The thermogenic effects in hypothermia of four substrates--alanine, glycine, ethano, and pyruvate - were studied in seventeen experiments. Albino rats were decapitated, and their livers were removed. The livers were homogenized with phosphate buffer at -5° C. After equilibration in a refrigerated Warburg apparatus at 20° C, the substrates were added and tissue respiration was recorded over three hours. Heat production was calculated from O2 uptake and CO2 production. Results showed that alanine, glycine, and pyrvate yielded 93.19, 89.86, and 89.89 x 10^6 kg-cal compared to a control value of 86.11 x 10^-6 kg-cal. Ethanol provided 110.31 x 10^-6 kg-cal, a value significantly greater than for the other substrates. The substrates studied, especially ethanol, did, therefore increase heat production in an artificially hypothermic environment in homogenized rat livers.

The role of operant behavior in the metabolism of brain 5-hydroxytryptamine (5-HT) turnover was investigated. Two and one-half hours following the administration of 150 mg/kg of para-chlorophenylalanine (PCPA), a specific inhibitor of tryptophan hydroxylase, levels of 5-HT were compared in sedentary and performing rats. Whole brain levels of serotonin were reduced in both responding and sedentary animals; however, differences between these groups were not statistically significant. The drug induced decrease in 5-HT levels was accompanied by a significant decrease in session responding. The degree of suppressed responding could be correlated with the level of 5-HT following PCPA, suggesting that the metabolism of serotonin is in part modulated by the rate of responding as maintained by the operant schedule.

A rabbit keratoconjunctivities model was used to evaluate ophthalmic formulations containing 1 percent sodium cephalothin in silicon oil, a 1 percent sodium cephalothin aqueous solution, and a 0.3 percent gentamicin sulfate solution. Rabit eyes were inoculated intracorneally with Pseudomonas aeruginosa, Staphylococcus aureus, or Streptococcus pneumoniae, After topical treatment, none of the antibiotic formulations were effective in the P. aeruginosa model; all three showed good activity against S. aureus, and against S. pneumoniae, the caphalothin formulations were more effective than gentamicin.In a related stability study, the cephalothin potency of the silicon formulation was maintained for 16 weeks at 4, 25, and 450 C These studies suggest that sodium cephalothin can be formulated as an effective and stable ophthalmic dosage form.

Recent investigations into the permeability of the kidney capillaries have produced conflicting reports. This study was an attempt to better describe the permeability of the kidney capillaries by using narrow-range macromolecular dextran fractions in four molecular sizes: MW 61,400, MW 77,000, MW 118,000, and MW 147,000. Permeability was measured by dextran concentration differences in plasma and kidney lymph. Permeability decreased as the dextran molecular weight increased. Molecular weights 61,400 and 77,000 penetrated into the kidney lymph. Molecular weight 118,000 exhibited greater difficulty in penetrating to the lymph. The largest fraction penetrated into the kidney lymph with greatest difficulty. Plasma expansion by saline infusion increased the permeability of all dextran fractions.

The abundance of microtubules in receptive dendrites suggests they may function in sensory transduction. Responses of frog muscle spindle receptors and joint receptors is inhibited within 25 minutes by 50 mM colchicine, a microtubuledisrupting agent. The inhibition is reversible upon removal of colchicine, and the time course of recovery is comparable to that of inhibition. Frog olfactory responses are briefly inhibited by washing the olfactory mucosa with perfusion fluid. Colchicine accentuates the inhibition and substantially retards the rate of recovery in a dose-dependent fashion. Colchicine does not affect axonal conduction, nor the oxygen uptake of isolated crab or frog leg nerves. The inhibitory action of colchicine is therefore an effect on the electrical excitability of the receptive dendrites or soma, and not an effect on axonal conduction.

Annual energy flow and mean annual biocontent of eighteen compartments were determined for a 0.94 ha north central Texas pond ecosystem. Annual primary production was 7,780 kcal m^-2 yr^-2, and community production-to-respiration ratio was 1.49. One-third of annual primary production accumulated on the substrate as silt and sedimentation. Community production, production-respiration ratio, and biocontents of all compartments except aquatic insects were large in summer, small in winter. Biocontents of four trophic levels in the pond were all of the same order of magnitude, approximately 50 kcal m^-2. Suspended and benthic organic material forprimary consumers and terrestrial insects for tertiary consumers were substantial allochthanous energy imports into the pond system.

