-owned dogs with histologically confirmed TCC of the urinary bladder. PROCEDURES: Each dog was treated with cisplatin (50 mg/m(2), i.v., q 21 d [reduced to 40 mg/m(2), i.v., q 21 d because of toxic effects]) and piroxicam (0.3 mg/kg [0.14 mg/lb], PO, q 24 h). A CBC, serum biochemical analyses, and urinalysis were performed prior to each cisplatin treatment. Tumor staging (determined from thoracic and abdominal radiographic and urinary bladder ultrasonographic findings) was performed before treatment and at 6-week intervals during treatment. RESULTS: 5 dogs received only 1 dose of cisplatin because of the rapid progression of disease (n = 2) or toxic effects (3). With regard to the neoplastic disease among the other 9 dogs, 1 had partial remission, 5 had stable disease, and 3 had progressive disease after 6 weeks of treatment. Median progression-free interval was 78 days (range, 20 to 112 days). Median survival time was 307 days (range, 29 to 929 days). Moderate to severe renal toxicosis and moderate to severe gastrointestinal toxicosis developed in 5 and 8 dogs, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Because of minimal efficacy and associated renal and gastrointestinal toxicosis, administration of cisplatin (40 to 50 mg/m(2)) with piroxicam cannot be recommended for treatment of dogs with TCC of the urinary bladder.     

USE OF CONTRAST‐ENHANCED COMPUTED TOMOGRAPHY TO STUDY THE CRANIAL MIGRATION OF A LUMBOSACRAL INJECTATE IN CADAVER DOGS

Volumes used in lumbosacral epidural injections for anesthesia have remained unchanged since the 1960s. The goals of this cross‐sectional observational study were to characterize the three‐dimensional spread of a lumbosacral epidural injection, as well as confirm that the commonly used volume of 0.2 ml/kg injected into the lumbosacral epidural space reaches the thoracolumbar (TL) junction in the majority (≥80%) of dogs. Ten clinically normal, adult, nonpregnant, mixed‐breed dogs were obtained within five minutes of euthanasia and 0.2 ml/kg of radiopaque contrast medium was injected into the lumbosacral epidural space. A computed tomography scan of the TL spine was performed immediately following the injection. Migration of contrast reached the TL junction in 8 of 10 (80%) dogs. Contrast was well visualized in all epidural planes with contrast travelling predominantly in the dorsal epidural space in 7 of 10 (70%) dogs. There was no significant difference in the weight of dogs where the epidural injectate reached the TL junction and those where it did not (P = 0.16), or in the weight of dogs where the cranial‐most point of the contrast column was in the dorsal versus the ventral epidural space (P = 0.32). This preliminary study supports the use of computed tomography to characterize injectate distribution in the canine thoracolumbar epidural space and provides evidence that a 0.2‐ml/kg volume is likely to reache the TL junction in most dogs. Further studies are needed in live dogs to determine if variables affecting human epidural injectate doses have similar effects in the dog.     

Epidemiology of Bovine Venereal Campylobacteriosis: Geographic Distribution and Recent Advances in Molecular Diagnostic Techniques

Bovine venereal campylobacteriosis (BVC) is a major cause of economic loss to the cattle industries in different parts of the world. Camplylobacter fetus subsp. venerealis (Cfv), the main causative agent of BVC, is highly adapted to the genital tract of cattle and is transmitted by carrier bulls. However, infertility and abortions can also be caused by the intestinal pathogens C. fetus subsp. fetus (Cff), and C. jenuni, which are not venereally transmitted. Bovine venereal campylobacteriosis, caused by Cfv associated with lowered fertility, embryo mortality and abortion, repeated returns to service, reduced pregnancy rates and extended calving intervals, has the highest prevalence in developing countries where natural breeding in cattle is widely practised. The epidemiology, pathogenesis and diagnosis of the disease have been the subject of previous reviews. The main focus of this review is to highlight the epidemiology of this disease with particular reference to geographical distribution and recent advances in molecular diagnostic techniques. It is hoped that further research interest of scientists will be stimulated with a view to finding lasting solutions to the reproductive problems associated with the disease for better livestock productivity, particularly in developing endemic countries.     

