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Mg F/kg Bw (mg + kg_bw)
Selected AbstractsDose determination and confirmation of a long-acting formulation of ceftiofur (ceftiofur crystalline free acid) administered subcutaneously for the treatment of bovine respiratory diseaseJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2002B. HIBBARD Hibbard, B., Robb, E. J., Chester Jr., S. T., Dame, K. J., Boucher, J. F., Alaniz, G. R. Dose determination and confirmation of a long-acting formulation of Ceftiofur (Ceftiofur crystalline free acid) administered subcutaneously for the treatment of bovine respiratory disease. J. vet. Pharmacol. Therap.25, 175,180. The objective of this work was to determine and confirm an effective dose of ceftiofur crystalline free acid sterile oil suspension (CCFA-SS, 100 mg ceftiofur equivalents (CE)/mL], a long-acting single-administration ceftiofur formulation, for the treatment of the bacterial component of bovine respiratory disease (BRD). Study 1 was a dose determination study that used an intratracheal Mannheimia haemolytica (Pasteurella haemolytica) challenge model to evaluate single-administration doses of CCFA-SS at 0.0, 1.1, 2.2, 3.3, 4.4 or 5.5 mg CE/kg body weight (BW) for the treatment of BRD. Data from this study were used to select doses for field testing in three multi-location clinical studies. In Study 2, the efficacy of a single administration dose of CCFA-SS at 4.4 mg CE/kg BW was compared with a negative control for the treatment of naturally occurring BRD in feedlot cattle. Treatments were administered when uniform clinical signs of BRD were present. Study 3 used a design similar to Study 2, and compared single-administration doses of CCFA-SS at 3.0 or 4.4 mg CE/kg BW with the positive-control tilmicosin (Micotil® 300 Injection, Elanco Animal Health) at 10 mg/kg BW. Study 4 compared the efficacy of single doses of CCFA-SS of 1.1,8.8 mg CE/kg BW with tilmicosin at 10 mg/kg BW. A total of 1176 cattle were included in these clinical studies. In Study 1, a dose of 4.55 mg CE/kg BW was determined to be effective. This was rounded to 4.4 mg CE/kg for field testing. In Study 2, a single dose of CCFA-SS at 4.4 mg CE/kg BW had a higher treatment success rate on day 14 (61%) than negative controls (26%, P < 0.01). However, in Study 3 this dose was judged to be at the beginning of an efficacious dose range for the treatment of BRD when compared with tilmicosin. In Study 4, day 28 treatment success rates were higher for CCFA-SS at 4.4,8.8 CE/kg BW than for tilmicosin (P=0.002) or the noneffective CCFA-SS dose of 1.1 mg CE/kg BW (P < 0.001). Based on decision criteria for Study 4, the effective dose was determined to be 4.4,5.5 mg CE/kg BW. These clinical studies demonstrated that a single dose of CCFA-SS (100 mg CE/mL) administered subcutaneously (s.c.) in the neck at 4.4,5.5 mg CE/kg BW is an effective treatment for BRD in feedlot cattle. However, this route of administration is no longer being considered for this formulation because of the ceftiofur residues that are present at the injection site for extended periods of time. [source] Transplacental mutagenicity of N -ethyl- N -nitrosourea at the hprt locus in T-lymphocytes of exposed B6C3F1 miceENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2001Hillary E. Sussman Abstract Previous studies have compared age-related differences in total mutagenic burden in mice of differing age (preweanling, weanling, or young adult) after single intraperitoneal (i.p.) injections of ethylnitrosourea (ENU). The purpose of the present investigation was to determine the effects of time elapsed since treatment on the frequency of hprt mutant T-cells (Mf) from mice treated transplacentally with single acute vs. multiple split doses of ENU. To this end, pregnant C57BL/6 mice (n = 13,16/group), which had been bred to C3H males, were given i.p. injections of 40 mg ENU/kg bw in a single dose on day 18 of gestation, in a split dose of 6 mg ENU/kg bw on days 12 through 18 of gestation, or DMSO vehicle alone. Groups of pups were necropsied on days 10, 13, 15 (single dose only), 17, 20, 40, and 70 postpartum for T-cell isolations and hprt Mf measurements using the T-cell cloning assay. The time required to reach maximum Mfs in T-cells isolated from thymus of transplacentally treated animals was 2 weeks, the same time span as previously observed after ENU treatment of adult, weanling, and preweanling mice. Mfs in T-cells isolated from spleens of control animals averaged 2.1 ± 0.3 (SE) × 10,6. In spleens of mice treated transplacentally with ENU in a single dose, Mfs reached a maximum at 15 days