The use of different fixatives and hydrophilic embedding media (Historesin™ and Unicryl™) for the study of embryonic tissues

Santander, R. González; Cuadrado, G. Martinez; Martínez, Meritxell; Monteagudo, Manuel; Alonso, F.J. Martínez; Lobo, M.V. Toledo

doi:10.1002/(sici)1097-0029(19970201)36:3<151::aid-jemt2>3.0.co;2-s

Cited by 12 publications

(2 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unicryl embedding, however, showed worse ultrastructural preservation, especially for the cell nuclei of HeLa cells. This comes into contradiction with previous studies using Unicryl, where it was especially appreciated for the preservation of structural integrity (Scala et al, 1992;Goping et al, 1996;Bogers et al, 1996;Gonzalez Santander et al, 1997). These discrepancies may be accounted for differences in protocols used.…”

Section: Discussioncontrasting

confidence: 66%

LR White is preferable to Unicryl for immunogold detection of fixationsensitive nuclear antigens

Philimonenko¹,

Janáček²,

Hozák³

2010

Eur J Histochem

View full text Add to dashboard Cite

The purpose of this study was to compare two electron microscopy embedding media – LR White and Unicryl – with regard to cell morphologyical and immunohistochemical preservation properties for the study of fixation-sensitive nuclear antigens. Human cervical carcinoma (HeLa) cells were fixed with 2% paraformaldehyde and 0.1% glutaraldehyde, and embedded in parallel in the two resins: LR White and Unicryl using; two different polymerization protocols were used for each resin. Preservation of fine nuclear structure was good after LR White and poor after Unicryl embedding. Immunogold labeling of Sm antigen was significantly stronger on LR White sections. Polymerization by UV light resulted in stronger and more specific labeling than heat polymerization. These results show that LR White is advantageous over Unicryl for the study of nuclear antigens requiring delicate aldehyde fixation

show abstract

Section: Discussioncontrasting

confidence: 66%

LR White is preferable to Unicryl for immunogold detection of fixationsensitive nuclear antigens

Philimonenko¹,

Janáček²,

Hozák³

2010

Eur J Histochem

View full text Add to dashboard Cite

show abstract

“…However, this is the first study to directly and objectively measure megakaryocytes in the bone marrow of living neonates. In this regard, it is important to keep in mind that routine tissue processing and paraffin embedding result in significant cell shrinkage (22,23), and therefore our values do not represent true cell diameters. Nevertheless, because all samples were processed and analyzed in similar fashion, our measurements do allow for comparisons between groups.…”

Section: Discussionmentioning

confidence: 99%

Megakaryocyte Size and Concentration in the Bone Marrow of Thrombocytopenic and Nonthrombocytopenic Neonates

