Concentration-time profiles of ethanol in arterial and venous blood and end-expired breath during and after intravenous infusion

Ethanol (0.40 g/kg) was administered to 13 healthy men by intravenous (i.v.) infusion at a constant rate for 30 min. The concentrations of ethanol in arterial blood (ABAC), venous blood (VBAC), and end-expired breath (BrAC) were measured at 17 exactly timed intervals. Blood-ethanol was determined by headspace gas chromatography and breath-ethanol was measured with a quantitative infrared analyzer (DataMaster). BrAC was multiplied by 2300 to estimate the concentrations of alcohol in blood. During the infusion of ethanol, ABAC exceeded VBAC by about 10 mg/dL on the average and ABAC was also higher than BrAC x 2300 by about 4 mg/dL on average. When infusion of alcohol ended, ABAC, VBAC, and BrAC were 94.8 +/- 2.06 (+/- SE), 84.7 +/- 1.54, and 89.3 +/- 2.10 mg/dL, respectively. The concentrations of alcohol in blood (ABAC and VBAC) and breath decreased abruptly after the administration of alcohol stopped and by 5 min postinfusion, the A-V differences in concentration of ethanol were small or negligible. The mean apparent half-life of the distribution plunge was 7 to 8 min, being about the same for ABAC, VBAC, and BrAC. The disappearance rate of ethanol was 15.5 +/- 0.55 mg/ dL/h (mean +/- SE) for arterial blood, 15.2 +/- 0.49 mg/dL/h for venous blood, and 16.3 +/- 0.73 mg/230 L/h for breath; no significant differences were noted (p > 0.05). We conclude that A-V differences in the concentration of ethanol exist during the loading phase but are rapidly abolished when the administration of ethanol terminates. In the post-absorptive phase of ethanol kinetics, when alcohol has mixed with the total body water, VBAC exceeds ABAC by about 1-2 mg/100 mL on average.     

Characterization of the minimal lethal dose of gamma irradiation for Penicillium citrinum

The use of nuclear power through radiation for the destruction of microorganisms which cause food decay, and toxicosis, is specifically for peaceful purposes. Penicillium citrinum is a fungus which produce mycotoxins responsible for intoxication in humans and animals as a result of eating contaminated food. There is little informations on the resistance of P. citrinum to radiation. The objective of this research is to determine the lethal dose of gama radiation for these microorganisms. Seventy six suspensions containing approximately 100,000 spores/ml received a dose of radiation between 0.2 and 2.2 KGy (KiloGray), being one sample still alive re-irradiated with doses up to 3.0 KGy. The fungus were totally destroyed with a 2.2 KGy. Seventy six suspensions containing approximately 100,000 spores/ml received a dose of radiation between 0.2 and 2.2 KGy, being one sample still alive re-irradiated with doses up to 3.0 KGy. The fungus were totally destroyed with a 2.2 KGy dose. An increase in the resistance to lower dose levels of radiation was observed, in relation to the fungus which had not received irradiation. Conclusion: the Minimum Lethal Dose (MLD) of gamma irradiation, for P. citrinum is 2.2 KGy; the re-irradiation of the surviving fungus demonstrate that occur appearance of radio-resistant mutants.     

Toxicity of cadmium, cobalt, uranium and zinc to Zoogloea ramigera

The toxic effects of cadmium, cobalt, uranium and zinc to the bacterium Zoogloea ramigera have been studied. This organism, which is abundant in sewage-treatment plants, responded to media supplemented with heavy metals by showing a prolonged lag phase and by decreasing its growth rate. The length of the lag phase was proportional to the metal concentration when Z. ramigera was exposed to cadmium, cobalt and zinc. When exposed to uranium (uranyl ions) the organism altered its growth behavior by showing an extended lag phase almost independent of the metal concentration. The order of toxicity of the metals to Z. ramigera was Cd²⁺ = Zn²⁺ > Co²⁺ > UO₂²⁺.     

Is rumination time an indicator of methane production in dairy cows?

As long as large-scale recording of expensive-to-measure and labor-consuming traits, such as dry matter intake (DMI) and CH₄ production (CH₄P), continues to be challenging in practical conditions, alternative traits that are already routinely recorded in dairy herds should be investigated. An ideal indicator trait must, in addition to expressing genetic variation, have a strong correlation with the trait of interest. Our aim was to estimate individual level and phenotypic correlations between rumination time (RT), CH₄P, and DMI to determine if RT could be used as an indicator trait for CH₄P and DMI. Data from 343 Danish Holstein cows were collected at the Danish Cattle Research Centre for a period of approximately 3 yr. The data set consisted of 14,890 records for DMI, 15,835 for RT, and 6,693 for CH₄P. Data were divided in primiparous cows only (PC) and all cows (MC), and then divided in lactation stage (early, mid, late, and whole lactation) to analyze the changes over lactation. Linear mixed models, including an animal effect but no pedigree, were used to estimate the correlations among traits. Phenotypic and individual level correlations between RT and both CH₄P and DMI were close to zero, regardless of lactation stage and data set (PC or MC). However, CH₄P and DMI were highly correlated, both across lactation stages and data sets. In conclusion, RT is unsuitable to be used as an indicator trait for either CH₄P or DMI. Our study failed to validate RT as a useful indicator trait for both CH₄P and DMI, but more studies with novel phenotypes can offer different approaches to select and incorporate important yet difficult to record traits into breeding goals and selection indexes.