摘要:

Smoking during pregnancy results in offspring with an average birth weight 200 g less than those of non-smoking mothers. The pathogenesis of this effect is still unknown and there is no general agreement about the causal relationship between maternal smoking and subsequent fetal growth retardation. In the present study, a model of maternal smoking during pregnancy in the rat was established using the P & I Walton Exposure Machine. The study consisted of three groups: control, pair-fed, and smokeexposed. Smoke-exposed animals were exposed continuously to tobacco smoke for cycles of 7 min, 16 times a day from d 5 to d 20 of gestation. On d 21 of gestation, fetuses from all groups were removed by cesarean section, weighed, and dissected. The fetal brain, liver, and lungs as well as the placentas were weighed and analyzed for nucleic acid content. Fetal weight was found to be significantly reduced in both pair-fed and smoke-exposed groups compared with the control group. There was also a significant reduction in fetal body weight of the animals in the smoke-exposed group in comparison to those in the pair-fed group. Exposing the mother to smoke affected neither fetal brain weight nor nucleic acid content whereas fetal liver and lungs showed a significant decrease in both weight and nucleic acid content. These results indicate that the fetal growth retardation associated with maternal exposure to tobacco smoke in the rat corresponds to a disproportionate type. In addition, the present results indicate that the maternal tobacco smoke exposure induced fetal growth retardation without placental growth retardation.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

We used the isoelectric focusing method developed by Wilson to analyze serum from individuals homozygous or heterozygous for cystic fibrosis. The presence of cystic fibrosis protein (CFP) was found in 37 out of 52 homozygous and 24 out of 34 heterozygous patients, which leads to a frequency of 71% for both families. Five out of 24 controls were found positive. The same study, performed on 26 plasma samples collected from the same patients, demonstrated that the detection of CFP is possible in plasma as well as in serum. Our results confirm the presence of a protein “marker” of CF in serum, but also underlines the lack of sensitivity of the isoelectric focusing technique to be used for diagnosis.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

