Plasma methotrexate, red blood cell methotrexate, and red blood cell folate values and outcome in children with precursor B-acute lymphoblastic leukemia: a report from the Children's Oncology Group

Plasma steady state methotrexate (MTX) level and red blood cell (RBC) MTX and folate concentrations were evaluated in 1124 children with newly diagnosed acute lymphoblastic leukemia enrolled in the Pediatric Oncology Group studies 9005 (lower risk; Regimens A and C) and 9006 (higher risk; Regimen A). These regimens included intermediate-dose MTX (1 g/m) given as a 24 hours infusion every other week for 12 doses during intensification. Plasma MTX level was evaluated at the end of MTX infusions. RBC MTX and folate concentrations were measured at the end of intensification. The 5 year continuous complete remission was 76±1.4% versus 85±3.0% for those patients with steady state MTX levels less than or equal to and greater than 14 μM, respectively (P=0.0125). Hispanic children had significantly reduced median steady state MTX levels, 8.7 μM, compared with non-Hispanic children, 9.95 μM (P=0.0015), but this did not correlate with a difference in outcome. Neither RBC MTX, RBC folate, nor the RBC MTX:folate ratio identified children at increased risk of failure.     

Galactose metabolites in blood from neonates with and without hypergalactosaemia detected by mass screening

Concentrations of galactose (Gal) in plasma and galactose metabolites in red blood cells (RBC) were determined in 18 normal neonates and 249 others with hypergalactosaemia according to the Paigen method. Normal neonatal values for plasma Gal, RBC galactose-1-phosphate (Gal-1-P), RBC uridine diphosphate glucose (UDP-Glc), and RBC uridine diphosphate galactose (UDP-Gal) were 0.96 ± 0.71 mg/dl, 1.69 ± 1.45 mg/dl of packed RBC, 1.00 ± 0.45 mg/dl of packed RBC, and 1.44 ± 0.45 mg/dl of packed RBC, respectively. The UDP-Gal concentration was higher and the UDP-Glc concentration lower than previously reported in normal children. Of the 249 cases with excessive Gal in whole blood, 23 showed high Gal concentrations in plasma; among these, four portacaval shunts and one case of congenital biliary atresia were diagnosed. In subjects homozygous or heterozygous for UDP-Gal-4 epimerase deficiency, concentrations of UDP-Gal and Gal-1-P were elevated only in RBC, corresponding to restriction of the metabolic abnormality to these cells. Most cases of hypergalactosaemia detected by the Paigen method have large excesses of Gal-1-P in RBC. Although a specific diagnosis based solely on blood Gal metabolites is difficult, individual concentrations reflect underlying conditions to some extent. Conclusion In neonates, uridine diphosphate galactose concentrations were higher and uridine diphosphate glucose concentrations were lower than previously reported paediatric values. Patients with high plasma galactose concentrations should be investigated by hepatic imaging. Received: 21 March 2000 / Accepted: 18 May 2000     

Hypoxia-induced post-translational changes in red blood cell protein map of newborns

Tyrosine (Tyr) phosphorylation is implicated in the modification of several erythrocyte functions, such as metabolic pathways and membrane transport, as well as in signal transduction systems. Here we describe the map of Tyr-phosphorylated soluble proteins of newborn red blood cells (RBC) using an in vitro model simulating RBC reoxygenation at birth after an intrauterine hypoxic event. We tested the hypothesis that a hypoxic environment and subsequent reoxygenation promote post-translational changes in the RBC protein map of newborns, in addition to desferrioxamine (DFO)-chelatable iron (DCI) release and methemoglobin (MetHb) formation. Umbilical cord blood RBC were incubated under hypoxic conditions for 16 h at 37 degrees C, and subsequently for 8 h under aerobic conditions. Control erythrocytes were incubated under aerobic conditions at 37 degrees C for the period of the experiment, i.e. for 24 h. Tyr-phosphorylation proteins were assessed using advanced high-resolution two-dimensional electrophoresis, 2-D immunoblot analysis with anti-phosphotyrosine (anti-pTyr) antibodies, and computer-aided electrophoretogram analysis. Higher DCI release and MetHb formation were observed in newborn RBC incubated under hypoxic conditions than in those incubated aerobically. Different immunoreactivity patterns with anti-pTyr antibodies were also observed between newborn RBC incubated under hypoxic conditions and controls. A hypoxic environment is a factor promoting DCI release, a well-known condition of oxidative stress. This is the first map of Tyr-phosphorylated soluble proteins of newborn RBC obtained using an in vitro model simulating RBC reoxygenation at birth after an intrauterine hypoxic event. Our results suggest that hypoxia increases Tyr-phosphorylation of antioxidant proteins, protecting RBC against oxidative stress.     

