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Biomedical subjects

V L Anderson

Publications and source records attributed to V L Anderson.

14 recordsLinked to original sources

Influence of crambe meal as a protein source on intake, site of digestion, ruminal fermentation, and microbial efficiency in beef steers fed grass hay.

Four ruminally and duodenally cannulated beef steers (558 +/- 37 kg) were arranged in a 4 x 4 Latin square to evaluate the influence of crambe meal as a protein source on intake, digestion, and microbial efficiency. Steers were offered chopped (10.2 cm) brome hay (6.2% CP) for ad libitum consumption and one of four supplements. Protein sources used were soybean and crambe meals (CM). Protein sources were blended to provide four levels of supplemental CM protein (0, 33, 67, and 100%). Protein supplements were fed to provide similar amounts of protein and energy. Amounts of supplements fed were 831, 885, 950, and 996 g of DM/steer daily for 0, 33, 67, and 100% CM treatments, respectively. Crambe meal represented 0, 2.00, 3.83, and 5.88% of the DM intake for respective treatments. Steers were allowed a 21-d adaptation to diets before each collection period. Supplements were offered at 0800 and forage at 0830. Crambe meal had no influence (P > .10) on forage and total DM intake (grams/kilogram of BW). Apparent total tract, ruminal, and postruminal digestion of OM, NDF, ADF, and N were unaffected (P > .10) by CM supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed

A statistical approach for the development of an oral controlled-release matrix tablet.

Tablet matrix compositions for optimized prolonged release were selected by surface response methodology. The extreme vertices experimental design was used to develop a surface response model which mathematically defined the release of active component from the tablet matrix as controlled by the percentage of the excipient components. The model, a statistical quadratic equation with a standard error of 3.3, was validated for accurate prediction of drug release profiles and used to identify optimum formulations. This study demonstrated a new application of the extreme vertices experimental design, an efficient method for evaluating a complex mixture system for controlled release, where specific constraints are placed on one or more of the components.

Administration, Oral

Dose-dependent pharmacokinetics of gentamicin in sheep.

Dose-related changes in the pharmacokinetics of gentamicin sulfate were investigated in 9 sheep given 3, 10, or 20 mg/kg of body weight IV in a crossover design with a 24-day washout period. The pharmacokinetics of the 3 mg/kg single dose were compared with that of the terminal phase pharmacokinetics of 3 mg of gentamicin/kg IV every 8 hours for 7 days in 8 additional sheep. Serum concentrations were monitored for 21 to 24 days after the dose. Polyexponential equations were fit to each data set. The number of exponential terms was determined by optimizing the fit for each data set. The pharmacokinetics of the 3 mg/kg single dose were mainly described by triexponential equations. The 10 mg/kg and the 20 mg/kg single doses and the 3 mg/kg multiple-dose data were described by a tetraexponential equation. The elimination rate constant was significantly smaller (P less than 0.05) after the larger single doses, and the serum gentamicin clearance increased as the dose increased (P less than 0.05). The crossover design sequence had a significant effect on serum gentamicin clearance and the area under the curve normalized to unit dose (P less than 0.01). The final exponential phase was not detectable with the present assay sensitivity under the 3 mg/kg single dose. The triexponential equation underpredicted the terminal serum concentrations determined after the 3 mg/kg multiple dose, whereas the 4 phase equation overpredicted the same terminal serum concentrations, perhaps reflecting saturation of the tissue pools that were mirrored by the serum gentamicin concentrations after 24 hours. The present study emphasized the complexity of the terminal phase gentamicin. pharmacokinetics and acknowledged the need for a long-term washout period when using the crossover design for gentamicin pharmacokinetic studies.

Animals

Irradiation-hyperthermia in canine hemangiopericytomas: large-animal model for therapeutic response.

Results of irradiation-hyperthermia treatment in 11 dogs with naturally occurring hemangiopericytoma were reported. Similarities of canine and human hemangiopericytomas were described. Orthovoltage X-irradiation followed by microwave-induced hyperthermia resulted in a 91% objective response rate. A statistical procedure was given to evaluate quantitatively the clinical behavior of locally invasive, nonmetastatic tumors in dogs that were undergoing therapy for control of local disease. The procedure used a small sample size and demonstrated distribution of the data on a scaled response as well as transformation of the data through classical parametric and nonparametric statistical methods. These statistical methods set confidence limits on the population mean and placed tolerance limits on a population percentage. Application of the statistical methods to human and animal clinical trials was apparent.

Animals

The importance of cauterization to maintain a healthy cervix. Long-term study from a private gynecologic practice.

A total of 13,897 patients from a private gynecologic practice were retrospectively analyzed with special regard to the benefits obtained from hot linear cautery. This has been performed as an office procedure since 1937, providing unique long-term follow-up. The exposed cervical transitional zone and mild, atypical, or dysplastic cervical cytology were so treated in 6,364 patients. A significantly higher percentage of carcinoma in situ and invasive disease was found in the noncauterized cervices. With the trend of cervical intraepithelial neoplasia (CIN) toward development at an earlier age in today's population, the importance of office cauterization in preventing cervical cancer becomes apparent.

Adolescent

The water-to-air transfer of 35SO4= by bursting bubbles.

The transfer of 35SO4= from water to air by bursting bubbles was studied as a function of three levels each of three variables in a bubbling solution. The variables were pH, surfactant concentration, and Na2 35SO4 concentration. One combination of the above variables was also studied at three different temperatures. Sterile water solutions containing different combinations of the above factors and a fixed amount of 22NaCl were bubbled in an enclosure for 1 hour. After bubbling, samples of the aerosol produced, the larger drops that fell out of the air, and the bulk solution were collected and assayed for their 35S and 22Na content using liquid scintillation counting. The 35S/22Na enrichment for each droplet sample as compared to the ratio for the bulk solution was determined, and it was found to be dependent upon the combination of the factor levels being bubbled. Both positive and negative enrichments were found, with large positive enrichments being found consistently only for the highest value of surfactant concentration. The temperature study showed no significant enrichment differences for any of the three temperatures studied.

Air

Logistic growth curve of chickens: a comparison of techniques to estimate parameters.

Parameters of a mathematical function of growth, fit to the body weight curve of two randombred control populations of each sex of chickens from hatching through 45 weeks of age, were estimated. The logistic function was chosen from among growth formulae that express rate of gain as a function of weight at a given time and gain to be made. Two logistic parameters, growth-rate constant and age at the point of inflection, were estimated by the methods of sample quantiles and nonlinear regression from weekly mean body weights of 225 males and 281 females of the Rhode Island Red (RIR) line, and 164 males and 239 females of the White Leghorn (WL) line. Males had a larger growth-rate constant than females of the same line. The RIR line had a larger rate constant than the WL line, for each sex. Age at the point of inflection was similar for males and females in the RIR line, but smaller for males than females in the WL line. Sample quantiles yielded larger, less precise estimates of the growth-rate constant than nonlinear regression. Estimates of age at the point of inflection were usually smaller using sample quantiles.

Aging