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)

Nutritional management of infants and children differs from that of adults because of the extra requirements for growth and the limitations of physiological immaturity. Although parenteral nutrition (PN) is an accepted practice and a potentially life-saving therapy for pediatric patients who cannot be fed through their gastrointestinal tract, it is associated with the risk of serious metabolic, mechanical, and infectious complications. Candidates for PN should be selected according to well-defined indications, with initial nutritional assessment and with careful attention given to fluid, electrolyte, vitamin, trace element, and caloric requirements. Total calories should be administered so that the nonprotein-calorie to gram-nitrogen ratio is in the range of 150 to 250:1. Although short-term supplemental nutritional support can be administered through a peripheral vein, long-term total PN is best delivered by central venous access. PN should be initiated and monitored in accordance with well-established protocols. The lowest complication rate and highest cost-effectiveness are achieved by an interdisciplinary team that includes one or more nurses, dietitians, pharmacists, and physicians. The development of safe, reliable, and miniaturized intravenous pumps with built-in monitors has made home parenteral nutrition possible and desirable in selected patients.
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PMID:Intravenous nutrition for the pediatric patient. 134 90

It has been shown that human umbilical cord blood contains stem/progenitor cells comparable in number to that of adult bone marrow. We report here the first successful cases of transplantation of umbilical cord blood cells. The patients were suffering from Fanconi's anemia, complicated by severe aplastic anemia. During pregnancy, it was shown that the mother was carrying a sibling unaffected by the disease and with HLA identical to the patient. Cord blood was collected and frozen in liquid nitrogen at birth. After conditioning with low-dose cyclophosphamide (20 mg/kg) and thoraco-abdominal irradiation (5 grays), the patients received a cord blood transplant of thawed cells. Three patients have been transplanted without any immediate side-effect. One has not enough follow-up, but two patients are alive and well with complete donor hematologic reconstitution and no chronic graft versus host disease. Potential developments of this technique are an extension of applicability with regard to other diseases that might be transplanted and whether such transplants can be performed in adults. The relative immaturity of the lymphoid system at birth may be advantageous in decreasing the graft versus host reaction if these cells are used in a mismatched transplantation. Cord blood cell banks may be useful for transplants in patients lacking an HLA-identical donor.
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PMID:Transplantation of umbilical cord blood in Fanconi's anemia. 198 24

In a randomized, prospective study the response of serum urea concentration to different protein intakes was studied in two groups of preterm infants with different gestational ages on the 8th and the 21st day of life. 16 very-low-birth-weight (VLBW) infants (GA: 29-31 weeks) and 17 low-birth-weight (LBW) infants (GA: 31-33 weeks) were fed either with fresh human milk or with fortified human milk. The protein intake varied between 2.1 and 3.3 g/kg/day. On the 8th day of life the VLBW infants did not respond to higher protein intakes by increased serum urea concentrations, although a clear correlation was found between protein intake and serum alpha-amino-nitrogen concentrations in these infants. The more mature LBW infants responded to a high protein intake by increased serum urea concentrations on the 8th day of life. On the 21st day of life protein intake correlated to both serum urea and alpha-amino-nitrogen concentrations in all infants studied. These findings are consistent with a somewhat limited capacity of the immature infant for expansion of urea production for some time after birth. This immaturity should be considered when metabolic responses to protein intake are studied and evaluated in such infants.
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PMID:Evidence for functional immaturity of the ornithine-urea cycle in very-low-birth-weight infants. 306 18

A prospective renal ultrasound study of 134 newborns (49 prematures weighing less than 2500 g and 85 more mature babies) was undertaken to investigate factors associated with increased renal cortical echogenicity (RCE). Increased RCE was seen in 39 (29 per cent) babies. It was significantly related to body weight, age, medical status, blood urea nitrogen, and serum creatinine. In view of the interdependence of these factors, however, multivariate analysis was performed, which revealed that age was the most important factor associated with increased echogenicity (r = -0.46), and the other factors had only small independent effects, increasing the multiple r to 0.56. The authors conclude that an infant's immaturity is the most important determinant of increased RCE.
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PMID:Factors associated with renal parenchymal echogenicity in the newborn. 353 33

