摘要:

In chronic granulomatous disease (CGD) polymorphonuclear leukocytes (PMN) are unable to kill phagocytized catalase-positive bacteria. Therefore, patients with CGD are prone to infections and dependent on antimicrobial agents able to penetrate PMN membranes and to act intracellularly. Owing to their good lipid solubility, trimethoprim/sulfamethoxazole and rifampicin passively diffuse the membrane. In contrast, fosfomycin is transported actively into the cell. In normal PMN, it reaches cellular-to-extracellular ratios of 1.83 after 15 min, in CGD-PMN 2.18 after 30 min. At concentrations between 16 and 200 mg/liter, fosfomycin was able to kill staphylococci surviving within CGD-PMN, thus compensating for the bactericidal deficiency in CGD. A combination of low concentrations of fosfomycin (8 mg/liter) plus rifampicin (0.06 mg/liter) was more effective at the intracellular level than either agent alone. Apart from a stimulation of PMN-chemiluminescence of yet unknown significance, the agent did not interfere with other neutrophil functions. Clinical investigations are indicated to study whether fosfomycin can be added to the small number of antibiotics useful in CGD.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Red cell enzymes of three children with transient erythroblastopenia of childhood were measured and compared with those of age-matched normal children and children with hemolytic anemia. While the activity of “age-dependent” enzyme such as hexokinase, aldolase, glucose-6-phosphate dehydrogenase, glutamic-oxaloacetic transaminase, and pyruvate kinase were greatly increased in the red cells of children with hemolytic anemia, they were not decreased in the red cells of children with erythroblastopenia of childhood. Only the activity of pyrimidine 5'-nucleotidase was consistently low red cells of these chidren. These findings are inconsistent with the usual concept that red cell enzyme activities decline throughout red cell life span. Rather, they suggest that there may be very rapid loss in the activity of some red cell enzymes during the first few days of red cell life with little further decline in enzyme activity.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

In 43 patients with cystic fibrosis (age 8-23 yr, 26 boys and 17 girls) attending a summer camp in a mountain rehabilitation center and in 25 parents (heterozygotes) plasma epinephrine, norepinephrine, dopamine and plasma activity of dopamine-β-hydroxylase were determined as well as the 24-h excretion of the free urinary amines (epinephrine, norepinephrine, dopamine), their Omethylated products (metanephrine, normetanephrine, 3-methoxytyramine) and the urinary phenolic acids (vanilmandelic and homovanillic). Also the metabolic breakdown product of serotonin in urine, the 5-hydroxyindoleacetic acid, was determined. Significantly elevated plasma dopamine (0.03–0.45 nmol/liter for controlsversus1.70–2.21 nmol/liter for cystic fibrosis) and slightly higher plasma norepinephrine levels were found in patients with cystic fibrosis. An increased 5-hydroxyindoleacetic acid excretion was noticed in adolescent patients which correlated with the disease state and the extent of lung involvement. No abnormalities of plasma amine levels were seen in the parents of the patients. Despite controversial results, CF patients seem to have an alteration in catecholamine metabolism which is reflected in higher plasma dopamine levels.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Metabolism of galactose was examined in dissociated brain cells from neonatal mice after 10–13 days in culture. Consumption of galactose at levels up to 26 mM was much less than consumption of glucose at corresponding concentrations. Lactate was consumed from the media at all galactose levels, in contrast to experiments with glucose in which lactate was formed and released into the media. Generation of CO2from 4 mM glucose was 9-fold greater than from an equimolar level of galactose. Relatively low concentrations of glucose could reduce uptake of galactose, whereas galactose at levels up to 11.6 mM failed to inhibit consumption of glucose or formation of lactate. In glucose-deficient states, galactose supplementation of the media led to a marked increase in sulfatide synthesis by oligodendrocytes in the culture with a maximum effect at 2.3 mM. Under these conditions, [l-14C]galactose was incorporated directly into the carbohydrate portion of sulfatide, although most of the label was found in phospholipids and in the nonlipid fraction of the cellular homogenate. These data suggest that galactose is poorly metabolized by brain cells, but does not exhibit toxic effects.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The occurrence of hyperlipidemia and fat accumulation in certain tissues of premature newborn infants is known. Lecithin-cholesterol acyltransferase (LCAT) catalyzes esterification of free cholesterol and is important in the transport and disposal of lipids. Cord plasma LCAT activity of full-term newborn infants is nearly one-half of that present in the adult plasma. The present study also has found a significant positive correlation between cord plasma LCAT activity and gestational age of the newborn. The rato of circulating cholesterol ester to free cholesterol was significantly lower only in newborn infants with gestational age less than 32 wk, in comparison to full-term newborn infants or adults. LCAT deficiency and decreased cholesterol ester formation may be responsible for the inadequate lipid clearance in premature newborn infants.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

