摘要:

The blood neutrophil response to endotoxin challenge was determined in one-day-old and young adult rats to test the hypothesis that the neonate is unable to mobilize neutrophils from bone marrow to the peripheral circulation at a rate similar to adults. Adult animals responded to endotoxin with a brief neutropenia followed rapidly by marked neutrophilia. The maximum adult neutrophil count occurred at 11 hr after challenge and returned to baseline values by 28 hr. In contrast, one-day-old rats showed a prolonged neutropenia after a comparable injection. Peak neutrophil counts in neonates occurred later than those seen in adults (16versus11 hr) and were also lower. However, neutrophilia, once established in the neonates, persisted considerably longer than in adults.The age at which the adult response to endotoxin is achieved was assessed by bleeding animals of increasing ages 7 hr after endotoxin challenge. A gradual progression toward the adult neutrophil response began at 2 wk of age. The most rapid change in endotoxin responsiveness occurred after 6 wk of age.SpeculationThe neonate, although probably possessing adequate bone marrow neutrophil reserves, may be unable to mobilize these stores rapidly and effectively. Coupled with other recognized defects in host defenses, this indolent response to inflammatory stimuli may in part be responsible for the unique propensity of the neonate to serious infection.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Serum α-fetoprotein (AFP) levels were monitored in 32 normal babies consecutively from 2 to 3 days, 2 wk, and 2 and 4 months after birth. In addition, serum AFP concentration was also measured in 116 random specimens from infants with normal liver enzymes and 10 infants born immaturely. Results were combined to establish normal AFP levels for infants at various ages. Serum AFP disappeared rapidly after birth. We found that it was not until 8 months of age that the normal AFP level in infants approached adult level. The half-lives of AFP degradation were estimated to be 5.5 days between birth and 2 wk, 11 days between 2 wk to 2 months, and 33 days between 2 and 4 months of age. In contrast to earlier belief, we felt that some AFP synthesis still exists after birth; however, the rate of synthesis may also decrease with age.SpeculationOur results favor the view that some α-fetoprotein (AFP) synthesis exists after birth. The rate of synthesis is slowly decreased with time. Any factor affecting the rate of synthesis may influence the serum AFP level. The wide range of variation in serum AFP levels in infants of various ages indicates that there must be more than one unknown factor affecting the AFP serum level. The normal range will be narrower if these factors become known. By using our age-dependent normal AFP serum levels, it would be interesting to see whether differential diagnosis of neonatal hepatitis from biliary atresia can be unproved and whether infants do have higher and more frequent elevation of serum AFP with hepatic disorders.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Blood volume (BV), red cell mass (RCM; Cr-51) and plasma volume (125I-labeled albumin) were measured in 205 piglets from 28 litters shortly after birth. Spontaneous cord rupture in healthy piglets occurred during delivery (n= 25) or within 190 sec of birth (n= 82). Spontaneous and induced delay of cord rupture resulted hi a tune-dependent increase hi BV and RCM. BV (± S.D.) at birth was 72.5 ± 10.5 ml/kg (RCM, 23.6 ± 4.6 ml/kg) in the 25 piglets with prenatal cord rupture and 110.5 ± 12.9 ml/kg (RCM, 38.4 ± 7.0 ml/kg) hi 17 piglets with late spontaneous cord rupture. The mean blood volume of all the 107 healthy piglets with spontaneous cord rupture was 90.2 ± 12.7 ml/kg (RCM, 30.1 ± 4.8 ml/kg). RCM was significantly (P< 0.05) increased hi nine piglets with intra-uterine growth retardation (RCM, 35.8 ± 11.2 ml/kg) and hi 13 with metabolic acidosis but without signs of asphyxia (RCM, 35.8 ± 6.7 ml/kg). In five piglets with cord wrapping, prenatal cord rupture, and acute asphyxia, BV (57.8 ± 7.3 ml/kg) was significantly decreased. In five other piglets with prenatal cord rupture and acute asphyxia, BV (67.9 ± 10.0 ml/kg) corresponded to that of the normal piglets with prenatal cord rupture. However, delay of cord rupture to 60 sec after birth did not increase BV (66.0 ± 11.8 ml/kg) in four piglets with acute asphyxia. Forty-one premature piglets delivered 6 days before normal term had their cords ruptured prenatally or within 5 sec of birth. Their hematocrit at birth (0.337 ± 0.028 liters/liter) was significantly decreased compared to the normal full-term piglets with corresponding tune of cord rupture (0.384 ± 0.033 liters/liter). RCM in 18 piglets with prostaglandin-induced prematurity (18.9 ± 3.4 ml/kg) was significantly lower than hi 23 piglets whose births had been induced by ovarectomy of their mothers (RCM, 22.1 ± 3.2 ml/kg).SpeculationThere is a great variability of placental transfusion in piglets (average, 24%; range, 0 to 60% of fetal blood volume) because natural cord rupture occurred at any time from sub partu to 3 nun after birth. This implies that hypo- or hypervolemiaper se, hi the otherwise well adapted newborn, must not represent a pathologic condition. On the other hand, hi the newborn with abnormal adaptation to extra-uterine life, abnormal blood volume may be carefully considered as either cause or consequence of maladaptation requiring appropriate treatment.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

