Endostatin concentrations in healthy dogs and dogs with selected neoplasms

Endostatin prevents angiogenesis and tumor growth by inhibiting endothelial cell proliferation and migration. The purpose of this study was to determine serum endostatin concentrations in 53 healthy dogs and in 38 dogs with confirmed malignant neoplasms. Endostatin concentration was determined with a competitive enzymatic immunoassay (EIA) with rabbit polyclonal antibody generated against a recombinant canine endostatin protein. Both the presence of cancer and increasing age were associated with increased serum concentration of endostatin. Endostatin concentration in healthy dogs was 87.7 +/- 3.5 ng/mL. Upper and lower limits of the reference range for serum endostatin concentration in healthy dogs were 60 and 113 ng/mL. Dogs with lymphoma (LSA) and hemangiosarcoma (HSA) had endostatin concentrations of 107 +/- 9.3 ng/mL. In conclusion, this study demonstrates that endostatin can be quantified in dogs and that endostatin concentrations are high in dogs with HSA and LSA.     

Escherichia coli heat-stable enterotoxin b (STb) in vivo internalization within rat intestinal epithelial cells

Heat-stable enterotoxin b (STb) is a low molecular weight toxin known to bind sulfatide, its receptor. The fate of STb bound to rat intestinal epithelium cells was followed using an anti-toxin gold labeled assay and transmission electron microscopy. The data suggest that STb toxin and the fusion protein maltose binding protein (MBP)-STb were internalized whereas its mutant I41 E-M42R with reduced hydrophobicity did not show internalization. There was a significant difference in the mean of gold particles per field between rat intestine incubated with STb or the fusion protein MBP-STb and the negative control consisting of intestine incubated with PBS alone. No subcellular compartment seems to be particularly aimed by the toxin as gold particles were randomly distributed within the cell.     

Insecticidal activity of N-arylalkylbenzhydrolpiperidines

Benzhydrolpiperidine (BZP) insecticides represent a novel class of chemistry. Their specificity and efficacy as well as their low mammalian toxicity give them excellent potential for commercialization. Several N-arylalkylbenzhydrolpiperidines were tested for activity against a variety of insects in the laboratory and greenhouse. These tests were used to select compounds for field trials and determine rates of application for field tests. The BZP compounds have good activity against Lepidoptera, with modest Coleoptera activity. They are toxic by oral administration and have about 100-fold lower activity by topical exposure. A methyl carbamate BZP, F4265, was the most active compound, with LC50 values of 6 mg litre(-1) or less for most Lepidopteran species tested. F4265 was active in a variety of field trials at 112-224gAI ha(-1). Whole-plant testing methods conducted in the greenhouse were effective in determining field test rates.     

Bone Strength and Acetylcholinesterase Inhibition as Endpoints in Chlorpyrifos Toxicity toFundulus heteroclitus

Brain acetylcholinesterase (AChE) inhibition was measured during 4-week and 4-day episodic exposures to chlorpyrifos. Organisms were exposed to a seawater (−) control, an acetone (+) control (0.1%), and 0.625, 1.25, 2.5, 5.0, and 10.0 μg of chlorpyrifos L⁻¹in each test. These episodic exposures significantly depressed AChE activity at 2.5, 5.0, and 10.0 μg L⁻¹(weekly test) and at 1.25, 2.5, 5.0, and 10.0 μg L⁻¹(daily test). Six-hour pulsed exposure to chlorpyrifos inhibited brain AChE activity at concentrations as low as 1. 25 μg L⁻¹. Stress at failure of caudal vertebrae following episodic exposure was also tested. Analysis of samples from daily 6-h treatments found no differences after 2 days; however, vertebrae were significantly weaker (than controls) after 4 days. Analysis of weekly 6-h exposures found weaker caudal vertebrae after 2 weeks but not after 4 weeks.     

N-acetyl- beta -D-glucosaminidase activity in the endometrial epithelium of the cow's uterus during the oestrous cycle and pregnancy

The levels of N-acetyl-beta-D-glucosaminidase (NAGase) were measured in the endometrial epithelial tissue of the bovine uterus during the oestrous cycle and during pregnancy. NAGase levels were significantly (P<0.001) higher in the epithelial tissue of the cow's uterus during the luteal phase of the cycle and during pregnancy than during the non-luteal phase. There were significantly (P<0.001) higher mean NAGase values in the epithelial than the subepithelial layers of the uterus in the two cycle phases and in pregnancy. Leucocyte numbers were significantly (P<0.05 and P<0.001) higher in the cows' uteri during the non-luteal phase than during the luteal phase and pregnancy, respectively. It is concluded that the endometrial epithelial layer is significantly active in terms of NAGase release and that this may be related to increased progesterone concentrations. In addition, the epithelial tissue (not leucocytes) appears to be the main contributor to the total NAGase activity in uterine tissue.     

