Biomedical subjects

C R Boyle

Publications and source records attributed to C R Boyle.

At least 37 records · Page 2Linked to original sources

PubMed1996

Changes in gonadal weights, serum lipids, and glucose during maturation in the juvenile northern bobwhite quail (Colinus virginianus).

Changes in serum lipids, serum glucose, and gonadal development during maturation of Colinus virginianus were determined in two trials. In Trial 1, sex, BW, and serum concentrations of total cholesterol, high, low, and very low density lipoprotein cholesterol, triglycerides, and glucose were determined every 2 d from 2 to 14 d and weekly from 21 to 49 d. Relative ovary or testis weights between 14 and 49 d were determined weekly. Body weight increased and all measured serum constituents changed in males and females between 2 and 49 d; however, relative testis weight decreased between 14 and 49 d. In Trial 2, sex, BW, cholesterol, and relative ovary and testis weights were determined in birds at 56 and 63 d of age. The distinctness of external sexual phenotype and its relationship to BW, cholesterol, and relative gonadal weight were also determined at 56 and 63 d. Body weight increased and serum cholesterol decreased in both sexes between 56 and 63 d, but had no association with the distinctness of external sexual phenotype. It was concluded that the development of external sexual identity in male and female Northern Bobwhite quail prior to sexual maturity was not related to changes in BW, gonad weight, serum lipids, or serum glucose before 63 d of age.

Aging↗

PubMed1996

Effects of acepromazine and buprenorphine on measured indices of the signal-averaged electrocardiogram in healthy dogs.

OBJECTIVES: To determine values for indices of signal-averaged electrocardiograms (SAECG) in healthy dogs, and to determine whether sedation with acepromazine and buprenorphine would alter these indices. ANIMALS: 15 healthy adult dogs. PROCEDURE: SAECG were recorded from each dog twice: prior to sedation and immediately after sedation with acepromazine (0.01 mg/kg of body weight, IV) and buprenorphine (0.007 mg/kg, IV). Time-domain methods were used to analyze the SAECG. All indices were calculated by use of a computer. Measured indices included QRS duration, duration of low-amplitude signals in the terminal part of the QRS complex, root mean square voltages of the terminal 30 and 40 milliseconds of the QRS complex, heart rate, and high-frequency noise levels. RESULTS: We did not detect significant differences between values measured when dogs were not sedated and values measured when dogs were sedated except in regard to heart rate (P = 0.0001) and high-frequency noise levels (P = 0.0004), which were lower when dogs were sedated. Late potentials were not visually identified in SAECG from any dog in this study. CONCLUSION AND CLINICAL RELEVANCE: Sedation facilitated recording of SAECG in dogs without altering the results.

Acepromazine↗

PubMed1995

Comparison of coagulation test results for blood samples obtained by means of direct venipuncture and through a jugular vein catheter in clinically normal dogs.

OBJECTIVE: To determine whether coagulation test results for blood samples obtained from heparinized jugular vein catheters in dogs are accurate. DESIGN: Prospective, controlled study. ANIMALS: Fourteen clinically normal dogs. PROCEDURE: Prothrombin time, activated partial thromboplastin time, concentration of fibrin degradation products, and fibrinogen concentration were measured in blood samples obtained by means of direct jugular venipuncture and through an indwelling jugular vein catheter 0, 2, 8, 24, and 48 hours after catheter placement. Blood samples were collected from the catheter by means of a 2-syringe technique, which involved discarding the first volume of blood collected. RESULTS: For all sample times, mean values for samples obtained from the jugular vein catheter were not significantly different from mean values for samples obtained by means of venipuncture. CLINICAL IMPLICATIONS: Blood samples for coagulation tests may be obtained from jugular vein catheters up to 48 hours after catheter placement in clinically normal dogs.

Analysis of Variance↗

PubMed1995

Changes in serum lipid, lipoprotein and corticosterone concentrations during neonatal chick development.

Broiler chicks were given a standard commercial starter diet from day 0 (day of hatch) to 9 days of age. Body weight and concentrations of the following serum constituents were measured daily: glucose (GLU), triglycerides (TRI), corticosterone (CORT), cholesterol (CHOL), and high (HDL) and low (LDL) density lipoproteins. Serum GLU and TRI increased at each sampling day to reach a peak on days 3 and 4, respectively, and then decreased thereafter. However, CHOL, HDL, and LDL decreased sharply by day 1 and then gradually decreased to day 5. Conversely, CORT peaked on day 1 and then decreased to day 4. It peaked again on day 5 and remained at that level throughout the remainder of the experiment. In summary, serum concentrations of all constituents measured fluctuated drastically between 1 and 5 days of age, with few changes occurring between days 6 and 9.

