Search PubMed⌕ Search

Biomedical subjects

D Gordon

Publications and source records attributed to D Gordon.

At least 469 records · Page 26Linked to original sources
PubMed1979

Special project consultants can aid hospital engineers.

Hospital engineers occasionally need consultants to study overall operations, suggest improvements, and develop cost-cutting programs. Day-to-day operations often keep in-plant engineers too busy to undertake these kinds of special projects. But given the crucial need for hospitals to cut energy consumption and costs, these special studies need to be done. The right consultant can do the job.

Consultants↗
PubMed1979

Assessment of early ventricular systole by first pass radionuclide angiography: useful method for detection of left ventricular dysfunction at rest in patients with coronary artery disease.

To identify abnormal left ventricular function without exercise stress in patients with coronary artery disease first-pass radionuclide angiograms were analyzed in 32 normal subjects (Group I); 31 patients with coronary disease and normal contrast ventriculograms (Group II); and 17 patients with coronary disease and depressed left ventricular function (Group III). Total ejection fraction (EF) was computed with standard angiographic methods and from each time-activity curve. During the first third of systole, ejection fraction was determined manually by averaging three to five beats and the value compared with that obtained with contrast ventriculography: (Formula: see text). Both total radionuclide ejection fraction (r = 0.95) and first-third ejection fraction (r = 0.91) correlated well with angiography. Intraobserver and interobserver variation was small, averaging 0.02 +/- 0.02 (range 0 to 0.05). The radionuclide first-third ejection fraction was 0.25 or greater in normal subjects and less than 0.25 in 29 of 31 patients (94 percent) in Group II and in all patients in Group III. It is concluded that the first-third ejection fraction obtained with first pass angiography identifies subtle abnormalities of left ventricular function at rest in more than 90 percent of patients with coronary disease that may not be recognized by total ejection fraction alone.

Adult↗
PubMed1979

A new right ventricular cardiac assist device.

At present no good method of assisting the right ventricle of the heart exists. This paper presents a new and effective approach to assisting the right ventricle of the heart which can be utilized independently or during cardiac surgery. Through implementation of this method, and timed inflation and deflation of several types of balloon catheters in the pulmonary artery, distal pulmonary arterial flow is augmented with subsequent unloading of the right side of the heart. This approach will be of great benefit in the treatment of atherosclerotic and congenital heart disease as well as in many cases of pulmonary hypertension.

Assisted Circulation↗
PubMed1979

Resonance induced alterations of intracellular biophysical properties.

A treatment of cancer by the application of external electromagnetic energy at a resonant frequency capable of the generation of heat intracellularly to induce selective thermal death of cancer cells is described. This process also allows for the detection of cancer cells by the use of differential resonant frequencies including nuclear magnetic resonance and electron spin resonance techniques. This process permits the selective treatment of cancer cells by the compartmentalized alteration of biophysical properties in the cancer cells and the detection of cancer cells by determination of their biophysical properties. The process comprises an ability to determine the respective resonant frequencies of cancer cells and normal cells at a cellular level. An external alternating electromagnetic field is then applied at the resonant frequency of the cancer cells which differs from the resonant frequency of the normal cells. The cancer cells absorb significant energy at this resonant frequency whereas the normal cells absorb minimal energy at this frequency. Generating the heat intracellularly instead of extracellularly results in the cell's membrane, which is an effective thermal barrier, enhancing the process by keeping the heat within the cell instead of outside of the cell. This process is enhanced by the nuclear differences between cancer cells and normal cells and by the energy changes characteristic of structural and conformational changes in the deoxyribonucleic acid and the histones of the nucleus including their interrelationship. This process promises great efficacy in the diagnosis and the treatment of neoplastic and also perhaps of artherosclerotic diseases.

Arteriosclerosis↗
PubMed1979

Intracellular hyperthermia. A biophysical approach to cancer treatment via intracellular temperature and biophysical alterations.

This paper introduces a new multi-disciplinary "intracellular" biophysical treatment of cancer. The basic concept uses locally induced heat energy after tumor phagocytosis of submicron particles whose composition permits magnetic excitation. The key to this process is the utilization of the cancer cell membrane to contain the energy within the cancer cell. Any magnetic or electric dipole contained within or introduced into the cell, or that is capable of being produced by an external field, can be used. Submicron particles are colloidally suspended, injected intravenously and are phagocytized by cancer cells. Application of an external high frequency or pulsed electromagnetic field then raises the particles' temperature thus generating intracellular heat in precise increments. This results in selective thermal destruction of cancer cells with little effect on normal cells. Experimental evidence is presented showing tumor cell destruction in spontaneous mammary tumors in Sprague Dawley rats. In addition, we suggest that certain biophysical properties are altered within the cancer cells and could be used to enhance this effect. Specific radioisotopes or tumor specific antibodies bound to particles or chemotherapeutic microspheres increase cancer cell sensitivity and affinity for these particles. This "intracellular" treatment of cancer has a wide potential range of applications.

Animals↗
PubMed1979

"Neuro-cardiovascular" surgery: innovations for the treatment and prevention of cardiovascular disease.