Sodium and potassium concentrations in red blood cells and plasma in children with congenital heart defect

The sodium and potassium concentrations of the red blood cells and plasma were investigated in 93 children with cardiac disease, most of them with congenital heart defect, and in 48 healthy children of the same age. The red blood cell sodium and potassium concentrations were constant within a narrow range in normal subjects, but varied profoundly in pathological conditions. Digitalis treatment caused RBC Na+ and plasma K+ levels to increase and the RBC K+ level to decrease by blocking the Na+-K+ pump. The highest RBC Na+ concentration was observed in critically ill patients with congestive heart failure treated with digoxin. An augmented RBC sodium value was found in heart malformations with left to right shunt and in congestive cardiomyopathy that was not treated, whereas in patients with right to left shunt lower RBC sodium, higher RBC potassium and plasma potassium values were registered without any treatment. In cases of hyperkinetic circulation without any congenital heart defect the value of RBC sodium was definitely low. A low sodium and a high potassium level of the RBC were found after total correcting heart surgery. It is concluded that measurement of changes in sodium and potassium concentrations of the red blood cells is not a reliable method for assessment of the efficacy of digitalis treatment. The results point to the accompanying phenomena at a cellular level in heart disease.     

Direct monitoring of arterial blood pressure in depressed and normal newborn infants during the first hour of life

Direct systolic, diastolic, and mean arterial blood pressure was continuously recorded during the first 64 min of life in 150 newborn infants. The data were analyzed at 4, 8, 16, 32, and 64 min. The highest blood pressure values were noted during the first few minutes of life in all newborn infants, with a rapid drop within 4 to 8 min. Decline in blood pressure was more gradual throughout the remainder of the observation period. Blood pressures of depressed newborn infants at birth (Apgar scores 6 or less at 1 and 5 min) were compared to those of normal newborn infants (Apgar scores 7 or greater at 1 and 5 min). The former demonstrated generally higher systolic pressures during the first 16 min and diastolic pressures at 4 min when infants were compared by their 1 min Apgar scores and higher diastolic pressures at 4 min when the infants were compared by their 5 min Apgar scores.     

Associated coarctation of the aorta and mitral valve disease: nine cases with surgical correction of both lesions in three.

Nine cases of the combination of coarctation of the aorta and mitral stenosis were evaluated over a seven-year period. Symptoms did not usually cause distress in infancy, but began subtly with pneumonia or cardiac failure at about 2 years of age. Important clues were differences in blood pressure between the arms and legs, paroxysmal dyspnea, congestive heart failure, right ventricular hypertrophy, and left atrial enlargement. Cardiac catheterization studies showed elevated right ventricular and main pulmonary artery wedge pressures. These features in patients with coarctation of the aorta should suggest associated mitral valve disease. The importance of demonstrating associated valvular lesions, particularly mitral stenosis, is emphasized. Two of our children had successful repair of the coarctation of the aorta and mitral stenosis simultaneously. In a third child, resection of the coarctation was followed in six years by mitral valve replacement.     

Red blood cell sorbitol in diabetic children

When red blood cells (RBC) were incubated with various concentrations of glucose, the RBC sorbitol level increased in a concentration-dependent manner. The elevated RBC sorbitol level was not reduced by further incubation in a glucose-free medium. In both diabetic and non-diabetic children, an increase of RBC sorbitol levels occurred in the oral glucose tolerance test and the return to baseline was delayed in diabetics compared with non-diabetics. In the majority of diabetics (87%), RBC sorbitol levels exceeded the upper limit of the normal range, which was arbitrarily determined as the mean + 2 s.d., in healthy non-diabetic children and adults. A good correlation was observed between RBC sorbitol levels and plasma glucose levels (r = 0.644). In both diabetics and non-diabetics, no correlation was observed between RBC sorbitol levels and age, and in diabetics the RBC sorbitol level was not related to the duration of disease. A good correlation was observed between RBC sorbitol levels, and hemoglobin Alc (HbAlc) or fructosamine levels in diabetic children.     

