Factors affecting serum oxytetracycline levels in beef calves

Fifteen Aberdeen Angus steers, 295-364 kg, were dosed with either 4.4 or 11 mg of oxytetracycline hydrochloride/kg im. The antimicrobial activity of the serum was determined periodically, and the resulting data were treated statistically to determine the sources of variation. Variance in serum levels of oxytetracycline activity was attributed to dose, time of bleeding, order of dosing, animal, and assay. The total variance component was proportionately greater for the 11-mg/kg dose than for the 4.4-mg/kg dose. Animal variance increased with the higher dose level of oxytetracycline. The influence of dose on serum level was tested by applying a t test to the mean serum levels and their standard deviations at each bleeding time. The 4.4- and 11-mg/kg serum levels were significantly different (p less than 0.01) at all bleeding times. The 4.4-mg/kg serum levels mutliplied by 2.5 were not significantly different (p less than 0.05) from the 11-mg/kg serum levels at all bleeding times.     

Specific glucocorticoid receptor in the iris--ciliary body of the rabbit

The cytoplasm of the iris--ciliary body of the rabbit contains a receptor capable of specifically binding dexamethasone. This binding protein has a high affinity for dexamethasone (average KD = 2.0 X 10(-8) M), a low capacity (average 4.8 X 10(-13) mol of steroid bound per milligram of protein), and extreme heat sensitivity; it exhibits a pattern of competition virtually identical to that obtained with glucocorticoid receptors from other tissues and shows characteristic physicochemical behavior in various salt concentrations. The demonstration of a specific dexamethasone receptor in the iris--ciliary body provides the first direct biochemical evidence that these tissues may function as a target organ for glucocorticoids.     

Sex differences in corticosteroids in man

The serum concentrations of progesterone (P), 17-OH-progesterone (17-OHP), 11-deoxycorticosterone (DOC), corticosterone (B), 11-deoxycortisol (S), 18-OH-11-deoxycorticosterone (18-OH-DOC), aldosterone (Aldo) and cortisol (F) were measured in 18 normal men (M), 14 normal women in the folicular phase (FF) and 14 normal women in the luteal phase (FL) of menstrual cycle from blood samples obtained between 0800 and 0900 h. Steroids were estimated by a sensitive and specific radioimmunoassay allowing the simultaneous determination of all steroids studied from one 3 ml serum sample. The mean steroid concentrations (ng/1dl) in FF were found to be as follows: P, 20.3; 17-OHP, 58; DOC, 3.8; B, 241; S, 20.7; 18-OH-DOC, 12.3; Aldo, 8.8; F, 9860. Apart from P, steroid concentrations in FF were significantly lower than in M. Serum 17-OHP, DOC, B and Aldo in FF were significantly lower than in FL. With the exception of P, there were no significant differences of mean steroid concentrations between M and FL.     

Analysis of the quality of clinical diagnosis from generalized findings of the pathologoanatomic service

A statistical analysis of generalized data of the pathoanatomical service on quality of clinical diagnosis in curative-prophylactic institutions in 54 administrative territories of the RSFSR was carried out. The structure (extensive indices) and frequency (intensive indices)of erroneous clinical diagnoses referring to the most important classes of diseases were identified. As to the structure of indices and frequency of clinico-anatomic disparities the first place was occupied by oncological diseases (20.1+/-0.11 and 14.2+/-0.22%), the second--by infectious diseases (16.5+/-0.1 and 13.0+/-0.34%), the third--by diseases of the digestive system (14.6+/-0.09 and 13.0+/-0.33%), the forth--by diseases of the urogenital system (14.0+/-0.09 and 12.2+/-0.49%), the fifth--by disease of the respiratory system (12.7+/-0.09 and 10.6+/-0.24%), the sixth--by diseases of the cardiovascular system (11.1+/-0.08 and 8.0+/-0.14%). The recommendation is put forward to carry on annually a complex satistical analysis of extensive and intensive indices of erroneous clinical diagnoses demonstrating the quality of clinical diagnosis in therapeutic institutions of a given administrative territory.     

Effects of changing diagnostic criteria on the risk of developing diabetes

OBJECTIVE: The American Diabetes Association (ADA) has recommended that the fasting plasma glucose (FPG) level used to diagnose diabetes be changed from 7.8 mmol/l (the level recommended by the National Diabetes Data Group [NDDG] in 1979) to 7.0 mmol/l. We examined the impact of this change on rates of progression to overt diabetes from different levels of FPG. RESEARCH DESIGN AND METHODS: Using the laboratory database of Mayo Clinic, we assembled a cohort of 8,098 nondiabetic Olmsted County residents 40 years of age or older on 1 July 1983. Subjects were followed for a median of 9 years. RESULTS: Among 7,567 individuals with follow-up FPG data, 778 (10.3%) progressed to ADA diabetes and 513 (6.8%; P < 0.0001) progressed to NDDG diabetes. The risk of developing ADA diabetes was 7, 19, and 39% for individuals with initial FPG values in the ranges of <5.6, 5.6-6.0, and 6.1-6.9 mmol/l, respectively. For progression to NDDG diabetes, the respective risks were 3, 11, and 25%. A clear gradient of risk was observed within the "normal" range of FPG (<5.6 mmol/l). Among the 793 individuals who developed ADA diabetes, 222 (29%) developed NDDG diabetes simultaneously and 291 (37%) developed NDDG diabetes later. In all FPG subgroups, progression to ADA diabetes occurred approximately 7 years sooner than progression to NDDG diabetes. CONCLUSIONS: The baseline level of FPG is a major predictor of an individual's risk of developing diabetes. The proposed change in the diagnostic criteria for diabetes will lead to earlier diagnosis among individuals who are destined to develop the disease.     

Catalysis of peroxynitrite reactions by manganese and iron porphyrins

Kinetics and products of peroxynitrite anion O=NOO- reactions, catalyzed by water-soluble manganese and iron porphyrins, were studied under basic and neutral conditions. In the absence of organic substrates peroxynitrite decomposes catalytically to give nitrite and dioxygen as major products. Catalytic decomposition competes with direct oxidation of sulfoxide to sulfone, while phenol is catalytically nitrated in o- and p-positions. A reaction mechanism is proposed.