Aging↗

PubMed1995

Liver and kidney concentrations of zinc, copper and cadmium in channel catfish (Ictalurus punctatus): variations due to size, season and health status.

Significant differences in liver and kidney concentrations of zinc (Zn), copper (Cu) and cadmium (Cd) were detected in normal Mississippi farm-raised channel catfish (Ictalurus punctatus) collected at different times of the year. These seasonal differences were not solely due to variation in fish size. Comparing the concentration of each metal in liver vs kidney indicated that Cd was lower in liver for all seasons studied, Cu was higher in liver for all seasons studied, and Zn was higher in the liver in the winter-killed (winter mortality syndrome) and the spring fish groups. Metal concentration was associated with body weight, as indicated by significant Pearson correlation coefficients for kidney Cd (all seasons and fall), liver Cu (summer), liver Zn (all seasons and winter), and kidney Zn (all seasons and winter). The adjusted means were not dramatically changed as compared to the raw data. Differences were noted when seasonal values obtained from normal fish were compared to tissues of moribund fish afflicted with winter mortality syndrome. Zinc was reduced in liver and kidney of these moribund fish.

Animals↗

PubMed1994

The effects of dietary fat on growth performance, carcass composition, and feed efficiency in the broiler chick.

In two experiments broiler chicks were fed nonisocaloric diets with either 0, 3, or 7% added lard. Megacaloric percentages of all major nutrients were the same in all diets. In Experiment 1 (broiler chicks 0 to 5 d of age), added dietary lard did not affect body, heart, spleen, or pancreas weight. Liver weight was suppressed by the inclusion of lard in the diet, yet liver composition changed, becoming higher in protein and lower in fat. Yolk sac weight decreased during the first 5 d posthatch, with the decrease being most pronounced by 3 d of age. There were no differences in feed consumption due to treatment in Experiment 1. In Experiment 2 (broiler chicks 6 to 11 d of age), added dietary fat resulted in differences in liver, body, and fecal excreta composition. Chicks given 7% added lard had lower liver fat throughout the trial than chicks fed no added lard. Additionally, these chicks had a higher body protein content at 6 and 7 d of age. However, body fat only increased in chicks fed 7% added lard by 11 d of age. Furthermore, chicks receiving 7% added lard had elevated fecal fat at Day 6, but did not consume more feed than chicks receiving 0 or 3% added lard. Additionally, chicks fed lard had lower liver weights than those fed 0% added lard.

Animals↗

PubMed1994

Effects of dietary thiouracil on thyroid activity, egg production, and eggshell quality in commercial layers.

The effects of thyroid suppression induced during the rearing period by providing various dietary thiouracil (TU) regimens on plasma thyroxine (T4) concentrations, growth, and subsequent egg production (EP) and eggshell quality were determined in Single Comb White Leghorn chickens. Thiouracil was provided in the feed at levels of 0, .1, and .2% from 0 to 6 wk of age in Experiment 1, and at levels of 0, .05, and .1% from 6 to 16 wk of age in Experiment 2. In both experiments, T4 concentrations were reduced during TU treatment. However, T4 later became elevated at 12 and 20 wk in both dosage level groups in Experiment 1. Additionally, BW and egg weights were suppressed by both TU treatments, and EP was reduced up to Week 23 in the .1% TU-treated birds and through Week 25 in the .2% TU-treated birds. No effects on EP were noted in Experiment 2, but feed consumption (FC) was reduced during Week 6 in birds fed .05% TU and during Weeks 6, 10, and 19 in birds fed .1% TU. Both liver and thyroid weights were increased in .1% TU-treated birds relative to controls at Week 16. Eggshell quality was affected only in Experiment 2, in which birds given .05% TU had a higher relative conductance, or maximum rate of water loss, at Week 38 than 0 and .1% TU dosage levels, and .1% TU-treated birds had a higher breaking strength than 0 and .05% TU-treated birds at Week 22.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗

PubMed1993

Ultrasonography as a tool for monitoring in ovo chicken development. 2. Effects of eggshell alteration and ultrasonography on embryonic and posthatch development.

