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

1. Young Wistar rats were used as an experimental model to determine the effects of protein-energy malnutrition on glucose tolerance and insulin release. 2. Malnourished rats presented some of the features commonly found in human protein-energy malnutrition, such as failure to gain weight, hypoalbuminaemia, fatty infiltration of the liver and intolerance of oral and intravenous glucose loads. 3. The rate of disappearance of glucose from the gut lumen was greater in the malnourished rats but there was no significant difference in portal blood glucose concentration between normal and malnourished rats 5 and 10 min after an oral glucose load. 4. Insulin resistance was not thought to be the cause of the glucose intolerance in the malnourished animals since these rats had a low fasting plasma insulin concentration with a normal fasting blood glucose concentration and no impairment in their hypoglycaemic response to exogenous insulin administration. Furthermore, fasting malnourished rats were unable to correct the insulin-induced hypoglycaemia despite high concentrations of hepatic glycogen. 5. Malnourished rats had lower peak plasma insulin concentrations than normal control animals after provocation with oral and intravenous glucose, intravenous tolbutamide and intravenous glucose plus aminophyllin. This was not due to a reduction in the insulin content of the pancreas or potassium deficiency. Healthy weanling rats, like the older malnourished rats, had a diminished insulin response to intravenous glucose and intravenous tolbutamide. However, their insulin response to stimulation with intravenous glucose plus aminophyllin far exceeded that of the malnourished rats. Thus the impairment of insulin release demonstrated in the malnourished rats cannot be ascribed to a 'functional immaturity' of the pancreas.
Clin Sci Mol Med 1976 Mar
PMID:Glucose tolerance and insulin release in malnourished rats. 81 69

In the adult mammalian lung, Ia+ dendritic cells (DC) constitute a significant population of immunologically potent accessory cells that are important in the regulation of immune responses to inhaled antigens. The newborn, in most species, displays an increased susceptibility to sensitization by inhaled antigens; whether an immaturity of pulmonary accessory cells is involved has not been determined. In the present study, the ontogeny and function of these cells were examined in fetal and newborn rats. Cells identified as DC in fetal and newborn rat lungs were Ia+, C11b+/-, OX41-, OX43-, W3/13-, W3/25-, and OX8-. They were characterized ultrastructurally by an eccentric, lobulated nucleus, a paucity of lysosomes, delicate cytoplasmic processes, and abundant membrane-associated Ia. Ia+ DC were first detected within the pulmonary mesenchyme at day 15 and by day 17 of gestation they were also present within the epithelium lining airways. The appearance of Ia+ DC preceded the migration of either T4 or T8 subclasses of T cells to the lung, the latter becoming significant only after birth, when the newborn was exposed to environmental antigens. In none of the fetal or newborn animals was Ia detected on alveolar type II cells. The accessory cell function of rat pulmonary DC, isolated from fetuses at 20 and 21 days of gestation and from newborns, was tested by an autologous mixed leukocyte reaction. At 20 and 21 days of gestation, pulmonary DC were 40 and 60% as effective, respectively, in stimulating cell proliferation in purified autologous adult splenic T cells as those isolated from adults.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1992 Mar
PMID:Ontogeny of Ia+ accessory cells in fetal and newborn rat lung. 154 Mar 99

Electron microscopic observations of an originally established mouse mastocytoma cell line (BSP-MST-2) revealed that the cytoplasm of many of the MST-2 cells contained small and low osmiophilic granules and a few mature electron-dense granules. Fluorescent- and immuno-histochemical examinations also suggested the immaturity of granules as the cytoplasmic reaction for serotonin (5-HT) was weak. Induction of further maturation of granules was investigated by administration of various chemical agents. Among the chemicals examined, sodium butyrate and hydrocortisone were effective. In the presence of 1 mM sodium butyrate for 24 h, the cytoplasmic granules contained an abundant dense matrix. MST-2 cells incubated with hydrocortisone at 5 micrograms/ml for 24 h showed a somewhat different granulopoietic pattern from those incubated with sodium butyrate, including numerous electron-dense progranules. Fluorescent- and immuno-histochemical studies showed increased reactions of cytoplasmic 5-HT of both butyrate- and hydrocortisone-treated MST-2 cells. The specificity of these morphological and cytochemical changes was confirmed by treatment with reserpine, a drug which depletes cellular 5-HT; electron-dense materials were virtually diminished and cytochemical reactions were significantly decreased. The mode of induced production of 5-HT in mastocytoma granules is discussed, in relation to mastocyte differentiation.
Virchows Arch B Cell Pathol Incl Mol Pathol 1987
PMID:Induction of granulopoiesis of mastocytoma cells: ultrastructural and cytochemical studies on production of serotonin in a cultured mouse mastocytoma cell line. 288 33