We increased the mass of interscapular brown adipose tissue in rats by dietary manipulation (“cafeteria” feeding), cold exposure, or by both. The animals were then used to determine the temperature response of the interscapular brown adipose tissue to dopamine or norepinephrine. These results, and the increase in blood glycerol values, were very similar for either catecholamine. These findings suggest that dopamine may have a role in releasing energy from brown adipose tissue similar to that of norepinephrine in the newborn infant.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Newborn rabbits were raised in either hypoxic or normoxic environments for 3 months. Data from electrophysiological studies carried out on isolated sinoatrial and ventricular preparations from the two groups show that the hypoxic group had changes in cellular transmembrane electrical activity that could be the basis for disorders of rate and conduction in vivo. This model will be useful to study the etiology and therapy of some arrhythmias seen in cyanotic congenital hypoxemic heart disease. (Pediatr Res 19: 64–66,1985)

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Measurement of anterior cerebral artery blood flow velocity with a continuous wave bidirectional Doppler was compared with cerebral blood flow (CBF) measured with radioactive microspheres in 11 paralyzed newborn lambs during hypoxic hypoxia. The Doppler probe was maintained in a fixed position during each experiment. The objectives of the study were to validate this noninvasive technique that is being used widely in the clinical setting to qualitatively assess changes in CBF, and to evaluate which of the velocity parameters measured provide the most information. Diastolic velocity (DV), peak systolic velocity (PSV), area under the velocity curve (AUC), and pulsatility index (PI) were examined under conditions of varied arterial oxygen content and compared to microsphere CBF. DV (r=0.72, p<0.001), AUC (r=0.72,p<0.001), and PSV (r=0.63,p<0.001) demonstrated stronger correlations with changes in CBF than did the PI (r=-0.41, p<0.05). DV (r=0.81, p<0.001), AUC (r=0.80, p<0.001), and PSV (r=0.75,p<0.001) also exhibited stronger relationships with changes in arterial oxygen content than did the PI (r=–036,p<0.05). These data demonstrate that changes in cerebral blood flow velocity are useful qualitative measures of changes in cerebral blood flow. However, the utility of this technique is dependent upon a stable probe position, and assessment of the actual velocity measurements (DV, PSV, AUC) rather than simply the pulsatility index.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The purpose of this study was to determine the effects of caffeine on growing rats and how protein energy malnutrition can modify these potential effects. Caffeine (1,3,7-trimethylxanthine) is not only the most commonly consumed, neurally active stimulant in our daily lives, but it is widely used in the management of apnea in the premature neonate. One group of dams (20%) (n=6) was begun on a 20% protein diet ad libitum. The second group (6%) (n=4) was begun on a 6% protein diet. A third group (20% + C) (n=4) was pair-fed to group 1 (20%) with the 20% protein diet, but beginning on day 3 the pups received 10 mg/kg body weight of caffeine via intragastric feeding needle every other day. The fourth group (6% + C) (n=5) was pair-fed with group 2 (6%) with the 6% protein diet and the pups received 10 mg/kg of caffeine in the same manner as the 20% + C group from day 3. Although the 6% protein diet was associated with the expected reduced body and brain growth, there were no additional growth alterations associated with caffeine administration in either the 20% or 6% diet groups. This growth failure was accompanied by the expected reductions in total whole brain DNA, RNA, protein, and cholesterol content regardless of whether caffeine was received or not. Effects of caffeine which were similar in both diet groups included an increase in brain RNA content and concentration and an increase in the RNA/DNA ratio. However, there were differential effects of caffeine seen depending on diet group assignment. These included an increase in brain DNA content and concentration in the 6% protein group only. Furthermore the protein/DNA ratio, an index of mean cell size, was increased in the 20% plus caffeine group and decreased in the 6% plus caffeine group. The present data and our previous work with theophylline on brain development (22) indicate that methylxanthine administration produces differential effects depending on dietary intake.

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Adenylate cyclase activity [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] was determined in vitro in fetal rabbit myocardial membranes from individual fetal pups at 21 to 31 days gestation (term, 31 days). Basal and NaF-stimulated adenylate cyclase activities did not change during 21-31 days gestation. Significant stimulation of the enzyme by l-isoproterenol was observed only in the presence of guanosine triphosphate (100 µM). Under these conditions, maximal adenylate cyclase stimulation by lisoproterenol (100 µM) was significantly higher at 25–31 than at 21 days gestation. Moreover, EC50(Kact) for l-isoproterenol at 25–31 days was significantly lower than at 21 days gestation. We conclude that, in fetal rabbit myocardial membranes, there is an increase in the sensitivity of adenylate cyclase stimulation by l-isoproterenol from 21 to 25–31 days gestation

ISSN:0031-3998    

出版商:OVID    

年代:1985

数据来源: OVID