postpartum [84.7 ± 15.8 (SE) × 10,6] and decreased to lower but still elevated levels at 40 days postpartum. In spleens of mice treated transplacentally with ENU in a split dose, Mfs reached a maximum at 13 days postpartum [74.0 ± 16.3 (SE) × 10,6] and decreased to background levels at 40 days postpartum. The areas under the curves describing the change in hprt Mfs over time for ENU-treated vs. control mice estimate the mutagenic potency for transplacental single- and split-dose exposures to be 1.9 and 0.8 × 103, respectively. Comparison of the mutagenic potency estimates for mice exposed to ENU in utero to 4-week-old mice given a similar dose of the same lot number of ENU indicates that the mouse is more susceptible to ENU-induced mutagenesis during fetal life. Environ. Mol. Mutagen. 38:30,37, 2001 © 2001 Wiley-Liss, Inc. [source] Seasonal Variation in Fluoride Intake: the Iowa Fluoride StudyJOURNAL OF PUBLIC HEALTH DENTISTRY, Issue 4 2004Barbara Broffitt MS; ABSTRACT Objectives: Although patterns of fluid intake change seasonally, little is known about how fluoride intake varies by season. Since even short-term increases in fluoride intake could potentially lead to more dental fluorosis, it is valuable to assess the degree of seasonal variation to determine if it increases fluoride intake to levels that could be considered a concern in young children. Methods: Questionnaires were mailed periodically to participants in the Iowa Fluoride Study beginning at 6 weeks of age and continuing for a number of years. Parents recorded the date; child's weight; estimates of the amounts of water and other beverages that their child consumed per week; the type and amount of any fluoride supplements used; and the type, amount, and frequency of dentifrice used, with an estimate of the proportion of dentifrice that was swallowed. Documented water fluoride levels from municipal sources and assay of individual sources were linked to water intake amounts. Total fluoride intake per kg body weight was estimated from water, other beverages, fluoride supplements, and ingested dentifrice. Generalized linear models compared temperature-related and seasonal effects after adjusting for the child's age. Results: Separate analyses for ages 0,12 months and 12,72 months showed different results. Children younger than 12 months of age did not exhibit significant seasonal or temperature-related variation in any of the components of fluoride intake. Children aged 12,72 months had higher fluoride intake (mg F/kg bw) from beverages in summer (P <.05), and fluoride intake from beverages increased with monthly temperature (P <.001). Conclusions: Fluoride intake from beverages for children aged 12,72 months is slightly higher in the summer and increases with mean monthly temperature. Fluoride intake from supplements and dentifrice did not change significantly with either season or temperature. [source] Total fluoride intake in children aged 22,35 months in four Colombian citiesCOMMUNITY DENTISTRY AND ORAL EPIDEMIOLOGY, Issue 1 2005Ángela M. Franco Abstract , Objective: To obtain information on the level of total fluoride intake from food, beverages and toothpaste by children at the age of 22,25 months of low and high socioeconomic status (SES) in major Colombian cities. Methods:, Daily fluoride intake was assessed by the duplicate plate method and by recovered toothpaste solution during a 3-day period and afterwards analysed by the microdiffusion method. Results:, Mean daily fluoride intake was 0.11 (±0.10), 0.14 (±0.12), 0.10 (±0.07) and 0.07 (±0.06) mg/kg body weight (bw)/day in Bogotá, Medellín, Manizales and Cartagena, respectively. The total fluoride intake was higher in low-SES subjects in the cities of Medellín and Bogotá. In the high-SES children of the four cities, the average intakes ranged from 0.06 to 0.09 mg F/kg bw, whereas, the low-SES children in three cities had intakes between 0.11 and 0.21 mg F/kg bw (Cartagena, 0.07). Toothpaste (containing 1000,1500 ppm F, with 1500 ppm F being more common) accounted for approximately 70% of total fluoride intake, followed by food (24%) and beverages (<6%). More than half the children had their teeth brushed by an adult, on average twice a day, using 0.22,0.65 g of toothpaste. Conclusion:, Children from three Colombian cities have a mean total daily fluoride intake above the ,optimal range'. Health authorities should promote an appropriate use of fluoridated dentifrices discouraging the use of dentifrices containing 1500 ppm F in children younger than 6 years of age and promoting a campaign of education of parents and oral health professionals on