The influence of creating and closing acoustic windows on embryonic and posthatch development for the purpose of chicken embryogenesis monitoring by real-time ultrasonography (US) was evaluated at 2, 6, 9, 14, and 17 days of incubation. Acoustic windows were closed using either a porous dialysis film and tape (FM) or an eggshell allograft attached with collodion (CP). Results from eggs closed in each manner with and without concurrent nonsterile US examination were compared with two control groups. Window creation reduced hatchability. The hatchability reduction was caused primarily by bacterial contamination. Contamination was more common in the FM eggs than in the CP eggs and was greater in eggs that also underwent US. Hatchability increased and contamination decreased when US was performed closer to hatch. Egg weight loss was increased after Day 6 of incubation in FM + US eggs treated on Day 2 and after Day 9 in all eggs with windows except CP eggs treated on Day 9 and CP + US eggs treated on Days 6 and 9. Hatch weight decreased in chicks from eggs that had windows, particularly in FM eggs.

Animals↗

PubMed1990

Effects of ammoniation of endophyte fungus-infested fescue hay on serum prolactin concentration and rectal temperature in beef cattle.

A group of 48 crossbred steers (approx 250 kg each) were used to determine the effects of various diets and treatments on serum prolactin concentrations and rectal temperatures. The steers were randomly assigned to groups fed the following: (1) endophyte fungus-infested fescue hay; (2) ammoniated endophyte fungus-infested fescue hay; (3) endophyte fungus-infested fescue hay plus 1 g of thiabendazole (TBZ)/9.1 kg of body weight at 7-day intervals; (4) ammoniated endophyte fungus-infested fescue hay plus 1 g of TBZ/9.1 kg at 7-day intervals; (5) ground Bermuda grass hay; and (6) endophyte-fungus-free fescue hay. Blood samples for prolactin determinations and rectal temperatures were obtained biweekly beginning on week 3 and continuing through week 9. A significant correlation (P less than 0.05) between low prolactin concentrations and high rectal temperatures in cattle eating endophyte-infested fescue hay was determined; however, as the prolactin concentrations approached normal (control animal) concentrations, this relationship between serum prolactin and rectal temperatures was not observed. Two antifungal agents used in this experiment (thiabendazole and ammonia) appeared to have different effects on the variables measured. Thiabendazole had no significant effect on prolactin concentrations or rectal temperatures of cattle ingesting endophyte-infested fescue hay, whereas ammoniation of this hay induced significantly higher (P less than 0.05) prolactin concentrations and lower rectal temperatures than in steers receiving only endophyte-infested fescue hay. Therefore, ammonia may be valuable not only as an aid in determining the cause of the fescue problem but also as a practical solution to some of the fescue-related economic problems in the cattle industry. Also, prolactin concentrations may be valuable in diagnosing fescue-related problems.

Acremonium↗

PubMed1989

Efficacy of oxfendazole against inhibited larvae of Ostertagia ostertagi in naturally infected calves in the southern USA.

Forty yearling calves were assigned to four equal groups; three of the groups were treated with oxfendazole at dose rates of 6.75 mg/kg, 4.50 mg/kg, or 2.25 mg/kg bodyweight while the fourth group served as an untreated control. The calves were native to north-east Mississippi, USA, and harboured natural infections of gastrointestinal nematodes. The study was conducted during July when inhibited early fourth-stage larvae may be found in large numbers after their acquisition in the spring. The calves were maintained in separate groups on concrete-floored pens for 17 days before the intraruminal administration of oxfendazole. Seven days after treatment, the calves were slaughtered and the gastrointestinal parasites counted. At all the dose rates examined oxfendazole exhibited an efficacy of at least 99.4 per cent against adults of Haemonchus placei, Trichostrongylus axei, Bunostomum phlebotomum, Cooperia species, T colubriformis, Oesophagostomum radiatum, and Trichuris ovis. The efficacy against adult Ostertagia ostertagi was at least 99.4 per cent at dose rates of 6.75 and 4.50 mg/kg bodyweight, but decreased to 93.7 per cent at 2.25 mg/kg. The efficacy of oxfendazole against inhibited larvae of O ostertagi decreased with dose rate from 78.8 per cent at 6.75 mg/kg, to 58.9 per cent at 4.50 mg/kg and 20.3 per cent at 2.25 mg/kg bodyweight.

Animals↗

PubMed1986

Blood magnesium values in healthy cattle and in cattle affected with anaplasmosis and eperythrozoonosis.

Magnesium (Mg) concentrations in plasma, serum, and erythrocytes (RBC) of calves subjected to splenectomy (SP), splenectomy-induced eperythrozoonosis (EP), and experimentally induced anaplasmosis (AN) were determined and compared with pre-SP, pre-EP, and pre-AN values. Mean serum and plasma Mg concentrations varied in parallel through most periods of the trial. Both were highest after SP, but neither value was significantly different from the pre-SP concentrations. Mean serum and plasma Mg values varied inversely with mean RBC values after SP and EP. Mean RBC Mg values increased significantly from previous periods during EP and AN and after AN, with the values after AN being significantly higher than those at all other periods. Mean plasma, serum, and RBC Mg concentrations were correlated to both mean percentage of parasitemia (%P) and packed-cell volume (PCV). The RBC Mg values increased significantly after mean %P reached 20 and the PCV began to decrease. There was evidence for a distinct lag variation in increasing RBC Mg concentrations with respect to both mean %P and PCV during AN. A strong correlation was observed between the RBC Mg values and the %P occurring 5 days previously and the PCV occurring 3 days previously.