We measured the concentrations of protein, insulin, and epidermal growth factor (EGF) in human milk from mothers delivering at term. Samples were obtained from d 1 (colostrum) to d 42 after birth. Human colostrum contains very high concentrations of protein [83.7 ± 7.4 g/1 (SEM)], insulin (3.75 ± 0.88 nM), and EGF (53.9 ± 6.9 nM). Similar concentrations have been measured in prebirth milk. Insulin, EGF, and protein in milk decline rapidly during the first few days of lactation but remain constant thereafter. Although the concentrations of insulin and EGF in mature milk are only 10% of those in colostrum, they are considerably higher than in serum. We also showed that human milk has a growth-promoting activity in cultured cells, causing a stimulation of protein synthesis in L6 myoblasts and 3T3-L1 fibroblasts and an increase in DNA synthesis in L6 cells and T47D breast cancer cells. This mitogenic activity declines as lactation progresses, with a similar time-course to the fall in insulin and EGF; however, the cell lines used here are not responsive to either of these two growth factors in the range of concentrations found in milk. This indicates that human milk also contains high concentrations of additional, unidentified growth factors. The occurrence of high concentrations of growth factors in milk suggests that they may be important for the proliferation and differentiation of infant tissues.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Total respiratory resistance (RT) was measured in 11 normal children, 2- 5.5 years of age (mean 4.16 years), and in 24 children with bronchial asthma, 2- 10.5 years of age (mean 6 years), by oscillating the respiratory system from 2- 32 Hz with a new microprocessor technique. Twenty-five children were ≤ 5 years of age. This technique was also compared with airway resistance (Raw) by body plethysmography both in terms of baseline values and response to bronchodilators. The absolute values for Raw are lower than R, with a mean percentage difference (±S.E.M.) of 30.3 ± 5.0%; however, good correlation between the two techniques was obtained (r=0.79). The changes of RTand Raw were not significantly different after aerosolized isoproterenol (P> 0.05). We determined the inverse relationship between height and RTwith correlation coefficient r=-0.79 (P< 0.01). In children, resonant frequency ranged from 6-24 Hz with a mean value of 16.57 ± 0.78 Hz. The forced oscillation method utilized clinically in this study provides an alternative to total body plethysmography or an esophageal balloon, which are technically difficult and preclude their routine use in small children. In conclusion, RTutilized in this study is a rapid and reproducible approximation of Raw. It allows evaluation of R, over a wide range of frequencies including resonant frequency and requires less cooperation than body plethysmography. It requires a relatively short time and allows objective assessment of obstructive airway disease and its responsiveness to bronchodilators in children under 5 years of age.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The present study was designed to determine whether the ontogenic changes in the salvage pathway for DNA synthesis of suckling rat intestine could be causally related to physiologic events during the weaning period. The intestinal activity of soluble thymidine kinase, extremely low in young sucklings (d 11, 0.057 ± 0.007 nmolmin−1·g tissue−1), increased dramatically between d 18 and 22 postpartum and reached a plateau (19.8 ± 0.5 nmol · min−1·g tissue−1) at the fourth postnatal week. Rat pups prevented from weaning showed an initial rise in the enzyme synthesis by d 18 as did their littermates weaned onto an adult diet. Compared with 22-d-old rats weaned onto chow pellets (14.1 ± 2.1 nmol · min” g tissue”), thymidine kinase concentration was reduced by one-half in rats of the same age, fed on mother's milk alone (6.5 ) 0.7 nmolmin”g tissue”) or on a liquid artificial diet either high in fat (mimicking rat milk, 7.4 ± 0.6 nmol · min” · g tissue ˜ ') or high in carbohydrate mimicking chow, 6.4 ±1.3 nmol min” g tissue”). The relative proportions of fat and carbohydrate in the diet had little or not effect on growth rate, intestinal wt, and DNA content per centimeter. In a second experiment, 9-d-old sucklings were treated for four consecutive d with either saline or hydrocortisone hemisuccinate at doses assumed to be in the physiologic (0.5 mg/100 g body wt per day) and pharmacologic (2.0 mg/100 g body wt per day) range. Low doses of the steroid failed to enhance precociously the intestinal synthesis of the enzyme and produced significant decreases in intestinal protein (-19% versus controls, P<0.05) and DNA content (—23%, P<0.01). In the jejunum as well in the ileum, the incorporation rates of pH]thymidine into DNA were reduced to a level about 70% of the controls (P=0.05). Higher doses of hydrocortisone had a marked suppressive effect on DNA synthesis in the jejunum and ileum, the values in the steroid-treated group being about one-half those of the control group.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The ventilatory response of 11 growing premature infants to external inspiratory resistive loads was evaluated. Air flow, tidal volume, minute ventilation, inspiratory duration and total breath duration were measured before and after application of a flow resistive load. A significant (P < 0.001) immediate decrease in minute ventilation and tidal volume was observed in all infants after load application. Minute ventilation and tidal volume remained decreased throughout the 10-min study period. Minute ventilation and tidal volume for the group decreased to 48 and 50% of control mean value, respectively. In addition, there was a significant (P < 0.001) sustained increase in inspiratory time resulting in an increase in the ratio of inspiratory time/total respiratory time.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

We determined erythrocyte 2,3-diphosphoglycerate (2,3- DPG), Po250%, whole blood hemoglobin concentration, and available O2from the 12th to the 30th d after birth in two matched groups of young rabbits. One group received iron parenterally on the 12th, 15th, and 18th d and the other received no iron supplement. In the untreated group there was a marked fall in hemoglobin concentration from the 12th to the 22nd d and thereafter a marked increase to the initial level on the 30th d whereas the iron-treated animals showed a marked rise in hemoglobin concentration from the 12th to the 22nd d, and a subsequent, slight decline from the 22nd to the 30th d. The average values of Po250% and 2,3-DPG, and the changes in Po250% and 2,3-DPG were virtually identical for both groups. During the first period (12-22 d) there was a marked rise in both 2,3-DPG and Po250% whereas in the second period (22-30 d) there was a somewhat smaller rise in 2,3-DPG and only a slight tendency toward a further rise in Po250%. In the untreated animals “available O2,” reflecting the O2delivery capacity of the blood, remained unchanged during the period of fall in hemoglobin concentration and showed a rise during the second period. In the iron-treated animals “available O2” rose markedly during the first period, with iron-treatment, and remained unchanged during the second period. We conclude that the marked postnatal rise in 2,3-DPG and Po250% in the rabbit seems to be independent of the changes in the hemoglobin concentration.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

