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)

Thirty-five paraffin-embedded medulloblastomas (19 from children and 16 from adults; 24 classic medulloblastomas, 10 desmoplastic medulloblastomas, 1 tumor with neuronal differentiation) were examined for reactions with antibodies against glial fibrillary acidic protein (GFAP), cytokeratins KL1 and MNF116, desmin, and vimentin. Only the tumor from the youngest patient, a 152-day-old boy, showed a positive immunoreaction for cytokeratins. Because of this age-related expression of cytokeratins in medulloblastomas primarily in very young children, cytokeratin positivity was interpreted as a sign of tumor immaturity. Five medulloblastomas showed scattered GFAP-positive reactive astrocytes and/or other positive, probably neoplastic, cells. Only two tumors showed GFAP immunoreactivity in unequivocally neoplastic cells. Of six tumors that reacted with vimentin, three showed strong reactivity throughout, one being the tumor from the 152-day-old boy. The remaining three demonstrated nests of vimentin-positive cells with weak or intense somatic immunoreactivity for vimentin. None of the 35 cases showed positivity for desmin; indicating that mesenchymal differentiation is restricted to the rare so-called medullomyoblastomas.
Childs Nerv Syst 1992 Sep
PMID:Age-related immunoreactivity pattern in medulloblastoma. 138 52

A physically active and athletic lifestyle is not only a healthy but a fulfilling choice for women. Although there is extensive literature on 'athletic amenorrhoea' which implies that exercise causes loss of the menstrual cycle, there is inadequate scientific evidence for a causal relationship. The reproductive system adapts to environmental, nutritional, emotional and physical stressors or 'threats' by downward adjustment towards the premenarcheal pattern. The hormonal milieu of this adaptation is low gonadal steroid and high glucocorticoid levels which synergistically increase the risk for a negative bone balance. Athletic women may become amenorrhoeic if reproductive immaturity, emotional stress and undernutrition coexist with increasing exercise loads. Treatment for athletic women with menstrual cycle changes requires that hypothalamic stressors be identified and decreased. In addition, as progesterone deficiency (from disorders of ovulation, whether flow is regular or absent) is the most prevalent menstrual cycle change, treatment with medroxyprogesterone on days 16 to 25 of their cycle will not only provide regular flow (if estrogen levels are sufficient) but will also promote increased bone density.
Sports Med 1992 Sep
PMID:Reproduction for the athletic woman. New understandings of physiology and management. 143 94

Individual, marital or familiar problems, life circumstances, lack of libido, anxiety or sex identity fragility or immaturity may determine or make worse the erectile deficit. A thorough diagnostic work up is essential for the prognosis and the choice of the more fitting therapy. Emotional and cognitive understanding of the psychogenic background of the symptom is combined with behavioral therapy based on modern principles of neuroriabilitation.
Arch Ital Urol Nefrol Androl 1992 Sep
PMID:[Treatment of psychogenic impotence]. 143 51

Abnormalities of the optical media or alignment of the eyes during the period of visual immaturity may produce pathologic changes in the brain resulting in the clinical entity of subnormal vision known as amblyopia. Efforts to prevent visual deterioration or restore normal acuity where amblyopia exists require early diagnosis and treatment. Although amblyopia affects between 1% and 5% of children, it is estimated that at most one-fourth of preschool children are screened for this major treatable eye disorder. Simultaneous photography of the corneal and fundus reflex from both eyes using an offaxis flash photorefractor appears to be a practical, efficient, and effective method of eye-screening in pre-verbal children. Previous studies of this modality have dealt with populations referred to ophthalmology centers. We report the results of a masked validation of a commercially available photorefractor in an unselected group of children between the ages of 6 months and 6 years.
Ala Med 1992 Sep
PMID:Photorefractor for detection of treatable eye disorders in preverbal children. 144 56

The immaturity of the lung of the very prematurely delivered newborn appears to make it hypersusceptible to injury by those very therapeutic measures that the infant requires shortly after birth--mechanical ventilation and hyperoxia. There is good experimental evidence to relate the immature lung's susceptibility to early hyperoxia-induced lung damage to deficient antioxidant defensive systems. Less than fully adequate nutritional support of these tiny newborns can have extremely detrimental effects on their lungs' ability to resist and repair on-going injury and to continue developing normally. Promising experimental means of possible protection from hyperoxic lung damage and progression to chronic lung disease (bronchopulmonary dysplasia) are reviewed.
Clin Perinatol 1992 Sep
PMID:Antioxidants, nutrition, and bronchopulmonary dysplasia. 152 71

