Staphylococcus aureus Bacteremia in Patients with Hematological Malignancies and/or Agranulocytosis

ABSTRACT. A total of 6 253 cases of Staphylococcus aureus bacteremia, including 274 (4.4%) endocarditis cases, were registered in Denmark in the period 1975–1984. Patients with hematological malignancies and/or agranulocytosis accounted for 479 of the bacteremia cases. The incidence of endocarditis in this group of patients was only 0.4% as compared to 4.7% in other patients with staphylococcal bacteremia (p<0.01). The lower incidence of endocarditis complicating bacteremia in these patients may justify a shorter course of therapy than usually recommended for suspected endocarditis. Patients with hematological malignancies and other patients with agranulocytosis had a higher mortality (49 and 46%, respectively) than other patients with S. aureus bacteremia (33%). The highest mortality was found in patients with multiple myeloma (71%, p<0.01), the lowest in patients with acute lymphocytic leukemia (28%, p<0.01). The higher mortality in these patients may indicate that empiric antibiotic regimens in granulocytopenic patients should include a specific anti-staphylococcal agent.     

Effect of a Moderately Energy- and Salt-reduced Diet on Body Compartments and Blood Pressure Control in Obese Men with Mild Hypertension

Abstract Ten middle-aged moderately obese men with untreated mild hypertension were studied during a 6-week weight maintenance period and a 9-week period on a diet containing 5 MJ when body mass decreased by 8.4 kg (SE 1.4). According to urinary sodium excretion there was a mean reduction of 89 mmol/day (SE 16) in sodium intake. Mean arterial pressure fell by 2.5 to 14.1 mmHg (95% confidence interval) which was correlated to the reduction of body mass. The sympathetic nervous activity diminished with decreasing noradrenaline excretion and heart rate. There were no changes in the renin-aldosterone system. Estimation of the body composition with a four-compartment model utilizing determinations of body mass, total body potassium and total body water (TBW) showed reductions of body fat (8.4 kg (SE 1.4)) and body cell mass (BCM) (2.4 kg (SE 0.6)), but not of TBW. Extracellular water (ECW) increased significantly as judged from ECW/BCM calculations. Plasma volume was determined by Evan's blue and did not change significantly. We suggest that the observed changes in body composition represent one aspect of the adjustment to a weight reducing diet, while blood pressure is lowered by another mechanism in the adaptive response to dieting, i.e. reduction in sympathetic nervous activity.     

POSTNATAL DEVELOPMENT OF RENAL FUNCTION IN PRE-TERM AND FULL-TERM INFANTS

ABSTRACT. Aperia, A., Broberger, B., Klinder, G., Herin, P. and Zetterström, R. (Department of Paediatrics, Karolinska Institute, St. Göran's Children's Hospital, Stockholm and Huddinge Hospital, Huddinge, Sweden). Postnatal deveopment of renal function in preterm and full-term infants. Acta Paediatr Scand, 70:183, 1981. –This study has been designed to examine the effect of gestational age (GA) on the postnatal development of renal function and has been performed in pre-term (PT) infants (GA=30–34 weeks) and in full-term (FT) infants (GA=39–41 weeks). Postnatal age has ranged from 1–35 days. From 8 hour urine samples collected after spontaneous voiding and a capillary blood sample, determinations have been made of the clearance of creatinine (C_Cr), the fractional excretion of β₂-microglobulin (FE_β2) and the fractional excretion of sodium (FE_Na). In some infants receiving fluid parenterally, simultaneous determinations were made of the clearance of creatinine and inulin. As judged from this study, C_Cr is a reliable indicator of the glomerular filtration rate (GFR). GFR was almost the same in newborn PT and FT, but from 0.3–1 week of age GFR increased significantly more rapidly in FT than in PT. From 1–5 weeks of age GFR increased at approximately the same rate in PT and FT infants. The absolute value for GFR in 3–5 weeks old infants was lower in PT than in FT. FE_β2 was higher in PT than in FT infants during the entire first month of life and FE_Na was higher in PT than in FT infants during the first week of life, suggesting a glomerular tubular imbalance at least at the level of the proximal tubule in PT infants. It is concluded that different stages of maturation will alter the preconditions for the renal adaptation to extrauterine life during at least the first month of life. Therefore special attention must be paid to the limited renal function in PT during their entire first month of life.     

Increase in Plasma Atrial Natriuretic Peptides during Acute Volume Expansion in Hypertensive Man

ABSTRACT. A new hormonal system originating from cardiac atria has recently been discovered. These peptide hormones have important functions in the regulation of blood volume and fluid homeostasis. We have measured plasma concentrations of atrial natriuretic peptides (ANP) in two patients during acute volume expansion. ANP concentrations increased in relation to an increase in right atrial pressure, and significant diuresis/natriuresis was observed. We conclude that hormonal as well as neuronal mechanisms are activated by acute volume loading in man.     

Body Composition,Intraerythrocyte Sodium Content,Volume Regulation and Blood Pressure during Moderate Sodium Restriction in Hypertensive Men

ABSTRACT. Eleven moderately obese middle-aged male outpatients with untreated mild hypertension reduced their sodium intake by about 120 mmol per day during 4–6 weeks. Diastolic blood pressure was then significantly reduced in comparison with a matched control group. The reduction of urinary sodium excretion was significantly correlated to the change in mean arterial pressure. Mean body mass showed a small significant decrease, although there were no significant changes in total body water or body fat as determined from measurements of ⁴⁰K and tritiated water. Nor did mean extracellular water or plasma volume (Evan's blue) show any significant change. The decrease in urinary sodium excretion was associated with increases in plasma renin activity and urinary aldosterone excretion, while a sympathetic nervous natriuretic index (urinary dopamine to noradrenaline excretion ratio) decreased. The low sodium diet period was followed by a period of energy reduction as well as sodium restriction for 15 weeks. Mean body mass was then reduced by about 8 kg. The systolic but not the diastolic blood pressure showed a significant decrease. The intraerythrocyte content of water, sodium and potassium did not change significantly during any of the diet periods. We conclude that moderate sodium restriction lowered the blood pressure and affected the renin-aldosterone and sympathetic nervous system to retain sodium which might explain the constancy of the plasma volume.