摘要:

SummaryQuantitative morphometric studies were performed on the pulmonary arteries of two newborns who died at 1 and 3 days of age with both transposition of the great arteries and persistence of the fetal circulation. Similar studies were performed on two normal control subjects (age 2 and 6 days), one newborn infant (age 1 day) with secondary persistence of the fetal circulation, and one newborn infant (age 2 days) with isolated D-transposition of the great arteries. Morphometric data, summarized herein, showed greatest mean percent wall thickness in the patients with persistent fetal circulation either alone or with D-transposition of the great arteries, as compared to those without it. When wall thickness was related to external diameter of the vessel, the greatest difference in thickness was observed in the smallest vessels (<150 μ in diameter). Extension of smooth muscle peripherally and to the smallest vessels (<50 μ) was similarly most marked in those infants with persistence of the fetal circulation, either secondary or with D-transposition of the great arteries. Alevolar/artery ratio determinations were similar among the six subjects. These comparative data indicate that cyanotic congenital heart disease and persistence of the fetal circulation may coexist but at the same time be unrelated in a single patient. Furthermore when such coexistence is unrecognized, pharmacologic manipulation of the ductus arteriosus may be hazardous.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummaryWe postulated that parents of infants who sustain near-death episodes associated with defective chemical regulation of breathing might share a similar defect. We, therefore, measured the ventilatory responses to progressive hypoxia and hypercapnia individually in eight sets of parents of infants who had sustained at least one near-death episode (apnea, cyanosis, pallor, limpness, and responsive only to mouth-to-mouth resuscitation); each infant had a ventilatory response to CO2which was more than 2 S.D. below the mean normal. Ventilatory function measured by vital capacity forced expiratory volume 1.0 and flow volume curves was normal in each group. Responses to hypercapnia and hypoxemia in both fathers and mothers were similar to 11 pairs of controls. Ventilation during CO2rebreathing normalized for surface area increased 0.87 liter/min/mm Hg in fathers, 0.94 in controls, 0.87 in mothers, and 0.75 in controls. Ventilation during progressive hypoxemia increased 88 liter/min/1/mm Hg in fathers, 92 in controls, 86 in mothers, and 101 in controls. None of these differences was significant.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummaryMetabolism of indomethacin was examined in freshly isolated hepatocytes prepared by liver collagenase perfusion of fetal (28) and neonatal rabbits of 3, 5, 10, 12, and 25 days of age. Initial cell viability was more than 90% and linear rates of metabolism were observed for up to 2 hr of incubation. Deacylation of indomethacin to desbenzoyl indomethacin showed a rapid increase early in postnatal development while microsomalO-demethylation to desmethyl indomethacin was increased significantly only in the hepatocytes from 25-day-old rabbits. Glucuronide conjugates of indomethacin and indomethacin metabolites accounted for less than 8% of the total metabolites in hepatocytes from 25-day-old rabbits and less than 2% in the 3− to 5-day-old rabbits. The maturational development of indomethacin in metabolism may account for previously reported gestational dependent half-life of the drug in the premature infant (9). However, the factors that regulate development of indomethacin metabolism appear to be under more than one control system.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummaryThe experiments reported herein compare growth kinetics and biochemical properties of cultured skin fibroblasts from patients with Duchenne muscular dystrophy (DMD) and matched normal controls.On day 7 after plating (6000 cells/cm2) cell number and DNA per dish are significantly reduced (P< 0.001) in the cultures from DMD patients (n= 14), compared to those from controls (n= 10). Moreover DMD cells contain less lipids and proteins per dish but more per cell than normal fibroblasts (not significant). Variations of media (McCoy's medium instead of Eagle's minimum essential medium) and sera (human cord serum instead of fetal calf serum) resulted in the same differences between DMD and control cells.Cell kinetic experiments (plating density: 2000 cells/cm2) show increased doubling times of DMD fibroblasts (P< 0.001;nDMD= 5;ncontrols= 4) whereas plating efficiency is equal for both DMD and controls.On day 7 the activity