Browsing by Subject "Notochord"

Now showing 1 - 3 of 3
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    Abnormal development of the notochord and perinotochordal sheath in duplicitas posterior, patch and tail-short mice
    (Murcia : F. Hernández, 1988) Center, Elizabeth M.; Marcus, Normala M.; Wilson, D.B.
    Interest in developmental interactions involving the notochord and perinotochordal sheath led to a comparative investigation of these structures in three mouse mutants. Alcian blue or periodic acid-Schiff staining of 9 1/2-13 days' gestational age embryos revealed a supernumerary notochordal-like mass of cells or a deflected notochord in association with duplication of the neural tube in mice of the duplicitas posterior stock. The perinotochordal sheath and basement membrane of the accessory notochordal masses were frequently defective. Patch and Tail-short embryos were also utilized for study by means of light rnicroscopy using Alcian blue staining. In Patch embryos, although the notochord was sometimes compressed dorso-ventrally . it had an intact perinotochordal sheath and a defined, but undulated, basement membrane. Mesenchymal cells between the notochord and neural tube were occasionally replaced by cell-free space. In contrast, in Tail-short embryos a poorly formed, lightly staining or totally absent notochordal sheath was revealed. Indeed, it was sometimes difficult to distinguish the notochord from surrounding mesenchymal cells. In both the Patch and Tail-short embryos the notochord was also deflected from its media1 position. In the three mutants studied, the director indirect effect of gene action appeared to be on the notochord and perinotochordal sheath. and the important role of these structures in abnormal axial development was established.
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    Histological study of timing and embryology of notochordal abnormalities in rat exposed in utero to Doxorubicin
    (Murcia : F. Hernández, 2002) Menegola, E.; Broccia, M.L.; Di Renzo, F.
    Experimental Doxorubicin-exposure in utero is correlated with foetal oesophageal atresia, tracheooesophageal fistula, axial alterations. While gastrointestinal and respiratory defects have been larg e l y investigated, only sporadic data have been published to date on notochordal and vertebral defects. The aim of this work was the study of the genesis of chordal and vertebral abnormalities in rat embryos and foetuses exposed to Doxorubicin and the study of their correlation with oesophageal and tracheal defects. For this purpose, pregnant rats were i.p. injected with saline (control) or with 4mg/Kg b.w. Doxorubicin on days 9.5 and 10.5 of gestation. Embryos and foetuses were morphologically analysed on days 10.5-15 and 16, 18, 20 of gestation respectively, fixed in formaldehyde and histologically processed. Slides were routinely stained with haematoxylin-eosin (11-15 days post coitum embryos and all foetuses) or specifically stained with aniline blue for the staining of basal laminae (10.5 days post coitum embryos). Moreover, some foetuses at term (20 days post coitum) were processed for bone and cartilage staining. The data obtained in the present work confirm the specificity of Doxorubicin in inducing gastro-intestinal and tracheal defects, describe the genesis of these defects step by step, describe the type and the genesis of notochordal abnormalities and their fate and exclude the role of Doxorubicin in inducing axial skeletal malformations.
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    Toxicity of malathion at early life stages of the Senegalese sole, Solea senegalensis (Kaup, 1858): notochord and somatic disruptions
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2018) Ortiz Delgado, Juan B.; Scala, Emanuele; Arellano, Juana M.; Úbeda Manzanaro, María; Sarasquete, Carmen
    The toxicity of malathion to Solea senegalensis was studied in a static renewal bioassay for 24, 48 and 72 h, with toxicant concentrations ranging from 1.56 until 100 µgL-1. The LC50 values of malathion for 48 and 72-h was 63.5 (95% C.I: 50.83-79.34) and 22.94 (95% C.I: 17.16-30.68) µgL-1 respectively. The survival of larvae was non-affected by exposure to malathion at concentrations up to 25 µgL-1 (24 h NOEC), 6.25 µgL-1 (48 h NOEC) and <1.6 µgL-1 (72 h NOEC). At the end of the experiment, surviving larvae from concentrations smaller than the 72h-LC50 were chosen to study morphological changes during malathion exposure. Results revealed a strong disruption in the notochord and trunk musculature integrity as a result of toxicant exposure. Noticeable changes in the composition and reduction of collagen fibers from the perinotochordal connective sheath and perimysium were clearly detected. The trunk musculature was also altered, showing a general disorganization of fibers. Moreover, malathion exposure provoked pericardial and yolk-sac oedemas and histopathological alterations in some other organ- systems and tissues (i.e. liver, pancreas, intestine).