Activation of the L-arginine nitric oxide pathway in severe sepsis

AIMS: To determine in children with sepsis syndrome and septic shock the time course of nitric oxide metabolites: nitrate and nitrite (nitrogen oxides). To determine whether serum concentrations of nitrogen oxides distinguished those children who died from sepsis from those who survived; those who required prolonged inotropic support compared with those who did not; and whether there was any relationship of the levels of nitrogen oxides to markers of tissue perfusion. METHODS: Nitrogen oxides were measured in 30 children with sepsis syndrome or septic shock at admission, 12, 24, and 48 hours. A non-septic control group had serum nitrogen oxides measured at admission. Markers of haemodynamics and tissue perfusion measured were mean arterial pressure, blood lactate, base deficit, gastric intramucosal pH, and deltaCO2 (DCO2: the difference between arterial and gastric intraluminal carbon dioxide tensions). Inotrope doses, number of organ systems failing at 48 hours, and outcome as survival were recorded. RESULTS: Children with sepsis had increased nitrogen oxide concentrations at presentation compared with a group of non-septic controls. Children with organ failure at 48 hours had higher serum nitrogen oxide concentrations than those with sepsis uncomplicated by organ failure at 48 hours. There was no difference in nitrogen oxide when patients were subgrouped according to the receipt of inotropes at 48 hours, and no association with markers of tissue perfusion, or survival. CONCLUSIONS: While this study shows that nitric oxide production is increased in sepsis in children, there was a limited relationship with clinically important markers of illness severity and no relationship to survival.     

Filterability of erythrocytes and whole blood in preterm and full-term neonates and adults

Filtration techniques are widely used to assess red blood cell (RBC) deformability and flow behavior of RBC in microcirculation. In this study filtration rates of RBC from 10 very low birth weight infants (24-30 wk gestation), 10 more mature preterm infants (31-36 wk gestation), 10 full-term neonates, and 10 adults were measured by using Nucleopore filters with pore diameters of 5 micron and filtration pressures of 1, 2, 5, and 10 cm H2O. The major results follow: At each of four filtration pressures, filtration rates of washed RBC were significantly (p less than 0.05) lower in the preterm infants than in the term neonates who in turn showed lower values than adults. The differences among the four groups became less as the pressure was increased from 1 to 10 cm H2O. The filtration rates increased with decreasing MCV (r = -0.86). The filter flow resistance (computed as ratio of filtration pressure and filter flow rate) decreased as the filtration pressure was raised from 1 to 10 cm H2O. The largest drop, 31% (p less than 0.05), was observed in the most immature infants, the smallest, 10% (p greater than 0.05), was seen in adults. At a pressure of 1 cm H2O the calculated mean transit time for RBC through the 5-micron pores was on an average 3.7 times longer in the smallest preterm infants than in the adults (19.7 +/- 7.8 and 5.3 +/- 1.4 ms, respectively), whereas the factor was only 2.7 at a pressure of 10 cm H2O (13 +/- 0.4 and 0.5 +/- 0.1 ms, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Elevated arterial blood pressure is associated with peri-intraventricular haemorrhage

In a prospective study, brain ultrasound scans were performed in 42 newborns (median birth weight 1700g, range 1020–3720 g; gestational age 32 weeks, 26–36) to reveal peri-intraventricular haemorrhage (PIVH) (grades I–IV) as well as echodensities (ED) and/or periventricular leucomalacia (PVL). ECG and arterial blood pressure were recorded on magnetic tape at 8h intervals during the first 24 h of life for further computer analysis. Heart rate (HR) and its variability (HRV) indices RMSM (long-term variability) and RMSSD (short-term variability), together with their coefficients of variation, were computed. Systolic (SBP), diastolic (DBP), and mean blood pressures (MBP) were detected as average values for 2-min stationary segments together with the respective minima and maxima. The indices of variability and their coefficients of variation were computed for the arterial pressure. PIVH was found in 12 newborns and ED in 8 (of whom two developed PVL). The remaining 22 served as controls. Neither HR, HRV nor BP variability differed between the groups. DBP was higher in the group with PIVH (39 mmHg) when compared to both the controls (33 mmHg,P<0.05) and the ED group (32 mmHg,P<0.01). MBP behaved respectively (45 mmHg, 38 mmHg, 37 mmHg,P<0.01). SBP behaved also similarly when gestational age and birth weight were used as covariates (57 mmHg, 48 mmHg, 47 mmHg,P<0.01).Our results suggest that elevated diastolic, mean and systolic blood pressure are significantly associated with peri-intraventricular haemorrhage in preterm newborn infants.     

