Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Response of the fetal kidney to metabolic acidosis was studied in five fetal lambs, 115-125 days gestation, in order to evaluate the renal contribution to elimination of hydrogen ion during intra-uterine development. Experiments were conducted on healthy unanesthetized fetuses, intact in utero, with catheters implanted at hysterotomy into a fetal femoral artery and vein and into the bladder via the urachus, four or more days prior to the study. A metabolic acidosis was induced by infusion of isotonic lactic acid, 15 m mole/kg, intravenously over a period of 90 minutes. Serial arterial samples were taken and urine collected in fractions before, during and for three hours following the infusion, for measurements of pH, bicarbonate, lactate and electrolytes as well as urine output. During the infusion, urine pH fell from 6.65 to 6.25 and was 6.34 three hours later (Figs. 1 to 4, Tabs. III to IV). Lactic acid infusion caused a prompt increase in urine output from a mean rate of 0.12 to a maximum of 0.28 ml/kg/min at the end of the infusion, returning to control rates three hours later. Lactate excretion increased from 0.05 to a maximum of 4.6 mumole/kg/min at the end of infusion; titratable acid increased from 0.22 to a maximum of 4 muEq/kg/min; the rates of excretion of lactate and titratable acid were still higher than control at the end of three hours. Ammonia excretion increased from 0.21 to a maximum of 0.56 muEq/kg/min three hours after the end of infusion. The acid infusion caused a small but significant fall in excretion of bicarbonate. During the 90 minutes of infusion and over the following three hours, about 800 mumole lactate was excreted while net acid excretion over the same period was no more than half that amount. The diuresis was also accompanied by a net loss of sodium and chloride, the excretion of these ions increasing more than threefold following acid infusion; excretion of potassium decreased to one-third its rate prior to the infusion. During the 90 minutes of infusion, blood pH fell from 7.36 to 7.13, base deficit rose from 3.8 to 16.4 mEq/L and lactate rose from 2.2 to 14.8 mM/L; there was also a small but significant rise in both blood PCO2 and PO2 (Figs. 1 to 2, Tabs. I to II). During the following three hours of recovery, pH rose gradually to 7.29, base deficit and lactate fell to 7.4 mEq/L and 8.7 mM/L respectively. Since renal excretion of net acid and lactate was small, the decrease in blood base deficit and lactate levels during the recovery must therefore be mainly due to equilibration in various fetal compartments as well as placental transfer. These experiments indicate that, in the lamb fetus, intact in utero, the kidney although limited by immaturity of several mechanisms, is capable of responding to an acid load and thus can make a small contribution to fetal homeostasis. The increase in excretion of net acid is accompanied by loss of sodium and chloride in the urine.
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PMID:Renal response to acid loading in the developing lamb fetus, intact in utero. 0 Apr 79

The 24-hr LD50 of colchicine in newborn rats is 0.24 mg/kg, which is about 1/10 that observed in the adult. The 24-hr LD50 of colchicine was relatively constant in rats over 25 days of age. In an attempt to determine the mechanism of the increased sensitivity of the newborn rat to the toxic action of colchicine, the distribution of 3H after the administration of 3H-colchicine (0.1 mg/kg) was measured in 10- and 35-day-old rats. The concentration of 3H was higher in all tissues of the newborn than the adult after ip administration, suggesting an immaturity in the pathway for colchicine elimination. After iv administration, radioactivity disappeared much more slowly from the plasma of the newborn rat than from the adult. This was due to a lower capacity of the liver of the newborn to concentrate colchicine and to excrete it into the bile. Development of the hepatic excretory mechanism responsible for excretion of colchicine occurred at the same age as did the increase in LD50. These results suggest that colchicine is more toxic in the newborn because the drug remains in the body for a longer time due to immaturity of the liver excretory process.
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PMID:Biliary excretion of colchicine in newborn rats. 0 Dec 30

