Medicine and Health Sciences Commons^™

Fusion Of Phospholipid Vesicles Arrested By Quick-Freezing. The Question Of Lipidic Particles As Intermediates In Membrane Fusion, E. L. Bearer, Nejat Düzgüneş, Daniel S. Friend, Demetrios Papahadjopoulos

All Dugoni School of Dentistry Faculty Articles

We have examined the early events in Ca2+-induced fusion of large (0.2 μm diameter) unilamellar cardiolipin/phosphatidylcholine and phosphatidylserine/phosphatidylethanolamine vesicles by quick-freezing freeze-fracture electron microscopy, eliminating the necessity of using glycerol as a cryoprotectant. Freeze-fracture replicas of vesicle suspensions frozen after 1-2 s of stimulation revealed that the majority of vesicles had already undergone membrane fusion, as evidenced by dumbbell-shaped structures and large vesicles. In the absence of glycerol, lipidic particles or the hexagonal HII phase, which have been proposed to be intermediate structures in membrane fusion, were not observed at the sites of fusion. Lipidic particles were evident in less …

Regulation Of Protein Synthesis By Leucine And Amino Acid Balance., John Patrick Mcgowan

University of the Pacific Theses and Dissertations

The effects of a physiologically balanced mixture of amino acids on the synthesis of proteins has been investigated. The roles of leucine and tryptophan, both implicated in the regulation of protein synthesis, were also studied. The balance of amino acids is important under specific rate-limiting conditions; the physiological balance "protects" the protein synthesizing system from the stressed condition of leucine limitation. Leucine is an important regulator of protein synthesis and the tryptophan effect on translation is dependent on the concentration of leucine. Thus tryptophan is a secondary regulator. The relative concentration of amino acids, described as balance, alterned the synthesis …

Modulation Of Membrane Fusion By Calcium-Binding Proteins, K. Hong, Nejat Düzgüneş, Demetrios Papahadjopoulos

All Dugoni School of Dentistry Faculty Articles

The effects of several Ca2+-binding proteins (calmodulin, prothrombin, and synexin) on the kinetics of Ca2+-induced membrane fusion were examined. Membrane fusion was assayed by following the mixing of aqueous contents of phospholipid vesicles. Calmodulin inhibited slightly the fusion of phospholipid vesicles. Bovine prothrombin and its proteolytic fragment 1 had a strong inhibitory effect on fusion. Depending on the phospholipid composition, synexin could either facilitate or inhibit Ca2+-induced fusion of vesicles. The effects of synexin were Ca2+ specific. 10 microM Ca2+ was sufficient to induce fusion of vesicles composed of phosphatidic acid/phosphatidylethanolamine (1:3) in the presence of synexin and 1 mM …

Synexin Facilitates Fusion Of Specific Phospholipid Membranes At Divalent Cation Concentrations Found Intracellularly., K. Hong, Nejat Düzgüneş, R. Ekerdt, Demetrios Papahadjopoulos

All Dugoni School of Dentistry Faculty Articles

The effect of synexin (an adrenal medullary protein) on the kinetics of Ca2+- and Mg2+-mediated membrane fusion was examined. Membrane fusion was studied by monitoring intermixing of the aqueous contents of phospholipid vesicles. Synexin facilitated Ca2+-mediated, but not Mg2+-mediated, fusion of phosphatidate/phosphatidylethanolamine (1:3) and phosphatidate/phosphatidylserine/phosphatidylethanolamine/cholesterol (1:2:3:2) vesicles. The threshold concentration of Ca2+ for fusion was decreased to approximately equal to 10 microM in the presence of synexin at 6 micrograms/ml and 1.5 mM Mg2+ in vesicle suspensions containing 50 microM lipid. This effect of synexin was drastically inhibited by including 25% phosphatidylcholine (mol/mol) in the vesicle membrane. It is proposed …

Contractility Of Isolated Cardiac Muscle Obtained From Normotensive And Treated Or Untreated Hypertensive Rat Hearts : Effects Of Inotropic Agents, Mary Bassey Amanam

University of the Pacific Theses and Dissertations

In the present study, the contractility of isolated cardiac muscle obtained from normotensive and treated or untreated hypertensive rat hearts were investigated. The effects of inotropic agents were also explored •

Some SHRs were subjected to chronic antihypertensive treatment. After their blood pressure had been lowered, positive and negative inotropic agents were used to study the papillary muscles. The effects of acidosis, increased extracellular calcium, hypoxia, and reoxygenation on the isolated papillary muscles obtained from their hearts were studied. The same was done for isolated cardiac muscles that were removed from WKYs and SHRs. Isoproterenol in the absence or presence …

The Role Of The Pharmacist In Health Care And Medical Treatment In Saudi Arabia As Perceived By The Patient, Mohammed H. Al Haidari

University of the Pacific Theses and Dissertations

Saudi Arabia, one of the developing countries, has a number of problems with the health care and medical treatment of the Saudi people. This study was undertaken to identify and to examine some of these problems and the role of the pharmacist in health education.

A questionnaire was developed and sent to 200 Saudi students in the United States; 111 completed questionnaires were returned. The questionnaire was also sent to Saudi Arabia where 51 persons were interviewed. Results of the questionnaire indicated that some of the problems identified were due to the attitudes of the person interviewed and others resulted …

A Comparison Of Cardiac Rehabilitation, Social Support, And Stress Management Training In Coronary Artery Bypass Graft Patients, Dana Robin Hill

University of the Pacific Theses and Dissertations

An experiment was conducted to investigate three different treatment strategies in the rehabilitation of coronary artery bypass graft (CABG) patients. Fifteen CABG patients were randomly assigned to one of three training groups: an outpatient cardiac rehabilitation exercise group (which met three times per week for three months); a second group which participated in weekly stress management training for seven weeks in addition to the cardiac rehabilitation exercise sessions; and a third group which participated in a weekly discussion on social support in addition to the exercise sessions. The groups were compared (pre- and post training) on the following physiological dependent …

Effects Of High And Low Dose Warfarin Sodium On Implanted Spontaneous Cγéâh, Joan-Marie Deweese-Mays

University of the Pacific Theses and Dissertations

Continuing the study of the relationships between fibrin investment of the tumor, vascularity, and tumor growth, we decided to investigate the relationship of warfarin sodium anticoagulation with tumor growth and vascularization. It was reasoned that if the previously observed altered tumor growth was due the heparin’s anticoagulant effect rather than a direct effect upon the tumor, another anticoagulant with a different mechanism of action would have the same tumor growth reducing capabilities. Warfarin sodium produces reduced fibrin polymer formation by a mechanism entirely different from that of heparin. Heparins’ immediate anticoagulant activity results from a blockade of thrombin’s activity results …

A Behavioral Intervention To Reduce Presurgical Anxiety, Alison J. Wheaton

University of the Pacific Theses and Dissertations

A multiple baseline study was conducted across five hysterectomy patients between the ages of 30-36. Three patients received a treatment intervention consisting of general and sensory information, muscle relaxation, a cognitive coping technique, and a pre-anesthetic interview. Two yoked, placebo control patients watched a 20-min video· tape about surgery, practiced recovery exercises, and made up stories from TAT cards. Self-report measures taken were the Hospital Stress Rating Scale, a recovery inventory, and postsurgical pain ratings. Physiological measures consisted of pulse, respiration, blood pressure, skin temperature, and blood lactates. Recovery variables were taken on amount of pain medication taken, number ·of …