The concept of performing surgery on the conduction system and the nervous system of the heart with the use of peripheral nervous tissue, Purkinje fibers or biophysical means, may solve many enigmas concerning the treatment of arrythmias. More importantly, a correlation is suggested between coronary artery disease, the state of depolarization of the myocardial cells, local electrical and magnetic fields, the state of local innervation of coronary blood vessels, the activity of the specialized conducting system, and higher central nervous system centers. This suggested correlation may contribute significantly in the treatment, and eventually, in the prevention of coronary artery disease.

Arrhythmias, Cardiac↗
PubMed1979

Sodium excretion in man, and adaptation to a low-sodium diet: effect of intravenous sodium chloride.

1. The aim of this study was to test whether a postulated gastrointestinal or portal monitor of sodium intake plays any part in adjusting renal sodium excretion when dietary sodium is reduced. 2. Normal male subjects were given 50 mmol of sodium chloride intravenously three times daily for 3 days to replace or to supplement a constant oral intake of sodium chloride. 3. When oral sodium chloride was replaced with intravenous sodium chloride, renal sodium excretion remained constant. 4. When oral sodium chloride was kept constant, sodium administered as intravenous sodium chloride was promptly excreted in three out of four subjects. There was a delay in the increase in sodium excretion in the fourth subject. 5. Infusions containing 50 mmol of sodium chloride in 50 ml given intravenously over 22 min produced a rise in plasma sodium concentration and a fall in concentration of total plasma solids. 6. These results provide no evidence for a gastrointestinal or portal monitor of sodium intake, but do not disprove the existence of such a monitor.

Adult↗
PubMed1979

Distribution of beta-endorphin in normal and schizophrenic human brains.

beta-Endorphin was measured by radioimmunoassay in post-mortem human brains. Samples of brain were taken from five discrete areas, both from control brains and brains of schizophrenic patients. No difference in beta-endorphin levels was found in these two groups of brains. beta-Endorphin was confirmed to be widely distributed in the brain, but there were considerable differences in the concentrations in different areas.

Brain Chemistry↗
PubMed1979

Left ventricular volumes by gated equilibrium radionuclide angiography: a new method.

To compare radionuclide end-diastolic (EDV) and end-systolic (ESV) volumes with angiographic volume, we studied 52 patients with equilibrium radionuclide angiography using 99mTc-human serum albumin within 48 hours of contrast angiography. Each RR interval was divided into 20--28 equally timed frames and a time-activity curve generated. End-diastolic counts were taken at the early peak of the curve and end-systolic counts at its nadir. Counts were divided by the total number of processed heart beats and normalized for: 1) dose per body surface area; 2) plasma volume; and 3) counts/ml of plasma. A cardiac phantom was developed and serial volumes were studied using a normalization factor. Radionuclide values were expressed as dimensionless units and compared with either biplane angiographic volumes (in the patient studies) or known phantom volumes. Good correlations were obtained with methods 1 and 2 in 35 patients (r greater than 0.84), but the best correlation was obtained in 17 patients when normalization for counts/ml of plasma was used (r = 0.98; y = 0.255 x -0.121). The standard error of the estimate (SEE) was +/- 11.5 ml for EDV and +/- 7.3 ml for ESV. The phantom study also showed an excellent correlation (r = 0.99), with a SEE of +/- 6.5 ml. We conclude that a radionuclide method independent of geometric assumptions can be used to estimate left ventricular volume in man.

Adult↗
PubMed1979

The psychiatric patient: a voice to be heard.

Patients' view of psychiatric care and its implications is a neglected area of inquiry, partly due to ideological factors as well as structural aspects of the National Health Service. It is acknowledged that patient satisfaction per se cannot be the major goal of the Health Services, but the path to improved welfare and treatment may be facilitated by patient satisfaction or at least by an awareness of patient opinion. Further exploration of this area is recommended.

Adolescent↗
PubMed1979

Ethnic differences in blood pressure with observations on noradrenaline and renin. 1. A working population.

115 factory workers (62 white, 53 black) were studied with measurements of blood pressure, plasma noradrenaline concentration, and plasma renin activity. Blood pressure was higher in blacks than in whites. There were no ethnic differences in plasma noradrenaline, which increased with age, but was not related to blood pressure. Mean plasma renin activity was 55% lower in blacks than whites and this difference was not related to differences in sodium intake. There were no associations between renin and noradrenaline, or between renin and blood pressure.

Adult↗
PubMed1979

Ethnic differences in blood pressure with observations on noradrenaline and renin. A hospital hypertensive population.

100 patients with essential hypertension (77 whites, 23 black) were studied with measurements of plasma noradrenaline concentration and plasma renin activity. Black patients had higher blood pressure than whites. There were no ethnic differences in mean plasma noradrenaline, but plasma renin activity was lower in blacks than whites, and this difference was not related to differences in sodium intake. Plasma noradrenaline increased with age in blacks, and in a white control group. Young white hypertensive patients (< 45 years) had higher plasma noradrenaline than controls, and in white hypertensives plasma noradrenaline was positively correlated with plasma renin.

Adolescent↗