The effect of transecting the vestibular nerve on the vestibular sensory epithelium was studied in adult guinea-pigs. When denervation was complete, after fifteen days, the vestibular hair cells began to show morphological features of immaturity. After two months, the majority of hair cells showed a supporting cell phenotype. By four months, both hair cells and supporting cells had become morphologically similar to the epithelial cells which line the vestibular cavities. When denervation was incomplete, hair cells and supporting cells retained their normal phenotype. This, plus the dedifferentiation after complete denervation, indicates that the phenotypes of the hair cells and supporting cells are innervation-dependent.
Neuroreport 1991 Sep
PMID:Dedifferentiation phenomena after denervation of mammalian adult vestibular receptors. 175 3

While morphologically the kitten's cochlea matures first at the basal or high-frequency region, behavioural and physiological evidence suggests that it responds first to low-frequency sound. Explanations of this paradox include the suggestion that the spatial representation of frequency within the cochlea changes as a function of age. We have used the [14C]-2-deoxyglucose technique to study the development of frequency representation in the central auditory system of the kitten. We report here that while the locations within the inferior colliculus (IC) where high- and mid-frequency sounds are represented shift markedly between 10 and 35 days of age, the location where low-frequency sound is represented does not alter. The IC representation of low frequencies is adult-like by 10 days of age but that of higher frequencies continues to mature until as many as 35 days. Despite its morphological immaturity with respect to other regions, the apex of the cochlea appears to be the first region to become tuned to those frequencies to which it is tuned in the adult. We found little labelling at 5 and 7 days of age to 75-80 dB stimuli, but it is quite possible that the high-frequency region might respond to very intense low frequencies before 10 days of age. to very intense low frequencies before 10 days of age.
Hear Res 1991 Sep
PMID:The development of frequency representation in the inferior colliculus of the kitten. 175 96

Studies of ontogenesis contribute to better understanding of regulatory events underlying the striking heterogeneity in B-cell differentiation pathways employed in the human mucosal immune system. This disparity is probably explained by exogenous environmental factors, although regional differences probably also exist in accessory cells and cytokines involved in local immune responses. IgA deficiency signifies a heterogeneous syndrome but is basically a manifestation of a defect in B-cell differentiation. The immaturity of the IgA system revealed in this disorder bears a striking resemblance to that seen in newborn infants. It may therefore be worthwhile to consider IgA deficiency in relation to the ontogeny of mucosal immunity.
Gastroenterol Clin North Am 1991 Sep
PMID:Ontogeny of the mucosal immune system and IgA deficiency. 191 20

Previous study has shown that midorganogenesis-stage rat embryos exposed to strong redox cyclers under moderate hypoxia in vitro develop severe necrotic defects on the right side. Similar effects can be produced by exposure to severe hypoxia alone. Studies presented here indicate that exposure to severe but survivable hyperoxia induces comparable necrotic degeneration on the left sides of all embryos. We hypothesize that the basis of these axially asymmetric defects is relatively precocious mitochondrial maturity on the left side of the embryo. In order to investigate this hypothesis, we compared mitochondrial oxygen utilization (NADH oxidase activities) on either side of rat embryos between days 11 and 14 of gestation. Activities were consistently higher on the left side during this period and significantly higher on day 11. We also found that the asymmetric embryotoxicity induced by niridazole, a strong redox cycler, could be attenuated by prior culture under hyperoxic conditions. We propose that mitochondrial immaturity on the right results in inadequate energy generation under hypoxic conditions, either directly or as a result of redox cycling. On the other hand, necrosis associated with hyperoxic conditions results from "leakage" of superoxide from functionally mature mitochondria on the left side.
Teratology 1991 Sep
PMID:Asymmetric development of mitochondrial activity in rat embryos as a determinant of the defect patterns induced by exposure to hypoxia, hyperoxia, and redox cyclers in vitro. 194 69

The ontogenesis of the pituitary gland is considered from anatomical and functional points of view. Embryogenesis of the hypothalamo-pituitary unit involving development of the hypothalamo-hypophyseal portal system is complete during early life as shown in several mammalian species. The ultrastructural characteristics of the different cell types during development are described according to observations made by using immunochemical techniques. The patterns of differentiation of the cell types are reviewed according to studies of pituitary glands from human anencephalic fetuses and encephalectomized rat fetuses as well as in vitro studies of cultured pituitary primordia in synthetic media. The maturation of the neuroendocrine mechanisms controlling the secretion of fetal hormones is also analyzed. During fetal life, the factors implicated in the regulation of pituitary hormone secretion are generally the same as in adults, but the intensity of the response of pituitary cells to their action is variable according to the species, thus reflecting an immaturity in the functioning of certain cell types.
J Electron Microsc Tech 1991 Sep
PMID:Fetal development and regulation of pituitary cell types. 196 May 69


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