Circulatory and Respiratory Physiology Commons^™

The Hippo/Yap Signaling Pathway In Cardiovascular Repair, Victor Camberos

Loma Linda University Electronic Theses, Dissertations & Projects

Following cardiovascular injury, neonatal mammalian hearts are capable of restoring damaged tissue while adult hearts cannot. Adults are hindered by their inability to replenish lost cardiomyocytes resulting in increased scar tissue formation and reduced cardiovascular function. The Hippo pathway and its downstream effector Yap1 have recently been identified as key modulators of cardiac development and regeneration in neonates. We investigated the role of Yap1 in a sheep model of cell-based cardiovascular repair in which regenerative neonatal cardiovascular progenitor cells (CPCs) were introduced following LAD ligation. Yap1 was induced in the infarcted regions of the heart following cell treatment, as shown …

The Effect Of Electrical Stimulation On Blood Flow In Chronic Wounds In Patients With And Without Diabetes, Daryl J. Lawson

Loma Linda University Electronic Theses, Dissertations & Projects

Background and Purpose. Only 3% of the U S population is afflicted by diabetes, yet one of the most common chronic wounds is the diabetic ulcer. Decrease in blood flow may be one reason why only 31% of neuropathic diabetic ulcers heal in 20-weeks. The purpose of this investigation was to compare healing rates and blood flow of chronic stage III and IV wounds in people with diabetes and those without diabetes over four weeks of treatment. Blood flow was measured before, during, and after stimulation using one of two different electrical stimulation waveforms in a 32°C room.

Subjects …

Prediction Of Fetal Sheep Brain Metabolic Rate During Hypoxia And Cord Occlusion, Adam D. Hickerson

Loma Linda University Electronic Theses, Dissertations & Projects

Many investigators have observed that fetal and neonatal animals are remarkably tolerant to hypoxia compared to the adult. The precise mechanisms however are still unclear. In order to better characterize the hemodynamic and metabolic responses of the fetal brain to hypoxic stress, we have designed a mathematical model to predict tissue oxygenation and metabolic rate of the fetal brain during both moderate hypoxia and severe asphyxia.

The model is based on the Krogh cylinder concept and is similar to one previously published by our lab. Several new concepts were added including the ability to run the model over time using …

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 …

Patterns Of Fetal Lamb Regional Cerebral Blood Flow During And After Prolonged Hypoxia, Stephen Ashwal, John S. Majcher, Nestor Vain, Lawrence D. Longo

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract not included]

Speculation: In the fetal lamb during prolonged intrauterine hypoxia, total and regional cerebral blood flows increase to the same extent without evidence of preferential shunting to critical brainstem or subcortical areas. Neuropathologic studies have indicated relative sparing of these areas during similar animal experimental or human neonatal conditions. This suggests that the pattern of hypoxic ischemic insult to the neonatal central nervous system associated with asphyxia may differ from that produced by hypoxia alone. In addition, during asphyxia these pathologic changes may result primarily from hypotension and decreased regional cerebral blood flow, or from regional metabolic derangements …

Value Of Oxygen With Innovar And Methohexital For Outpatient Oral Surgery, Andrew D. Harsany

Loma Linda University Electronic Theses, Dissertations & Projects

This paper demonstrates the value of oxygen in maintaining arterial blood gas in an adequate range during outpatient oral surgery. Dental extractions were completed on ten patients under an anesthetic technique utilizing Innovar and methohexital with supplemental nasal oxygen. Blood gas samples were drawn at five stages during the procedure.

The mean of the PaO₂ samples drawn with the patient at the point of deepest sedation was approximately three times the normal value.

Oxygen for pulmonary ventilation provides a reservoir in the lungs, saturation of hemoglobin, and increased oxygen in the plasma which provides a margin of safety if …

Effect Of Lateral Positioning On Central Venous Pressure, Romelda C. Jereos

Loma Linda University Electronic Theses, Dissertations & Projects

This experimental study was conducted to investigate the effects of lateral positioning on central venous pressure. It was hypothesized that lateral positioning would not significantly change the central venous pressure so long as the subjects were placed on the same horizontal plane for both supine and lateral measurements. It was also hypothesized that the length of time spent in the lateral position would not alter the pressure.

It is recognized that several factors do indeed play important roles in the maintenance of central venous pressure. The effect of one particular influencing factor, gravity, was central to this study. The difference …

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 …

Relationship Of Ventilation Ability And Positioning In Left-Sided Congestive Heart Failure Patients, Nancy E. Carson

Loma Linda University Electronic Theses, Dissertations & Projects

Proper positioning is used to relieve dyspnea, edema, and fatigue in congestive heart failure patients. According to the review of literature, improved ventilation as measured by specific lung volumes and lung mechanics occurred with upright positioning in normal persons. The effects of specific changes in lung volumes related to position change in congestive heart failure patients has not been documented in literature, although various recommendations related to positioning are made. This exploratory study was undertaken with nine congestive heart failure patients to see if a relationship existed between degree of head elevation and lung ventilation ability as measured by water-bell …

A Follow-Up Study Of Patients With Chronic Obstructive Lung Disease And Their Practice Of The Breathing Pattern, A. Theodora Djagia

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this descriptive survey was to do a follow-up study on patients with COPD to find out to what extent these patients have followed instruction to continue exercising the abdominal and diaphragmatic muscles, with the utilization of a breathing pattern. Literature was reviewed which revealed contradictory findings in regard to the physiological benefits of the use of the breathing pattern. Nine patients met the criteria and signed a consent sheet to be visited in their homes. An Observation Data Sheet and Interview Guide were the tools used to collect data. A point system was constructed and used with …

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 …

The Effects Of Particular Sounds On Certain Indices Of Cardio-Pulmonary Functions, Harold F. Googe, Jane Mundin

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to identify the effects of particular sounds upon certain indices of cardio-pulmonary function and the degree and pattern of changes which occurred in the indices. The specific physiological parameters chosen to be monitored were heart rate, respiratory rate, mean tidal volume, instantaneous minute volume, and oxygen consumption. The hypothesis was that particular sounds will cause changes in certain indices of cardio-pulmonary functions. This was a controlled experiment, in which nine healthy males and nine healthy females, of a denominational, medically oriented University listened to a specially constructed tape of background music interspersed with an …