In a comparative study of the lactational performance of 11 adolescent and 11 adult breast-feeding mothers from the US, adolescents were found to produce significantly less milk and lactate for a significantly shorter period of time than their adult counterparts. All subjects were assessed at 6-24 weeks postpartum. The adolescents produced 37% and 54% less milk at 6 and 24 weeks postpartum, respectively, than adult women. These differences in milk production were significant even when adjusted for differences in the frequency and duration of breast feeding episodes and use of supplementary feeds. The amount of dietary energy the infants of adolescents received from human milk alone was clearly inadequate, at every time point, to support normal growth rates. In both groups, the average frequency of nursing episodes during the first 12 weeks postpartum was 7 or more per 24 hours (consistent with current recommendations for adequate lactation); adolescents, however, spent significantly less time nursing and provided greater quantities of supplementary feeds. While all adult women breast-fed throughout the study period, 20% of adolescents had stopped breast feeding by 12 weeks, 50% weaned by 18 weeks, and 64% had discontinued breast feeding by 24 weeks. Unexpectedly, the energy, lactose, fat, total nitrogen, protein nitrogen, nonprotein nitrogen, sodium, potassium, calcium, and phosphorous concentrations showed little difference between the two age groups. The absence of data from the first 6 weeks of life makes it impossible to rule out a role for early formula supplementation in the decreased milk production of adolescents. It is believed,however, that adolescents may be biologically incapable of producing a full complement of milk because of their developmental immaturity.
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PMID:Lactational performance of adolescent mothers shows preliminary differences from that of adult women. 917 81

There is increasing evidence to suggest that insulin-like growth factors (IGF) I and II play a crucial role in fetal lung development. Expression of IGF-I and II has been demonstrated to be predominant during fetal life and decreases prior to birth. Antenatal glucocorticoids are reported to improve lung immaturity. The aim of this study was to investigate the effect of antenatal glucocorticoid administration on IGF-I and II expression in nitrofen-induced congenital diaphragmatic hernia (CDH) in rats. A CDH model was induced in pregnant rats following administration of 100 mg nitrofen on day 9.5 of gestation (term = 22 days). Dexamethasone (0.25 mg/kg) was given intraperitoneally on days 18.5 and 19.5 of gestation. Cesarean section was performed on day 21. The fetuses were divided into three groups: I, normal controls; II, nitrofen-induced CDH; and III, nitrogen-induced CDH with antenatal dexamethasone treatment. mRNA was extracted from whole lung and a reverse transcription-polymerase chain reaction (RT-PCR) was performed to evaluate the relative amounts of IGF I and II mRNA. Levels of mRNA were expressed as a ratio of the band density divided by that of beta-actin, a housekeeping gene known to be expressed at a constant level. Immunohistochemistry using anti-rat IGF I and II antibody was also performed in each group. Levels of IGF I mRNA were significantly increased in group II (0.50 +/- 0.08) compared to group I (0.34 +/- 0.10) or group III (0.32 +/- 0.06) (P < 0.05). Levels of IGF II mRNA were also significantly increased in group II (0.95 +/- 0.20) compared to group I (0.42 +/- 0.07) or group III (0. 31 +/- 0.09) (P < 0.05). Strong IGF I and II expression was observed in the hypoplastic CDH lung (group II), mainly in the bronchiolar epithelium. IGF I and II expression in group I and III lungs was either absent or weak. The finding of significant reductions in IGF I and II mRNA and protein levels in dexamethasone-treated CDH lung suggest that dexamethasone may accelerate the fetal stage of lung development.
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PMID:Effect of antenatal glucocorticoid administration on insulin-like growth factor I and II levels in hypoplastic lung in nitrofen-induced congenital diaphragmatic hernia in rats. 1037 16

Although extensive data are available on the impact of nutrient and protein administration on growth, plasma amino acids, and nitrogen balance in the newborn and growing infants, relatively few studies have carefully examined the dynamic aspects of protein metabolism in vivo and particularly in the micropremie or ELBW infant. These studies show that the very preterm infants, either because of immaturity or because of the intercurrent illness, have high rates of protein turnover and protein breakdown. This high rate of proteolysis is not as responsive to nutrient administration. Intervention strategies aimed at promoting nitrogen accretion, such as insulin, human growth hormone, or glutamine, have not thus far resulted in enhanced protein accretion and growth. This may be, in part, due to limitations in delivery of adequate calorie and nitrogen.
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PMID:Protein metabolism in the extremely low-birth weight infant. 1069 May 63