Salish Sea Chinook salmon exhibit weaker coherence in early marine survival trends than coastal populations

Identifying factors that influence anadromous Pacific salmon (Oncorhynchus spp.) population dynamics is complicated by their diverse life histories and large geographic range. Over the last several decades, Chinook salmon (O. tshawytscha) populations from coastal areas and the Salish Sea have exhibited substantial variability in abundance. In some cases, populations within the Salish Sea have experienced persistent declines that have not rebounded. We analyzed a time series of early marine survival from 36 hatchery Chinook salmon populations spanning ocean entry years 1980–2008 to quantify spatial and temporal coherence in survival. Overall, we observed higher inter‐population variability in survival for Salish Sea populations than non‐Salish Sea populations. Annual survival patterns of Salish Sea populations covaried over smaller spatial scales and exhibited less synchrony among proximate populations relative to non‐Salish Sea populations. These results were supported by multivariate autoregressive state space (MARSS) models which predominantly identified region‐scale differences in survival trends between northern coastal, southern coastal, Strait of Georgia, and Puget Sound population groupings. Furthermore, Dynamic Factor Analysis (DFA) of regional survival trends showed that survival of southern coastal populations was associated with the North Pacific Gyre Oscillation, a large‐scale ocean circulation pattern, whereas survival of Salish Sea populations was not. In summary, this study demonstrates that survival patterns in Chinook salmon are likely determined by a complex hierarchy of processes operating across a broad range in spatial and temporal scales, presenting challenges to the management of mixed‐stock fisheries.     

Aryl‐Glycosidase Activities in Germinating Maize

Soluble protein extracts of germinating maize seedlings exhibited a limited ability to hydrolyze purified xylans, and specific assays were unable to confirm the presence of endo‐β‐1,4‐xylanase activity. However, extracts contained a variety of aryl‐glycosidase activities, including β‐glucosidase, β‐xylosidase, and α‐l ‐arabinofuranosidase. These activities peaked in three‐ to four‐day seedlings and were particularly concentrated in shoot and root tissues. Maximal levels of β‐glucosidase were two orders of magnitude greater than those of β‐xylosidase or α‐l ‐arabinofuranosidase. Isoelectric focusing gels revealed multiple forms of these enzymes. The principal β‐glucosidase and α‐l ‐arabinofuranosidase protein species were clustered at pI 4.8–4.9 and pI 5.8–6.0, respectively. β‐Xylosidase activity appeared to be associated with both of these enzymes, and no evidence was obtained for a distinct β‐xylosidase.     

Experimental demonstration of guiding and bending of electromagnetic waves in a photonic crystal

The routing and interconnection of optical signals through narrow channels and around sharp corners are important for large-scale all-optical circuit applications. A recent computational result suggests that photonic crystals may offer a novel way of achieving this goal by providing a mechanism for guiding light that is fundamentally different from traditional index guiding. Waveguiding in a photonic crystal and near 100 percent transmission of electromagnetic waves around sharp 90 degree corners were observed experimentally. Bending radii were made smaller than one wavelength.     

Acute altitude exposure (3800 meters) and metabolic capacity in the middle gluteal muscle of equids

Even relatively short exposure to high altitude canproduce changes in the metabolic capacity of muscle. This study examined the changes in citrate synthase (CS). β-hydroxyacyl-CoA-dehydrogenase (HOAD), lactate dehydrogenase (LDH) and total protein (TP) activity of skeletal muscle in equids after acute high altitude exposure (3800 m). The middle gluteal muscles of trained equids (one Quarter Horse, one Shetland pony, and four Arabians) were sampled before altitude exposure (225 m) and after nine days of sub-maximal exercise at altitude (3800 m). Muscle biopsies were take from a location 10 cm dorsocaudal to the tuber coxae at an angle of 45°. The insertion site was standardized to a depth of 8 cm. Tissue homogenates were assayed for TP and maximal activity of CS, HOAD, and LDH. All samples were run in duplicates and comparisons performed using a paired Student's t-test (significance set at P<0.05). Altitude did not change CS, HOAD or TP. CS for pre-altitude and altitude averaged 31.2±2.9 and 32.6±4.4 μmoles/g/min, respectively (P=0.51). HOAD values averaged 17.9 ±2.1 and 18.2±2.9 μmoles/g/min, respectively (P=0.85). Altitude acclimatization decreased LDH activity. Pre-altitude and altitude LDH averaged 725.4 ±43.4 and 672.7±51.5 μmoles/g/min, respectively (P=0.04). The decrease in LDH is consistent with decreases in skeletal muscle observed in other mammals at high altitude and suggests that muscles do not become more glycolyctic in altitude hypoxia.     

Hemothorax associated with telangiectatic osteosarcoma in a dog

Hemothorax in a dog was attributed to bleeding from an intrathoracic mass attached to the sixth through the tenth ribs. The mass contained numerous cavernous, blood-filled spaces as well as bands of osteoid and occasional foci of osseous tissue. The diagnosis was telangiectatic osteosarcoma. Telangiectatic osteosarcoma is an uncommon variant of osteosarcoma. Cavernous, blood-filled spaces and paucity of bone are important histologic features. Metastasis was described in one of the seven telangiectatic osteosarcomas reported in dogs, and none was found in this case.