Land use and forest cover on private parcels in the Upper Midwest USA, 1970 to 1990

This paper analyzes the interactions between land use and forest cover in the Upper Midwest, USA from 1970 to 1990. New data are presented and interpreted to evaluate the effects of land-use changes, especially abandonment of agriculture and dispersed development, on forest cover throughout the region. Forest-cover data were collected from Landsat satellite imagery and land use was interpreted from aerial photographs for land parcels, based on archival maps of land ownership. In general, forest cover increased throughout the region and throughout the period. Simultaneously, the area used for agriculture declined, much of it being converted to natural uses, and the area of land in low density residential development increased. Forest cover increased most rapidly on low density residential lands and in counties in which a large percentage of homes were for seasonal use (i.e., vacation homes). The data suggest that the transformation of the region from an extractive (i.e., forestry and agriculture) to a recreation-based service economy has played a significant role in the increasing forest cover observed throughout the region. This revised version was published online in July 2006 with corrections to the Cover Date.     

Analyzing a forest conversion history database to explore the spatial and temporal characteristics of land cover change in Guatemala's Maya Biosphere Reserve

We analyzed forest clearing and regrowth over a 23-year time period for 21 forest concession and management units within the Maya Biosphere Reserve(MBR), Guatemala. The study area as a whole experienced a clearing rate of0.16%/year from 1974 through 1997. The overall clearing rate appears rather low when averaged over the entire study area over 23 years because most of the reserve was inaccessible. However, despite the granting of legal protection to the MBR in 1990, clearing rates continued to rise, with the highest rates occurring in the most recent time period in the analysis, 1995 to1997. Higher rates of clearing relative to regrowth occurred in newly established communities and in the Reserve's buffer zone, where the clearing of high forest was preferred for pasture development. Exploratory models were built and analyzed to examine the effects of various landscape variables on forest clearing. The different units in the analysis showed different relationships of forest clearing with variables such as forest cover type and distance to access(roads and river corridors). Where available, socio-economic household survey data helped to explain patterns and trends observed in the time series Landsat imagery. A strong relationship between forest clearing and distance to access was demonstrated. More clearing occurred further from roads during later time periods as farmers moved deeper into the forest to find land to clear. Communities inside the MBR that were less dependent on farming had forest clearing to regrowth ratios of one:one or less. These communities used fallow fields in greater proportions than communities in the Reserve's buffer zone. General trends in clearing by forest cover type suggest a preference for clearing high forest (bosque alto) types found on the higher elevation, better-drained soils, and fallow fields,and an avoidance of low-lying, seasonally flooded terrain(bajos). Satellite remote sensing observations of forest clearing and regrowth patterns can provide an objective source of information to complement socio-economic studies of the human driving forces in land cover and land use change. This revised version was published online in July 2006 with corrections to the Cover Date.     

Induction and recovery characteristics and cardiopulmonary effects of sevoflurane and isoflurane in bald eagles

OBJECTIVE: To compare induction and recovery characteristics and cardiopulmonary effects of isoflurane and sevoflurane in bald eagles. Animals-17 healthy adult bald eagles. PROCEDURES: Anesthesia was induced with isoflurane or sevoflurane delivered in oxygen via a facemask in a crossover design with 4 weeks between treatments. Eagles were intubated, allowed to breathe spontaneously, and instrumented for cardiopulmonary measurements. Time to induction, extubation, and recovery, as well as smoothness of recovery, were recorded. RESULTS: Administration of sevoflurane resulted in a significantly quicker recovery, compared with isoflurane. Temperature, heart rate, and respiratory rate significantly decreased over time, whereas systolic (SAP), diastolic (DAP), and mean arterial blood pressure (MAP) significantly increased over time with each treatment. Temperature, heart rate, SAP, DAP, and MAP were significantly higher with isoflurane. Blood pH significantly decreased, whereas PaCO(2) significantly increased over time with each treatment. Bicarbonate and total carbon dioxide concentrations significantly increased over time with each treatment; however, there was a significant time-treatment interaction. The PaO(2) and arterial oxygen saturation increased over time with isoflurane and decreased over time with sevoflurane with a significant time-treatment interaction. Six eagles developed cardiac arrhythmias with isoflurane, as did 4 with sevoflurane anesthesia. CONCLUSIONS AND CLINICAL RELEVANCE: Isoflurane and sevoflurane administration resulted in smooth, rapid induction of and recovery from anesthesia similar to other species. Isoflurane administration resulted in tachycardia, hypertension, and more arrhythmias, compared with sevoflurane. Sevoflurane was associated with fewer adverse effects and may be particularly beneficial in compromised bald eagles.     

A persistent outbreak of ulcerative enteritis in bobwhite quail (Colinus virginianus)

Ulcerative enteritis is a disease that typically responds well to medication. An outbreak of ulcerative enteritis that was persistent and unresponsive to treatment is described. The outbreak started in semimature birds and progressively spread to younger birds. Confounding factors leading to this persistence were a significant coccidosis problem, a feed mixing error, and suspected antibiotic resistance. Although Clostridium colinum was never isolated, a bacitracin-resistant Clostridium perfringens was cultured from affected birds. Only the combined treatment of the flocks with an anticoccidial and tylosin was effective in controlling clinical disease. Numerous other management and treatment strategies were unsuccessful in lowering the severe mortality.