MEDICA@MUSC (Medical University of South Carolina)
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Statistical Analysis of a Seining Survey
Get PDFThe surf zone at Folly Beach, South Carolina was seined on a biweekly basis for two years (October 1969 through October 1971). A total of 5,517 specimens of fish and one invertebrate species (Arenaeus cribrarius) representing 20 families, 33 genera, and 42 species were collected. The five most important species collected in the surf were Menidia menidia, Arenaeus cribrarius, Trachinotus carolinus, Menticrrhus littoralis, and Anchoa mitchilli. A computer based information system was used to generate the necessary reports and summary statistics. Stepwise multiple regression techniques were used to relate occurrence of the five important surf species to selected physical parameters. Water temperature (℃) was the only parameter found to be predictive of occurrence for A. cribrarius, T. carolinus, and M. littoralis. Water temperature (℃) and salinity (o/oo) were identified as important for M. menidia, whereas water temperature (℃) and visibility (m) were of predictive value for A. mitchilli
The Effects of Prenatal Amphetamine Administration on Activity and the Levels of Brain Catecholamines in Young Mice
Get PDFC5713L/6J mice were injected with D-amphetamine sulfate for the last six days of gestation. Their offspring were compared with those of saline-injected and untreated controls. Although the amphetamine-treated mothers gained less weight than controls during treatment and three days post partum, this did not affect litter size or body or brain weight of the offspring at birth. Injections of either drug or saline altered the rate of weight gain for the first month. The offspring of the amphetamine-treated mothers had lower levels of brain norepinephrine on the day of birth and higher levels of norepinephrine and dopamine than either control group on day 30. Their open field activity was higher than either control group on day 22, but jiggle platform activity was lower than saline controls at all times studied. The catecholamine levels of saline -injected controls were higher than those of untreated controls at days 21 and 30
The Enterobacteriaceae: A Preliminary Study of New Methods of Identification: Rapid Biochemical Testing and Salt Tolerance
Get PDFCommercially available reagent-impregnated paper strip tests and tablet substrate tests were evaluated in comparison to the standard biochemical tests using representative members of the Enterobacteriaceae. For the most part, these tests were found to be unreliable or difficult to interpret. Standard media for key biochemical tests were then modified and a new inoculation procedure developed to allow for test results after four hours incubation. Representative members of the Enterobacteriaceae were tested using the modified standard media and, where a given test was critical for the differentiation of the organisms, the rapid test results were in complete agreement with the control test results. The same Enterobacteriaceae were tested to determine their ability to tolerate varying concentrations of sodium chloride. The pathogenic species were more sensitive to this salt than were the common saprophytes. The former were inhibited at concentrations exceeding four per cent while the latter tolerated six to eight per cent sodium chloride
Studies of Cardiovascular Energy Changes Occurring With Drug Administration under Normal Acid Base Balance and During Hypercapnia, Ischemia, and Metabolic Acidosis
Get PDFReflex autonomic changes occurring with the use of cardiovascular drugs may, as a side effect, increase cardiac work and oxygen demand. Improvement of coronary flow and/or a decrease in myocardial work load without increasing oxygen utilization are the desired effects of drugs used in the treatment of coronary insufficiency. The improvement of cardiac function is the purpose of drugs used in the treatment of heart failure. In either case the therapeutic effect may be accomplished through a direct myocardial effect and/or a decrease in cardiac pressure work load through extracardiac action. Through animal experimentation and patient correlation of the many parameters involved, a better understanding of the cardiodynamic effect of these drugs may be determined. This in turn may lead to drug therapy which is more apt to alleviate symptoms than those now used for specific treatment. The following studies will be included: 1) cardiovascular changes occurring during the administration of several drugs used in the treatment of cardiovascular disease will be evaluated. 2) correction of cardiovascular depression accompanying both metabolic and respiratory acidosis will be attempted with the use of several buffers and their relative efficiency determined
Observations on the Formation and Dissolution of Various Thrombi in vivo by Direct Visualization