Anaplasmataceae Infections↗

PubMed1979

Multifactorial genetic models for quantitative traits in humans.

Quantitative traits measured in human families can be analyzed to partition the total population variance into genetic and environmental components, or to elucidate the genetic mechanism involved. We review the estimation of variance components directly from human pedigree data, or in the form of path coefficients from correlations between pairs of relatives. To elucidate genetic mechanisms, a mixed model that allows for segregation at a major locus, a polygenic effect and a sibling environmental correlation is described for nuclear families. In each case appropriate likelihoods are derived as a basis, using numerical maximum likelihood methods, for parameter estimation and hypothesis testing. A general model is then described that allows for several familial sources of environmental variation, assortative mating, and both major gene and polygenic effects; and an algorithm for calculating the likelihood of a pedigree under this model is indicated. Finally, some of the remaining problems in this area of biometric analysis are pointed out.

Genetic Variation↗

PubMedDate not supplied

Placental immunopathology and pregnancy failure in the FIV-infected cat.

Placental HIV infections frequently result in infected babies or miscarriage. Aberrant placental cytokine expression during HIV infections may facilitate transplacental viral transmission or pregnancy perturbation. The feline immunodeficiency virus (FIV)-infected cat is a model for HIV infections due to similarities in biology and clinical disease. The purpose of this study was to evaluate placental immunomodulator expression and reproductive outcome using the FIV-infected cat model. Kittens were cesarean delivered from FIV-B-2542-infected and control queens near term; placental and fetal tissues were collected. Real-time RT-PCR was used to measure expression of representative placental Th1 cytokines, interleukin-1beta (IL-1beta) and interferon-gamma (IFN-gamma), a Th2 cytokine, IL-10, and chemokine receptor CXCR4. On average, control queens delivered 3.8 kittens/litter; 1 of 31 kittens (3.2%) was non-viable. FIV-infected queens produced 2.7 kittens/litter; 15 of 25 concepti (60%) were non-viable. FIV was detected in 14 of 15 placentas (93%) and 21 of 22 fetuses (95%) using PCR. Placental immunomodulator expression did not differ significantly when placentas from infected cats were compared to those of control cats. However, elevated expression of Th1 cytokines and increased Th1/Th2 ratios (IL-1beta/IL-10) occurred in placentas from resorptions. Therefore, increased placental Th1 cytokine expression was associated with pregnancy failure in the FIV-infected cat.

Animals↗

PubMedDate not supplied

Evaluation of the hemodynamic effects of interpleural bupivacaine in dogs.

The hemodynamic effects of interpleural (IP) bupivacaine were studied in six halothane-anesthetized dogs. On four separate occasions, each dog received IP saline (S), or bupivacaine at a low dosage of 1.5 mg/kg (L), high dosage of 3.0 mg/kg (H), or high dosage of 3.0 mg/kg with epinephrine 5 micrograms/mL (HE). Heart rate, systolic and mean arterial pressures, and base excess were significantly lower in the H dosage group than in the other treatment groups. Cardiac output, expressed as a percentage of change from baseline, was significantly higher in the L group than in the H and S groups. Pulmonary arterial pressure and respiratory rate were significantly higher in the HE group than in the other three groups. Mean plasma concentrations of bupivacaine peaked between 5 and 15 minutes after IP injection. Maximum plasma concentrations in individual dogs were variable; however, mean maximum plasma concentrations in the H and HE groups were not significantly different. Clinically significant hypotension occurred in one dog in the H group and in one dog in the HE group. No pulmonary complications were detected.

Analgesia↗

PubMedDate not supplied

Radiographic bone loss correlations and technetium-99m-MDP bone uptake in ligature-induced periodontal disease in the beagle.

