Concentrations Of Serum Constituents Research Articles

Concentrations of serum constituents in cold-stressed calves from heifers fed inadequate protein and(or) energy.

A study with neonatal calves was conducted to determine the effects of maternal crude protein (CP) and(or) metabolizable energy (ME) malnutrition, cold stress (0 or 21 degrees C), and age on concentrations of selected serum constituents. For each of 2 yr, 60 artificially bred Angus heifers were assigned randomly to a 2 x 2 factorial nutritional plan 150 d before predicted parturition. The diets provided each heifer with either .32 or .96 kg/d of CP and 8.7 or 12.6 Mcal/d of ME. Blood samples were obtained from heifers at parturition and from their calves at birth and at 12, 24, 36, 48, and 72 h of age. Sera were analyzed for concentrations of blood urea nitrogen (BUN), creatinine (Creat), iron, total protein (TProt), alkaline phosphatase (AlkPhos), total bilirubin (TBil), and cholesterol (Chol). Mean correlations of these constituents in calf sera between 12-h adjacency intervals were high, but those between longer times (48 or 60 h) were low. Simple correlations of serum constituents between cows and calves at birth were low except for BUN (r = .578 and .295 for yr 1 and 2, respectively). There were significant main treatment effects for maternal CP consumption on BUN levels, for environmental temperature on BUN, Creat, and TBil levels, and for years on BUN, Creat, iron, and AlkPhos levels in calves. Significant polynomial relationships were found over hours of age for all variables. Blood urea N decreased in normal calves but remained relatively constant at a low level in deficient calves. Year x hour of age interactions occurred for iron, TProt, AlkPhos, TBil, and Chol. Protein x year x hour of age interactions were found for iron and Chol. These results suggest that random sampling times are not useful for decision making during the first 72 h after birth. Consideration must be given to multiple samples taken at specific calf ages, to environmental temperatures, and to maternal protein nutritional levels when interpreting calf blood sera data.

Effect of anthelmintic treatment on the productivity of Iambs infected with the intestinal nematode, Trichostrongylus colubriformis

Liveweight gain, food intake, wool growth and concentration of serum constituents were measured in four groups of three-month-old lambs. Groups 1 and 2 were infected on five days each week with 2500 Trichostrongylus colubriformis larvae for 18 weeks. Group 2 lambs were treated with fenbendazole (5 mg kg-1) at week 10 and week 15. Group 3 lambs were similarly infected for 10 weeks, treated with fenbendazole, but given no further larvae. A fourth control group remained uninfected throughout the trial. All lambs were killed at week 20. Mean worm populations were 16,130, 430 and zero for groups 1, 2 and 3 respectively. Over the first 10 weeks of infection, liveweight gain was reduced by 52, 43 and 51 per cent and wool growth by 33, 28 and 27 per cent respectively, in groups 1, 2 and 3. Serum hypophosphataemia and hypoalbuminaemia occurred in all three infected groups. Between weeks 10 and 20 overall weight gain and wool growth in group 1 lambs were 44 and 46 per cent lower than the controls, whereas weight gains of group 2 and group 3 lambs were similar to or slightly higher than in the controls. However, wool growth in these two groups after treatment was only 73 to 74 per cent of control values. Serum phosphorus concentrations increased to control levels within one week of anthelmintic treatment and serum albumin concentrations by two to four weeks. The ability of group 2 lambs to improve their performance after anthelmintic treatment, in the face of continued challenge, was attributed to development of resistance to reinfection.

Temporal changes in the concentrations of serum constituents in healthy men. Distributions of within-person variances and their relevance to the interpretation of differences between successive measurements.

The distributions of within-person variances in the concentrations of 10 commonly assayed serum constituents have been derived from data on 37 healthy male subjects studied at weekly intervals over a period of five months. All 10 distributions appear to be of log-normal form. The relevance of the findings to the interpretation of differences between serial measurements in a given individual is discussed. Examples are given to show how the information on within-person variances for a particular analyte, organised into a simple graph, may be used to test medical opinions on threshold values for serial changes in the concentration of this analyte in a given individual. In this way, biological variability as well as analytical error may be taken into account quantitatively when assessing the significance of a difference between two serial measurements.

The effect of a daily intake of Ostertagia circumcincta larvae on body weight, food intake and concentration of serum constituents in sheep

The effect of daily doses of Ostertagia circumcincta larvae on food intake, growth rate and concentration of serum constituents was studied in two experiments. In the first (expt A) three groups of six sheep were dosed daily with 1000 (group I), 3000 (group III) or 5000 (group V) larvae and killed after eight weeks. A fourth group of eight worm-free sheep were group housed as controls for food intake and growth rate. In the second (expt B), two groups of eight lambs (ALC and ALI) were fed ad libitum and the latter dosed daily with 4000 larvae. A third group of eight sheep (PF) were pair-fed to the intake of group ALI. All sheep were killed after 14 weeks. Intakes above 1000 larvae/day adversely affected performance without inducing overt clinical signs of parasitism. Groups I, III and V consumed 6.1, 6.7 and 27.9 kg dry matter (DM) respectively per kg gain in body weight. In expt B infection lowered DM intake by 20 per cent and body weight gain by 16 per cent. Food consumed per kg gain in body weight was 17.4, 10.4 and 11.9 kg DM for groups ALI, ALC and PF respectively. Mean worm burdens at slaughter were 9358, 29,200, 37,323 and 18,450 for groups I, III, V and ALI respectively; a high percentage of fourth stage larvae being present in group ALL Worm egg concentrations in faeces were similar in all infected groups and were not related to worm burden or performance. Serum pepsinogen concentrations were elevated with larval intakes above 1000 larvae/day and may be of value in giving an early indication of subclinical ostertagiasis. Slight hypoalbuminaemia occurred in groups V and ALI from about week 7. Changes in Ca and P concentrations were small and inconsistent. There were no significant differences in serum total protein, globulin or urea N concentrations between groups.

Quantitative Studies of the Reaction of Complement Fixation with Syphilitic Serum and Tissue Extract

Summary Titrations of complement under the conditions of the test for syphilis were made to determine the effect of the fixation period and of the different reagents, separately or in combination, upon the form of the curve representing the degree of hemolysis fifteen minutes after the addition of sensitized cells; the reaction-mixture was kept in a water bath at 37°C. The form of the hemolytic curve was practically constant when relatively small amounts of complement were required for 50 per cent hemolysis and the concentration of serum constituents in the titration was not too low; it varied, however, when large amounts of complement were necessary for 50 per cent hemolysis. In titrations made in the presence of tissue-extract and of serum from patients with syphilis the form of the hemolytic curve varied with the concentrations of complement and of the antigen. Under all the different conditions of these comparative titrations the experimental data could be closely approximated by the alternation formula of von Krogh with suitable constants. This furnished a means of interpolation for the 50 per cent hemolysis point. Linear interpolation may be used if log X is plotted against log , where X is the concentration of complement and Y is the degree of hemolysis. In titrations of complement in the presence of antigen and of serum from persons with syphilis there was a linear relation between the amounts of complement and of serum required for 50 per cent hemolysis when the proper amounts of antigen were provided to yield the maximal reactions with the given quantities of serum, as well as between the quantities of complement and of antigen necessary for 50 per cent hemolysis when sufficient serum was used to yield the maximal reaction with the given quantities of antigen. When antigen is present in too great an excess, the intensity of the reaction diminishes and may even disappear completely; but, with a considerable excess of serum, the reaction appears not to change appreciably; that is, does not diminish. The relationships observed in these studies between serum and complement and between antigen and complement constitute a fundamental basis for the quantitative determination of the reaction.