Lesional pulmonary edema caused by substances which are directly caustic for the gastrointestinal pathways (strong acids and bases, inhaled vomit) are opposed by their immediate and long-term gravity with those due to cardiotropic medicamentatous toxins or volemic overloading which lead to curable pulmonary edema. Material and human factors, in favour of accidental intoxication are compensated for by the fact that many toxins produce vapours which are strongly irritant for the upper respiratory pathways: this prevents prolonged exposure and therefore wards off edema. Drug intoxication by ingestion can lead to pulmonary edema by relative or absolute volemic overload, by allergic accidents or by immaturity of the enzyme degradation systems. It seems to us that the notions of "neurological" and "metabolic" toxic edema should be abandoned. In lesional edema the treatment is that of the acute respiratory failure. The combination of pethidine, promethazine, and chlorpromazine gives good immediate results. Owing to careful follow-up, hemodynamic pulmonary edema should most frequently be avoided.
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PMID:[Nonhemodynamic pulmonary edema due to toxins]. 0 74

Gastric acid secretion was measured in 20 infants aged 6-438 days. The values for the basal acid output and that after stimulation with 6 mug/kg pentagastrin subcutaneously were found to be related to age, body weight and body surface area. But these correlations were not comparable to those in adults. Standard values for different age groups in childhood must therefore be established. Furthermore, the results indicate parietal-cell immaturity during the first six months of life. Measurement of fasting serum-gastrin concentration by radioimmunoassay in 74 infants, aged 1-438 days, and 154 adults as controls revealed a high serum-gastrin level in infants, with an exponential decrease during the first year of life. Despite comparable pH values in gastric juice at one year of life, the gastrin concentrations were higher than those in adults (at a statistically significant level). On the other hand, normal serum-gastrin concentrations were found in ten pregnant women just before delivery. The results suggest a negative feed-back mechanism between gastric-acid secretion and fasting serum-gastrin levels, but such mechanism probably being limited by extragastric gastrin secretion.
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PMID:[Serum-gastrin levels and gastric-acid secretion in infants (author's transl)]. 1 82

The direction of differentiation of the stem cells with respect to the physiological activity of thymus determined by the age of an animal was studied by means of histological analysis of hemopoietic colonies in the spleen of lethally irradiated mice. The immaturity of thymus of its involution are characterized by the inhibition of differentiation of the stem cell along the granuloid path. An analysis of the data on differentiation of the stem cells in mice of different age, as well as in thymectomized mice allows to draw a conclusion that the process of differentiation of the hemopoietic stem cells is thymus-dependent.
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PMID:[Relationship between hematopoietic stem differentiation and the functional state of the thymus]. 2 66

The role of the medullary H+-sensitive chemoreceptors on the drive of breathing was studied in 10 unanesthetized newborn animals (8 lambs and 2 kids). The experiment consisted of sequential measurements of ventilation (VE) during a progressive change in the arterial pH (pHa) and in the pH of the cisternal cerebrospinal fluid (pHCSF), induced by intravenous infusion of hydrochloric acid (HCl) followed after an 8-h steady state of acidosis by rapid bicarbonate [HCO3-] infusion. It is shown that a rapid change in [HCO3-]CSF occurs during the infusion of HCl or NaHCO3. As a consequence both CSF and arterial pH change in the the same direction and large changes in pHCSF (from 7.331 to 7.227) were observed. Such CSF acidosis did not contribute to further increase VE beyond the level by hyperventilation induced by the initial fall of pHa. The ventilatory response to the decrease in pHa was found to fall off with moderate to severe acidosis (pHa less than 7.20). In conclusion, this study demonstrates an instability of the pHCSF during neonatal metabolic acidosis and it suggests an immaturity of both the H+-sensitive medullary and peripheral chemoreceptors in the 8-day-old newborns.
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PMID:Central chemical regulation of respiration in term newborn. 4 60

