Estradiol-induced synthesis of vitellogenin. III. The isolation and characterization of vitellogenin messenger RNA from avian liver

The messenger RNA of the hormone-induced protein vitellogenin was isolated from the liver of estrogen-treated roosters. Starting from total polysomal RNA, the vitellogenin messenger was purified 67-fold by oligo (dT)-cellulose chromatography and sizing on a sucrose gradient. The messenger was translated in vitro into a 170 000 dalton polypeptide chain, having the immunochemical characteristics of vitellogenin. From electrophoretic and immunochemical analysis of the in vitro product of translation at least 63% of the messenger activity of the RNA preparation could be attributed to vitellogenin mRNA. Gel electrophoresis of the most purified fraction revealed residual contamination with the larger ribosomal RNA species. The molecular weight of the messenger RNA molecule, obtained by contour length measurements in the electron microscope, lies between 2.5 - 10(6) and 2.8 - 10(6).     

Hormonal control of vitellogenin synthesis in avian liver

Estradiol induces the synthesis of vitellogenin in the avian liver. We describe the precursor-product relationship between vitellogenin and the yolk proteins phosvitin and lipovitellin. The high rate of vitellogenin synthesis is a consequence of the accumulation of a stable messenger RNA. We suggest that estradiol acts at the level of the genome by opening a hitherto non-transcribed gene.     

A second example of anti-Lu14

Anti-Lu 14 has been found in the serum of a gravida 2 pregnant woman who had not been given any blood transfusions. Her husband is Lu:14 but otherwise of common Lutheran blood type. Maternal immunization probably occurred during the first pregnancy. The second child did not inherit the father's Lu14 gene and was not affected by the maternal antibody.     

Automated Knowledge Acquisition for Strategic Knowledge

Strategic knowledge is used by an agent to decide what action to perform next, where actions have consequences external to the agent. This article presents a computer-mediated method for acquiring strategic knowledge. The general knowledge acquisition problem and the special difficulties of acquiring strategic knowledge are analyzed in terms of representation mismatch: the difference between the form in which knowledge is available from the world and the form required for knowledge systems. ASK is an interactive knowledge acquisition tool that elicits strategic knowledge from people in the form of justifications for action choices and generates strategy rules that operationalize and generalize the expert's advice. The basic approach is demonstrated with a human–computer dialog in which ASK acquires strategic knowledge for medical diagnosis and treatment. The rationale for and consequences of specific design decisions in ASK are analyzed, and the scope of applicability and limitations of the approach are assessed. The paper concludes by discussing the contribution of knowledge representation to automated knowledge acquisition.     

Hemodynamic study in children under 1 year of age

A practical procedure for hypophysectomy of the mouse by paraphyaryngeal approach has been developed by modifying the technics of Motizuki [5] and Lostroh and Jordan [4]. Postoperative care in C3H/He strain of female mice was also studied. The main points improved are as follows: (a) The dental drill bar made of a needle with 2mm outer diameter was devised for making a hole in the cranium (Fig. 2). The bar does not grind the cranium, but cuts it in the circle, resulting in speeding up of the operation and in little bleeding, since the hole is very small. (b) Special attention was paid in breathing of mice during the operation. A longitudinal midline incision of about 1cm was made in muscle encircled the trachea and a pinhole was made by sewing needle into the trachea. A small piece of cotton wool was put on the pinhole and covered by the muscle. It admirably keeps the tracheal hole open for breathing during operation (Fig. 1). (c) After the operation, the mouse was placed in a chamber filled with an atmosphere of 95% O2-5%CO2 gas until recovered, otherwise, all mice died in a few days after operation with inflamation of the lung. The temperature of the recovery chamber is recommended to be kept at about 28 degrees C for ensuring the resuscitation. The intraperitoneal injections of hydrocortone-acetate (0.25mg/0.1ml) just before and 2 days after operation further ameriolated the survival rate.