Search results for "Microscopy"

Comparative study of T84 and T84SF human colon carcinoma cells: in vitro and in vivo ultrastructural and functional characterization of cell culture …

2005

To better understand the relationship between tumor heterogeneity, differentiation, and metastasis, suitable experimental models permitting in vitro and in vivo studies are necessary. A new variant cell line (T84SF) exhibiting an altered phenotype was recently selected from a colon cancer cell line (T84) by repetitive plating on TNF-alpha treated human endothelial cells and subsequent selection for adherent cells. The matched pair of cell lines provides a useful system to investigate the extravasation step of the metastatic cascade. Since analysis of morphological differences can be instructive to the understanding of metastatic potential of tumor cells, we compared the ultrastructural and …

Intravital Microscopy for Measuring Microcirculatory Blood Flow in Pulmonary Surface Metastases of Rats

2015

Reactive neurogenesis during regeneration of the lesioned medial cerebral cortex of lizards

1995

Abstract This study reports that lesion of the adult lizard medial cortex (lizard hipocampal fascia dentata) induces a short period of intensive neurogenesis which we have termed reactive neurogenesis; a cell proliferation event that occurs in the subjacent ependyma. Specific lesion of the medial cortex was achieved by intraperitoneal injection of the neurotoxin 3-acetylpyridine and proliferating cells were detected using tritiated thymidine or 5-bromodeoxiuridine pulse labelling. After lesion, granule neurons in the lizard medial cortex cell layer appeared pyknotic and died; they were then removed and progressively replaced by a set of new neurons. These neurons were mostly generated from …

Transitory disappearance of microglia during the regeneration of the lizard medial cortex

1994

In normal lizards, microglial cells populate the medial cortex (a zone homologous to the hippocampal fascia dentata), with a preferential distribution along the border between the granular cell layer and the plexiform layers. Intraperitoneal injection of the neurotoxin 3-acetylpyridine (3AP) induces a selective lesion in the medial cortex with a rapid degeneration of the granular layer and its zinc-enriched axonal projection. Within 6-8 weeks, the granular layer is, however, re- populated by a new set of neurons generated in the subjacent ependyma and the cell debris is removed. The aim of this study was to determine to what extent microglia were involved in the scavenging processes during …

The nature of host tissue destruction in tumor invasion

1986

The nature of host tissue destruction in tumor invasion was investigated in experimentally induced carcinomas and sarcomas, xenografted into skeletal muscle. By means of light and electron microscopy it was shown that in both carcinomas and sarcomas the confrontation of host tissue with the invading tumor cells does not result in immediate destruction of host tissue but in a transitory state of coexistence which gradually proceeds to progressive host tissue atrophy. This process of progressive atrophy, which finally results in the total disappearance of the invaded host tissue, is considered to be caused mainly by the increasing pressure and competitive withdrawal of oxygen and nutrients by…

Scanning electron microscopy of the cervix uteri.

1974

Scanning electron microscopy has been used in the study of five cases of the cervix uteri: two normal cases; one case of indirect metaplasia; one case of carcinoma in situ whose colposcopic examination showed an erosio vera surrounded by leucoplasia, mosaic, base, and an area of atipic transformation zone and one case of invasive carcinoma.

S100α and S100β proteins in human cutaneous sensory corpuscles: Effects of nerve and spinal cord injury

1998

S100 protein in the vertebrate peripheral nervous system consists of homo- or heterodimers of S100α and S100β proteins, the first predominating in neurons and the second in glial cells. Recently, however, occurrence of S100β protein in neurons has been reported. The expression of S100 protein by Schwann cells, as well as their derivatives in sensory corpuscles, depends on the sensory axon (i.e., the Schwann cell–axon contact). The present study analyzed the distribution of S100α and S100β proteins in human cutaneous sensory corpuscles and the effects of peripheral or central sensory axon severance in the expression of these proteins. Simple or double immunohistochemistry was carried out usi…

Immunoelectron microscopic localization of nitric oxide synthase III in the guinea pig organ of Corti

1998

Nitric oxide synthase III (NOS III) was identified in the guinea pig cochlea on an ultrastructural level using a post-embedding immunolabeling procedure. Ultrathin sections of London Resin (LR) White-embedded specimens were incubated with various concentrations of a commercially available antibody to NOS III and the immunoreactivity visualized by a gold-labeled secondary antibody. Analysis of ultrathin sections of the organ of Corti in the second turn of the cochlea showed that NOS III could be localized in the endothelial cells of the blood vessels under the basilar membrane, which was comparable to its location in similar cells types in various biological systems. Besides this, NOS III wa…

Endometrial stromal sarcomas: immunohistochemical, electron microscopical and cytogenetic findings in two cases.

1999

Uterine sarcomas are approximately 3% of all malignant uterine corpus tumours. Of these, the tumours that originate solely in the stromal elements of the uterine wall are infrequent and have not been well characterized cytogenetically. We report two cases of endometrial stromal sarcomas (ESS), one low grade and one high grade, diagnosed by conventional histology, immunocytochemistry, electron microscopy and cytogenetics. Morphologically clear-cut differential structures were seen at optical, immunohistochemical, and electron microscopic levels, permitting a clear differential diagnosis. The low-grade ESS expressed hormonal receptors and vimentin, whereas the high-grade ESS showed no hormone…

Pig liver gene therapy by noninvasive interventionist catheterism

2006

The efficacy of noninvasive interventionist catheterism in large animals as an alternative to the hydrodynamic procedure, described for small animals, is evaluated. Basically, gene transfer is performed by implantation and fixation of a balloon catheter within the suprahepatic vein of anesthetized pigs, through the femoral vein. The catheter tip is identified by fluoroscopy, injecting a contrast solution that marks large or small hepatic territories. Animals were injected with a 100 ml pTG7101 plasmid solution (40 microg/ml), which contains the human alpha-1 antitrypsin gene, perfused at a rate of 7.5 ml/s and efficacy and toxicity of the procedure were evaluated. The results show: (i) the …