Effect of free amino acids and vitamins on cleavage and developmental rate of bovine zygotes in vitro

Due to the complicated media used for culturing bovine embryos, most of the nutrient requirements are unknown. Recently, we developed a simple, serum-free medium (CR1) that allows bovine embryos to develop in vitro. Therefore, our objective was to determine whether development of bovine embryos would be improved by the addition of free amino acids and vitamins to CR1. Oocytes were recovered from slaughterhouse ovaries and matured 22 +/- 2 h, following which the oocytes were randomly allotted to treatment. The experiment was a randomized block design with a 2 x 5 factorial treatment structure. The oocytes were fertilized with or without cumulus cells intact. The five fertilization media were 1) Control (CR1 +/- 10 micrograms/mL of phenol red); 2) control + basal medium Eagle (BME) essential amino acids (EAA) + minimum essential medium (MEM) nonessential amino acids (NEA) + MEM vitamins (VIT); 3) control + EAA + NEA; 4) control + EAA + VIT; and 5) control + NEA + VIT. Cleavage rate was greater (P < .001) when cumulus cells remained on the oocytes during fertilization (51.7 vs 73.2% without and with cumulus cells, respectively). The frequency of blastocysts was increased (P < .001) when EAA or NEA were added to CR1; however, adding VIT had no effect or tended (P = .12) to decrease the frequency of embryos attaining the blastocyst stage. This experiment demonstrates that development of bovine embryos in vitro can be improved by the addition of free amino acids to a simple medium. Contrary to work in rodents, the mixture of vitamins in MEM was not beneficial for bovine embryos.     

Colour is what the eye sees best

It has been argued by Watson, Barlow and Robson that the visual stimulus that humans detect best specifies the spatial-temporal structure of the receptive field of the most sensitive visual neurons. To investigate 'what the eye sees best' they used stimuli that varied in luminance alone. Because the most abundant primate retinal ganglion cells, the P cells, are colour-opponent, we might expect that a coloured pattern would also be detected well. We generalized Watson et al.'s study to include variations in colour as well as luminance. We report here that our best detected coloured stimulus was seen 5-9-fold better than our best luminance spot and 3-8-fold better than Watson's best luminance stimulus. The high sensitivity to colour is consistent with the prevalence and high colour contrast-gain of retinal P cells, and may compensate for the low chromatic contrasts typically found in natural scenes.     

Transfer of the IL-6 gene into a human colorectal carcinoma cell line and consequent enhancement of tumor antigen expression

As part of the FINMONICA project, serum total cholesterol (TC) and high density lipoprotein cholesterol (HDLC) concentrations were determined in 1216 AMI patients (937 men, 279 women) aged 35-64 years in the province of Kuopio in eastern Finland during the 5-year period 1983-87. The distributions were compared with the corresponding distributions in a representative sample of the general population of the same area (1026 men, 1021 women). The mean serum TC levels did not differ between the AMI patients and the normal population. Only the prevalence of a very high serum TC level (> 8.0 mmol l-1) among women was significantly higher in the AMI group than in the population sample. On the other hand, in both sexes the age-adjusted mean HDLC was significantly lower in the AMI group than in the population sample. Our findings emphasize the importance of HDLC measurement as a part of the assessment of the lipid risk factor profile in patients with AMI.     

Mechanisms of efferent neuronal control of the reflex nicitating membrane response in rabbit (Oryctolagus cuniculus)

Efferent mechanisms controlling the nicitating membrane (NM) reflex response to air puff in the albino rabbit were analyzed using stimulation, lesions, and recording techniques. In brief, stimulation of the sixth nerve (abducens) yields short-latency NM extension. Stimulation of the fourth and seventh nerves and the superior cervical ganglion has essentially no effect on the NM. Stimulation of the third nerve causes short-latency retraction of the NM. Lesions and recording data are consistent with this result - the sole efferent neuronal control of NM extension is the sixth cranial nerve and of NM retraction is the third cranial nerve. The NM extension response appears to be mediated by mechanical actions via retraction of the eyeball by the retractor bulbi muscle, and NM retraction appears to result from direct activation of muscle fibers in the NM by the third nerve. The superior cervical ganglion appears to play no role in reflex NM retraction in the rabbit, in contrast to its action in the cat.     

Theoretical and methodological considerations in the age-job satisfaction relationship.

Research investigating the form and magnitude of the relationship between age and job satisfaction has produced mixed and generally inconclusive results. Potential explanations for such results relate to the largely atheoretical nature of research in this area as well as the inconsistent application of proper statistical and methodological controls. Our study addresses both areas of concern in an effort to permit more accurate and informed interpretations of both the form and magnitude of the age–job satisfaction relationship. We conducted hierarchical polynomial regression analyses, controlling for three different tenure measures, to examine several forms of the age–job satisfaction relationship for an all-female sample of registered nurses (N?=?81). Results supported both a U-shaped and a linear relationship between age and job satisfaction. Implications for both theory and research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)