Efficacy of protamine zinc insulin for treatment of diabetes mellitus in cats

OBJECTIVE: To evaluate effects of protamine zinc insulin (PZI) on control of glycemia in cats with newly diagnosed diabetes mellitus or poorly controlled diabetes. DESIGN: Clinical trial. ANIMALS: 67 diabetic cats. PROCEDURE: 34 cats with newly diagnosed diabetes and 33 cats with poorly controlled diabetes were treated with PZI twice daily for 45 days. Control of glycemia was assessed on days 7, 14, 30, and 45 by evaluation of clinical response, change in body weight, serum fructosamine concentration, blood glucose concentration measured 1, 3, 5, 7, and 9 hours after administration of PZI, lowest blood glucose concentration, and mean blood glucose concentration during the 9-hour period after administration. Adjustments in dosage of PZI were made as needed to attain control of glycemia. RESULTS: For all cats, a significant increase in mean dosage of PZI and significant decreases in 9-hour mean blood glucose concentration, lowest mean blood glucose concentration, and mean serum fructosamine concentration were detected. For cats with poorly controlled diabetes, 9-hour mean blood glucose concentration and mean serum fructosamine concentration were significantly decreased on day 45, compared with day 0. Ninety percent of owners reported improvement or resolution of clinical signs by day 45. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that PZI was effective for control of glycemia in cats with newly diagnosed or poorly controlled diabetes and may be used as an initial treatment or as an alternative treatment in cats that do not respond to treatment with other types of insulin.     

Pharmacokinetics of the insulin-sensitizing agent troglitazone in cats

OBJECTIVE: To determine pharmacokinetics of troglitazone in healthy cats after i.v. and oral administration of a single dose of the drug. ANIMALS: 5 healthy ovariohysterectomized adult cats. PROCEDURE: Using a randomized crossover design, cats were given 5 mg of troglitazone/kg of body weight i.v. and 40 mg of troglitazone/kg orally. Blood and urine samples were collected after drug administration, and concentrations of troglitazone in plasma and urine were determined by use of high-performance liquid chromatography. RESULTS: Area-moment analysis was used to calculate pharmacokinetic variables. Terminal phase half-life was 1.1 +/- 0.1 hours. Steady-state volume of distribution was 0.23 +/- 0.15 L/kg. After i.v. administration, clearance was 0.33 +/- 0.04 L/h/kg. Drug was not detected in urine samples. Mean bioavailability of orally administered troglitazone was 6.9%. CONCLUSIONS AND CLINICAL RELEVANCE: The overall disposition of troglitazone in cats was similar to that reported in other species, including humans. Troglitazone has low and variable oral bioavailability. Clearance of the compound is moderate. Little if any unchanged troglitazone is excreted in urine; thus, metabolism and biliary excretion play predominant roles in elimination of the drug. On the basis of troglitazone pharmacokinetics in healthy cats, as well as on the basis of pharmacodynamics of the drug in humans and other animals, a regimen that uses a dosage of 20 to 40 mg/kg administered orally once or twice per day to cats will produce plasma concentrations of the insulin-sensitizing agent that have been documented to be effective in humans.     

Adventitious rooting of <Emphasis Type="Italic">Eucalyptus globulus</Emphasis> × <Emphasis Type="Italic">maidennii</Emphasis> mini-cuttings derived from mini-stumps grown in sand bed and intermittent flooding trays: a comparative study

Eucalyptus globulus Labill and hybrids thereof have low lignin content, favoring cellulose extraction, but are often recalcitrant to clonal propagation. This work analyzed biochemical and morphological changes during adventitious rooting of mini-cuttings of E. globulus × maidenni obtained from mini-stumps cultured in drip fertigated sand bed or intermittent flooding tray commercial propagation systems. Morphological (% rooting, root number and length, mean rooting time) and biochemical parameters (peroxidase activity, total phenolic content and flavonoid content) were monitored to characterize the rooting phases. All of the rooting parameters were equivalent in both systems, indicating comparable efficiency of both methods in clonal propagation. Kinetic profiles of biochemical parameters were also similar, although the activity of peroxidases was an order of magnitude higher and the phenolic content about three times lower in cuttings derived from intermittent flooding-grown mini-stumps than in those derived from sand bed-grown mini-stumps. Taken together, results suggest that rooting phases were similar in both systems: induction before day 5, formation from day 5 to 15, and elongation from day 15 to 45. These data may contribute to the development of rooting phase-specific mineral nutrient solutions to maximize clonal propagation and plant survival.     

Pharmacokinetics of the antihyperglycemic agent metformin in cats.

OBJECTIVE: To determine the pharmacokinetics of metformin in healthy cats after single-dose IV and oral administration of the drug. ANIMALS: 6 healthy adult ovariohysterectomized cats. PROCEDURE: In a randomized cross-over design study, each cat was given 25 mg of metformin/kg of body weight, IV and orally. Blood and urine samples were collected after drug administration, and concentrations of metformin in plasma and urine were determined by use of high-performance liquid chromatography. RESULTS: Disposition of the drug was characterized by a three-compartment model with a terminal phase half-life of (mean +/- SD) 11.5+/-4.2 hours. Metformin was distributed to a small central compartment of 0.057+/-0.017 L/kg and to 2 peripheral compartments with volumes of distribution of 0.12+/-0.02 and 0.37+/-0.38 L/kg. Steady-state volume of distribution was 0.55+/-0.38 L/kg. After IV administration, 84+/-14% of the dose was excreted unchanged in urine, with renal clearance of 0.13+/-0.03 L/h/kg; nonrenal clearance was negligible (0.02+/-0.02 L/kg). Mean bioavailability of orally administered metformin was 48%. CONCLUSIONS: The general disposition pattern of metformin in cats is similar to that reported for humans. Metformin was eliminated principally by renal clearance; therefore, this drug should not be used in cats with substantial renal dysfunction. CLINICAL RELEVANCE: On the basis of our results, computer simulations indicate that 2 mg of metformin/kg administered orally every 12 hours to cats will yield plasma concentrations documented to be effective in humans.     