of the membrane bound enzyme 5‘-nucleotidase either per mg protein or per μg DNA is significantly elevated in cells from DMD patients (P< 0.0005;nDMD= 8;ncontrols= 9) independent of cell density.Thus all findings in cultured DMD fibroblasts: increased doubling time, tendency to more voluminous cells, and elevated 5'-nucleotidase activity per cell suggest, that the DMD cells behave similar to prematurely aging cells. Until now we were not able to check whether any alterations of the plasma membrane are inducing early senescence or, reversely, premature aging is the cause of the postulated membrane alterations.If these findings were to be confirmed in cultured amniotic cells from DMD fetuses, they could serve as a potential prenatal diagnosis of the disease.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummaryEstimated cerebral blood flow (eCBF) was measured sequentially in seven term infants with evidence of hypoxic-ischemic encephalopathy (HIE) and compared with that of normal-term infants. The eCBF was determined by a noninvasive method involving brief bilateral jugular venous occlusion with simultaneous measurement of occipitofrontal circumference. There was a significant decrease in eCBF on day 2 (30 ± 4 ml/min/100 g brain weight) and on day 4 (36 ± 5 ml/min/100 g brain weight) compared with control values (56 ± 4 ml/min/100 g brain weight; 54 ± 4 ml/min/100 g brain weight) (P< 0.01). The alveolar CO2was significantly lower on days 2 and 4 in the HIE group (P< 0.001), and these values increased to control values by day 6. There was no significant correlation between estimated cerebral blood flow and alveolar CO2in infants with HIE. We conclude that term infants with evidence of hypoxic-ischemic encephalopathy demonstrate lowered eCBF in the first 4 days of life.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummarySimultaneous plasma renin activity and aldosterone levels were measured in the chronically catheterized fetal lamb and pregnant ewe between 100 days gestation and term (140 to 150 days). Amniotic fluid renin levels were not statistically different after the addition of sheep renin substrate [0.76 ± 0.18 ng/ml/hr (mean and S.E.) under 120 days and 1.33 ± 0.29 after 125 days]. Amniotic fluid renin levels were unmeasurable without the addition of renin substrate. Basal plasma renin activity levels increased from 4.27 ± 0.66 ng/ml/hr (P< 0.01) (mean and S.E.) between 95 to 120 days of gestation in the fetal lamb to 10.14 ± 1.46 between 125 to 150 days; these levels were greater than the amniotic fluid levels (P< 0.001). Basal plasma renin activity levels in the pregnant ewe increased from 2.61 ± 0.40 ng/ml/hr under 120 days of gestation to 7.13 ± 1.41 (P< 0.01) after 125 days; these levels were greater than the simultaneous amniotic fluid levels (P< 0.001).The basal amniotic fluid, fetal, and maternal aldosterone levels of 5.0 ± 0.53, 3.45 ± 0.53, and 5.83 ± 0.76 ng/dl (mean and S.E.) increased to 8.97 ± 0.86, 6.67 ± 1.21, and 12.28 ± 2.87 ng/dl, respectively, (P< 0.05). Neither the fetal nor the maternal levels were statistically different from the amniotic fluid aldosterone levels during development.These data suggest that active renin and renin substrate pass poorly into the amniotic fluid; however, aldosterone from both the fetus and mother pass easily and contribute to the level of this steroid in amniotic fluid.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummaryWe sought to test the hypothesis that hyperinsulinemiaper sealters the flux of surface active material (SAM) into tracheal fluid by continuously infusing insulin (0.24 ± 0.04 units/kg/hr, mean ± S.E.) from 112 through 135 days gestation into five chronically catheterised fetal lambs, from which tracheal fluid could be collected.Serum insulin levels in these fetuses (95 ± 10 μU/ml) were greater than in five chronically catheterised control fetuses of the same gestational age (10 ± 1 μU/ml,P< 0.001) and in the mothers (38 ± 6 μU/ml,P< 0.001). Serum glucose levels in the insulin-treated fetuses (10 ± 1 mg/dl) were lower than in the control fetuses (19 ± 1 mg/dl,P< 0.001) and in the mothers (60 ± 3 mg/dl,P< 0.001). Arterial blood gases (pH 7.37 ± 0.01, PO223.3 ± 0.05 mm Hg, PCO241.5 ± 0.9 mm Hg) and hematocrit (33 + 1% at 127 days gestation and 31 ± 1% at 135 days gestation) in the insulin treated fetuses were not different from the controls.SAM flux into the tracheal fluid of the insulin-treated fetuses was 1 μg/kg/hr, coefficient of variation 373%. This was lower than SAM flux in the control fetuses (26 μg/kg/hr, coefficient of variation 28%,P< 0.01). Moreover, among the control fetuses, SAM began to appear in tracheal fluid at 119 days gestation and was present in all five fetuses by 125 days gestation, whereas SAM did not begin to appear in the insulin-treated fetuses until 127 days gestation and did not appear at all in three of them.