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Biomedical subjects

G D Adams

Publications and source records attributed to G D Adams.

At least 37 records · Page 2Linked to original sources
PubMed1991

Controlled ruminal infusion of sodium bicarbonate. 1. Influence of postfeeding infusion interval on ruminal milieu.

Four ruminally cannulated, lactating Holstein cows were assigned to a 4 x 4 Latin square to monitor the effects of intraruminal NaHCO3 infusion on changes in the rumen environment. Sodium bicarbonate (110 g), dissolved in 3.8 L of water, was infused twice daily at a constant rate for 2 h starting at 0, 2, or 4 h postfeeding. All cows had access to their diet containing sorghum silage and concentrate in a 35:65 ration (DM basis) for 45 min twice daily. Ruminal fluid was collected at feeding and every 30 min postfeeding for 12 h on the last day of each 7-d period. Dry matter intake was lower for buffer infusion at 2 to 4 h than for water-infused control but was not affected by the other NaHCO3 infusions. Although total milk yield was not affected, milk fat percentage and fat yield tended to be lower for the NaHCO3 treatments. Compared with the water infusion, the NaHCO3 infusion from 2 to 4 h postfeeding most effectively prevented the postfeeding increase in ruminal free proton concentration. Additionally, volume of ruminal liquid was increased for the NaHCO3 infusions from 0 to 2 h and 4 to 6 h; ruminal liquid turnover time was increased for the NaHCO3 infusion at 4 to 6 h, but ruminal kinetics otherwise were not affected by NaHCO3. Although infusion of NaHCO3 from 2 to 4 h prevented severe alterations in ruminal acid-base status, it did not increase total VFA concentration or the acetate:propionate ratio. Although total VFA concentrations were not affected by NaHCO3 infusion, acetate:propionate ratio was higher for the NaHCO3 infusion from 0 to 2 h than for the control. Based upon alterations in ruminal acid-base status, exogenous buffer ideally should be provided to the rumen from 2 to 4 h postfeeding; however, our results indicate that the effectiveness of this regimen might be improved if buffer is combined with a rapidly released or unprotected dietary buffer.

Acid-Base Equilibrium↗
PubMed1991

Controlled ruminal infusion of sodium bicarbonate. 2. Effects of dietary and infused buffer on ruminal milieu.

Four ruminally cannulated, lactating Holstein cows were assigned to a 4 X 4 Latin square to monitor the effects of NaHCO3 infusion on ruminal environment of cows receiving dietary sodium bicarbonate. Sodium bicarbonate (110 g) was mixed with 3.8 L of water and infused at a constant rate into the rumen from 0 to 2, 2 to 4, or 4 to 6 h postfeeding twice daily. All cows were fed sorghum silage and concentrate in a 35:65 DM ratio for 45 min twice daily. Ruminal fluid was collected at feeding and every 30 min postfeeding for 8 h on the last day of each 1-wk experimental period. Dry matter intake was not affected by NaHCO3 infusion. Yields of milk and its components were reduced with 4- to 6-h NaHCO3 infusion. At certain isolated times, especially during infusion, NaHCO3 infusion increased ruminal fluid buffer. Concentrations of ruminal fluid total VFA were not affected by NaHCO3 infusions, whereas acetate to propionate ratio tended to be reduced. Ruminal liquid volume tended to be increased by 0- to 2-h NaHCO3 infusion, and ruminal outflow rate tended to be reduced by the 2- to 4-h infusion. Intraruminal infusion of NaHCO3 into cows receiving supplemental dietary NaHCO3 altered ruminal acid-base status as typically reported for those receiving dietary NaHCO3; however, these alterations were not accompanied by shifts in ruminal VFA patterns or in milk composition that normally result from such feeding regimens. The effects of NaHCO3 infused directly into the rumen may be different from those of dietary NaHCO3 and are possibly related to the different time of entry into the rumen relative to feeding.

Acid-Base Equilibrium↗
PubMed1990

Insulin-like growth factor-I in dairy cows: relationships among energy balance, body condition, ovarian activity, and estrous behavior.