A girl presented with an important growth retardation, hepatomegaly, fasting hypoglycemia, lactic acidosis, increased serum cholesterol, triglycerides and uric acid, and increased liver glycogen (7.5%). There was no rise in blood glucose after IV galactose or fructose, but glucagon gave a delayed response. Type Ib glycogen storage disease was suggested by the low normal activity of glucose-6-phosphatase (G-6-Pase) which reached 1.8 units/g (normal, 2 to 10 units/g) and the normal activity of other glycogenolytic enzymes, measured in homogenates prepared in H2O from previously frozen liver tissue. After portacaval shunt (PCS), height increased by 29 cm in 3 years. Serum cholesterol decreased from 618 to 216 mg/dl, and triglycerides decreased from 890 to 116 mg/dl. During an oral glucose tolerance test, peak values for glucose (mg/dl) and insulin (μunits/ml) were, respectively, 210 and 50 before and 280 and 90 after PCS. Sixty min after the IV administration of a tracer dose of [2-3H;U-14C]glucose, the3H/14C ratio in blood glucose decreased to 24% of its initial value indicating a functional G-6-Pase (mean ± S.E. in control subjects: 59% ± 7; in type la CSD: 92% ± 3). The activity of G-6-Pase measured as described above increased to 3.8 units/g of liver 1 year after PCS and 7.85 units/g of liver after 3 years. At that time, a simultaneous assay of the enzyme in a fresh, previously not frozen liver biopsy, homogenized in 0.25 M sucrose, revealed only about 29% of the activity of the same sample prepared in H2O (mean ± S.E. in three controls: 95.8% ± 8.9).SpeculationThe higher than normal utilization of [2-3H;U-14C]glucose observed after portacaval shunt hi this patient suggests that besides the postulated defect of the microsomal glucose-6-phos-phate transport system (19), other hitherto unexplored pathogenetic mechanisms should be investigated, including the regulation of the synthesis of glucose-6-phosphatase, to explain the unpaired degradation of glycogen hi type Ib glycogen storage disease.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

There are no prospective studies evaluating residual β-cell function and islet cell antibody status during the first 2 years after the diagnosis of diabetes hi children. We report such a prospective study of 21 insulin-dependent diabetic children. The relationship of residual β-cell function during the 2 years after diagnosis, to age at diagnosis, islet cell antibody (ICA) status, histocompatability status, and exogenous insulin is reported.Twenty-one children were studied for at least 2 years after the diagnosis of diabetes. Blood was obtained at the time of diagnosis for the determination of ICA and histocompatability status. ICA status was determined 12 months after diagnosis, and again at 24 months if ICA had been detected at 12 months. Residual β-cell function was assessed serially by measuring 24-hr urinary C-peptide. The 24-hr C peptide excretion was expressed relative to 24-hr creatinine excretion. This ratio is termed urinary C peptide excretion (UCP). Islet cell antibodies were measured by indirect immunofluorescence on human O-group pancreas. Fluorescein-labeled anti-C3C was used to determine whether the islet cell antibodies were able to fix complement. A standard NIH micro-lymphocytotoxicity test was used to determine histocompatability status at the A, B, and C loci.Throughout the entire study period, the UCP of each diabetic was always below the mean of the group of nondiabetic children. For all diabetic children, the UCP decreased during the 24 months after diagnosis. Most children's (14 of 21) UCP had faUen below 0.20 during the 12 months after diagnosis. Twelve of 21 diabetic children were ICA positive at diagnosis. Five had unaltered titers of ICA 12 months later and four had no ICA detectable at 12 months, whereas for three the titer had fallen by at least two dilutions. The magnitude of the UCP 12 months after diagnosis correlated significantly with age at the time of diagnosis (r= 0.557;P< 0.05). Similarly, there was also a significant correlation between the UCP 24 months after diagnosis and age at diagnosis (r= 0.446;P< 0.05). There was no significant difference between insulin dose, expressed as units/kg/day at 12 and 24 months after diagnosis. There was no