The pathogenesis of necrotizing enterocolitis (NEC) presumptively is due to an inappropriate intestinal epithelial immunologic response of immature gut to luminal stimuli. Glutamine is essential for intestinal crypt cell proliferation and enhances the cellular response to growth factors. We aimed to test the hypothesis that the supplementation of enteral feedings with glutamine may stimulate an immature intestine and decrease the intestinal inflammatory change in NEC. Immediately after birth, the neonatal rats were weighed and randomized into one of four treatment groups. Group 1 consisted of rats whom were breast-fed. Group 2 (NEC group) consisted of neonates whom were fed with a special rodent formula. Rats in groups 3 and 4 were fed in a similar fashion to those in group 2, and glutamine 0.3 mg/kg per day and dexamethasone 0.5 mg/kg per day were added to their formula, respectively. The neonatal rats were weighed and killed on day 4: the last 4 cm of terminal ileum was harvested for morphological studies and detection of nitrite and nitrate levels in tissue. The animals in the NEC group showed various degrees of inflammatory changes similar to clinical NEC. The inflammatory changes of the intestine appeared to be attenuated in both glutamine- and steroid-treated animals compared to those in the NEC group. Only steroid treatment decreased the tissue levels of these nitrogen oxides that were increased in rats in the NEC group. We herein provide evidence that maturational agents such as glutamine and dexametasone can attenuate the local intestinal inflammatory damage in experimental NEC. These findings support the hypothesis that the gut immaturity in premature infants represents a risk factor for NEC.
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PMID:Enteral glutamine supplementation and dexamethasone attenuate the local intestinal damage in rats with experimental necrotizing enterocolitis. 1455 27

Fusarium verticillioides, a fungal pathogen of maize, produces fumonisin mycotoxins that adversely affect human and animal health. Basic questions remain unanswered regarding the interactions between the host plant and the fungus that lead to the accumulation of fumonisins in maize kernels. In this study, we evaluated the role of kernel endosperm composition in regulating fumonisin B1 (FB1) biosynthesis. We found that kernels lacking starch due to physiological immaturity did not accumulate FB1. Quantitative polymerase chain reaction analysis indicated that kernel development also affected the expression of fungal genes involved in FB1 biosynthesis, starch metabolism, and nitrogen regulation. A mutant strain of F. verticillioides with a disrupted a-amylase gene was impaired in its ability to produce FB1 on starchy kernels, and both the wild-type and mutant strains produced significantly less FB1 on a high-amylose kernel mutant of maize. When grown on a defined medium with amylose as the sole carbon source, the wild-type strain produced only trace amounts of FB1, but it produced large amounts of FB1 when grown on amylopectin or dextrin, a product of amylopectin hydrolysis. We conclude that amylopectin induces FB1 production in F. verticillioides. This study provides new insight regarding the interaction between the fungus and maize kernel during pathogenesis and highlights important areas that need further study.
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PMID:Amylopectin induces fumonisin B1 production by Fusarium verticillioides during colonization of maize kernels. 1647 53

Cerebral white matter injury, characterised by loss of premyelinating oligodendrocytes (pre-OLs), is the most common form of injury to the preterm brain and is associated with a high risk of neurodevelopmental impairment. The unique cerebrovascular anatomy and physiology of the premature baby underlies the exquisite sensitivity of white matter to the abnormal milieu of preterm extrauterine life, in particular ischaemia and inflammation. These two upstream mechanisms can coexist and amplify their effects, leading to activation of two principal downstream mechanisms: excitotoxicity and free radical attack. Upstream mechanisms trigger generation of reactive oxygen and nitrogen species. The pre-OL is intrinsically vulnerable to free radical attack due to immaturity of antioxidant enzyme systems and iron accumulation. Ischaemia and inflammation trigger glutamate receptor-mediated injury leading to maturation-dependent cell death and loss of cellular processes. This review looks at recent evidence for pathogenetic mechanisms in white matter injury with emphasis on targets for prevention and treatment of injury.
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PMID:Pathogenesis of cerebral white matter injury of prematurity. 1829 74


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