1. After reaching its final destination the GnRH neuronal network develops under the influence of both excitatory and inhibitory inputs. 2. In the first 2 weeks of life, the immaturity of the GnRH neuronal system is reflected in sporadic unsynchronized bursts of the decapeptide, which determine the pattern of serum gonadotropin levels observed in female rats: high FSH levels and transient bursts of LH. The main inhibitory neuronal systems that operate in this period are the opioid and dopaminergic systems. A decrease in their inhibitory effectiveness may not be sufficient correctly to activate and synchronize the GnRH neuronal system. 3. There is a concomitant increase in excitatory inputs, mainly noradrenaline, excitatory amino acids, and NPY, which increase the synthesis and release of GnRH at the beginning of the juvenile period and participate in the coupling of GnRH neural activity to the ongoing rhythmic activity of a hypothalamic circadian oscillator. 4. The morphological changes of GnRH neurons which take place during the third and fourth weeks of life, and which are probably related to increasing estradiol levels, reflects the increasing complexity of the GnRH neuronal network, which establishes synaptic contacts to enable the expression of pulsatility and of the positive feedback of estradiol, both necessary components for the occurrence of puberty.
Cell Mol Neurobiol 1995 Feb
PMID:Development of gonadotropin-releasing hormone (GnRH) neuron regulation in the female rat. 764 7

Literature reports that chronically ingested ethanol induces changes in the morphology of the small bowel mucous membranes. It has a topical toxic effect on the epithelium of the proximal jejunum and a blood-borne effect on the epithelium of the ileum because its absorption is almost complete in the stomach, duodenum and proximal jejunum. In addition there are also reports showing stimulation of enterocyte proliferation after segmental intestine resection. In this report we compare a group of rats submitted to resection of the proximal jejunum and fed a liquid diet containing 35% of the total calories intake as ethanol for four weeks to its control pair-fed group. In both groups we studied the mucosal alkaline phosphatase (APase) activity by histochemical as well as biochemical methods. We found a decreased APase activity in the homogenate of the intestinal mucous membrane in the alcoholic group and a reduced enzymatic activity in the brush border of the ileum enterocytes, as demonstrated by histochemical qualitative and densitometric assays. The result suggests that this change in APase activity of the brush border may represent enterocyte immaturity induced by long-standing ethanol intake in the remnant ileum after proximal resection.
Cell Mol Biol (Noisy-le-grand) 1995 Mar
PMID:Ileum brush border alkaline phosphatase activity in an experimental model of chronic alcoholism after small bowel proximal resection in the rat. 778 32

Our previous creatine phosphokinase (CK) activity studies in human sperm revealed differences among men and among sperm populations within the same specimen. Samples with low sperm concentrations, high incidence of abnormal sperm morphology, and diminished fertility had higher per sperm CK activity. In the present work, we demonstrated, with 14C-FDNB covalent CK active site modification and with direct CK immunocytochemistry, that the higher CK activity is related to an increased content of CK and of other proteins in sperm. Also, sperm heads with higher CK content were significantly larger and rounder and showed a higher incidence of amorph configuration. We suggest that these biochemical and morphological irregularities are related and are due to a failure of spermatogenesis, more specifically, to a higher retention of cytoplasm, which in normal sperm development is lost to the Sertoli cells as residual bodies. Thus higher CK activity and larger or irregular head size in human sperm signify cellular immaturity and a failure to complete spermatogenesis.
Mol Reprod Dev 1993 Mar
PMID:Incomplete development of human spermatozoa is associated with increased creatine phosphokinase concentration and abnormal head morphology. 847 Dec 51

Spermatozoa mature during epididymal transit, acquiring the abilities to swim progressively, fertilize oocytes, and produce viable offspring. In this study, we investigate the capacity of spermatozoa retrieved from the midcorpus and distal cauda regions of the epididymis of the cynomolgus monkey to penetrate homologous zona pellucida. Successful in vitro fertilization by ejaculated macaque sperm is dependent upon the addition of caffeine and dbcAMP. Therefore, the effect of these cyclic nucleotide mediators was also examined in this study. Results of sperm motion analysis indicate no difference in baseline values (without stimulators) for any motion parameter. With the addition of caffeine and dbcAMP, curvilinear velocity significantly increased only for the distal cauda sperm (P = 0.05). Amplitude of the lateral head displacement was significantly increased for distal cauda sperm (P < 0.01); although elevated above baseline, the increase observed after activation by corpus sperm was significantly lower than that achieved by cauda sperm (P < 0.05). The addition of caffeine and dbcAMP was an absolute requirement for zona penetration by both midcorpus and distal cauda sperm. With activation, zona penetration was significantly decreased for corpus sperm compared to cauda sperm (P < 0.001). These results suggest that cynomolgus monkey sperm reaching the midcorpus region of the epididymis have not completed all of the maturational changes requisite for successful fertilization; this immaturity is evidenced by decreased sperm motion and by impedance at the level of zona penetration.
Mol Reprod Dev 1996 Apr
PMID:Effects of caffeine and dbcAMP on zona pellucida penetration by epididymal spermatozoa of cynomolgus monkeys (Macaca fascicularis). 905 45