Get PDFThis investigation was an attempt to ascertain the effects of various physical factors on the formation and dissolution of various thrombi in the living animal. The main method consisted of crushing living veins in the mesenteries of the small intestines of frogs and rats and, with horizontally aimed microscopes: 1. Watching the formation of precipitous, sticky coatings on blood cells and blood cell masses. 2. Observing the building of intravascular material into easily detectable thrombi. 3. Studying the various phenomena occurring in the thrombi and in the adjacent blood streams. 4. Observing the eventual disintegration of most of the fresh thrombi. The word thrombus, introduced over 100 years ago by Virchow (1846), has come to be defined in most modern medical dictionaries (Blakiston, Dorland, and Stedman) as a coagulum of the blood formed in situ during life, partially or completely obstructing a blood vessel or cavity of the heart. Welch (1920) more broadly defined a thrombus as a solid mass or plug formed in situ within living blood vessels or the heart from constituents of the blood. As this paper will show, thrombus formation may be much more complicated than simple clotting of the blood. The word embolus, also introduced in its present connotation by Virchow (1846), is defined as a semi-solid blood clot or some other foreign substance carried within flowing blood streams from the point where it is formed to some other position in the vascular system where it either partially or completely obstructs blood flow. One of the great medical problems today is that of thrombosis and its sequelae. DeBakey (1954), whc has studied thrombosis for years and also has reviewed the literature carefully, points out that we do not have precise knowledge of how thrombi form, and further, that in spite or the use of drugs such as heparin, dicoumarol, fibrinolysin, streptokinase, and trypsin in recent years, there is no agreement that thrombosis is decreasing. Thrombi can and do develop under a variety of clinical conditions such as: (1) Following surgical operations. (2) After traumatic or infected childbirth. (3) A complication or various diseases. (Carlotti, Hardy, Linton and White, 1947, showed that the incidence of pulmonary embolism is greater in medical patients than in surgical patients. ) (4) Mechanical trauma of different kinds (fractures, crushes, burns, etc.). Some of these clinical conditions can and do kill humans. Since direct investigations of thrombus formation and dissolution are rare, most of our present concepts of thrombosis are based on guesses (Welch and Faxon, 1941). Although hundreds of studies have been undertaken on thrombosis and allied problems, we have not yet learned whether all thrombi are formed by identical methods, or exactly how any one thrombus is formed. We will cite observations made in the living animal and in non-living tissues, and give known explanations as well as theoretical discussions of the phenomena observed. Finally, we will suggest new areas of exploration in this important part of circulatory pathology
The Effects of Reserpine on Adrenal Responses to Nicotine and on Cardiovascular Responses to Exogenous Epinephrine and Norepinephrine
Get PDFSince the isolation or reserpine by Bein et al (1) in 1952, there have been numerous investigations dealing with the pharmacological and physiological properties of this drug. A good proportion of this work has dealt with the effects of reserpine on the function of the sympatho-adrenal system. The present investigation has two primary objectives and is therefore divided into two chapters. The first chapter is concerned with a study of the effects of previous reserpine treatment on the responsiveness of the adrenal medulla to chemical stimulation and the reactivity of the cardiovascular system to this stimulation. In chapter two an evaluation of the responses obtained from different parameters of the cardiovascular system to exogenous epinephrine and norepinephrine is made in control and reserpinized dogs
A Study of the Influence of Acid-Base Changes on Myocardial and Vasopressor Responses to Arterenol and Epinephrine
Get PDFIt is well known that when the body is subjected to various stress conditions there is almost always a reflex release of certain neurohumoral substances in an attempt to compensate for these abnormal conditions. Acid-base changes, for example, are some of the most frequent occurring under these conditions. As mentioned throughout this thesis there is a direct correlation between acidosis end extreme hypotension or shock. The objective of these experiments was to investigate and determine the influence of acidosis on the cardiovascular response to the sympatho-adrenal hormones, arterenol and epinephrine, which are released in large amounts during shock. These studies included: 1) the influence of metabolic acidosis on the responsiveness of the myocardium to epinephrine and arterenol, 2) the role of endogenous release of epinephrine and arterenol in contributing to metabolic acidosis and loss of responsiveness to these amines and 3) the production of acidosis by exogenous intravenous infusion of lactic acid, arterenol or epinephrine
Studies of the Changes in Cardiovascular Functions during Hypothermia
Get PDFIn the past few years general hypothermia has been investigated as a means of reducing the oxygen requirements of the body sufficiently to allow exclusion of the heart from the circulation and thus permit intracardiac surgery under direct vision. There is also an important group of patients whose poor physical condition precludes radical surgery of any type. If the oxygen demands of the brain and other vital organs can be sufficiently reduced by hypothermia, it is conceivable that these patients would be able to withstand the shock of reduced circulation and even peripheral vascular embarrassment for short periods of time. Hypothermia is capable of significantly reducing metabolism and of producing a “physiologic hypotension.” As such, the use of this modality suggests itself as a potentially valuable technique in a variety of conditions