In this study we have characterized by DNA analysis the molecular basis of an α -thalassemia condition found in an infant, with 16% Hb Bart's at birth, who developed an hematologic picture similar to the α -thalassemia carrier state. Restriction endonuclease analysis and hybridization with α and ζ specific probes have provided strong evidence that this patient carries a genetic compound of deletion a-thalassemia-2 lesion (-α ) and a non-deletion defect {(αα)th} with both a-structural genes intact on chromosome 16. He inherited the deletion a-thalassemia α-2 chromosome (-α) from the father and the chromosome with nondeletion α-thalassemia defect from the mother. Because the deletion of one, two, or three α-globin structural genes is associated with 1-2%, 5-6%, or 25%, Hb Bart's respectively, these findings suggest that the non-deletion chromosome {(αα )th'} contains two α -globin structural genes that are less active than a single a gene (-α).

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Plasma and red cell fatty acids were measured in 44 children with third degree malnutrition: 22 children with marasmus, 11 children with kwashiorkor, and 11 with marasmic kwashiorkor (MK). The presence of edema, dermatosis, hair changes, and hypoalbuminemia were positively correlated with the red cell percentage linoleic acid and negatively correlated with red cell percentage arachidonic acid. Red cell percentage linoleic acid in kwashiorkor was decreased from the control value of 15.3% to 10.9%. In marasmus and MK, there were significantly greater decreases, to 7.7% and 8.0%, respectively. Red cell arachidonic acid in kwashiorkor was significantly (P<0.001) decreased to 9.8% (control value of 13.1%) whereas in marasmus there was no significant change. Only one sample, plasma from an infant with marasmus, had any detectable eicosatrienoic acid (20:3,ω 9). Similar changes in fatty acid composition have been reported in infants with acrodermatitis enteropathica, in an infant with biotin deficiency, and in biotin-deficient rats.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Neuraminidase activity in fibroblasts obtained from a patient with combined β-galactosidase-neuraminidase deficiency (β- gal−/neur−) was partially restored by fusion with two ML I cell lines and an ML II cell line. As observed with neuraminidase activity, β-galactosidase also showed complementation with an increase in activity when β-gal-/neur−fibroblasts were fused with an ML II or a GHi gangliosidosis cell line. Both GM, gangliosidosis and sialidosis fibroblasts secreted a “corrective factor” which, when added to medium above β-gal−/neur−fibroblasts, was pinocytosed and partially corrected its deficiencies for these two enzymes.This partial correction of β -galactosidase and neuraminidase activities persisted for at least 72 h after removal of the “corrective factor” from the medium. A “corrective factor” with similar properties was obtained from glycoproteins isolated by chromatography of human spleen homogenates on concanavalin A-Sepharose. Treatment of -β-gal−/neur−fibroblasts with leupeptin or EP475, two inhibitors of lysosomal thiolproteases, partially restored β-galactosidase activity but caused no significant improvement in neuraminidase levels. The partial corrective effect of leupeptin on partial corrective effect of leupeptin on β-galactosidase activity persisted for at least 2 d after removal of the drug, even in the presence of cycloheximide. -galactosidase activity persisted for at least 2 d after removal of the drug, even in the presence of cycloheximide.

ISSN:0031-3998    

出版商:OVID    

年代:1984

数据来源: OVID