The objective was to determine relationships among concentrations of insulin-like growth factor-I in serum, energy balance, body condition, and ovarian activity during early lactation. From 0 to 12 wk postpartum, 11 pluriparous Holstein cows were individually fed a total mixed diet and bled twice weekly for quantification of insulin-like growth factor-I and progesterone. Estrous behavior was monitored twice daily and body condition scores were recorded weekly. Individual feed intake and milk production were recorded daily and milk composition and BW were measured weekly. Cows with positive (3.43 Mcal/d; n = 5) energy balance during the first 12 wk postpartum had greater concentrations of insulin-like growth factor-I in serum and greater luteal-phase progesterone secretion than in cows with negative (-1.69 Mcal/d; n = 6) energy balance. Interval to first ovulation or first estrus did not differ between cows with positive versus negative energy balance. Correlation coefficients among weekly averages revealed positive correlations between energy balance and serum progesterone, and energy balance and serum insulin-like growth factor-I. Body condition scores were not correlated with energy balance or serum insulin-like growth factor-I. We conclude that reduced luteal activity that accompanies negative energy balance may be associated with reduced concentrations of insulin-like growth factor-I in serum.

Animals↗
PubMed1989

Human adjuvant disease. A new cause of chylous effusions.

Connective-tissue disease occurring after cosmetic surgery with silicone injections or implants has been reported. This disorder has been called human adjuvant disease. One patient is described in whom a chylous effusion and systemic lupus erythematosus-like disorder developed after mammary augmentation with silicone gel-filled prostheses. This patient represents still another example of human adjuvant disease. A brief review of the literature regarding human adjuvant disease is also presented.

Adult↗
PubMed1989

Utilization of wheat in complete rations for lactating cows.

Effects of different amounts of wheat, protected amino acids, and increased rumen escape protein in high wheat rations were evaluated in two trials with dairy cows. In trial 1, concentrate mixtures with 0, 40, or 60% hard red winter wheat were included in a complete ration with 45% sorghum silage (dry basis). Intake of DM and CP was not affected by treatment. Milk yield declined (28.8, 28.0, 27.3 kg/d) as amount of wheat in the ration increased. In a second trial, concentrate mixtures with 60% wheat were compared with a control corn-base mixture. One wheat mixture was supplemented with protected lysine and methionine and another had protected lysine and methionine plus estimated rumen escape protein equal to the control. Intake of DM and CP was not affected. Milk yield of cows fed rations containing wheat, with or without protected amino acids, was lower than that of cows fed the control ration or the wheat ration in which rumen escape protein was equal to the control (29.1 and 29.0 vs. 30.8 and 30.2 kg/d). Responses of cows fed concentrate mixtures containing wheat appeared to be related to utilization of protein.

Amino Acids↗
PubMed1988

Amiodarone-induced pneumonitis. Assessment of risk factors and possible risk reduction.

Problems with pulmonary toxicity have emerged as a potentially limiting factor for amiodarone use. We prospectively studied 33 subjects treated with amiodarone for refractory arrhythmias. Serial clinical, radiographic and pulmonary function tests were correlated with the dose and duration of amiodarone treatment to define: a) prevalence of lung toxicity, b) subgroups of patients at particular risk for toxicity, c) potential interaction between amiodarone dose and toxicity. Considering all subjects, no significant change in lung volumes or airflow indices were noted; carbon monoxide diffusing capacity (DCO) underwent a mean reduction of 20.3 percent during treatment. Symptoms of possible pulmonary toxicity occurred in 27.3 percent of subjects. No type or degree of pretreatment cardiopulmonary dysfunction predicted lung toxicity. However, maintenance dose was correlated with toxicity; patients treated with doses of less than or equal to 400 mg per day from the start of treatment had insignificant reductions in DCO and did not develop symptoms.

Adolescent↗
PubMed1987

Influence of dietary protein on reproductive performance of dairy cows.

From 10 +/- 3.5 d after parturition to 149 +/- 3.5 d of lactation, 146 cows (109 Holstein and 37 Ayrshires) were fed either a 15 or 20% crude protein diet of 45% sorghum silage and 55% concentrate. Milk production was enhanced by the 20% protein diet, but percentage of milk fat and protein were unchanged. Average daily intake of DM was unaffected by diet. Actual decreases in body weight and condition were small, although cows on 15% protein lost more condition. Concentration of plasma urea nitrogen increased rapidly during the first 4 wk of the experiment with cows on the 20% protein diet maintaining a 10 mg/dl advantage after the 4th wk on experiment. Diet did not affect the postpartum interval to first normal corpus luteum and standing estrus. Cows were inseminated artificially between 55 and 145 d post-calving with one freeze batch of semen from one bull of each appropriate breed mainly by one inseminator. Overall, days open, services per conception, and percentage cows pregnant on experiment were 80, 1.40, and 85, respectively. Concentration of protein in the diet did not affect these reproductive traits. There was no conflict between the amount of dietary protein provided for lactation and reproduction in this experiment.