The adult llama (Lama glama) has several compensatory mechanisms that allow it to successfully survive at high altitude. Llama fetuses at 0.6-0.7 of gestation, and near-term llama fetuses studied close to surgery, did not increase cerebral blood flow and decreased cerebral oxygen delivery during acute hypoxemia. It is not known whether these responses were the result of immaturity or surgical stress. The aim of this study was to determine whether the lack of increase in cerebral blood flow and the decrease in cerebral oxygen delivery during hypoxemia in the fetal llama is characteristic of this high-altitude species near term, and under nonstressed conditions. We chronically catheterized 7 llamas and their fetuses near to term, at 0.7-0.9 of gestation. Fetal cardiac output, cerebral and regional blood flows, systemic blood pressure, heart rate, pH, and blood gases, organ vascular resistances and organ oxygen deliveries were determined at least 4 days after surgery, both during the basal state and after 1 hr of acute fetal hypoxemia. During hypoxemia the llama fetus did not increase cerebral blood flow and markedly decreased its cerebral oxygen delivery. There was also a marked decrease in kidney blood flow and oxygen delivery. These results indicate that, in contrast to fetuses of lowland species, the fetal llama does not increase the cerebral blood flow during hypoxemia, suggesting specific cellular mechanisms to preserve brain integrity during oxygen limitation.
Comp Biochem Physiol A Mol Integr Physiol 1998 Mar
PMID:Cardiorespiratory responses to acute hypoxemia in the chronically catheterized fetal llama at 0.7-0.9 of gestation. 968 9

The discovery of leptin has generated an extraordinary interest in the field of obesity but also in the understanding of the relationship between metabolic status and the neuroendocrine system. Following the initial demonstration that leptin administration to fasting mice can 'protect' neuroendocrine secretions and prevent the changes that are associated with fasting, the concept has emerged that a normal leptin secretion is a prerequisite for normal neuroendocrine secretions. Several unfavorable metabolic situations are associated with low plasma leptin, increased secretion of hypothalmic neuropeptide Y (NPY), and hypogonadism, and a causal relationship has been evoked. Severe dietary restriction in juvenile female rats is associated with low plasma leptin and sexual immaturity. Cessation of food restriction leads to immediate increase in plasma leptin followed 4 days later by vaginal opening. If food restriction is maintained, central leptin infusion can induce sexual maturation, thus demonstrating that leptin can act as a signal for the onset of puberty. In untreated type-I diabetic rats, hypogonadism is associated with very low plasma leptin and increased hypothalmic NYP synthesis and oestrous cyclicity. Fasting rapidly inhibits growth hormone (GH) secretion in association with low plasma leptin and elevated hypothalmic NPY. Central infusion of leptin to fasting rats was able to completely prevent the collapse of GH secretion and to maintain a normal low NPY synthesis. In summary, normally elevated plasma levels appear to be a prerequisite for normal GH and gonadotropin secretion in the rat. Degradation of metabolic conditions results in a rapid reduction of circulating leptin that could represent the signal for several alterations of neuroendocrine secretions. At the level of the hypothalamus, leptin could act on NPY neurons to transduce part or all of this 'metabolic' message. The possibility that changing plasma levels for leptin also affect peripheral endocrine targets, such as pituitary, ovary, adrenal or pancreas, is likely since these endocrine organs express functional long-term leptin receptors.
Mol Cell Endocrinol 1998 May 25
PMID:Metabolic control of sexual function and growth: role of neuropeptide Y and leptin. 972 77

The Bayer-Technicon hematological devices differentiate leukocytes by their peroxidase activity and their volume, displaying them as separate clusters. Peroxidase deficiencies are manifested by the irregular location of these clusters. This makes it possible to identify persons totally or partially lacking myeloperoxidase. The deficiency is quantified by the myeloperoxidase index, which is expressed for every routine analysis and for which normal values were determined. Values of the myeloperoxidase index confirm varying degrees of deficiency and prevalence. Family studies using these degrees show that the hereditary pattern must be more complicated than the classical autosomal-recessive mode. A bigenic mode is suggested. While about half of the totally deficient individuals detected were free of typical symptoms, in the other half we found infectious complications that were sometimes life-threatening. The hematological devices allow the identification of persons suffering from eosinoperoxidase deficiency and from MPO deficiency of the monocytes. The latter symptom seems to indicate immaturity of these cells and may lead to unexpected diagnosis of malignancy.
J Mol Med (Berl) 1998 Sep
PMID:Prevalence of myeloperoxidase deficiency: population studies using Bayer-Technicon automated hematology. 976 44


1 2 3 4 5 6 7 8 9 Next >>