UMLS:C0029713 - FACTA Search

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Query: UMLS:C0029713 (immaturity)
4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fetuses of diabetic mothers who were exposed to excessive glucose show delayed maturation. Under these conditions, altered growth factor expression or signaling may have important regulatory influences. We examined the role of epidermal growth factor (EGF) in lung development and maternal diabetes in the rat. In order to evaluate the possible role of glucose for the expression of EGF and the growth of lung tissue, we performed in vitro studies with organotypic cultures of fetal alveolar cells obtained from control rats. Compared to pups of normal rats, the newborn rats of untreated diabetic rats had reduced body weight, but normal lung weight relative to body weight. The air:mesenchyme ratio and the average size of alveoli per mm(2) lung tissue were reduced. The immunoreactivity (IR) of EGF, which was quantified using a computerized image analysis system, appeared with increased intensity and was associated with a reduced intensity of surfactant protein A-IR. The only difference observed between pups of treated diabetic rats and controls was a decrease in the lung weight:body weight ratio. In organotypic cultures, the presence of 13 mmol/L glucose in the cell media increased immunoreactive staining against EGF, but decreased the incorporation of thymidine as compared to the results obtained with alveolar cells grown in a normophysiological concentration of glucose (3 mmol/L). Addition of EGF increased the thymidine incorporation only in cells grown in 3 mM glucose. These findings may indicate immaturity of the lungs of pups of untreated diabetic rats, and subtle alterations in the lungs of pups from treated diabetic rats. The results also suggest that glucose plays a role in the expression of EGF, and that cells exposed to high concentrations of glucose are less responsive to EGF.
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PMID:Epidermal growth factor and lung development in the offspring of the diabetic rat. 1063

A light microscopy study was carried out on 48 placentae. Seventeen placentae were obtained from non-diabetic mothers while the other 31 placentae were from both women with controlled diabetes and women who had an abnormality of the glucose tolerance test. All the women delivered at 38-40 weeks of gestation. Placentae from diabetic patients showed immaturity of the villi, hypertrophy of the capillaries and thickening of the basement membrane of the trophoblastic villi (3.2 +/- 0.35 microns) and the amniotic membrane (1.8 +/- 0.3 microns). Focal fibrinoid necrosis, an increase in the number of Hofbauer cells and dilatation of villi capillaries were also commonly observed in placentae from diabetic mothers, and the normal cuboidal cells lining the amniotic membrane tended to become tall columnar (17.6 +/- 6.3 microns) with distally located nuclei. Similar findings were observed in patients who had a potentially abnormal glucose tolerance test, which suggests the possibility of primary lesion in origin. Therefore, control of hyperglycemia may only partially prevent the development of placental abnormalities.
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PMID:Basement membrane thickening in the placentae from diabetic women. 1084 57

Prenatal diagnosis of amniotic fluid enables fetal maturity evaluation, particularly that of fetal lungs. The aim of the study is to evaluate the diagnostic value of on alpha-amylase/glucose index in amniotic fluid in comparison to routinely performed tests, used for prenatal fetal lung maturity evaluation, particularly in respect of PG concentration, whose predictive value is almost 100%. The study was carried out on 180 pregnant women, chosen by random selection, hospitalized in Polish Mother's Health Centre Hospital in the period from 15.06.1994 to 31.12.1995. 223 samples of amniotic fluid were tested- in all samples following assays and tests were performed: bubble stability test (BST), optical density, orange cells test, phosphatidylglycerol concentration (PG), glucose concentration, alpha-amylase activity urea and creatinine concentration. The alpha-amylase/glucose index in amniotic fluid is statistically significant with PG concentration. The value of the alpha-amylase/glucose index is < 6.0 when amniotic fluid assay indicates fetal immaturity, but when amniotic fluid assay indicates fetal maturity, its value is 36.0. The evaluation of fetal lung maturity on the basis of the alpha-amylase/glucose index multiply decreases the cost of examinations. Authors make a suggestion to implement this method in all hospital departments of the country.
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PMID:[Alpha-amylase/glucose index in amniotic fluid as a new method in prenatal assessment of fetal maturity]. 1175 81

