Animal Experimentation and Research Commons^™

Exogenous Surfactant As A Delivery Vehicle For Intrapulmonary Therapeutics, Brandon J. Baer

Electronic Thesis and Dissertation Repository

As an organ system, the lung has unique advantages and disadvantages for direct drug delivery. Its contact with the external environment allows for the airways to be easily accessible to intrapulmonary delivery. However, its complex structure, which divides into more narrow airways with each branch, can make direct delivery to the remote alveoli challenging. The objective of this thesis was to overcome this issue by using exogenous surfactant, a lipoprotein complex used to treat neonatal respiratory distress syndrome, as a carrier for pulmonary therapeutics. It was hypothesized that therapeutics administered with a surfactant vehicle would display enhanced delivery to the …

Chronic Hypoxia, Exercise Training, And Skeletal Muscle Capillarity: Angiogenic Regulation And Morphological Consequences, Ivan Mark Olfert

Loma Linda University Electronic Theses, Dissertations & Projects

Angiogenesis is important in health and disease. In particular, exercise training is known to increase skeletal muscle capillarity, providing there is sufficient training intensity. The stimulus for this may be intracellular hypoxia activating angiogenic growth factor gene expression. Acute hypoxia alone has been shown to increase the gene expression of several key angiogenic regulators, e.g. vascular endothelial growth factor (VEGF) and to a lesser degree transforming growth factor-β1 (TGF-β1), basic fibroblast growth factor (bFGF), and thrombospondin-1 (TSP-1), an endogenous negative angiogenic regulator. Paradoxically, however, chronic hypoxia is generally not found to increase mammalian skeletal muscle capillarity. Accordingly, we hypothesized that …

Cerebral Microcirculatory Effects Of Maturation, Scott R. Elliott

Loma Linda University Electronic Theses, Dissertations & Projects

The present studies demonstrate that in the second (2B) and fourth (4B) branches of newborn and adult sheep middle cerebral arteries, 5-HT2 serotonergic receptors mediate contractile responses to serotonin and that alpha-1 adrenergic receptors mediate contractile responses to norepinephrine. In addition, tissue sensitivity to 5-HT and NE decreases significantly with maturation, but does not vary with branch order. These age-related changes were associated with a decrease in affinity and maximum response in 2B and 4B segments of 5-HT and NE contracted arteries, respectively. Norepinephrine and 5-HT occupancy at the pD₂ rose significantly in 2B segments, but did not change …

The Rate Of The Healing Process In Venous Thrombi Produced By A Sclerosing Agent With Special Attention To Endothelial Lining, Kiyoshi Tanaka

Loma Linda University Electronic Theses, Dissertations & Projects

Despite extensive clinical and experimental investigations of venous thrombosis, relatively little is known about the early phases of healing of the venous thrombus. Soon after its discovery heparin has become the most popular agent for the prevention and treatment of venous thrombosis, but there are a number of unanswered questions regarding the most satisfactory treatment for venous thrombosis.

One area of controversy has been the duration of anticoagulation therapy for acute venous thrombosis. If the anticoagulant is discontinued too soon, the thrombus may continue to propagate. Prolonged anticoagulant therapy exposes the patient to the risk of serious hemorrhage. The objective …

Cardioregulatory Role Of The Abdominal Ganglion Of Aplysia Californica, George Maeda

Loma Linda University Electronic Theses, Dissertations & Projects

An isolated heart-abdominal ganglion preparation of this mollusc was developed and used to study the cardioregulatory function of the ganglion and nerves. The heart was perfused with artificial sea water through an atrial cannula and the gastro-esophageal artery was catheterized for blood pressure monitoring. The presence and cardioregulatory effects of axons in the nerves was investigated by electrical stimulation. Fine-tipped glass microelectrodes inserted into ganglionic neurons were used to determine the relationship between the neuronal and cardiac activities.

The principal results are listed below.

1. Primarily inhibitory responses are obtained from both right and left connective stimulation, with some evidence for …

A Study To Demonstrate The Immediate Destination Of An Embolus Formed In The Lumen Of A Peripheral Venous Catheter, Rosemarie Morikone Emori

Loma Linda University Electronic Theses, Dissertations & Projects

This study was designed to show the immediate destination of an embolus formed in the lumen of an intravenous catheter placed in a peripheral vessel. The hypothesis stated that clots injected into a peripheral vessel will lodge in the lungs. A subhypothesis was that the clot may lodge anywhere along the circulatory pathway.

Indications of need for the study as shown by the review of literature were the following: (1) the complications resulting from the frequent use of intravenous polyethylene catheters, (2) experimental studies that showed that clots were formed around intravenous catheters, (3) the evidence that intravenous catheters predispose …