A polygraphic study of the states of vigilance in the young chicken was performed in the first week after hatching. At hatching, three stages of vigilance were present and their polygraphic characteristics were similar to those of the adult. Quantitative data showed a relative immaturity of the young chicken since percentages of paradoxical sleep and slow wave sleep were high in the first 8 h after hatching (PS/TS equals 16.5%). These values diminished rapidly and reached the adult values observed on the third day (PS/TS equals 6.4%). Our experimental conditions showed the presence of a nycthemeral rhythm of the states of vigilance by the third day.
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PMID:[Polygraphic study of sleep in young chickens at hatching, evolution at third and fourth days]. 4 8

A specific antiandrogenic steroid cyproterone acetate was administered daily to mice of three different inbred strains starting from the day of birth until the age of 30 days. The total dose per mouse was 17.2 mg. This treatment resulted in developmental retardation which was manifested in a number of ways: at the age of 30 days, the weight of the body was well as spleen, testes and particularly thymus was significantly reduced; histologically, the normal proportion of the red and white pulp in the spleen was changes; spermatogenesis (but not oogenesis) was markedly retarded corresponding to the age of 12-15 days in normal males; also skin displayed a persisting immaturity as reflected by an abundance of mast cells. Minor signs of toxic changes were seen in the liver. Skin grafts from CA-pretreated donors had a subnormal immunogenicity; when transplanted across the MSA-barrier, they survived significantly longer than control grafts and about 23% took. Significantly prolonged survival was also observed with H-3 incompatible skin grafts from CA-pretreated donors, particularly from male donors. Across the barrier dicated, but did not reach a level of significance. The present study extends our previous observations concerning the androgen dependence of a normal immunogenic expression of H-antigens. The antiandrogenic effect of CA is comparable to the more complex effect of neonatal orchiectomy in terms of the subnormal immunogeneity of MSA-incompatible skin grafts from 30-day-old males which seems to be arrated at a stage typical for 1-2-day-old normal males.
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PMID:Retardation of development including immunogenic expression of histocompatibility antigens in mice--by postnatal administration of antiandrogenic steroid. 4

The authors analyzed 50 cases of foetal hypotrophy using morphological methods. In the introduction of their paper they reviewed findings reported in the literature on placental causes and briefly also data on the sequelae of foetal hypotrophy for the foetus. Bioptic examination of the placenta can help to differentiate between foetal hypotrophy and immaturity. In foetal hypotrophy of placental origin it is important to differentiate between a primarily hypoplastic placenta (associated sometimes with congenital malformations of the foetus) and secondary insufficient placentas due to impaired uteroplacental circulation or other causes. In some instances both basic disorders may combine.
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PMID:[Placenta and hypotrophy of the fetus]. 5 Jan 44

Maternal age and parity, according to the findings of the Inter-American Investigation of Mortality in Childhood, have a direct relationship to the health and survival of the infant. Among the results of this broad undertaking are data suggesting that babies born close in succession, especially within large families and as birth order ascends, are at greater risk of dying. Also, the offspring's future is increasingly threatened as the mother's age tends toward the extremes of the childbearing years. Compromise of the mother's health, in turn, was indicated in the earlier Investigation, a study of deaths in adults, which revealed unexpectedly high maternal mortality in the Latin American cities that it covered. Immaturity, or low birthweight, and malnutrition emerged as the two major underlying or associated causes of death in the Latin American projects of the Inter-American Investigation of Mortality in Childhood. Despite the marked variations in the data available from the different areas, there appeared to be some correlation between these two indicators of deficits in growth and development. Mortality due to immaturity was especially high for babies of young mothers, with increases occurring as the birth order rose. Not only are the risks greater for mothers having low-weight babies when they are young (under 20), but they increase even more with the second, third, and fourth products when the birth intervals become shorter. Maternal age, birth order, and birthweight are factors that must be considered in combination in the programming of protective health measures.
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PMID:Results of the Inter-American Investigations of Mortality relating to reproduction. 6 75


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