The NADH shuttle system, which transports the substrate for oxidative metabolism directly from the cytosol to the mitochondrial electron transport chain, has been shown to be essential for glucose-induced activation of mitochondrial metabolism and insulin secretion in adult beta-cells. We examined the role of these shuttles in the fetal beta-cell, which is immature in being unable to secrete insulin in response to glucose. The activity and concentration of the two key enzymes of the NADH shuttles, mitochondrial glycerol phosphate dehydrogenase (mGPDH) and mitochondrial malate dehydrogenase (mMDH), were eight- and threefold lower, respectively, in fetal compared with adult rat islets. Likewise, mGPDH and mMDH activity was fivefold lower in islet-like cell clusters (ICCs) and sevenfold lower in purified beta-cells compared with adult islets in the pig. The low level of enzyme activity was a result of low gene expression of the mitochondrial enzymes in the fetal beta-cells. Increasing NADH shuttle activity by transduction of fetal rat islets with mGPDH cDNA enabled the fetal islets to secrete insulin when stimulated with glucose. We concluded that the immaturity of the NADH shuttles contributes to the inability of fetal beta-cells to secrete insulin in response to glucose.
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PMID:Role of NADH shuttles in glucose-induced insulin secretion from fetal beta-cells. 1235 38

Fetal pancreatic beta-cells release insulin poorly in response to glucose; however, the cellular mechanism for this is unknown. By using fura-2 to measure changes in the cytoplasmic free Ca(2+) concentration in beta-cells, we examined human/porcine fetal islet-like cell clusters (ICCs) and human adult islets for the presence of functional K(+)(ATP) and voltage-activated Ca(2+) ion channels. The effects of glucose, glyceraldehyde, leucine, KCl, and the channel effectors glipizide and BAY K8644 were studied. In fetal human/porcine ICCs and adult islets, KCl, glipizide, and BAY K8644 increased [Ca(2+)](i). Both glucose and glyceraldehyde increased [Ca(2+)](i) in islets but had no effect on ICCs. Leucine increased [Ca(2+)](i) in islets and porcine but not human ICCs. We hypothesize that the beneficial effect of leucine in fetal porcine, but not human ICCs, is attributable to time-dependent maturation of the beta-cells, because porcine ICCs examined were at 87% of the gestational period, and human ICCs were at 42%. Our data demonstrate that both K(+)(ATP) and voltage-activated Ca(2+) channels, required for glucose-stimulated increase in [Ca(2+)](i), are functional early in gestation. This suggests that the cause of the immaturity of fetal human/porcine beta-cells is at a more proximal step of glucose-induced metabolism than the channels on the cell surface.
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PMID:Insulin secretagogues, but not glucose, stimulate an increase in [Ca2+]i in the fetal human and porcine beta-cell. 1278 84

