Richard H. Gadsden

The Effect of Treatment on Mortality in Mild Hypertension: Results of the Hypertension Detection and Follow-up Program

In the Hypertension Detection and Follow-up Program, 7825 (71.5 per cent) of the 10,940 participants had diastolic blood pressures averaging between 90 and 104 mm Hg on entry into the study and were designated Stratum 1. Half were referred to their usual source of care in the community (the referred-care group), and half were treated intensively in special clinics (the stepped-care group). Five-year mortality in the Stratum 1 patients given stepped care was 20.3 per cent lower than in those given referred care (P less than 0.01). Particularly noteworthy was the beneficial effect of stepped-care treatment on persons with diastolic pressures of 90 to 104 mm Hg who had no evidence of end-organ damage and were not receiving antihypertensive medication when they entered the study. This subgroup had 28.6 per cent fewer deaths at five years among those treated with stepped care than among those treated with referred care (P less than 0.01). These findings support a recommendation that in patients with mild hypertension, treatment should be considered early, before damage to end organs occurs.

Effects of Metabolic Acidosis on Ventricular Isometric Systolic Tension and the Response to Epinephrine and Levarterenol

Hyperglycemia and hypoxia acidosis are known to occur during periods of shock. The plasma levels of catechol amines have been reported to be elevated during periods of shock. Injection of epinephrine or levarterenol can produce increments in blood glucose and have been shown to elicit a metabolic acidosis. In the present studies the effects of reducing circulating blood volume or infusion of lactic acid and of forced CO2 inhalation on ventricular isometric systolic tension (VCF) and the cardiovascular response to test injections of levarterenol were studied. The experiments with a reduction in circulating blood volume and with lactic acid infusions resulted in a decrease in arterial pH. whole blood total CO2 and whole blood CO2 combining power. Concomitant with these changes there was a marked depression of VCF and the response to test injections of levarterenol. Correction of the acid-base changes with 2-amino-2-hydroxymethyl, 1, 3-propane diol resulted in an immediate improvement in VCF and in the response to levarterenol. This change occurred despite a greater increase in blood lactate levels. Anaerobic metabolism with lactate production leads to a decrease in total blood CO2 and an increase in dissolved CO2. This decrease in the CO2-carrying capacity would lead to an increase in tissue CO2. Since the heart is markedly depressed by CO2, this increment could be largely responsible for the myocardial depression. The oxygen debt which the heart can incur is thought to be limited. Therefore, the build-up of CO2 one of the end-products of aerobic metabolism, would depress oxidative metabolism according to the law of mass action. This hypothesis was further tested by forced CO2 ventilation which resulted in a marked depression of VCF and the response to levarterenol. Correction of the respiratory acidosis by the administration of THAM which increased the CO2-carrying capacity of the blood resulted in an immediate improvement in VCF and the levarterenol response.

Lactobezoar and gastric perforation in a neonate.

Summary A lactobezoar and gastric perforation are described in a premature infant with multiple ulcers and pneumatosis of the stomach occurring during the recovery phase of hyaline membrane disease.

Time-related changes in the plasma concentrations of prolactin, gonadotropins, sex hormone-binding globulin, and certain steroid hormones in female runners after a long-distance race.

Running is associated with an increase in plasma concentrations of certain anterior pituitary hormones and adrenal steroids. This study reports such increases after a marathon race. Six trained female runners, 26 to 42 years old, participated in a marathon race. Fasting (resting) blood samples were collected a few weeks before the race (baseline) and immediately (0 hour), 1 hour, and 4 hours after the run. The data were analyzed with the use of two-way analyses of variance (F-test), paired t-test, and Pages test. At 0 hour, compared with baseline, significant increases were observed in the plasma concentrations of testosterone (T), dehydroepiandrosterone sulfate (DHEA-S), cortisol (F), free T index (T/SHBG), and prolactin (PRL). At 1 hour, levels of these steroid hormones and PRL declined, some significantly. At 4 hours, levels of all hormones except DHEA-S returned to baseline. No significant changes were observed in concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and sex hormone-binding globulin (SHBG), as evaluated by F-test. Running-associated changes in plasma hormonal concentrations revert to baseline in four hours, although DHEA-S may take a little longer.

Determination of blood halothane levels by gas chromatography

SummaryA method of isolation by distillation of halothane from blood and its subsequent Chromatographic detection and quantitation have been described. The method is simple, rapid, and inexpensive. It lends itself well to incorporation into anaesthetic investigations when blood (and tissue) anaesthetic levels must be obtained In serial manner.The accuracy of the method, based on tests of reproducibility and recovery, is within ±5 per cent. These data are not of a selected nature and represent a testing of the isolation and Chromatographic techniques for quantitative analytical adequacy.Some data obtained from animal experiments are presented. Detailed correlation of these data with cardiovascular and acid-base investigations will appear elsewhere.13RésuméNous avons décrit une méthode d’identification de l’halothane par sa distillation du sang et sa détection chromatographique subséquente et son titrage. La méthode est simple, rapide, peu coûteuse. Elle peut être entreprise aussi bien avec d’autres investigations anesthésiques quand les niveaux d’anesthésie dans le sang et dans les tissus doivent être obtenus en série.La précision de cette méthode basée sur des tests de reproduction et de réveil est de +5 pour cent. Ces valeurs ne sont pas de nature sélective et elles représentent un test d’identification et de technique chromatographique pour une analyse quantitative adéquate.Nous avons présenté quelques données obtenjues des expériences sur des animaux. Nous publierons ailleurs la corrélation detaillée entre ces notions et des investigations sur l’équilibre acide-base et sur le système cardiovasculaire.

