Digital Commons Network^™

Resource Partitioning In Seven Species Of Sympatric Intertidal Chitons (Mollusca: Polyplacophora), Richard D. Piercy

Loma Linda University Electronic Theses, Dissertations & Projects

Space (intertidal height and location/exposure on the rock surface), and food {gut contents) were partitioned among 7 species of sympatric intertidal chitons: Mopaliidae - Mopalia hindsii, M. ciliata, ~· lignosa, M. muscosa, and Katharina tunicata; and Ischnochitonidae - Tonicella lineata and Cyanoplax dentiens. Species distribution relative to intertidal height (-0.3m to +0.9m) showed significant differences. M. hindsii, ~· ciliata, M. lignosa, and T. lineata preferred slopes or undersides of rocks while ~· muscosa, K. tunicata, and c. dentiens occurred on the top horizontal surfaces or in more exposed habitats. Chitons differed significantly in their associations with Lithothamnion, macrophytic algae, Ulva, …

The Role Of The Salivary Glands In Uptake Of Fluoride In Teeth And Bone, Robin E. Vance

Loma Linda University Electronic Theses, Dissertations & Projects

The cariostatic capability of fluoride is generally recognized, in addition, it may also have a beneficial effect on bone. Fluoride is thought to exercise its cariostasis through a local effect on teeth, however, the possibility exists that fluoride exerts its action through a systemic mechanism. Fluoride uptake by rat teeth and its effectiveness as a cariostatic substance was studied in parotidectomized, submaxillariectomized, and totally sialoadenectomized animals (both parotid and submaxillary glands removed). The uptake of fluoride in bone was also quantitated for comparison purposes.

Rats were injected daily with 15 micromoles of fluoride dissolved in 0.1 ml saline. The rats …

Autoradiography Of Photomembrane In Hemigrapsus Nudus, Carol Fulenwider

Loma Linda University Electronic Theses, Dissertations & Projects

Protein synthesis was studied in the visual cells of Hemigrapsus nudus by light microscope autoradiography. Two hours before sunset, crabs were injected with a single dose of tritiated leucine and sacrificed at time intervals coincident with dynamic retinal changes observed in electron microscope (EM) studies of related Arthropods (Blest, 1978 and Stowe, 1980).

Two separate experiments were performed to examine time periods in the renewal process. Some periods in each experiment were overlapped to develop more accurate decay curves. Experiment I followed time regimes of 0.5, 1.5, 2.5, 3.0, 3.0, 5.0, and 6.0 hours after sunset. Autoradiographs of retinula cells …

The Role Of Vasopressin In The Fetal Renal Response To Hypertonicity, Lori L. Woods

Loma Linda University Electronic Theses, Dissertations & Projects

In order to study the effects of hyperosmolality on fetal renal function and to gain insight into the role of AVP in the fetal urine concentrating mechanism, two types of studies were performed. In whole animal studies 9% NaCl was injected intravenously into 8 chronically catheterized pregnant ewes of 130-135 days gestation and their fetuses, followed by a continuous infusion of 9% NaCl into the ewes. Fetal and maternal plasma osmolalities rose initially by 5% and remained elevated for the next four hours. Fetal arterial and venous pressures increased transiently. Fetal urine flow increased transiently by 73%, remained elevated for …

Age-Related Changes Of Neurites In Meissner Corpuscles Of Diabetic, Vicky R. Ras

Loma Linda University Electronic Theses, Dissertations & Projects

This thesis is based on a qualitative and quantitative study of the neural component of Meissner corpuscles of diabetic and non-diabetic mice. Age-related changes were also documented in these mechanoreceptors. Corpuscles from forty-six diabetic mice and forty-six non-diabetic mice ranging from 2.5 to 17 months old were studied. Forepaw index digital pads were formalin-fixed and frozen-sectioned parallel to each digit and perpendicular to the skin. Serial sections were then silver-impregnated to allow light microscopic examination of the neurites in the corpuscles.

Neurites became more coarse, tortuous, branched, varicose, and thus more complex until middle age. Corpuscle size appeared greatest at …

1-0-Alkyl-2-Acetyl-Sn-Glycero-3-Phosphorylcholine (Platelet Activating Factor): Interactions With Sheep Platelets, Duane O. Beaumont

Loma Linda University Electronic Theses, Dissertations & Projects

Platelet Activating Factor (PAF) seems to link platelet function with allergy and inflammation. Early events associated with the action of PAF on platelets are poorly understood, but PAF appears to interact with a platelet membrane receptor. Two photoaffinity-labelling analogs of PAF, diazoacetyl PAF and trifluorodiazoacetyl PAF, were designed for examining the interaction between PAF and its platelet receptor. These photoactive compounds were selected on the basis of the structure-activity relationship of PAF, and the general guidelines of the photoaffinity labelling technique. Some progress has been made in their synthesis and characterization.