Twin fetuses experience much higher rates of perinatal mortality/morbidity than age- and weight-matched singletons. Across species, the prepartum increase in fetal plasma cortisol is responsible for maturing a number of systems in preparation for birth and the immediate postnatal period. In sheep, it is known that basal adrenocortical function is delayed in twins relative to singletons. Thus, it could be argued that relative immaturity in twins may explain their increased susceptibility to stress in the perinatal period and their relatively poor perinatal outcome. However, whether adrenocortical responsiveness to stress is also diminished in the twin fetus and whether the fetal cardiovascular, metabolic and endocrine defences to acute stress are comparatively weak in the twin fetus is unknown. This study investigated the effect of twinning on adrenocortical responsiveness to either the physiological stress of acute hypoxaemia or to an exogenous ACTH test, and on the fetal cardiovascular, metabolic and endocrine responses to acute hypoxaemic stress. Twenty Welsh Mountain sheep fetuses were chronically instrumented (1-2% halothane) at 121 +/- 3 days of gestation (term is ca 145 days) with amniotic and vascular catheters and with a transit-time flow probe around a femoral artery. The animals were divided into two groups based upon fetal number (singletons, n= 10; twins, n= 10), as determined at surgery. At 130 +/- 2 days, a 1 h episode of acute, isocapnic hypoxaemia (to reduce carotid P(O(2)) to 12 +/- 1 mmHg) was induced in all fetuses by reducing the maternal inspired O(2) fraction (F(IO(2)); 9% O(2) in N(2)). Fetal cardiovascular variables were recorded at 1 s intervals throughout the experimental protocol and arterial blood samples taken at appropriate intervals for biophysical (blood gases, glucose, lactate) and endocrine (catecholamines, vasopressin, cortisol, ACTH) measures. At 133 +/- 2 days a 2.5 microg bolus dose of synthetic ACTH (Synacthen; Ciba Pharmaceuticals, UK) was injected i.v. into eight of the singleton and six of the twin fetuses to determine adrenocortical steroidogenic sensitivity to exogenous ACTH. Under basal conditions, twins had lower plasma cortisol concentration, arterial blood pressure and femoral blood flow relative to singleton fetuses. Twins responded to acute hypoxaemia with similar pressor and vasopressor responses compared to singleton fetuses. However, the rate pressure product, an index of myocardial work, tended to decrease during hypoxaemia in twins, in contrast to the increase observed in singletons. Similar increases in the fetal plasma concentrations of ACTH, AVP, noradrenaline and adrenaline were observed during hypoxaemia in both groups; however, both the increments in fetal plasma concentration of cortisol in response to acute hypoxaemia and to exogenous ACTH were blunted in twins relative to singletons. This study shows that basal adrenocortical function as well as adrenocortical responsiveness is blunted in the twin relative to the singleton fetus. Further, the mechanism for adrenocortical blunting resides at the level of the adrenal cortex rather than higher up the axis. Relative adrenocortical immaturity in the twin fetus may reflect a specific endocrine adaptation to prolong gestation in multiple ovine pregnancies; however, such an adaptation does not affect the cardiovascular, metabolic or endocrine defence responses to acute hypoxaemia in the twin fetus.
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PMID:Adrenocortical responsiveness is blunted in twin relative to singleton ovine fetuses. 1507 82

Morbidity and mortality of preterm neonatal calves are higher than of calves born at normal term, possibly and in part due to immaturity of physiological functions. Physiological parameters were therefore studied during the first week of life in seven preterm calves, born on day 277 of gestation after dams were injected prostaglandin F2alpha and flumethason. Calves were fed colostrum of the first milking for the first 3 days and from day 4 to day 7 the same colostrum diluted with milk replacer. Body weight increased during the first week of life by 2.2 kg. Heart rate and respiratory rate were always relatively high, whereas values of rectal temperature, blood gases, haematological, metabolic and endocrine traits were in the range and behaved similarly as is the experience in full-term neonatal calves. Major exceptions were glucose and insulin, the concentrations of which barely rose postprandially, and growth hormone, the responses of which to growth hormone releasing factor analogue 1-29 were extremely variable and in part very small. In conclusion, calves born 2 week before normal term that survived the first week of life, although physiologically immature, were well able to handle ingested nutrients and to control their metabolism.
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PMID:Physiological traits in preterm calves during their first week of life. 1537 20

Nuclear transfer in cattle has been shown to cause a high frequency of conceptus loss, excessive accumulation of allantoic fluid, increased birth weight as well as peri- and neonatal deaths. The aims of this preliminary study were to investigate the in vivo development of embryos and fetuses produced by a novel somatic cell cloning method, denominated handmade cloning (HMC), and to characterize the premature calves delivered by Caesarian section. Twenty-five day 7 fresh embryos including seven blastocysts produced by aggregation of two day 4 embryos, and seven vitrified embryos were transferred to synchronized Holstein-Friesian heifers. Embryos produced by aggregation had higher in vivo developmental competence than single embryos (67% versus 38% pregnancy rate on day 28). On days 28, 42, 63 and 250 after estrus, 12 (48%), 5 (20%), 3 (12%) and 2 (8%) recipients of fresh embryos remained pregnant, while 1 recipient of a vitrified embryo was pregnant. One recipient was euthanized due to development of hydrallantois. Caesarian sections were performed on the remaining three recipients on days 252 or 259. The premature calves weighed 60 kg, 47 kg and 45 kg, respectively, and displayed increased weights of body, heart, liver, kidneys, thyroid glands and increased size of placentomes. Furthermore, they had reduced respiratory function, hypoxia, acidosis and altered glucose metabolism. In conclusion, these preliminary data show that handmade somatic cell cloning resulted in an overall delivery rate of 9%, one case of hydrallantois (3%), oversized placentomes and fetuses, disproportionate growth of several internal organs and metabolic immaturity of the premature calves.
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PMID:Clinical experience with embryos produced by handmade cloning: work in progress. 1583 62

