Influence of high temperature stress of 16-day embryos on subsequent hatchability

Two experiments were conducted to determine the effect of acute heat stress on late-stage chicken embryos. Embryos were incubated at a normal control temperature (37.5 degrees C.) for 16 days and were then subjected to 40.6, 43.3, 46.1 or 48.9 degrees C. for various periods of time in another incubator of the same type. At the end of the stress period all embryos were placed back into the control incubator for the remainder of the incubation period. Exposure of embryos for 24 hours to a temperature of 40.6 degrees C, caused no major detrimental effects on hatchability. Exposure for 6 hours to the temperature of 43.3 degrees C, caused a decrease in hatchability with a severe decline in hatchability occurring after 9 hours of exposure. Exposure to 46.1 degrees C. for 3 hours or 48.9 degrees C for 1 hour killed all embryos. Chicks which hatched following a severe heat stress had a high incidence of clubbed, wiry down and exhibited an unsteady gait.     

Intraoral reconstruction in head and neck cancer surgery

The effect of prostaglandins (PGs) on the hepatic biotransformation of hexobarbital (Hechi) and p-chloro-N-methylaniline (PCMA) was determined in male rats. PCMA metabolism in slices was decreased by all PGs (PGA1, PGB1, PGE1, PGE2, PGF1alpha, PGF2alpha), ranging in concentration from 1 mu M to 1 mM. PGA1, at 1 mM, produced the greatest degree of inhibition, 39%. PG addition to microsomes, however, failed to alter PCMA metabolism. In contrast to PCMA biotransformation, Hechi metabolism was increased by all PGs in slices but not in liver subfractions. PGs of the E and F series were the most potent, producing a two-fold increase in Hechi metabolism at 1 mM after a 20 min preincubation. The increased effect was observed as early as 10 min and lasted for 4 hr. The relationship of PG metabolism and binding to cytochrome P-450 is presented as a possible mechanism to account for the opposite effects on Hechi and PCMA, type I and II substrates respectively, metabolism.     

Light intensity and housing for pigeons

Four light intensities were used in completely enclosed pigeon housed for 14 hours per 24 hours. Open front pens with only natural light were also used. There were four pens per treatment and five pairs of young, breeding age, White Carneaux per pen for 420 days. Results per treatment, 16, 30, 44 and 61 lumens per sq. m. and open pens, were respectively as follows for each objective: squabs raised-252, 220, 288, 203, and 212 with no significant differences except for the 44 lumen treatment which was higher than all others except 16; body wt./squab in g.-522, 526, 522, 508, and 531 at four weeks of age with no significant differences; feed per squab in kg.-4.7, 5.3, 4.5, 5.5, and 5.1 with only a significant difference between treatments 44 and 61 lumens; percent hatchability-89.7, 82.1, 89.6, 78.0, and 82.9 with no significant differences; percent squabs raised-93.7, 88.7, 97.9, 91.0, and 89.5 with no significant differences. The average number of squabs raised per treatment for all enclosed artifically lighted pens was 241 compared to 212 for the open pens with only natural light.     

Dependence of centriole formation on protein synthesis

Electron microscope observations were made of rat peroneal nerve after crushing using intravenously injected horseradish peroxidase (HRP) as a tracer protein to indicate changes in vascular permeability. At 1/2 h and 2 d after the crush there was gross leakage of HRP from damaged capillaries at the site of injury but none from vessels above or below this. Ultrastructurally vessels at the site of crush showed broken and separated endothelial cells. Proximally and distally there was little abnormal in the vessel walls; vesicles containing HRP were absent and tight-junctions between cells remained intact. Twenty-one days after the crush, leakage of HRP was found both at the site of crush and along the distal segment. The only change in vessel walls was an obvious increase in vesicles filled with HRP. Tracer was also found both in perivascular locations and throughout the endoneurial space.