Short- and long-term impacts of an introduced large herbivore (Buffalo, Bubalus bubalis L.) on a neotropical seasonal forest

Herbivory of large mammals is a key factor influencing plant communities, with effects on plant growth, survival and reproduction. These effects may be more pronounced when the herbivores are exotic ungulates. We evaluated the impacts of buffaloes (density of 1 individual per hectare) on sapling and shrub assemblages in a semideciduous seasonal forest in southern Brazil. We also investigated whether these impacts could affect the long-term maintenance of forest communities. To address these points, we used two distinct approaches in fragments of seasonal forests located in buffalo farms: firstly, by establishing a buffalo-exclusion experiment (over 14?months), and secondly, by comparing areas with three different histories of buffalo occurrence (protected from buffalo encroachment for 3 and 10?years and freely accessed by buffalo). In both approaches, we evaluated the following ecological attributes: plant cover, richness, diversity (Shannon index), biomass and average height. The results of the exclusion experiment did not indicate any significant effect of buffalo exclusion for the evaluated ecological attributes. On the other hand, species composition differed between communities when comparing buffalo presence versus 10?years of buffalo exclusion. Moreover, richness increased and average height decreased after this 10-year period. We also detected an increase in diversity and a retraction of soil compaction, after 10?years of exclusion. We conclude that forest patches do not show short-term responses to buffalo removal. Nevertheless, in the long-term absence of large herbivores, the forest tends to develop in complexity by increasing in species richness.     

Effects of heavy metals in soil on microbial diversity and activity as shown by the sensitivity-resistance index,an ecologically relevant parameter

A sensitivity-resistance index was developed, and proved to be a very sensitive biomonitor of soil pollution with heavy metals. The index was developed by a step-by-step approach. Ultimately, the bacterial soil microflora was divided into three groups, senstivive, tolerant, and resistant microflora. Zn and Cd sensitivity was defined as no growth occurring in the presence of 5 and 0.5 mg l^-1 of these metals, respectively, while resistance was defined as distinct growth in the presence of 50 and 16 mg l^-1, respectively. The sensitivity: resistance ratio of a referent clay soil (0.57 mg Cd kg^-1 and 140 mg Zn kg^-1) was 0.53, but for polluted (6 mg Cd kg^-1 + 670 mg Zn kg^-1) clay soil, the ratio was 0.24. For a referent (0.06 mg Cd kg^-1 + 12 mg Zn kg^-1) sandy soil the sensitivity: resistance ratio was 1.50 whereas polluted (2.3 mg Cd kg^-1 + 252 mg Zn kg^-1) sandy soil had a ratio 0.19. The ecological value of the sensitivity-resistance lies in its capacity to reflect potential deradation of aromatic compounds. It has been shown repeatedly that sensitive bacteria grow significantly better on a range of selected aromatic compounds. It has been speculated that resistance fo heavy metals may reduce the bioremediation capacity of soil towards chlorinated aromatics and polyaromatic hydrocarbons.     

The adoption of drones in German agriculture: a structural equation model

Drones are one of the latest tools to have been added to farmers’ precision agriculture technology tool kit. Despite the proclaimed benefits, adoption rates of drones are low and literature regarding the adoption of drones in agriculture is scarce. Therefore, this study investigates whether an extended Technology Acceptance Model (TAM) can contribute to the understanding of latent factors influencing farmers’ intention to adopt a drone. The sample of 167 German farmers was collected in 2019 via an online survey. Using partial least squares structural equation modelling and a binary model, the TAM explains 69% of the variance in the intention to use a drone by German farmers. According to the results, raising farmers’ awareness of farm-specific areas of drone application and the confidence level of using a drone can increase farmers’ intention to adopt a drone. The results are of interest for agribusinesses developing drones as well as selling or providing drones. Furthermore, the results are of interest for researchers in precision agriculture technologies.

     

Penile prolapse and urethral obstruction secondary to lymphosarcoma of the penis in a dog

A 5-year-old Chihuahua presented for clinical signs of dysuria and penile prolapse. Radiographic studies identified a urethral obstruction distal to the junction of the proximal and middle third of the os penis that appeared to be secondary to swelling of the penis. Penile resection combined with a scrotal urethrostomy was performed. Histopathological examinations of tissue samples of the body of the penis revealed lymphosarcoma. Lymphosarcoma of the penis is a rare finding in all species. It can occur as a primary tumor of the penis in dogs. Penile lymphosarcoma should be considered in the differential diagnosis of dogs affected with penile prolapse and dysuria.     

Obsidian hydration profiles measured by sputter-induced optical emission

The variation of concentrations of hydrogen, sodium, potassium, lithium, calcium, magnesium, silicon, and aluminum as a function of depth in the hydration layer of obsidian artifacts has been determined by sputter-induced optical emission. The surface hydration is accompanied by dealkalization, and there is a buildup of alkaline earths, calcium and magnesium in the outermost layers. These results have clarified the phenomena underlying the obsidian hydration dating technique.