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)

Semicarbazide, a lathyrogen, was given to growing rats to elucidate the consequences of altering the molecular structure of fibrous proteins within the lung. Static pressure-volume (P-V) measurements during deflation of saline-filled lungs showed normal recoil pressure and compliance values within the physiological range of lung volume. Quasi-static P-V measurements were also normal during slow reinflation, even beyond physiological limits to a recoil pressure of 20 cm H20. However, the lungs of experimental rats ruptured at much lower recoil pressures than controls. Histology was normal in lungs fixed at 20 cm H20. In contrast, lungs showed dilation of terminal air spaces, rupture of alveolar walls, and an increase in mean linear intercept in experimental compared with control specimens, when fixed at 30 cm H20. Biochemical analyses revealed reduced cross-linking of lung collagen without change in its total content. There were no detectable changes in the quantity or quality of lung elastin. It is concluded that semicarbazide may selectively impair the maturation of lung collagen and that immaturity of lung collagen is associated with a reduction in the tensile strength of lung tissue, without changes in elasticity within physiological volume limits.
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PMID:Effects of a molecular change in collagen on lung structure and mechanical function. 113 68

Pulmonary elastic fibers in a patient with panacinar emphysema due to alpha-1-antitrypsin deficiency and three patients with centriacinar emphysema related to anthracosis were studied by electron microscopy and by light and electron microscopic immunohistochemistry for elastin. Four types of abnormal elastic fibers were found: (1) finely disrupted fibers, (2) fibers with vacuolar changes and deposits of electron-dense granular material, (3) accumulations of small, rounded amorphous components of elastic fibers near bundles of microfibrils, and (4) large, confluent masses consisting mainly of aggregates of irregularly and compactly arranged, small-sized amorphous components. The amorphous components in these four types of abnormal elastic fibers tended to stain evenly with antielastin antibody. This is attributed to greater penetration of antielastin antibody into fibers that were incompletely polymerized because of immaturity or hydrolytic damage. Finely disrupted fibers were frequently found in the patient with panacinar emphysema and were presumed to have been damaged by elastase. The other three types of elastic fibers were frequently found in the patients with centriacinar emphysema. The vacuoles and electron-dense deposits in elastic fibers probably represented the consequence of damage to elastic fibers. The small round amorphous components in elastic fibers might be formed from abnormal elastogenesis. The large, confluent elastic masses were thought to be formed by the aggregation of elastic fibers in areas of coalescence of alveolar walls undergoing structural remodeling.
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PMID:Morphogenesis of abnormal elastic fibers in lungs of patients with panacinar and centriacinar emphysema. 266 9

To study the morphologic alterations of pulmonary elastic fibers in cynomolgus monkeys with paraquat toxicity, peroxidase- and ferritin-labeled antielastin antibodies were used for the light and electron microscopic localization of elastin. One week after paraquat, alveolitis, tissue damage and alveolar dilatation were present; elastic fibers were frayed and more diffusely and intensely stained than those of control animals. In the latter, staining was localized in peripheral regions of the amorphous components and, to a lesser extent, in some microfibrils of elastic fibers. At 3 to 4 weeks, diffuse staining was evident in damaged interstitial elastic fibers and in newly formed elastic fibers in areas of intraalveolar fibrosis. At 8 weeks, the interstitium contained many elastic fibers which showed staining only in peripheral regions of the amorphous components. These observations suggest that: 1) preembedding immunohistochemical staining for elastin is localized in peripheral regions of normal elastic fibers because the antielastin antibody can penetrate into mature and undamaged amorphous components only to a very limited extent; 2) in early stages of paraquat toxicity this staining is more diffuse and intense because elastase from inflammatory cells partially degrades the elastic fibers and permits greater penetration of the antibody into the amorphous materials; 3) in later stages the staining pattern returns to normal as inflammation subsides and elastic fibers are repaired; however, newly formed elastic fibers in areas of intraalveolar fibrosis stain diffusely, reflecting increased penetration of the antibody because of immaturity and incomplete cross-linking, and 4) degeneration of elastic fibers of alveolar walls in paraquat lung may lead to alveolar dilatation, which is associated with irregular fibrosis and constitutes one of the processes of pulmonary structural remodeling in paraquat lung.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pulmonary elastic fiber degradation in paraquat toxicity. An electron microscopic immunohistochemical study. 337 Jun 14

Amino acid analysis of human fetal lung elastin was undertaken in 49 instances of live-born neonates, ranging from 380 g to full term, and in 3 abortuses of 12-14 wk gestation. The data suggest that formation of the cross-linking agents, desmosine and isodesmosine, occurs early, between 14 and 22 wk. The ratio of neutral to charged amino acids remains low until the 36th wk when it attains adult levels. The composition of elastin was independent of sex and duration of survival. In three neonatal pulmonary diseases (respiratory distress syndrome, atelectasis, and hemorrhage) ratios were significantly lower than those found in nondiseased lungs. This may be a reflection of immaturity or may be a predisposing factor in neonatal lung disease. The latter hypothesis is attractive and receives indirect support from the association of a more polar elastin with other diseases, including adult emphysema and atheromatous aortic change.Our finding of relatively high polarity in elastin from human fetal lung is consistent with previous observations in a variety of fetal organs of other species.
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PMID:Lung tissue elastin composition in newborn infants with the respiratory distress syndrome and other diseases. 483 91

This study evaluates the use of composite grafts of cultured human keratinocytes and de-epidermalized, acellular human dermis to close full-thickness wounds in athymic mice. Grafts were transplanted onto athymic mice and studied up to 8 wk. Graft take was excellent, with no instances of infection or graft loss. By 1 wk, the human keratinocytes had formed a stratified epidermis that was fused with mouse epithelium, and by 8 wk the grafts resembled human skin and could be freely moved over the mouse dorsum. Immunostaining for keratins 10 and 16 and for involucrin revealed an initial pattern of epithelial immaturity, which by 8 wk had normalized to that of mature unwounded epithelium. Mouse fibroblasts began to infiltrate the acellular dermis as early as 1 wk. By 8 wk fibroblasts had completely repopulated the dermis, and blood vessels were evident in the most superficial papillary projections. Dermal elements, such as rete ridges and elastin fibers, which were present in the starting dermis, persisted for the duration of the experiment. Grafts using keratinocytes from dark-skinned donors as opposed to light-skin donors had foci of pigmentation as early as 1 wk that progressed to homogenous pigmentation of the graft by 6 wk. These results indicate that melanocytes that persist in vitro are able to resume normal function in vivo. Our study demonstrates that composite grafts of cultured keratinocytes combined with acellular dermis are a useful approach for the closure of full-thickness wounds.
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PMID:Evaluation of human skin reconstituted from composite grafts of cultured keratinocytes and human acellular dermis transplanted to athymic mice. 875 50