Dendrites of cockroach tibial spine mechanoreceptors contain hundreds of free microtubules, which may have some relation to the generation of electrical activity. Deflection of a spine produces a train of action potentials. Continuous perfusion over a period of 4 hours results in no response decrement. Perfusion with 10mM colchicine reversibly inhibits the response within 5-7 minutes. Irreversible inhibition is produced by perfusion with 1mM vinblastine sulfate in perfusion solution containing 1% dimethyl sulfoxide. Deuterium oxide does not inhibit at concentrations less than 50%, nor does it counteract inhibition by 10mM colchicine. Colchicine may be affecting (1) intracellular microtubules, (2) membraneous tubulin, (3) other membrane components, or (4) axoplasmic transport of essential materials to the sensory dendrites.

The myocardium is known to release CPK, LDH1 , and GOT in response to ischemia as a result of myocardial infarction. This study was designed to induce the release of cardiac enzymes without adversely effecting the myocardium by perfusion hypothermia, thereby suggesting that these enzymes are not as specific in the diagnosis of myocardial infarction as once thought. Hypothermia was by in vivo perfusion of the left anterior descending coronary artery. Enzyme activity was measured from sera samples spectrophotometrically and electrophoretically. Significant CPK and LDH1 increases were observed in animals perfused between 25 and 19 C. These results indicate that, while heart function remained unchanged, an alteration occurred in the membrane integrity of the myocardial cells.

The literature on the effects of phytohormone on algae is clouded with contradictory reports. Reports have been published which substantiate and deny the effects of phytohormones in enhancing the growth and developmental processes in algae. The overall aim of this study was to investigate the response, if any, of the phytohormones indole-3-acetic acid (IAA), gibberellic acid A3 (GA) and kinetin on the physiology of the green alga, Scenedesmus quadricauda. Results obtained for the uptake of 14^C-IAA an(j l4C-kinetin by Scenedesmus strongly support the presumption that the alga does not absorb the hormones. The retention of the phytohormones by the alga is due to adsorption, and is independent of hormone concentration. Most of the label was adsorbed by the outer pectic layers of the cell wall.

Azotobacter vinelandii 12837 was grown in Burk's glucose media and transferred onto Burk's n-butanol agar plates to allow for the formation of cysts. The patterns of the vegetative cell proteins were compared for each successive day of cyst formation, using the polyacrylamide gel isoelectric focusing technique. The findings revealed that, as the cysts developed to maturity, definite changes occurred in the protein constitution, indicative of the biochemical and physiological changes which cells undergo during cyst development. Also, as a control to show that the changes in protein patterns during encystment were not due to physiological condition, Azotobacter vinelandii strain OP was grown in three different media, and proteins from the cells were compared using PAGIF.

The peptidoglycan layer of Vitreoscilla stercoraria, ATCC 15218, was isolated from intact cells after treatment with sodium lauryl sulfate (SLS) and digestion with Pronase. Amino acid and amino sugar content was analyzed and 67% of the total present was made up of glutamic acid, alanine, diaminopimelic acid (DAP), and glucosamine in a molar ratio of 1:1.7:1:0.7. Electron microscopy of the final peptidoglycan product showed a thin, delicately folded sacculus which exhibited a morphology different from that of the intact vegetative cells. Within these sacculi occurred electron-dense structures which were assayed and found to be poly- 3-hydroxybutyrate (PHB) granules. The final yield of peptidoglycan was 2.9% of the dry weight of the intact vegetative cell.

Drumming was recorded for 11 of 13 Nearctic stonefly species, representing 4 families. Both male and female signals were obtained from 5 species, and were either 2-way or 3-way communications. Signals were species-specific; those of males and females varied from 3-39 and 1-14 beats/ signal, respectively. Duration of male signals varied from 105-8,016 ms; those of females, except Perlinella drymo (1 beat), varied from 402-1318 ms. Signals among related taxa showed greatest similarities. Duration of male signals of Perlinella drymo became progressively shorter at each of 4 temperatures from 7-29 0C. Females of Perlinella drymo would only repeatedly answer male signals recorded at near their own temperature, and would not repeatedly answer recorded male signals of 8 other species.