The standard platelet aggregation assay was unreliable in testing …

A Restriction Analysis Of Klebsiella Pneumoniae Phage Sbs, Heidi A. Walters-Khan

Loma Linda University Electronic Theses, Dissertations & Projects

A Klebsiella phage was isolated from the San Bernardino sewage and its physiochemical properties analyzed. The present study found the density of the phage to be 1.44 g/ml, the burst size to be 10, and the phage had a latent period of 20-25 minutes. The DNA was found to be double stranded and linear. Its molecular weight was 41.66 + 0.72 kilobase pairs. The DNA was digested with a battery of endoncleases and partial restriction maps determined. The potential of the phage as a vector for Klebsiella is discussed in the text.

The Effect Of Dietary Alpha - Linolenic Acid On Apparent Risk Factors Of Cardiovascular Disease, Kelvin D. Lindbeck

Loma Linda University Electronic Theses, Dissertations & Projects

Eight healthy male lacto-ovo-vegetarian subjects averaging 28.0 ± 3.6 years of age (22 to 53 years) were fed a diet rich in α-linolenic acid (18:3 ω 3) for four weeks. Arterial blood pressure and body weight were recorded each week. Plasma 6-keto-prostaglandin F_1α (6-keto- PGF_1α ), thromboxane B₂ (TXB₂), total cholesterol, triglyceride, and total phospholipid fatty acid composition were analyzed at 0, 2 and 4 weeks.

Systolic blood pressure increased significantly between weeks 0 and 1 (106.5 ± 2.7 mmHg to 114.0 ± 3.7 mmHg; p < 0.003), but decreased to 107.3 t 2.6 mrHg (p < 0.02) at week 2. There was an insignificant increase in both systolic and diastolic blood pressures after four weeks. There was no significant change in either total cholesterol or triglyceride levels during the four weeks.

Plasma 6-keto-PGF_1α levels increased significantly from 60.13 ± …

The Effects Of Biological Response Modification And Diet On The Immune Respose Of Tumor-Bearing Mice, David Grant Lovell

Loma Linda University Electronic Theses, Dissertations & Projects

The effect that diet and other modifiers may have upon the immune system of BALB/c mice bearing tumor were studied, mice were injected s.c. with 10⁶ herpes simplex virus Type 2- Adult male BALB/c transformed (H238) cells in the thigh causing a visible fibrosarcoma within 1-2 weeks. Mice were fed either a diet low in protein (milk) and low in fat (Diet 1), or another diet low in protein (wheat) and high in fat (Diet 8). Spleen cells were collected for assays of cytotoxic T-lynphocyte (CTL) and natural killer (NK) cell activity. At 3 weeks post-injection, a decrease in …

The Effects Of Maternal Administration Of Methadone On Beta-Endorphin Content In The Brain And Pituitary Of The Rat Progeny, Randall L. Braun

Loma Linda University Electronic Theses, Dissertations & Projects

Methadone is often used in the maintenance and detoxification of opioid-dependent pregnant women. This use of methadone during pregnancy is known to be associated with teratogenic effects observed in the progeny. The present study is an attempt to gain insight into possible pathophysiologic mechanism(s) responsible for these teratogenic effects: specifically, a relationship between maternal methadone administration and the content of the endogenous opioid peptide, beta-endorphin, in the brain and pituitary of the rat progeny.

In brief, nulliparous mature female Sprague-Dawley rats received daily injections (5 mg./kg.) of methadone hydrochloride (methadone-treated) or a similar volume of physiological saline (controls), treatment started …

The Effect Of Dextrose Ingestion On Cardiovascular Endurance, Judith M. Axford

Loma Linda University Electronic Theses, Dissertations & Projects

This study was designed to investigate the effectiveness of dextrose on cardiovascular endurance. The subjects were nineteen male students enrolled at Loma Linda University in Riverside, California. The subjects were exercised to their maximum while being tested on the treadmill.· Subjects were each tested twice. Thirty minutes before exercising, they ingested one hundred grams of dextrose for one test and ten ounces of sugar-free Kool-aid for the second test. The difference in exhaustion times was then recorded.

The data indicated that dextrose ingestion decreased exhaustion time on the treadmill. Subjects were able to exercise for a longer period of time …