Degree Discipline

The Effect of Long-Term Moderate Amounts of Ethanol on Paraventricular Nuclei Activity on Cold Stressed Adult Rats (open access)

The Effect of Long-Term Moderate Amounts of Ethanol on Paraventricular Nuclei Activity on Cold Stressed Adult Rats

The effects of moderate, long-term intake of ethanol on the hypothalamic response to cold stress were examined. The long-term experimental animals were given .25 ml of 28% ethanol or .25 ml of water orally once a day, five days a week for fourteen months. A stainless steel electrode was then surgically implanted into the paraventricular nucleus, after which the animal was subjected to cold stress (-150 C, 10 min.). Recordings were taken in the forms of frequency and activity. The data clearly indicate that: (1) alcohol fed rats exhibited a suppressed response to cold stress compared to sham-fed rats; (2) this suppression of activity occurred at the level of the hypothalamus, and (3) mortality was significantly lower in alcohol-fed males than it was in sham fed males. This study clearly points out the need for further work in the area of the beneficial effects of moderate doses of alcohol.
Date: December 1990
Creator: McKinnon, Mark S. (Mark Steven)
System: The UNT Digital Library
Environmental Correlates to Genetic Variation in the Coral Reef Fish, Thalassoma bifasciatum (open access)

Environmental Correlates to Genetic Variation in the Coral Reef Fish, Thalassoma bifasciatum

Genetic variation was examined in bluehead wrasse, Thalassoma bifasciatum, populations along the Florida Keys. Interpretion of mean heterozygosity (H), percent polymorphic loci per population (P), genetic similarity, and F and G statistics demonstrated a clear division of wrasse populations into "northern" and "southern" groups. Correlation and cluster analyses indicated the six reefs can be grouped in a similar fashion based on genetic and environmental data. The conclusion from this analysis of wrasse populations in the Florida Keys is that substantial population subdivision occurs in response to differing selective pressures created by heterogeneous environments.
Date: December 1988
Creator: Pirkle, Michelle S. (Michelle Serpas)
System: The UNT Digital Library
The Phospholipase B Response in Mice Infected With Fasciola Hepatica and Histochemical Demonstration of the Enzyme Source (open access)

The Phospholipase B Response in Mice Infected With Fasciola Hepatica and Histochemical Demonstration of the Enzyme Source

The phospholipase B activity was assayed in the small intestines, spleen and liver/bile duct of nonsensitized and sensitized mice infected with Fasciola hepatica. The primary infection resulted in a significant increase in phospholipase B activity in the small intestine, spleen and liver/bile duct over that of uninfected control animals. The response to the challenge infection was characterized by an earlier increase in enzyme activity with values significantly above those found for the primary infection in the same tissues. These data demonstrate that one response of mice to infection with F. hepatica is characterized by an increased phospholipase B activity. Thus, the enzyme response is not unique to cestode and nematode infections, but also is part of or associated with the inflammatory mechanisms against trematode infections. In addition, phospholipase B was demonstrated in leukocytes using electron microscopic histochemical techniques. Leukocytes were harvested from peritoneal exudates of mice. Cells were fixed in 4% calcium-forol fixative for 30 minutes at roan temperature for electron microscopy, after which they were incubated at 370C in medium at pH 6.6 containing 2 aM lysolecithin and Cal2 . The fatty acids released during the hydrolytic reaction were trapped as a calcium precipitate and were converted to a …
Date: December 1987
Creator: Pirkle, M. Scott (Michael Scott)
System: The UNT Digital Library