Gut contents of 2,500 stonefly nymphs, comprising 10 species, from the Gunnison and Dolores Rivers, Colorado were examined from Dec., 1974-Oct., 1975. Perlidae species were carnivorous feeding primarily on chironomids, mayflies and caddisflies. Seasonal patterns of ingestion and preference varied among species and predator sizes and between rivers. Early instar polyphagous species utilized detritus in the fall, eventually shifting to carnivorous habits as they grew through winter-spring. Pteronarcids fed predominantly on detritus. Dietary overlap of predators was greatest in the Gunnison River, with subtle mechanisms such as prey species and size selectivity, temporal succession and seasonal shifts to detritus-plant material in some, providing reduction of competition. A more complete partitioning of prey resources was evident in the Dolores River.

A model for the study of the relationship of immunity to cancer is found in AKR mice which harbor Gross virus. This genetically transmitted virus is present in a latent form for months before it spontaneously induces leukemia. Many investigators have demonstrated near normal humoral responses, but abnormal cellular immunity in the preleukemic animal. With increasing age, pathology of the disease is expressed, reflecting diminished immunity. In this study, the ontogeny of humoral antibodies of AKR/J and SWR/J mice was assayed by microagglutination techniques in response to thymus-independent, thymus-dependent, and solubilized antigens. Simultaneous injections of thymusdependent and -independent antigens provided data suggesting an impaired humoral response in the AKR mouse.

Data on the life cycle of Hydropezrla crosbvi were collected from January, 1974, to March, 1976, in Clear Creek, Denton County, Texas. Laboratory investigation helped in establishing instar number, egg incubation and description, and first instar descriptions. Adult Hydroperla crosbyi emerge in February - March when water temperature increases to a mean of 15 C. Eggs undergo a diapause, hatching when decreasing water temperature reaches 18 C in October - November. Maximum growth occurs when water temperatures are coldest. Male and female nymphs undergo ca. 12 and 14 instars, respectively. Larvae of Simuliidae and Chironomidae are the preferred food items of nymphs throughout the growth season.

Azotobacter and various fungi were grown together in nitrogen-free media. Maximal fungal growth in the medium used was possible only at the expense of Azotobacter cells and growth was always accompanied by acid production. When the medium reached a pH of 2, the bacterial cells were aggregated on fungal hyphae and the culture fluid appeared to be free of Azotobacter. Aspergillus niger grew well at the expense of viable bacteria and other fungi grew well on heat-killed cells of A. vinelandii. Members of the genus Hormodendrum, although not causing significant decrease in pH, were also able to clear turbid cultures of Azotobacter. However, clearing, which involved the attachment of bacteria to fungal hyphae, was dependent on acid production by the fungi. Bacterial aggregation was followed by hyphal attachment, bacterial inactivation, and finally, bacterial cell lysis.

Aryl hydrocarbon hydroxylase activity was studied in cultured human lymphocytes using 3-methylcholanthrene, 1,2- benzanthracene, and 4'-bromoflavone as inducers. The substrates used to run the 60 minute assay were benzo(α)pyrene and diphenyloxazole. At the optimum bromoflavone concentration for induction of aryl hydrocarbon hydroxylase, the induced enzymatic activity compared favorably with that of aryl hydrocarbon hydroxylase induced by 3MC in a 96 hour lymphocyte culture using BP as the assay substrate. The whole cell human lymphocyte system was found to have as much or more activity in 20 ml vials using Joklik's-Modified Minimum Essential Medium at a pH optimum of 7.5 with no co-factor added as did the Roswell Park assay system. The whole cell assay showed that levels of aryl hydrocarbonhydroxylase inducibility in lumphocytes from smokers and non-smokers varied without regard to the subjects' smoking habits. The assay system also indicated that intact lymphocytes generate a similar group of benzo(α)pyrene metabolites as that produced by a hepatic microsomal preparation from C57B1/6J mice.

This study used polyacrylamide gel electrophoresis to study the acid-phenol soluble proteins of five strains (A. vinelandii 12837, A. vinelandii 0, A. chroococcum 8004, A. macrocytogenes 8702, A. tumefaciens) of bacteria grown on Burk's nitrogen-free media, Trypticase Soy Broth, and 0.3% butanol medium. The results showed that the protein patterns can be used for the identification and possibly the taxonomic classification of the Azotobacter. The change of phenotype of the bacteria in different media followed the change of protein quantity and quality. There was no absolute similarity between any two of the species studied and this suggests a genetically heterogenous group of organisms while the amount of common proteins suggests close genetic relationships. Further studies are necessary to confirm the status of A. tumefaciens.