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummaryGlycocholate binding by plasma proteins and erythrocytes from fetal and adult blood has been studied, and the results have been used to derive a compartmental model of the distribution of glycocholate in blood. This model assumes that glycocholate is distributed between the aqueous phase, albumin binding sites, binding sites on other plasma proteins, and erythrocytes. Whereas glycocholate binding by albumin was saturable fetal blood: dissociation constant (0.5 mM), concentration of binding sites (11.3 μmoles/g protein); adult blood: dissociation constant (0.42 mM), concentration of binding sites (20.1 μmoles/g protein)], binding by other plasma proteins was not. The association of glycocholate with erythrocytes appeared to be based on partitioning rather than binding of the bile salt to specific sites. The value of the partition coefficient was 6.0. The compartmental model indicates that, in fetal blood, 46% of the glycocholate is in free solution, and 37% is bound to albumin. In blood from adults, the corresponding values are 31% in free solution and 59% bound to albumin.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummaryThe visual evoked potential (VEP) of five healthy, near-term exteriorized fetal lambs was compared with the VEP obtained from the same animals during the first hour after ventilation. Characteristics of the individual wave components and their relationship to blood pressure, heart rate, and arterial blood gas measurements concomitantly obtained were examined. Results show that the VEP of the healthy fetus is a stable, reproducible signal consisting of four basic components, and that the latencies (msec) and the amplitude (μV) of the individual components of the VEP are similar to those of the newborn. In two related experiments, fetal asphyxia of unknown duration was encountered during fetal exteriorization and instrumentation. In the first case, neonatal acidosis persisted despite aggressive resuscitation efforts and was accompanied by an atypical VEP. In the second case, the neonatal VEP obtained after 15 min of resuscitation was markedly depressed despite restoration of acid-base balance but gradually recovered during the remainder of the 1-hr newborn period. In conclusion, the VEP is a reproducible measure of cortical function in the healthy fetus and neonate and may reflect the acute status of cerebral function during fetal asphyxia and neonatal resuscitation.SpeculationThe initial success of neonatal resuscitation after birth asphyxia is predicated upon the response of blood pressure, heart rate and blood gas measurements, yet these measurements indicate only indirectly whether brain damage has occurred during asphyxia, or whether brain recovery is eminent. The visual evoked potential may provide a reproducible measure of the effectiveness of current resuscitation practices.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummaryThe bronchodilatory response of three β2-agonists (fenoterol, salbutamol, and terbutaline), administered by a metered aerosol inhaler, was assessed in 19 asthmatic children after histamine-induced bronchoconstriction. At 1-min intervals, the changes in total pulmonary flow resistance (R1) and dynamic lung compliance (C dyn) were measured. After rank-ordering according to the base line value of C dyn (62 to 200% predicted), the patients were divided into two groups according to lung compliance: (1) patients with greater compliance (C dyn, 129 to 200% predicted) and (2) patients with lesser compliance (C dyn, 69 to 116% predicted). The effect of the three bronchodilators on the mean decrease of R1and on the increase of C dyn was studied and analyzed for each drug separately. In all patients, salbutamol was the most efficient bronchodilator of small airways (P< 0.02). The most striking feature of this β2-mimetic was observed in patients whose lungs were initially overinflated (functional residual capacity over 120% predicted) but not obstructed before the histamine challenge (P< 0.005). In these subjects C dyn and R1are normalized after inhalation of salbutamol.After fenoterol and terbutaline inhalation, obstruction of the large airways was not fully alleviated. In addition, these two drugs seemed not to affect the ventilatory asynchronism (C dyn alterations) in patients whose lungs had been overinflated before drug inhalation (C dyn again around 150% predicted).

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID