Search results for " Phase-Contrast"

A new technique for analysis of human sperm morphology in unstained cells from raw semen

2014

Sperm morphology analysis is a fundamental component of semen analysis, but its real significance has been clouded by the plethora of techniques used for its evaluation. Most involve different fixation and staining procedures that induce artefacts. Herein we describe Trumorph (Proiser R+D, Paterna, Spain), a new method for sperm morphology analysis based on examination of wet preparations of spermatozoa immobilised, after a short 60°C shock, in narrow chambers and examined by negative phase contrast microscopy. A range of morphological forms was observed, similar to those found using conventional fixed and stained preparations, but other forms were also found, distinguishable only by the o…

Crystal inclusions in subepithelial fibroblasts of the brood pouch of sea horses (hippocampus kuda)

1968

In the subepithelial connective tissue of the inactive broodpouch of sea horses (Hippocampus kuda), fibroblasts with striking crystal inclusions are described light microscopically and electron microscopically in the tunica adventitia of capillaries. These very electron dense crystals turn out to be hexagonal prisms of heterogeneous structures. Results of the X-ray microanalysis and comparison with other crystalline cell inclusions so far described allow the conclusion that they contain an iron protein stored as crystals. The structure and genesis of these crystals as well as the possible importance of the iron protein for the biology of these animals are discussed.

Endothelial capillaries chemotactically attract tumour cells.

2001

Directional migration of capillaries towards tumour implants is generally assumed to be regulated by chemotaxis. Preliminary evidence has also been presented for the existence of a reverse chemotactic signalling pathway, with capillaries attracting tumour cells via paracrine factors. By using a variety of endothelial cell types and tumour cell lines, this study has systematically investigated chemotaxis between endothelial cells and tumour cells in two- and three-dimensional systems. Checkerboard analysis revealed faint attraction of human umbilical vein endothelial cells (HUVECs), but not porcine aortic endothelial cells (PAECs), by tumour cells. In reverse, both PAECs and HUVECs potently …

Unmasking epithelial-mesenchymal transition in a breast cancer primary culture: a study report

2012

Abstract Background Immortalized cancer cell lines are now well-established procedures in biomedicine for a more complete understanding of cellular processes in cancer. However, they are more useful in preparation of fresh tumour tissue, in order to obtain cancer cells with highly preserved individual tumour properties. In the present study we report an analytical investigation on a breast cancer primary cell culture isolated from a surgical specimen obtained from a patient with an infiltrating ductal carcinoma. The objective of the research was to reveal unrecognized aspects of neoplastic cells, typical of the tumour from where the cells were derived, but masked in fixed tissue sections, i…

Neuronal and BBB damage induced by sera from patients with secondary progressive multiple sclerosis.

2009

An important component of the pathogenic process of multiple sclerosis (MS) is the blood-brain barrier (BBB) damage. We recently set an in vitro model of BBB, based on a three-cell-type co-culture system, in which rat neurons and astrocytes synergistically induce brain capillary endothelial cells to form a monolayer with permeability properties resembling those of the physiological BBB. Herein we report that the serum from patients with secondary progressive multiple sclerosis (SPMS) has a damaging effect on isolated neurons. This finding suggests that neuronal damaging in MS could be a primary event and not only secondary to myelin damage, as generally assumed. SPMS serum affects the perme…

Microcinematographic Studies of Mycoplasma hominis Cells

1973

Cells of two strains of Mycoplasma hominis growing in liquid medium on a glass surface were observed continuously, and cinematographic pictures were taken. Most of the observed structures showed reversible changes of their shape, suggesting the presence of contractile material in membrane or cytoplasma. The frequency and speed of such variations were measured. The deformations seem to be related to multiplication. The mechanisms of these phenomena are unknown.

Induction of oxiapoptophagy, a mixed mode of cell death associated with oxidative stress, apoptosis and autophagy, on 7-ketocholesterol-treated 158N …

2013

7-Ketocholesterol (7KC) has been suggested to induce a complex mode of cell death on monocytic cells: oxiapoptophagy (OXIdation, APOPTOsis, and autoPHAGY) (Monier et al. (2003) [12]). The aim of the present study, realized on 158N murine oligodendrocytes, was to bring new evidence on this mixed form of cell death. On 158N cells, 7KC induces an overproduction of reactive oxygen species (ROS) revealed by dihydroethidium staining, a loss of transmembrane mitochondrial potential measured with DiOC6(3), caspase-3 activation, and condensation and/or fragmentation of the nuclei which are typical criteria of oxidative stress and apoptosis. Moreover, 7KC enhances cytoplamic membrane permeability to …

The bronchial circulation in COVID-19 pneumonia.

2021

American journal of respiratory and critical care medicine : AJRCCM 205(1), 121-125 (2022). doi:10.1164/rccm.202103-0594IM

The lady with a history of blood transfusion who developed palpable purpura and microhaematuria

1999

Primary ciliary dyskinesia assessment by means of optical flow analysis of phase-contrast microscopy images

2014

Primary ciliary dyskinesia implies cilia with defective or total absence of motility, which may result in sinusitis, chronic bronchitis, bronchiectasis and male infertility. Diagnosis can be difficult and is based on an abnormal ciliary beat frequency (CBF) and beat pattern. In this paper, we present a method to determine CBF of isolated cells through the analysis of phase-contrast microscopy images, estimating cilia motion by means of an optical flow algorithm. After having analyzed 28 image sequences (14 with a normal beat pattern and 14 with a dyskinetic pattern), the normal group presented a CBF of 5.2 +/- 1.6 Hz, while the dyskinetic patients presented a 1.9 +/- 0.9 Hz CBF. The cutoff …