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)

Mast cells at immature stages of development were identified in human tissues by electron microscopic techniques. General morphologic criteria of immaturity (such as a high apparent nuclear:cytoplasmic ratio and small cell size), the presence of few granules (those present being smaller than those in mature mast cells) and a lack of features of mast cell activation were used together to determine the level of maturity. Mast cells were identified as being of the T or TC type by immunogold staining with polyclonal rabbit IgG anti-chymase and murine monoclonal anti-tryptase primary antibodies and the appropriate gold-labeled secondary antibodies. Only those cells with tryptase-positive granules were recognized as mast cells. Immature T mast cell granules contained the same characteristic discrete scrolls found in their mature counterparts and all stained positive for tryptase. The presence of trace amounts of chymase in a minority of these granules, as in mature T mast cells, could not be ruled out. The majority of granules in immature TC mast cells had one or more amorphous electron-dense cores rather than the grating and lattice substructures characteristic of granules in mature TC mast cells. Secretory granules in immature TC mast cells stained positively for tryptase and chymase. Occasional immature TC mast cells contained a complete granule or a portion of a granule with the substructure characteristic of mature TC mast cells, favoring the concept that these TC mast cell forms are developmentally related. Essentially all mast cells in foreskin of newborns appeared immature, whereas 10, 5, 10, and 15% of the mast cells in adult lung, foreskin, bowel mucosa and bowel submucosa, respectively, appeared immature. The distribution of T and TC types of immature mast cells seemed to parallel that of the mature mast cell types. These compositional and ultrastructural differences between immature T and TC types of mast cells suggest that from the time granule formation begins, and possibly before this time, each type of human mast cell follows a distinct developmental pathway.
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PMID:Ultrastructural analysis of maturing human T and TC mast cells in situ. 264 87

1. In situ patch-clamp recordings of early embryonic large-conductance K+ channels consistently revealed (86% of patches) a complex behaviour characterized by noisy fluctuations between open and closed states of relatively short duration. 2. This behaviour is similar to the buzz mode, a type of gating observed only very rarely in some channels. Its prevalence in proliferative neuroepithelium may thus constitute a criterion of immaturity. 3. In 89% of patches, the buzz mode was converted to a 'normal' mode by intracellular exposure to trypsin. 4. These observations suggest that the immature channel protein includes (or is affected by) a cytoplasmic component, the presence or absence of which determines certain sets of conformational transitions.
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PMID:Gating mode conversion by proteolysis in a large-conductance K+ channel from embryonic rat telencephalon. 773 27

The most common aetiology of meconium ileus is a deficiency in trypsin activity caused by cystic fibrosis. The pathogenesis of meconium ileus without mucoviscidosis is less well understood, although a number of causative factors have been suggested. The symptoms and clinical course of nine patients with meconium ileus without mucoviscidosis were reviewed, and the myenteric plexus of a surgical specimen of intestine was examined histologically and cytometrically. The nuclei of the intramural ganglion cells were much smaller than were seen in normal newborn infants. The nuclear areas resembled those seen in fetuses of 5-6 months gestational age, but the number of ganglion cells approached normal. This immaturity of the ganglia was observed both in the contracted distal ileum and dilated proximal ileum. Patients with an ileostomy passed solid faeces for about 1 to 2 months postoperatively, after which time the faeces became watery. The intramural ganglia were mature at the time of ileostomy closure. We conclude that immaturity of the myenteric plexus in the ileum and colon seems to be the main aetiologic factor in meconium ileus without mucoviscidosis.
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PMID:Immaturity of the myenteric plexus is the aetiology of meconium ileus without mucoviscidosis: a histopathologic study. 784 97

Previous studies have demonstrated enhanced intestinal trypsin uptake and decreased liver clearance of trypsin in newborn rats compared to adults. In order to examine the effectiveness of the reticuloendothelial system (RES) in clearing trypsin, bovine trypsin (1.25 mg/100 g body weight) plus trace 125I-trypsin were injected into the portal vein of 2-week-old (n = 57) and adult (n = 44) control rats or following RES stimulation using intraperitoneally injected lipopolysaccharide or RES suppression with intraperitoneally injected oleic acid emulsion. Plasma, liver and spleen 125I activities were assessed at 1, 5 or 15 min following infusion in control, stimulated and suppressed animals. Newborn control rats had significantly increased 125I plasma levels with decreased liver and spleen 125I activity compared to control adults. RES stimulation in the newborns did not lead to any change in liver or plasma levels although splenic values increased while adults had a decrease in liver 125I activity. RES suppression in the newborns led to increased plasma and decreased spleen 125I-trypsin values while adult rat levels were unchanged. The immature reticuloendothelial system in newborns is poorly responsive to RES stimulation although it can be made even further inefficient by RES suppression. The combination of RES immaturity and lack of response to stimulation may make newborns susceptible to proteolytic damage, especially during times of increased systemic levels of proteolytic enzymes.
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PMID:Reticuloendothelial system uptake of infused 125I-trypsin in newborn and adult rats. 905 94

Human cultured mast cells (HCMCs) grown from cord blood mononuclear cells in the presence of stem cell factor (SCF) and interleukin-6 (IL-6) expressed tryptase but no or low chymase in their cytoplasm. The addition of IL-4 to these cells strikingly increased chymase expression. Consequently, the activity of chymase was significantly higher in IL-4-treated mast cells than that in IL-4-nontreated mast cells, whereas the activity of tryptase and histamine content were comparable in both cells. Electron microscopic immunocytochemistry also showed that secretary granules containing chymase increased in IL-4-treated mast cells. Interestingly, the IL-4-induced increase of chymase expression in HCMCs was accompanied by morphological maturation of the cells. Cytoplasmic projections were few in IL-4-nontreated HCMCs, and a small number of secretary granules were observed, most of which were empty or partially filled with discrete scrolls with rough particles showing immaturity. In contrast, IL-4-treated HCMCs had extremely abundant cytoplasmic projections and had many secretary granules filled with electron-dense crystal materials. Taken together, immature HCMCs grown only with SCF and IL-6 expressed tryptase with no or a low amount of chymase, and addition of IL-4 promoted cell maturation together with the expression of both tryptase and a high amount of chymase. Our findings will raise a possibility of a linear pathway of human mast cell development from tryptase single positive mast cells into tryptase and chymase double positive mast cells as the cells mature and will suggest that this maturation process is promoted by IL-4.
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PMID:Interleukin-4 promotes the development of tryptase and chymase double-positive human mast cells accompanied by cell maturation. 941 84