Monitoring in non-traumatic coma. Part I: Invasive intracranial measurements.

The arterial blood pressure, intracranial pressure, and organ system failure scores were reviewed for 49 infants and children with non-traumatic coma from various causes. The neurological outcome was good in 21 patients, moderate in five, and poor in 23. There was no significant difference in maximum intracranial pressures between patients with a good outcome and those with a poor one, but patients with a poor outcome had significantly lower minimum cerebral perfusion pressures. During the period of admission 18 patients had cardiovascular failure, none had renal failure, and two developed severe coagulopathy. Seventeen of the 19 patients in whom at least one of these systems failed died. Our findings emphasise the diversity of illnesses associated with raised intracranial pressure in children and the number who develop multiple organ failure, and the values and limitations of using minimum cerebral perfusion pressure and the organ system failure scores as guides to severity of illness and prognosis.     

Hypertension screening in schools: results of the Dallas study.

The purpose of this study was to determine the prevalence of persistent blood pressure elevations in an eighth-grade population composed of three ethnic groups, and to determine the feasibility of using school health facilities for hypertension screening. Blood pressure was recorded in 10,641 subjects (90% of the total eighth-grade population) in the Dallas Independent School District. Blacks made up 46% of the population; non-Latin whites, 40.1%; and Latin-Americans, 13.9%. On the first blood pressure screening, 8.9% had systolic or diastolic pressures or both at or above the 95th percentile. Of those whose blood pressures were elevated on the first examination, 98.3% were reexamined. After the third examination, 1.2% continued to have systolic hypertension, and 0.37% diastolic hypertension. No student had diastolic pressure above 90 mm Hg on all three examinations. The prevalence of persistent hypertension was similar for the three ethnic groups. Analysis of variation in blood pressure measurements revealed that the school nurses introduced a relatively small increase in variability. These data indicate that although school screening initially identifies large numbers of students as having inconstant pressure elevations, subsequent follow-up examinations show that less than 2% have persistent hypertension.     

Pressure passive cerebral blood flow and breakdown of the blood-brain barrier in experimental fetal asphyxia.

Cerebral blood flow (CBF) was studied in non-exteriorized near-term sheep fetuses using the radioactive microsphere technique. By partially occluding the umbilical vessels for a period of 1--1 1/2 hours a progressive and severe asphyxia with a final arterial pH of 6.90 was achieved. Varying the mean arterial blood pressure in the fetuses by blood withdrawal or infusion in this state, CBF was measured at different perfusion pressures (mean arterial blood pressure (MABP) minus central venous pressure (CVP)). A passive flow/pressure relationship--loss of autoregulation--was found, with hyperemia reaching CBF values up to 6 times normal at normal MABP of about 60 to 70 mmHg, and severe ischemia reaching CBF values close to zero in large cortical areas at MABP of 30 mmHg. CVP remained essentially unchanged at 10--15 mmHg. The severe and prolonged asphyxia rendered the blood-brain barrier leaky to the albumin tracer Evans blue. In four other fetuses umbilical cord clamping was omitted. However, only in one of these cases was acidosis completely avoided, and CBF autoregulation maintained. The three other fetuses were acidotic at the end of the surgical procedure and had impaired autoregulation.     