Animals↗
PubMed1985

Two methods for administering colostrum to newborn calves.

Comparison was of immunoglobulin G concentrations in blood serum of calves to which colostrum was administered by nipple bottle or by esophageal tube. Pooled batches of colostrum were given by the designated method soon after birth and at 12 and 24 h thereafter. Blood samples to measure immunoglobulin G concentrations were taken before initial feeding and at 4-h intervals thereafter through 32 h. The rate of increase of immunoglobulin G concentration following feeding was essentially the same for calves given colostrum by the two methods, and the concentration attained by 20 h after initial feeding was similar for the two groups and adequate for calf survival.

Animal Feed↗
PubMed1982

Feeding milk containing Staphylococcus aureus to calves.

Newborn calves from dams free of staphyloccocal udder infection were assigned to treatment groups in two experiments. Following colostrum feeding for 2 days, a culture of Staphylococcus aureus was added to pasteurized milk fed to one group twice weekly for a total of nine feedings. A control group received only pasteurized milk. Bull calves were in a short experiment to determine whether the organism was established in body tissues, and a second experiment was to determine the effect on incidence of mastitis at calving. No staphylococcus aureus was isolated from any body tissue or surfaces of bull calves necropsied at about 7 wk of age. Moreover, there was no difference in incidence of staphylococcal udder infection at first calving between heifers exposed to the organism as calves and controls. There appears little reason for concern about detrimental effects of feeding mastitic milk to calves under conditions where they are maintained in individual pens.

Animal Feed↗
PubMed1981

Optimal radiotherapy treatment planning for carcinoma of the cervix uteri.

A study is described in which an optimal time-dose-fractionation (TDF) value for radiotherapy of carcinoma of the cervix uteri is found using clinical data for points 2 cm from the cervical os proximally along the direction of the cervical canal and 2 cm laterally to the canal. The optimal TDF value was found to be 127 +/- 10 for regimens utilizing external beam cobalt 60 irradiation (or external irradiation of equivalent quality) in combination with intracavitary radium irradiation.

Female↗
PubMed1980

Metabolic sequelae of experimental leptospirosis in grivet monkeys.

Leptospira interrogans serovars balcanica and tarassovi both induced mild subclinical infections in grivet monkeys. The activities in serum of lactate dehydrogenase, alpha-hydroxybutyrate dehydrogenase, aspartate aminotransferase, alanine aminotransferase and creatine phosphokinase and the level of alpha 1-antichymotrypsin increased in a few days after infection. Concomitant decreases in serum iron levels were observed in some cases. These changes occurred in the absence of any observable clinical signs though there were histopathological lesions in some organs. No haematological changes or alterations in other sreum components were detected.

Alanine Transaminase↗
PubMed1980

Benign leptospirosis: the pathology of experimental infection of monkeys with Leptospira interrogans serovars balcanica and tarassovi.

Grivet monkeys experimentally infected with Leptospira interrogans serovars balcanica and tarassovi showed no clinical disease, but severe meningoencephalitis was demonstrated histologically in animals killed 26 and 33 days after infection. The meningeal and perivascular reactions were exclusively lymphocytic. Mild focal lesions of degeneration and cellular infiltration were also present in the kidneys and femoral musculature.

Animals↗
PubMed1975

Oral inhalation system for exposing rabbits to cigarette smoke.

An oral inhalation system for exposing rabbits to cigarette smoke has been developed. The essential components of the system comprise a smoke delivery device that adapts to the oral cavity, a molded face mask, and a sealable body enclosure. The functional capability of the system has been validated by detecting the presence of nicotine in plasma and by measuring the deposition of dotricontane labeled with radioactive carbon (14C) in lungs after exposure to cigarette smoke.

Animals↗