The goal of this study was to develop an animal model for the study of acute periodontal disease using silk ligatures in combination with a soft diet in eleven purebred beagle dogs. The silk ligatures were placed subgingivally on the mandible second and fourth premolar on one side of the mouth; the opposite side served as a control. Dogs were monitored during the 16-20 weeks of ligature placement, and for 48 weeks after ligature removal. Development of periodontal disease was evaluated by radiopharmaceutical uptake into bone, radiographic evidence of alveolar bone loss, attachment loss, gingival index and prostaglandin level. Bone loss occurred on the ligatured side during the ligature phase of the study. Radiopharmaceutical uptake was correlated with radiographic evidence of bone loss during the ligature phase. No significant bone loss occurred during the post-ligature phase. Progressive periodontal disease was induced during ligature placement. However, a chronic less aggressive form was not sustained by soft diet alone after ligature removal.

Acute Disease↗

PubMedDate not supplied

Consequences to chicks hatched from Escherichia coli-inoculated embryos.

An Escherichia coli causing negligible mortality in embryonated chicken eggs was adapted to grow in media containing nalidixic acid. This isolate (EcNAL) was inoculated into 12-day-old embryonated eggs. Additional embryos inoculated with tryptose phosphate broth (TPB) served as controls. Six days later, all surviving eggs were moved to hatching units. One hatcher contained half of the TPB-inoculated eggs; the chicks hatching from these eggs served as negative controls. The EcNAL-inoculated eggs and the remaining TPB-inoculated eggs were moved to a second hatcher and allowed to hatch together; chicks hatching from these TPB-inoculated eggs served as contact controls. On day of hatch and at intervals thereafter, chicks from each of the treatment groups were sampled. Their body and yolk weights were recorded, and various tissues were cultured for the presence of the EcNAL bacterium. Hatchability of the EcNAL-inoculated embryos was markedly lower than that of either control group. Chicks from EcNAL-inoculated embryos also had low but detectable levels of mortality, lowered body weights, and increased yolk-to-body weight ratios. These same chicks had persistently high levels of EcNAL in the yolk and lower but detectable levels of the organism in the lungs and tracheas, which lasted a few days. The contact controls, on the other hand, were similar to the negative controls as far as having negligible mortality, steadily increasing body weights, and declining yolk-to-body weight ratios. However, in contrast to the negative controls, EcNAL was recovered primarily from the respiratory tract of the contact controls for a brief period of 3-4 days after hatch.

Animals↗

PubMedDate not supplied

Effects of an Arkansas strain of infectious bronchitis vaccine on the head-associated lymphoid tissue (HALT).

Chicks were vaccinated with an Arkansas strain of infectious bronchitis virus (IBV) vaccine when they were 1 day (Trial 1) or 4 weeks old (Trial 2). Starting at 4 weeks 3 days of age, chicks in both trials were subjected to an assay that measures the immunofunctional response of the gland of Harder (GH), one of the components of the head-associated lymphoid tissue (HALT). The assay involved multiple ocular exposures to killed Brucella abortus antigen, after which tears were collected and titered for antibodies to B. abortus. Following this, select tissues from vaccinated and unvaccinated chicks were collected and examined microscopically for specific lesions. Both functional and structural alterations were detected in the HALT of IBV-vaccinated chicks. Antibody titers to B. abortus in vaccinated chicks were significantly lower (P less than 0.05) than in unvaccinated controls. Structurally, there were elevations (P less than 0.01) in the number of lymphoid cells and follicles found in the mucosal lining of the nasal cavity. This occurred in the vaccinated chicks of both trials. Otherwise, histologic changes were confined to the chicks vaccinated at 4 weeks of age (Trial 2). In that trial, there were elevations in lymphoid-cell and follicle numbers in the eyelid (P less than 0.01) and lacrimal gland (P less than 0.05).

Analysis of Variance↗

PubMedDate not supplied

Influence of antigen concentration, inoculation interval, number of exposures, type of housing, and placement concentration on the tear antibody response to Brucella abortus in chickens.

A series of trials was run in leghorn chicks to examine select conditions affecting the tear antibody response to killed Brucella abortus antigen given by eyedrop administration. Specific conditions examined were concentration of antigen, number of antigen exposures, and interval between antigen exposures. Trials were also run to determine the earliest age at which the assay was functional in both broilers and leghorns. Two types of housing (isolators and battery cages) were examined, as were two levels of placement concentration, or bird density (0.32 and 0.64 ft. [0.03 and 0.06 m2]/chicken). All trials included intraperitoneally inoculated chicks as a comparison; tears as well as serum were assayed for antibodies. Of the various antigen regimens evaluated, two exposures of 20% B. abortus given 3 days apart was found to give a satisfactory antibody response in the tears 1 week later. Furthermore, response to B. abortus was found to be somewhat proportional to age, with the minimum age for a satisfactory response being 3 weeks in leghorns or 4 weeks in broilers. Statistically, there were no differences in antibody responses due to the types of housing or levels of placement used.

Age Factors↗