Feasibility and safety of AS-3 red blood cells for neonatal transfusions

OBJECTIVES: Most extremely low birth weight (<1 kg) infants receive red blood cell (RBC) transfusions. RBCs stored up to 42 days can be transfused safely in small volumes to preterm infants; however, because the formulation of RBC anticoagulant/preservative solutions differs, clinical studies are required to document the safety of each solution before widespread use. Our goal was to study the feasibility and safety of AS-3 anticoagulant/preservative solution to preterm infants. STUDY DESIGN: Two clinical studies were conducted in sequence: (1) a randomized trial to compare RBC transfusions given as stored (< or =42 days) AS-3 RBCs (11 infants) versus fresh (< or = 7 days) citrate, phosphate, dextrose, and adenine RBCs (10 infants) and (2) a subsequent evaluation of the safety of stored AS-3 RBCs in 33 additional preterm infants given 120 AS-3 RBC transfusions. RESULTS: Results of both the randomized study and the subsequent evaluation documented that AS-3 RBCs stored < or =42 days and transfused in small volumes (15 mL/kg) were safe for RBC transfusions of preterm infants. Donor exposure was significantly reduced, clinical transfusion reactions were rare, and post-transfusion blood hematocrit, pH, and plasma Na, K, Ca, lactate, and glucose measurements were similar when AS-3 and citrate, phosphate, dextrose, and adenine RBC transfusions were compared. CONCLUSIONS: AS-3 RBCs can be used safely for small-volume RBC transfusions for preterm infants.     

Timing of fetal nucleated red blood cell count elevation in response to acute hypoxia

We determined the effect of an acute episode of severe hypoxia on peripheral nucleated red blood cell (RBC) counts in the fetal rat. Timed pregnant rats were randomized to a 2-hour exposure to hypoxia (placement in a chamber containing a gas mixture with 9% O2 +3% CO2 + balanced N2) or to a 2-hour exposure to a sham chamber containing room air. Two maternal animals per group underwent cesarean section immediately after the 2-hour period and then 4, 12, 24, 36, 48, and 60 h after exposure. Fetal nucleated RBC counts were compared between groups at each time interval. The nucleated RBC counts were not significantly different in the hypoxia group until 12 h (mean +/- SEM 158.0 +/- 22.4 RBC/10 high-power fields vs. 90.6 +/- 11.0; p = 0.03) and 24 h (133.2 +/- 16.0 vs. 84.1 +/- 9.0; p = 0.04) after exposure. There were no differences between groups 36, 48, and 60 h after exposure. In the near-term rat fetus, acute hypoxia was associated with a delayed but transient increase in peripheral nucleated RBC counts.     

Determinants of blood glucose variability in adolescents with insulin-dependent diabetes mellitus

Metabolic control and blood glucose variability in children with insulin-dependent diabetes mellitus (IDDM) during and after puberty were studied. Seventy-two children (43M, 29F), aged 10-19 years, with a 2-16-year duration of IDDM participated in the study. Fourteen of the patients were prepubertal (Tanner stage 1), 27 pubertal (Tanner 2-4) and 31 postpubertal (Tanner 5). They performed self-monitoring of blood glucose (SMBG) five times daily, every 2 days for 4 weeks. The SD (SDbg) for all values in each patient was calculated as a measure of blood glucose variability. Weight-length index, linear growth velocity and Tanner stage were recorded. Hemoglobin (Hb)A_Ic, alkaline phosphatase and sex hormone levels in serum were analyzed. Subjectively experienced hypoglycemic episodes were recorded. HbA_Ic levels showed no relation to Tanner stage. SDbg was lower in stage 5 than in stages 2-4 ( p = 0.02). There was no significant correlation between HbA _lc and SDbg, but the variability was significantly lower in individuals with mean blood glucose in the lower quartile compared with those in the upper three quartiles ( p < 0.001). Alkaline phosphatase concentration, as a measure of growth velocity, was the main independent determinant of SDbg ( r = 0.35, p < 0.005). There was an inverse correlation between levels of sex hormones and SDbg. We conclude that blood glucose variability is lower after than during puberty. This variability seems to be related to linear growth velocity or its biochemical marker.     