adequate toothbrushing practices. [source] Pharmacokinetics of ivermectin after maternal or fetal intravenous administration in sheepJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 5 2008R. PÉREZ In pregnant sheep at 120,130 days of gestational age, a study was undertaken in order to characterize the pharmacokinetics and transplacental exchange of Ivermectin after maternal or fetal intravenous administration. Eight pregnant Suffolk Down sheep of 73.2 ± 3.7 kg body weight (bw) were surgically prepared in order to insert polyvinyl catheters in the fetal femoral artery and vein and amniotic sac. Following 48 h of recovery, the ewes were randomly assigned to two experimental groups. In group 1, (maternal injection) five ewes were treated with an intravenous bolus of 0.2 mg ivermectin/kg bw. In group 2, (fetal injection) three ewes were injected with an intravenous bolus of 1 mg of ivermectin to the fetus through a fetal femoral vein catheter. Maternal and fetal blood and amniotic fluid samples were taken before and after ivermectin administration for a period of 144 h post-treatment. Samples were analyzed by liquid chromatography (HPLC). A computerized non-compartmental pharmacokinetic analysis was performed and the results were compared by means of the Student t-test. The main pharmacokinetic changes observed in the maternal compartment were increases in the volume of distribution and in the half-life of elimination (t˝,). A limited maternal-fetal transfer of ivermectin was evidenced by a low fetal Cmax (1.72 ± 0.6 ng/mL) and AUC (89.1 ± 11.4 ng·h/mL). While the fetal administration of ivermectin resulted in higher values of clearance (554.1 ± 177.9 mL/kg) and lower values of t˝, (8.0 ± 1.4 h) and mean residence time (8.0 ± 2.9 h) indicating that fetal-placental unit is highly efficient in eliminating the drug as well as limiting the transfer of ivermectin from the maternal to fetal compartment. [source] Effects of Dietary Recombinant Bovine Somatotropin Levels on Growth, Plasma Recombinant Bovine Somatotropin Concentrations, and Body Composition of Juvenile Korean Rockfish, Sebastes schlegeliJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2007Gwangyeol Yoo This experiment was conducted to study the effects of the graded recombinant bovine somatotropin (rBST) levels on growth, plasma rBST concentrations, and body composition of Korean rockfish, Sebastes schlegeli, and to estimate the optimum oral dosage of rBST. Seven experimental diets were formulated to be isonitrogenous and isocaloric and to contain 49.0% crude protein and 16.7 kJ available energy/g, with 0, 5, 10, 15, 20, 25, or 50 mg rBST/kg body weight (BW)/wk (rBST0, rBST5, rBST10, rBST15, rBST20, rBST25, and rBST50, respectively). After the feeding trial, fish fed all the diets supplemented with rBST showed higher weight gain (WG), feed efficiency (FE), specific growth rate (SGR), and protein efficiency ratio (PER) than those fed the rBST0 diet (P < 0.05). WG of fish fed rBST15, rBST20, rBST25, and rBST50 diets was significantly higher than that of fish fed rBST0 and rBST5 diets (P < 0.05); however, there were no significant differences among fish fed rBST10, rBST15, rBST20, rBST25, and rBST50 diets. FE of fish fed rBST15 and rBST20 diets was significantly higher than that of fish fed rBST0, rBST5, rBST10, and rBST50 diets, and fish fed rBST10, rBST25, and rBST50 diets had significantly higher FE than those fed rBST0 and rBST5 diets (P < 0.05). SGR of fish fed all the diets supplemented with rBST was significantly higher than that of fish fed rBST0 diet (P < 0.05); however, there were no significant differences among fish fed all the diets supplemented with rBST. PER of fish fed rBST15 and rBST20 diets was significantly higher than that of fish fed rBST0, rBST5, and rBST50 diets, and fish fed rBST10, rBST25, and rBST50 diets had significantly higher PER than those fed rBST0 and rBST5 diets (P < 0.05). Whole-body protein of fish fed rBST15 diet was significantly higher than that of fish fed rBST0, rBST5, and rBST10 diets (P < 0.05); however, there were no significant differences among fish fed rBST15, rBST20, rBST25, and rBST50 diets. Plasma rBST concentrations of fish fed all the diets began to rise at 3 h after oral administration of rBST; the maximum plasma rBST concentration peaked at 12 h and returned to the basal level at 24 h. Broken-line model analyses of WG and FE were 12.8 and 13.2 mg rBST/kg BW/wk, respectively. These results indicated that the optimum oral dosage could be greater than 12.8 mg rBST/kg BW/wk but less than 13.2 mg rBST/kg BW/wk in juvenile Korean rockfish. [source] | ||||||||||