Assessment of phosphatidylcholine, lysophosphatidylcholine, and sphingomyelin in human serum

We describe a method for analyzing the choline-containing phospholipids, namely phosphatidylcholine, lysophosphatidylcholine, and sphingomyelin that is highly sensitive, easy to perform, and very reliable. The method employs enzymic hydrolysis of choline from these phospholipids by phospholipase D with subsequent oxidation of choline by choline oxidase and generation of hydrogen peroxide. Hydrogen peroxide is then reduced by peroxidase with p-hydroxy-phenylacetic acid acting as an oxygen acceptor to form a fluorescent product which is stable for at least 24 h without loss of linearity. The analysis requires a 5 microL sample volume and demonstrates linearity over a wide range (133 mumol/L-6.65 mmol/L). The CVs are less than 3%.

Effects of Extracorporeal Circulation upon Blood Lipids

Abstract A lipid profile (total lipids, free fatty acids, triglycerides, and serum lipase) and evidence of fatty emboli were studied in patients undergoing cardiopulmonary bypass with median sternotomy or thoracotomy and with or without cardiopulmonary bypass. Although hyperlipemia developed in all patients, there was no statistical difference between the thoracotomy and median sternotomy groups. A marked rise in all four lipid profile factors occurred when both cardiopulmonary bypass and median sternotomy were utilized. Examination of the sputum and urine for evidence of fat and funduscopy for evidence of fat embolization proved to be useless. The postoperative rise in lipid profile factors showed no statistically significant effect on the incidence of neurological or pulmonary complications. A Pall blood filter was used in a second group of patients undergoing cardiopulmonary bypass, but the incidence of neurological or pulmonary complications was similar.

Some effects of carbaryl on Ehrlich ascites tumor cells in vitro and in vivo.

SummaryCarbaryl produced moderate but significant inhibition of the development of the Ehrlich ascites tumor in mice and reduced appreciably the rates of incorporation of isotopically-labeled precursors into ribonucleic acid, deoxyribonucleic acid, and protein in Ehrlich ascites tumor cellsin vitro.

Blood levels and cardiovascular dynamics during fluroxene anaesthesia in dogs

SummaryA gas chromatographic technique has been described which allows the quantitative measurement of blood and vapour concentrations of trifluoroethylvinyl ether (fluroxene). Using this method, arterial and venous blood levels of fluroxene were measured during increasing inspired concentrations of the agent, and correlated with concurrent changes in circulatory dynamics.During light levels of anaesthesia (6.0 per cent) arterial and venous concentrations of fluroxene were 32 and 26 mg./100 ml. respectively. At this time there was minimal depression of the cardiovascular system. When the inspired concentration was increased there was progressive depression of aortic pressure, ventricular contractile force, aortic flow, and calculated stroke volume. Heart rate was not significantly altered until deep levels of anaesthesia were obtained. Calculated peripheral resistance was not significantly altered, and it is felt that this, along with the depression of contractile force, indicates that myocardial depression plays a primary role in the over-all circulatory depression occurring during deep levels of fluroxene anaesthesia.In the animals in which anaesthesia was induced with thiopental and maintained with fluroxene for two hours, there was only minimal depression of the cardiovascular system. Most of the observed depression occurred during the thiopental induction, and maintenance with fluroxene failed to produce any further depression.RésuméOn a utilisé une technique chromatographique pour l’analyse quantitative des concentrations de fluroxène (Fluoromar). On a mesuré les niveaux de fluroxène dans le sang artériel et dans le sang veineux durant différents degrés d’anesthésie, et on les a mis en corrélation avec les changements dans la dynamique circulatoire.Durant l’anesthésie légère, il y eut peu de dépression circulatoire (6.00%). En augmentant la concentration de mélange inspiré, une dépression progressive de la pression aortique, de la force de contraction ventriculaire, du courant aortique et du débit systolique s’est produite en même temps qu’augmentait le niveau sanguin de l’anesthésique. La vitesse du pouls n’a pas changé tant qu’on n’a pas atteint une anesthésie profonde. Quelle que fut la profondeur de l’anesthésie, la résistance périphérique n’a pas varié sensiblement. Ces observations, en plus de la dépression de la contractilité du myocarde, indiquent que la dépression du myocarde joue un rôle de premier plan dans la dépression circulatoire générale observée.

The effects of deep hypothermia on myocardial function and general metabolism.

Summary When circulation was maintained by a mechanical pump, the intact heart performing minimum external work exhibited a marked decrease in energy utilization per minute when temperatures were lowered to 10 to 15° C. This decrease occurred despite an increase in isometric systolic tension and apparently was due largely to bradycardia. On the other hand, this measure of energy utilization, based on coronary flow and A-V oxygen differences, was increased for each contraction and was accompanied by an increased efficiency of oxygen utilization. Plasma and renal electrolyte changes indicated an uncompensated metabolic acidosis occurring with the increased metabolic activity during rewarming. The acidosis was of such degree that it may be considered as significantly contributing to myocardial depression and refractoriness following hypothermia.