significant relationship between ICA status and insulin dose at 12 or 24 months. There was no discernible relationship between the evolution of ICA or UCP with histocompatability antigens at the A, B, or C loci.SpeculationThe positive correlation between urinary C peptide and age at diagnosis of diabetes suggests that pancreatic size and potential for subsequent growth might be factors influencing the impact of a diabetogenic insult. For insulin-dependent children, the impact of the diabetogenic process is usually greatest during the 12 months after diagnosis. Potential therapeutic efforts to limit islet cell damage need to be applied early, and it is possible they may not need to be continued much beyond 12 months after diagnosis.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Interrelationships of high-density lipoprotein cholesterol (C-HDL) with total plasma cholesterol (TC), triglyceride, and low-density lipoprotein cholesterol, as well as longitudinal maintenance of C-HDL rank order (tracking) from birth to age 2 years were assessed in 76 hypercholesterolemic neonates (cord blood, TC > 95 mg/dl) with focus upon 34 hyperalphalipoproteinemic neonates who had cord blood C-HDL > 61 mg/dl, ≥ the 99th percentile. Cord blood C-HDL correlated closely (P< 0.01) with C-HDL at 6, 12, and 18 to 24 months (r= 0.32, 0.49, and 0.39, respectively). C-HDL levels at 12 months and 18 to 24 months were closely associated (r= 0.68 andP< 0.01). C-HDL at birth, 6, and 12 months correlated positively (P< 0.01) with TC levels (r= 0.28, 0.30, and 0.36, respectively). Conversely, C-HDL at birth, 6 and 12 months correlated inversely with TG (P< 0.01) (r= −0.41, −0.40, and −0.49, respectively). At birth and at 18 to 24 months, C-HDL correlated inversely (p< 0.05) with C-LDL (r= −0.36 and —0.31, respectively). Of neonates having cord blood C-HDL in the highest quartile, 38, 56, and 60%, respectively at ages 6, 12, and 18 to 24 months retained C-HDL levels in the highest quartile; 56, 75, and 70%, respectively, retained C-HDL levels > the 50th percentile. Of 13 neonates having the highest initial cord blood C-HDL levels, cord blood C-HDL ≥ 69 mg/dl, nine had one or more C-HDL values > 70 mg/dl (the 90th percentile for childhood), throughout the 12− to 60-month follow-up period. Moreover, where more than one follow-up measurement was available, there was relative stability of elevated C-HDL measurements. Many infants with cord blood hyperalphalipoproteinemia are likely to have persistent elevations of C-HDL at ages 1 and 2 years. If they maintain elevated C-HDL into adulthood, they may, speculatively, be at reduced risk for coronary heart disease, given the strong inverse association of C-HDL with coronary heart disease.SpeculationMany infants with cord blood hyperalphalipoproteinemia are likely to have persistent elevations of high-density lipoprotein cholesterol (C-HDL) at ages 1 and 2 years. If they maintain elevated C-HDL into adulthood, they may, speculatively, be at reduced risk for coronary heart disease, given the strong inverse association of C-HDL with coronary heart disease.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

We have examined extracts of fibroblasts from patients with mannosidosis, mucolipidosis (ML) II, ML III, and normal controls for α-D-mannosidase activity against 4-methylumbelliferyl-α-D-mannopyranoside to test for the presence of the “intermediate” pH S.5 enzyme activity that has been called the “Golgi mannosidase.” Fibroblast extracts were prepared by sonication and sedimented to separate membrane-associated activities from cytosolic and lysosomal α-D-mannosidases. Membranes were extracted by salt washes (0.4 M NaCl) to desorb the lysosomal enzymes that sertimented with membranes. The α-D-mannosidase activity remaining with membranes showed many properties described for the Golgi mannosidase including: 1) an “intermediate” pH optimum (pH 5.5–6.0), 2) activity with the synthetic 4-methylumbelliferyl substrate, 3) lack of inhibitability by 200 mM methyl- α-D-mannopyranoside, and 4) partial resistance to solubilization by salt washing, and to a single extraction with the non-ionic detergent Triton X-100.This intermediate activity was the major α-D-mannosidase activity remaining in membranes from normal fibroblasts following sedimentation and salt washing, and was the major component of the α-D-mannosidase activity in extracts of fibroblasts from patients with mannosidosis, ML II, and ML III, in all of which, the lysosomal “acid” α-D-mannosidase was greatly reduced.The specific activity of intermediate α-D-mannosidase in membranes from fibroblasts from patients with mannosidosis, ML II, and ML III was not reduced compared to that of fibroblasts from controls. These studies provided no evidence to support the prior suggestion of a deficiency of “Golgi mannosidase” in ML II or ML III.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID