A search for quantitative trait loci for ovulation rate in cattle

Seventy-seven polymorphic microsatellites were analysed in offspring of three elite sires that were part of the foundation of an experimental population selected for twinning rate at the US Meat Animal Research Center, Clay Center, Nebraska. All females were assessed for ovulation rate by rectal palpation of corpora lutea over 8–10 consecutive oestrous cycles from approximately 12 to 18 months of age, and associations between ovulation rate and sire allele were examined in each of the three sire groups. A preliminary analysis was performed using selectively genotyped daughters of each sire. Markers found significant or approaching significance were also genotyped in all daughters, sons and granddaughters of these sires. A test of marker associations limited to the granddaughter data provided an independent confirmation of marker effect and significance relative to the initial test with daughter data. Putative ovulation rate quantitative trait loci were detected on chromosomes 7 and 23. Marker UWCA20 on chromosome 7 was associated with an effect in excess of one phenotypic standard deviation and accounted for approximately 10% of phenotypic variation ovulation rate. Marker CYP21 (steroid 21-hydroxylase) on chromosome 23 was associated with an effect of slightly less than half a phenotypic standard deviation and accounted for approximately 4% of phenotypic variation.     

Hypoxia in childhood pneumonia: better detection and more oxygen needed in developing countries.

Even though hypoxia is a major risk factor for death in children with acute respiratory infection in developing countries, oxygen is not part of first line treatment. Because oxygen is not readily available in developing countries it tends to be given to the most seriously ill children, whose outcome is poor. Oxygen might be useful if given earlier in the course of the disease. Clinical signs are not clear cut, however, though the presence of cyanosis and grunting together with a raised respiratory rate can significantly increase the detection of hypoxaemia. A simple oximeter would make detection easier, and oxygen concentrators are more cost effective than bottled oxygen. Ideally oxygen should be given to children in the early stages of clinical pneumonia to prevent deterioration.     

The expression of plasmalemma transcobalamin-II receptors on human blood lymphocytes stimulated by mitogens]

The influence of mitogens on the expression of surface membrane TC-II receptors of human blood lymphocytes and internalization of (TS-II+57Co-CNCbl) complex into cytoplasm were investigated. Mature lymphocytes have a very small number of surface receptors to plasma TC-II but their expression is increased significantly by PHA or Con-A stimulation. CBl transport to cytoplasma is activated in definite sequence by two different mechanisms. Stimulated cells take free CBl without participation of TC-II in early hours of mitogen action (12-42 hrs) before maximal 3H-thymidine incorporation into DNA. On day 3 of cultivation, specific mechanism of CBl transport triggers and the number of lymphoblast receptors is increased manifold. Radioactive CBl enters cytoplasma due to interaction of TC-II-CN [57Co] CBl of the medium with surface membrane receptor of the cells. Thus, the definition of TC-II receptors as an important functional parameter may serve a marker of proliferating cells.