Patent ductus arteriosus, indomethacin, and intestinal distension: effects on intestinal blood flow and oxygen consumption

To determine the relative importance of patent ductus arteriosus, indomethacin, and intestinal distension as factors that promote terminal ileum ischemia, eight near-term fetal lambs were surgically prepared by in situ cannulation of the proximal and distal ends of a loop of terminal ileum, formalin infiltration of the ductus arteriosus, and placement of a snare around the ductus arteriosus to control its patency. The incisions were closed; the lambs were delivered and mechanically ventilated. Terminal ileum blood flow and oxygen consumption were measured after the loop of ileum had been distended with 0.9% NaCl to luminal pressures of 1-2, 7, and 18 mm Hg (0.13-0.26, 0.93, and 2.38 kPa) (pressures observed in the intestinal lumen after feeding and during pathologic conditions). The effect of these pressures on terminal ileum blood flow and oxygen consumption was examined: 1) with ductus closed, 2) with ductus open, and 3) 1 h after administration of indomethacin (0.3 mg/kg; 0.8 mumol/kg) with ductus closed. Both open ductus and indomethacin produced a significant decrease in intestinal blood flow. This occurred over the entire range of luminal pressures examined. In all three study conditions, terminal ileum blood flow fell commensurate with a fall in perfusion pressure. Despite this absence of pressure-flow autoregulation, oxygen consumption was maintained when the ductus was closed or open. In contrast, indomethacin inhibited the ability of the terminal ileum to autoregulate its oxygen consumption. These findings suggest that both open ductus and indomethacin present an increased risk of intestinal ischemia. We hypothesize that indomethacin's beneficial effect on ductus closure may be counterbalanced by its negative effect on intestinal perfusion and metabolism.     

6-巯嘌呤细胞药理学研究对急性淋巴细胞白血病治疗的指导作用

目的建立一种高效、快速、灵敏的方法，探讨6-巯嘌呤（6-MP）细胞药理学。方法应用反相高效液相色谱分析技术，定量测定急性淋巴细胞白血病(ALL)患儿红细胞内6-MP三种代谢产物浓度6-巯嘌呤核苷酸（6-TGN）,6-次黄巯嘌呤单核苷酸(6-TIMP)和6-甲基巯嘌呤（6-MeMP）。选择31例ALL缓解期随访的患儿，口服6-MP50～75mg/（m     

Indomethacin and the cardiopulmonary adaptations of transition

The present investigation examines the biochemical and physiologic changes produced in fetal rabbit lungs by adding a prostaglandin synthetase inhibitor, sodium indomethacin trihydrate, to the pulmonary perfusate. A control group was similarly perfused without adding indomethacin. The ductus arteriosus was ligated and perfusion was then continued for 2 h while pulmonary artery pressures were monitored. At the end of this period, with perfusion continuing, the lungs were inflated with air at 5 cm H2O increments. Volume changes were recorded. After deflation, the lungs were lavaged with normal saline. Phospholipids were extracted from lung homogenates and lavage. Total lipid phosphorus was determined. Pulmonary vascular resistances in both groups manifested a sharp increase in pressure with ligation of the ductus. After 2 h of perfusion, pulmonary pressures in the control groups had returned very nearly to preligation levels, while in the indomethacin-treated group, pulmonary pressures remained significantly elevated. The first full inflation produced a slight fall in pulmonary vascular resistance in all control animals and a slight rise in all the treated rabbits. Perfused but untreated lungs had higher volumes during inflation as compared to both indomethacin-perfused lungs and unperfused untreated lungs. In this model, prostaglandins appear to have a significant role at two key points in transition: 1) the gradual accommodation to mechanically or hemodynamically mediated increases in pulmonary vascular resistance and 2) the drop in pulmonary vascular resistance which occurs with the first inflation of the lungs. No direct effect of prostaglandin inhibition on surfactant production was documented.     

Upper limits of brain blood flow autoregulation in stable infants of various conceptional age

In healthy adults cerebral blood flow is autoregulated and kept constant over a wide range of mean arterial blood pressures (MAP) between 60 and 150 mmHg. In 27 stable infants with different conceptional ages ranging from 33 to 50 weeks, Doppler measurements of mean flow velocity at the anterior cerebral artery have been recorded simultaneously with mean arterial blood pressures (MAP) during a period of 6 h. The range of autoregulation and its upper limit could thus be determined. The upper limit was found to increase with advancing age. In the infants with conceptional ages between 33 and 35 weeks, the upper limit of autoregulation varied between 45 and 60 mmHg, while the upper limit shifted to a MAP of 100 mmHg at 47 weeks conceptional age. A significant positive linear relationship existed between the upper limit of autoregulation and conceptional age.