et al. 2007

View full text Add to dashboard Cite

Thrombocytopenia is frequent among sick neonates, but little is known about its underlying mechanisms. It is known, however, that neonatal megakaryocytes are smaller and of lower ploidy than their adult counterparts and that smaller megakaryocytes produce fewer platelets than larger, more polyploid, megakaryocytes. We hypothesized that neonatal megakaryocytes would not increase their size in response to thrombocytopenia, thus limiting the ability of neonates to mount a response. To test this, we obtained marrow specimens from thrombocytopenic and nonthrombocytopenic neonates and adults. Megakaryocytes were immunohistochemically stained, quantified using an eyepiece reticle, and measured using an image analysis system with incorporated electronic micrometer. We found that, after adjusting for differences in cellularity, neonates and adults had similar megakaryocyte concentrations. When samples from the same sources were compared (tibial clot and vertebral body sections in neonates, iliac crest biopsies in adults), there were also no differences in megakaryocyte concentration between thrombocytopenic and nonthrombocytopenic subjects. The megakaryocyte diameter, however, was greater in adults than in neonates (19.4 Ϯ 3.0 versus 15.3 Ϯ 1.7 m, p Ͻ 0.0001). Thrombocytopenic adults also had a higher proportion of large megakaryocytes than nonthrombocytopenic adults (p Ͻ 0.001). This was not observed among thrombocytopenic neonates, suggesting a developmental limitation in their ability to increase megakaryocyte size. T hrombocytopenia is a common problem among sick neonates, affecting 20% to 35% of neonates admitted to neonatal intensive care units (NICUs) (1,2). In approximately 50% of cases, the thrombocytopenia is thought to be secondary to increased platelet consumption, mainly associated with sepsis, necrotizing enterocolitis (NEC), or alloantibodies. In the remainder of cases, the mechanism underlying the thrombocytopenia is frequently unclear, although a mounting body of evidence suggests that decreased platelet production causes or complicates many such cases (3-5).In adults with thrombocytopenia due to increased platelet consumption, the marrow attempts to compensate by increasing megakaryocyte number, size, and ploidy (6 -8). It is unknown whether thrombocytopenic neonates can compensate in a similar manner, particularly since megakaryocytes from normal fetuses and neonates are smaller and of lower ploidy than megakaryocytes from adults (9 -12). Indeed, the number and size of megakaryocytes in thrombocytopenic neonates have never been systematically evaluated, and it is not known whether neonates are capable of increasing their megakaryocyte size and number in response to platelet consumption.This study was designed to answer this question by quantifying the megakaryocyte number and size in bone marrow samples from thrombocytopenic and nonthrombocytopenic neonates. Because small megakaryocytes with low DNA content cannot be reliably differentiated from other cell types using hematoxylin and eosin-st...

show abstract

Methyl tert butyl ether targets developing vasculature in zebrafish (Danio rerio) embryos

2011

View full text Add to dashboard Cite

Disruption of vascular endothelial growth factor (VEGF) signaling during early development results in abnormal angiogenesis and increased vascular lesions. Embryonic exposure to 0.625 to 10 mM methyl tert butyl ether (MTBE), a highly water soluble gasoline additive, resulted in a dose dependent increase in pooled blood in the common cardinal vein (CCV), cranial hemorrhages and abnormal intersegmental vessels (ISVs). The EC50s for the lesions ranked in terms of likelihood to occur with MTBE exposure were: pooled blood in the CCV, 3.2 mM [95 % CI: 2.2 – 4.7] > cranial hemorrhage, 11 mM [5.9 – 20.5] > abnormal ISV, 14.5 mM [6.5 – 32.4]. Organ systems other than the vascular system appear to develop normally, which suggests MTBE toxicity targets developing blood vessels. Equal molar concentrations (0.625 to 10 mM) of the primary metabolites, tertiary butyl alcohol (TBA) and formaldehyde, did not result in vascular lesions, which suggested that the parent compound is responsible for the toxicity. Stage specific exposures were carried out to determine the developmental period most sensitive to MTBE vascular disruption. Embryos treated until 6-somites or treated after Prim-5 stages did not exhibit a significant increase in lesions, while embryos treated between 6-somites and Prim-5 had a significant increase in vascular lesions (p ≤ 0.05). During the critical window for MTBE-induced vascular toxicity, expression of vegfa, vegfc, and flk1/kdr were significantly decreased 50, 70 and 40%, respectively. This is the first study to characterize disruption in vascular development following embryonic exposure to MTBE. The unique specificity of MTBE to disrupt angiogenesis may be mediated by the down regulation of critical genes in the VEGF pathway.

show abstract

The use of different fixatives and hydrophilic embedding media (Historesin™ and Unicryl™) for the study of embryonic tissues

Cited by 12 publications

References 18 publications

LR White is preferable to Unicryl for immunogold detection of fixationsensitive nuclear antigens

LR White is preferable to Unicryl for immunogold detection of fixationsensitive nuclear antigens

Megakaryocyte Size and Concentration in the Bone Marrow of Thrombocytopenic and Nonthrombocytopenic Neonates

Methyl tert butyl ether targets developing vasculature in zebrafish (Danio rerio) embryos

Contact Info

Product

Resources

About