The ontogeny of the alimentary tract of coregonid larvae: normal development

1988 ◽  
Vol 33 (6) ◽  
pp. 841-850 ◽  
Author(s):  
H. Loewe ◽  
R. Eckmann
1977 ◽  
Vol 168 (3) ◽  
pp. 507-511 ◽  
Author(s):  
G J Wishart ◽  
G J Dutton

1. A precocious development of UDP-glucuronosyltransferase activity (EC 2.4.1.17) towards o-aminophenol is demonstrated in 15-17 day foetal rat liver in utero after dexamethasone administration to the mother. 2. This stimulation of liver transferase activity in utero is directly proportional to the dose of dexamethasone infected. 3. Precocious development of transferase activity in utero can also be effected with the natural glucocorticoid cortisol by multiple injections of large amounts of this hormone into the mother. 4. Transferase activity towards o-aminophenolin foetal lung, kidney and upper alimentary tract can also be precociously stimulated by dexamethasone in 17-day foetuses in utero. 5. Natural development of hepatic transferase activity between days 18 and 20 of gestation is retarded after foetal hypophysectomy by decapitation in utero. 6. Overall glucuronidation of o-aminophenol, as observed in foetal rat liver, is also precociously stimulated by dexamethasone. 7. From this and from evidence previously presented we suggest that glucocorticoids, which are known to increase in rat foetuses between days 17 and 20 of gestation, trigger the normal development in utero of hepatic transferase activity towards o-aminophenol which occurs at that time. We also suggest that these hormones are responsible for the rise in activity of the enzyme in foetal lung, kidney and upper alimentary tract which occurs during the same gestational period.


Development ◽  
1957 ◽  
Vol 5 (2) ◽  
pp. 143-152
Author(s):  
H. H. El Shatoury ◽  
C. H. Waddington

It has been shown that in the normal development of wild-type Drosophila larvae, a process of hypertrophy or proliferation leading to the formation of groups of non-nucleated cellular masses occurs in the mid-gut (stomach) and at the imaginal primordia of the hind-gut and the salivary glands in both the first and second instars (Shatoury & Waddington, 1957b). The process takes place just at the time when the lymph glands hypertrophy and release cells into the body-cavity and the excessive growths of the organs of the alimentary tract regress and are resorbed as soon as the lymph glands become regenerated. The appearances strongly suggest that there is a causal connexion between the proliferation of the lymph glands cells and the hypertrophy which occurs in the gut and salivary glands.


Author(s):  
Michael T. Postek

Silicon occurs naturally in plants in the form of its hydrated oxide (SiO2.nH2O) commonly called silica. Silica has been shown to be a necessary element in the normal development of many plants, playing an array of roles including strengthening, protection, and reduction of water loss. Deposition of silica in various portions of the plant body, especially the leaves, may also be viewed as a way for the plant to dispose of any excess silica taken up beyond that necessary for normal metabolism.Studies of this “opaline” silica have thus far been limited to species of the Cyperaceae and Gramineae known to possess significant quantities of silica. Within the Magnoliaceae, certain “glistening” idioblast cells at the foliar veinlet termini and vein sheaths of Magnolia grandiflora (1) have been suspected to be siliceous in nature.


Author(s):  
Thomas T.F. Huang ◽  
Patricia G. Calarco

The stage specific appearance of a retravirus, termed the Intracisternal A particle (IAP) is a normal feature of early preimplantation development. To date, all feral and laboratory strains of Mus musculus and even Asian species such as Mus cervicolor and Mus pahari express the particles during the 2-8 cell stages. IAP form by budding into the endoplasmic reticulum and appear singly or as groups of donut-shaped particles within the cisternae (fig. 1). IAP are also produced in large numbers in several neoplastic cells such as certain plasmacytomas and rhabdomyosarcomas. The role of IAP, either in normal development or in neoplastic behavior, is unknown.


1994 ◽  
Vol 3 (1) ◽  
pp. 79-88 ◽  
Author(s):  
Theresa A. Kouri

Lexical comprehension skills were examined in 20 young children (aged 28–45 months) with developmental delays (DD) and 20 children (aged 19–34 months) with normal development (ND). Each was assigned to either a story-like script condition or a simple ostensive labeling condition in which the names of three novel object and action items were presented over two experimental sessions. During the experimental sessions, receptive knowledge of the lexical items was assessed through a series of target and generalization probes. Results indicated that all children, irrespective of group status, acquired more lexical concepts in the ostensive labeling condition than in the story narrative condition. Overall, both groups acquired more object than action words, although subjects with ND comprehended more action words than subjects with DD. More target than generalization items were also comprehended by both groups. It is concluded that young children’s comprehension of new lexical concepts is facilitated more by a context in which simple ostensive labels accompany the presentation of specific objects and actions than one in which objects and actions are surrounded by thematic and event-related information. Various clinical applications focusing on the lexical training of young children with DD are discussed.


1987 ◽  
Vol 57 (01) ◽  
pp. 118-122 ◽  
Author(s):  
C Thomas Kisker

SummaryAnimal models have added significantly to our understanding of adult hemorrhagic and thrombotic diseases. Few models, however, have been developed for studies of the hemostatic disorders in the fetus and newborn. This report reviews the current information on animal models of fetal and neonatal hemostasis. The requirements of a relevant model are addressed and previous studies using fetal and neonatal animal models are reviewed. A recommendation of a single animal for all studies of fetal and neonatal hemostasis is not possible. However, the lamb has been the most frequently studied and appears to provide relevant information regarding normal development and the factors which may adversely influence hemostasis in the fetus and newborn.


2019 ◽  
pp. 50-54
Author(s):  
V.O. Golyanovskiy ◽  
◽  
Ye.O. Didyk ◽  

Pregnant women with intrauterine growth restriction (IUGR) have an increased risk of adverse perinatal and long-term complications compared with the birth of children with normal body weight. Thus, IUGR is one of the main challenges for the global health system, especially in poor and developing countries. Morpho-functional studies of the placentas help in determining the causes of IUGR, and therefore, timely prevent complications in pregnant women with IUGR. The objective: The purpose of this study is to investigate various morphometric and pathomorphological changes in the placenta, including inflammatory, in cases of IUGR, and to establish a correlation of these results with the etiology and complications for the fetus. Materials and methods. In the current study, 54 placentas of the fetuses with IUGR (the main group) were compared with 50 placentas of the fetuses with normal development (control group). The criteria for the inclusion of IUGR were gestational age more than 30 weeks and all fetuses with a weight less than 10th percentile for this period of pregnancy. The placenta material was studied pathomorphologically with laboratory screening for infection and inflammation. Similarly, the results were determined for placentas of the fetuses with normal development compared to placentas with IUGR. Results. The placenta study showed the presence of calcification in the case of IUGR, as well as in the case of prolonged pregnancy. However, calcification of the placenta in the case of IUGR was more progressive compared with placenta in the normal pregnancy. In addition, the presence of intrauterine infection and inflammation was observed, which could also lead to an adverse outcome for the further progression of pregnancy with IUGR. Conclusion. A comparative macro- and microscopic pathomorphological study of the placentas in the two groups has shown a significant increase in the pathological changes in all the anatomical structures of the fetuses with IUGR. Key words: Intrauterine growth restriction (IUGR), fetal weight, pathomorphological changes of the placenta.


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