Restriction of protein calories during stages of immaturity has a major influence on glucose metabolism and increases the risk of type 2 diabetes in adulthood. However, it is known that reduction of food intake alleviates insulin resistance. We previously demonstrated an improved insulin-induced glucose uptake in skeletal muscle of chronically undernourished adult rats. The purpose of this work was to investigate whether this condition is present during suckling, a period characterized by physiological insulin resistance as well as elucidate some of the underlying mechanisms. With this aim, 10-d-old pups from food-restricted dams were studied. We showed that undernourished suckling rats are glucose normotolerants, despite their depressed insulin secretion capacity. The content of the main glucose transporters in muscle, GLUT-4 and GLUT-1, was not affected by undernutrition, but fractionation studies showed an improved insulin-stimulated GLUT-4 translocation. p38MAPK protein, implicated in up-regulation of intrinsic activity of translocated GLUT-4, was increased. These changes suggest an improved insulin-induced glucose uptake associated with undernutrition. Insulin receptor content as well as that of both regulatory and catalytic phosphoinositol 3-kinase subunits was increased by food restriction. Insulin receptor substrate-1-associated phosphoinositol 3-kinase activity after insulin was enhanced in undernourished rats, as was phospho-glycogen synthase kinase-3, in line with insulin hypersensitivity. Surprisingly, protein tyrosine phosphatase-1B association with insulin receptor was also increased by undernutrition. These adaptations to a condition of severely limited nutritional resources might result in changes in the development of key tissues and be detrimental later in life, when a correct amount of nutrients is available, as the thrifty phenotype hypothesis predicts.
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PMID:Maternal food restriction enhances insulin-induced GLUT-4 translocation and insulin signaling pathway in skeletal muscle from suckling rats. 1590 22

Mortality from cancer of the prostate is increasing in the Asia-Pacific, when much of this region is undergoing a transition to a Western lifestyle. The role that lifestyle factors play in prostate cancer appears limited, but existing data mainly are from the West. We conducted an individual participant data analysis of 24 cohort studies involving 320,852 men (83% in Asia). Cox proportional hazard models were used to quantify associations between risk factors and mortality from prostate cancer. There were 308 deaths from prostate cancer (14% in Asia) during 2.1 million person-years of follow-up. The age-adjusted hazard ratio (95% confidence interval; CI) for men with body mass index (BMI) 28 kg/m2 or more, compared with below 25, was 1.55 (1.12 - 2.16); no such significant relationship was found for height or waist circumference. The BMI result was unchanged after adjustment for other variables, was consistent between Asia and Australia/New Zealand (ANZ) and did not differ with age. There was no significant relationship with diabetes, glucose or total cholesterol (p > or = 0.18). Smoking, alone, showed different effects in the two regions, possibly due to the relative immaturity of the smoking epidemic in Asia. In ANZ, the multiple-adjusted hazard ratio for an extra 5 cigarettes per day was 1.12 (95%CI: 1.03 - 1.22), whereas in Asia it was 0.77 (0.56 - 1.05). Body size is an apparently important determinant of prostate cancer in the Asia-Pacific. Evidence of an adverse effect of smoking is conclusive only in the predominantly Caucasian parts of the region.
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PMID:The impact of modifiable risk factors on mortality from prostate cancer in populations of the Asia-Pacific region. 1769 31

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