Production rates of seven species of fish, along with food-web interactions, were determined for one year in a pond. Production of fish in the pond amounted to 208.9 q/m2/yr. Over 95% of the production occurred in the summer, with Y of Y fish contributing 83.8%. There were two food-web interactions observed in Y of Y fishes: crappie vs. bass and bullhead vs. sunfish. When Y of Y fish shifted to benthic diets in the spring, the small biomass of benthos available could not sustain the larger biomass of fish. Competition for the available food resulted in decreased production rates for the fish community.

Hexokinase has been found in a soluble and a bound form in homogenates of Ascaris suum muscle. Cellulose acetate electrophoresis, isoelectric focusing, and ion exchange chromatography confirmed the presence of only one molecular form of hexokinase in this muscle. A procedure for purifying hexokinase from Ascaris muscle has been developed. The physical and catalytic properties of the enzyme are comparable to mammalian hexokinases. The enzyme is a monomer with a molecular weight of 100,000 as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis and gel filtration. The Michaelis constants for glucose and ATP are 4.7 x 10-3 M and 2.2 x 10-4 M, respectively. Ascaris' hexokinase also exhibits end-product inhibition by glucose 6-phosphate and ADP. It is postulated that the kinetic para meters of the enzyme are the results of its function, that of generating glucose 6-phosphate primarily for glycogen synthesis.

This investigation studies effects of environmental factors on growth and carotenogenesis in Corynebacterium strain 7ElC. Changes in pH were found to effect growth more than carotenogenesis. However, certain nutrients or long incubation periods stimulated carotenoid formation more than growth. Dark conditions in a mineral salts-glucose medium stimulated growth, but minimized carotenogenesis. Tryptic soy broth or yeast extract elicited carotenogenesis in darkness. Although brief light exposure during inoculation was photoinductive, continuous exposure to light following inoculation was required for maximum pigment synthesis. Dark grown stationary phase cells required 24-hours of light for maximum pigment synthesis. Chloramphenicol inhibition of carotenogenesis in dark grown cells exposed to light showed that enzymes needed for carotenoid synthesis were absent from dark grown cultures.

This study examines ultrastructural changes occurring in seven- and fourteen-day populations of Trypanosorfa lewisi when 60 mg sodium salicylate is administered to the host. These changes were related to the host-immune response. Seven-day trypanosomes showed approximately 10 posterior volutin granules. Seven-day trypanosomes whose host had received salicylate exhibited. 30 to 40 volutin granules, and their posterior tip exhibited volutin granules in high numbers sometimes excluding other cellular elements. Fourteen-day trypanosones showed fewer volutin granules than seven-day, salicylate-treated ones. Salicylate treatment caused no additional ultrastructural alterations. Thus the volutin granules are not linked to the reproduction inhibiting antibody (ablast in) but may be involved in the formation of the trypanocidal antibodies.

The work described in this thesis was undertaken to study the reasons why Azotobacter vinelandii ATCC 12837 after incubation in Burk's nitrogen-free liquid will not form as many colonies when plated on Difco Tryptic Soy Agar as when planted on Burk's nitrogen-free agar. The difference in growth of A. vinelandii on the two agars was established by performing viable cell-plate counts. The difference in growth was most apparent at 24-hours incubation of the Burk's liquid-media cultures. Phase contrast microscopic observations of Tryptic Soy media cultures of A. vinelandii disclosed the regular formation of fungoid cells at early stages of growth of the bacteria, 18 to 24 hours.

The life history and ecology of Neochoroterpes mexicanus was studied from data collected September, 1971, to August, 1972, and January to December, 1973, in the Brazos River, Texas. Nymphal development, instar analysis, voltinism, standing crops, and production estimates were determined from the quantitative samples taken in 1971 and 1972. Aspects of the life history and food habits of 230 specimens were arrived at from qualitative samples and light box captures in 1973. Laboratory investigation in 1973 helped in establishing instar analysis, egg incubation and description, and first instar descriptions. Neochoroterpes mexicanus appeared to have three generations per year with brood overlap in the summer and fall. It displayed 16 and 19 instars for overwintering and combined summer generations respectively.