Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Typescript. Vita. Includes bibliographical references (leaves 108-112).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S. in mechanical engineering)--Washington State University, December 2006. / Includes bibliographical references (p. 74-76).

The monoamine uptake blocking agents, imipramine HC1 (5 mg/kg i.v.) and desipramine HC1 (4.8 mg/kg i.v.), and the monoamine oxidase inhibitor, pargyline HC1 (30 mg/kg i.v.) antagonized bulbospinal inhibition (BSI) of the monosynaptic reflex (MSR) in unanaesthetized cats decerebrated at the mid-collicular level. The effect of imipramine was quantitatively more on BSI of the quadriceps (QUAD)-MSR compared to that on BSI of the posterior biceps-semitendinosus (PBST)-MSR. Imipramine's action on this inhibition was also quantitatively greater compared to that of the equimolar dose of desipramine. Pretreatment of the animals with the tryptophan hydroxylase inhibitor, DL-p-chlorophenylalanine (p-CPA) (300 mg/kg i.p. for 3 consecutive days) completely eliminated the blocking action of imipramine. However, pretreatment of the animals with the tyrosine hydroxylase inhibitor, DL-α-methyl-p-tyrosine methyl ester HC1 (α-MPT) (126 mg/kg i.p. given 16 and 4 hours before the recording ) had no effect on imipramine's action. These findings strongly suggest that a 5-hydroxytryptamine (5-HT, serotonin) system antagonizes BSI of the MSR. They do not support the proposal of Clineschmidt and Anderson (1970) that the bulbospinal inhibitory pathway involves a 5-HT interneurone in the spinal cord. Imipramine HC1 (5 mg/kg i.v.) and pargyline HC1 (30 mg/kg i.v.) blocked recurrent inhibition (RI) of the MSR evoked by stimulation of a dorsal root. Imipramine blocked RI of the QUAD-MSR but had no effect on RI of the PBST-MSR. Pretreatment of the animals with either p-CPA or α-MPT prevented the blocking action of imipramine on RI. Application of a 'cold block' which potentiated RI of the QUAD-MSR also eliminated the blocking action of imipramine on this inhibition. These observations suggest that a supraspinal monoaminergic system which involves 5-HT and noradrenaline links has a tonic inhibitory effect on RI of the QUAD-MSR. / Pharmaceutical Sciences, Faculty of / Graduate

A preparation is described utilizing a constant flow, right-heart bypass for perfusion of the isolated main pulmonary arteries at controlled pressures. It is demonstrated that stepwise increments of pressure in the pulmonary arteries are accompanied by increases in systemic vascular resistance and in hind-limb vascular resistance. These changes were demonstrated over the whole range of 5-120 cm H₂O pressure in the pulmonary arteries. In contrast there were no significant changes in renal vascular resistance or heart rate. It is .also shown that changing the temperature of the perfusate in the pulmonary artery from 37°C to 30°C is associated with a decrease in systemic vascular resistance. The effects of raising the pulmonary arterial pressure and of cooling the pulmonary artery were abolished by cervical vagotomy. It is suggested that there is a tonic reflex vasoconstrictor tone generated by activity of receptors lying in or close to the walls of the pulmonary artery. It is further suggested that the differential effects on systemic vascular resistance and renal resistance may distribute cardiac output preferentially to the kidney providing one mechanism by which changes in blood volume may lead to appropriate changes in renal solute excretion. The later hypothesis was put to test by collecting urine from the intact kidneys of animals with isolated pulmonary pouch preparation. A step increase in the pouch pressure evoked a corresponding rise in the urinary volume, osmolar clearance, sodium excretion rate, but not the free water clearance and the potassium excretion rate. The response may be caused by renal hemodynamic changes as a result of the reflex increase in systemic arterial pressure. The rise in sodium excretion rate continued even after the release of the pressure in the pulmonary artery pouch thus the role of a natriuretic hormone in the reflex was suspected. A series of animals with one kidney intact and one kidney isolated and perfused with constant pressure was used in attempt to demonstrate the natriuretic action. These results confirmed the hemodynamic effect on the urinary function of the intact kidney. In the isolated kidney there was no statistically significant increase in sodium excretion rate, therefore the role of a natriuretic agent in the reflex response to distension of the pulmonary artery is still uncertain. / Medicine, Faculty of / Cellular and Physiological Sciences, Department of / Graduate

No description available.

Issued also as thesis (PH. D.) Clark university. / Bibliography: p. 219-236. Also issued in print.

Thesis (Ph.D.)--New Jersey Institute of Technology, Department of Electrical and Computer Engineering, 2000. / JT20011220. MBT20090708 ANT20100114 Typescript. Includes bibliographical references (leaves 167-173). Also available via the World Wide Web.

Published also as Thesis (Ph. D.)--Columbia University. / Bibliography: p. 89-91.

Human soleus H-reflex gain was measured in supine lying and in standing vertically while stabilised by a backboard. H-reflex amplitude was less in stabilised standing than in supine lying. The reduction was partly due to the effect of gravitational load. When the same load was applied (by compression of the body between shoulders and feet) while lying supine the corresponding reduction was 70%. The results are discussed in relation to possible gravitational load receptors. In a second series of experiments a collapsible landing platform was used to differentiate between reflex and programmed contributions to EMG activity in landing from a jump. Post-landing activity of the calf muscles was a short latency spinal reflex triggered by ankle rotation. In the rectus femoris muscle, activity was programmed for short falls and had a reflex component in longer falls. When the collapsible platform caused a landing to occur at a time later than anticipated, reflex gain was increased in the gastrocnemius, biceps femoris and rectus femoris muscles. Experimental results were consistent with the time that would be required for descending pathways to modulate the reflex gain and an appropriate model is proposed.